Joshua G Davimes

Study Design: A descriptive cross-sectional study of the anatomical variations, morphometry, and histology of the iliolumbar veins (ILVs).Purpose: This study aimed to describe the anatomical variations of the ILVs and determine their tissue composition in South African cadavers of European descent.Overview of Literature: A safe anterior surgical approach to the L4/L5 intervertebral disc space requires understanding the anatomy of the ILVs. Limited understanding of ILVs and their variations may lead to inadvertent avulsion of veins with subsequent hemorrhage and damage to the adjacent nerves intraoperatively. Variations in ILVs are population specific, but such reports are limited in the South African population.Methods: Eighty-nine adult cadavers were dissected to reveal ILV patterns. The variations (origin, course, and drainage pattern), morphometries, and topography of the ILVs were studied. A total of 19 (10 proximal, nine distal) ILVs were processed for hematoxylin and eosin, Ma...

Full dataset is located at http://wiredspace.wits.ac.za/handle/10539/29924. The human face is important in social, cultural and recognition contexts. Many research fields make use of faces to understand human interaction and identify individuals. Studies relying on facial image data often make use of ad hoc datasets specifically created for those studies as there is a dearth of large scale controlled and matching facial image databases. Actualistic (taken in a real life, natural setting) and standardised databases of facial images can be of extreme value to many research areas, such as facial identification and recognition. While multiple face databases are available, the majority, if not all, are developed in order to address very specific questions and hypotheses with limited standardisation, severely limiting their potential applicability. The Wits Face Database was developed as a generic, yet actualistic dataset of facial images obtained from consenting young adult South African...

Forensic facial comparison is a commonly used, yet under-evaluated method employed in medicolegal contexts across the world. Testing the accuracy and reliability of facial comparisons requires large scale controlled and matching facial image databases. Databases that contain images of individuals on closed-circuit television (CCTV), with matching formal and informal photographs are needed for this type of research. Although many databases are available, the majority if not all are developed in order to improve facial recognition and face detection algorithms through machine learning, with very limited if any measure of standardisation. This paper aims to review the available databases and describe the development of a high resolution, standardised facial photograph and CCTV recording database of male Africans. The database is composed of a total of 6220 standardised and uncontrolled suboptimal facial photographs of 622 matching individuals in five different views, as well as corresp...

The evolution and function of sleep remains an enigma in modern science. Significant variation can be observed within species and across taxa. Little is understood about how sleep exists, or presents itself in species surviving in extreme conditions. For example, harsh desert ecosystems with notably lower survival rates for resident species. It has been hypothesized that specialized sleep-related behaviours impact thermoregulation to promote survival advantage. The threatened Arabian oryx (Oryx leucoryx), a member of the Cetartiodactyl superorder, is a large desert dwelling ungulate species successfully residing in the arid zones of the Middle East. Arabian Oryx exhibit numerous morphophysiological adaptations and capabilities to cope with their harsh environment. The current thesis provides an examination of the neuroanatomy, physiology and behavioural patterns related to sleep in wild, free-roaming Arabian oryx under natural conditions. It was our objective to determine whether the extreme conditions and climate of the Arabian Desert has led to novelties within the organization of the oryx’s sleep related neuronal architecture, seasonal behaviour patterns and sleep physiology. Using immunohistochemistry and stereology our results indicate the sleep related nuclei in the brain of the oryx exhibit a typical mammalian organizational plan with additional order-specific and novel, species- specific features. Actigraphy revealed that oryx exhibit temporal niche switching patterns seasonally presenting with winter diurnal- and summer nocturnal activity and intermittent patterns during the transitional periods of spring and autumn. Polysomnography results indicate novel sleep patterns between seasons and physiologically confirm activity-based temporal niche switching at a seasonal level. Our work covers the first examination of the Arabian oryx brain sleep centers as well as its year-long activity patterns. Importantly, it is the first examination of physiological sleep in wild mammals within a desert environment. Our results suggest that ambient temperature acts a dominant driving force for the adaptive behavioural and physiological features described. The Arabian oryx is a remarkable species, well adapted to such an extreme environment and its highly plastic survival mechanisms appear unique. Considering the continual desertification of our planet and the predicted consequences of climate change, knowledge of such species and their continued conservation is of vital importance.

The sternalis muscle is an infrequent, non-pathological anatomical variant typically misrepresented in a clinical context. It presents with 3–8% prevalence, according to cadaveric studies. The muscles were identified during routine cadaver prosection at the School of Anatomical Sciences, University of the Witwatersrand. Here, we report two cases of the sternalis muscle in two South African White cadavers. Analysis of the sternalis muscles revealed unilaterally present, distinctly defined muscle masses on the right (case number 1, female) and left (case number 2, male) hemithorax, lateral to the sternum. The muscles occurred with a prevalence of 2.25% within the cadaveric population examined. The prevalence of the sternalis muscle is generally low, especially in the European population. Their presence represents the remnants of the cutaneous muscles in the ventral thorax of lower animals. Clinically, the sternalis muscle may be misinterpreted as a pathological mass or lesion, thus accurate knowledge regarding its variations and prevalence is of importance.

The hand metrics of Palaeolithic artists show a number of distinctive features that contrast with the low-variance hand metrics of modern Europeans, and with the majority of other modern humans. For example, the D2/D4 ratio in the Palaeolithic artists has a much greater spread of values and a greater degree of sexual dimorphism. We find that living San people, who represent the minority of modern humans that have high-variance genetics, also have a hand metric phenotype like the Palaeolithic artists, different from modern Europeans and other low-variance genetics modern humans. The increased variance and sexual dimorphism of the phenotypic D2/D4 ratio in the San measurements are in keeping with genetic evidence that the San represent one of the oldest human lineages with the greatest genetic diversity. The findings have the implication that the European Palaeolithic cave artists may have been derived from San-like migrants who brought an established artistic tradition from Africa to Europe, only to be replaced as a population, leaving no evidence of their genetics in modern Europeans, as observed for other Palaeolithic genes such as Oase 1.

The Arabian oryx inhabits an environment where summer ambient temperatures can exceed 40 °C for extended periods of time. While the oryx uses a suite of adaptations that aid survival, the effects of this extreme environment on inactivity are unknown. To determine how the oryx manages inactivity seasonally, we measured the daily rhythm of body temperature and used fine-grain actigraphy, in 10 animals, to reveal when the animals were inactive in relation to ambient temperature and photoperiod. We demonstrate that during the cooler winter months, the oryx was inactive during the cooler parts of the 24-h day (predawn hours), showing a nighttime (nocturnal) inactivity pattern. In contrast, in the warmer summer months, the oryx displayed a bimodal inactivity pattern, with major inactivity bouts (those greater than 1 h) occurring equally during both the coolest part of the night (predawn hours) and the warmest part of the day (afternoon hours). Of note, the timing of the daily rhythm of bo...

Global escalation of crime has necessitated the use of digital imagery to aid the identification of perpetrators. Forensic facial comparison (FFC) is increasingly employed, often relying on poor-quality images. In the absence of standardized criteria, especially in terms of video recordings, verification of the methodology is needed. This paper addresses aspects of FFC, discussing relevant terminology, investigating the validity and reliability of the FISWG morphological feature list using a new South African database, and advising on standards for CCTV equipment. Suboptimal conditions, including poor resolution, unfavorable angle of incidence, color, and lighting, affected the accuracy of FFC. Morphological analysis of photographs, standard CCTV, and eye-level CCTV showed improved performance in a strict iteration analysis, but not when using analogue CCTV images. Therefore, both strict and lenient iterations should be conducted, but FFC must be abandoned when a strict iteration pe...

The Arabian oryx, Oryx leucoryx, is a member of the superorder Cetartiodactyla and is native to the Arabian Desert. The desert environment can be considered extreme in which to sleep, as the ranges of temperatures experienced are beyond what most mammals encounter. The current study describes the nuclear organization and neuronal morphology of the systems that have been implicated in sleep control in other mammals for the Arabian oryx. The nuclei delineated include those revealed immunohistochemically as belonging to the cholinergic, catecholaminergic, serotonergic and orexinergic systems within the basal forebrain, hypothalamus, midbrain and pons. In addition, we examined the GABAergic neurons and their terminal networks surrounding or within these nuclei. The majority of the neuronal systems examined followed the typical mammalian organizational plan, but some differences were observed: (1) the neuronal morphology of the cholinergic laterodorsal tegmental (LDT) and pedunculopontin...

Study Objectives
The Arabian oryx lives under hyperarid conditions in the Arabian Desert and exhibits temporal niche switching of activity patterns at a seasonal level. The objective of the current study was to provide a polysomnographic-based study of sleep in free-roaming Arabian oryx in their natural habitat to determine whether extreme seasonal climate variations resulted in changes in sleep patterns and physiology associated with the seasonal switching of temporal niches.

Methods
Electroencephalography, nuchal electromyography, actigraphy, and subcutaneous temperature were recorded in free-roaming Arabian oryx in the Mahazat as-Sayd Protected Area, Kingdom of Saudi Arabia during winter and summer.

Results:
Total daily sleep time in winter was 6.69 and 3.77 hr in summer. In winter, oryx exhibited nocturnal sleep typical of artiodactyls of around 60 kg body mass. In summer, oryx slept mostly during the day and subcutaneous temperature was seen to rise during sleep, but not as rapidly as the rises observed in ambient air temperature. Rapid eye movement sleep formed a very small percentage of total sleep time, especially so in the summer.

Conclusions
The unusual sleep patterns and physiology during summer appear to be related to high ambient air temperatures that affect both intrinsic and extrinsic factors necessary for survival. The Arabian oryx appears to use sleep physiology as an adaptive thermoregulatory mechanism in the hot summer months.

The Arabian oryx, a moderately large mammal that inhabits a harsh desert environment, has been shown to exhibit seasonal variations in activity and inactivity patterns. Here we analyzed the continuous year-round activity patterns of twelve free-roaming Arabian oryx under natural conditions from two varying desert environments in Saudi Arabia using abdominally implanted activity meters. We simultaneously recorded weather parameters at both sites to determine whether environmental factors are responsible for temporal niche switching as well as the seasonal structuring and timing of this behavioural plasticity. Our results demonstrate that Arabian oryx undergo temporal niche switching of 24 h activity patterns at a seasonal level and exhibit distinct nocturnal/crepuscular activity during summer, diurnal activity during winter and intermittent patterns of behaviour during the transitional seasons of autumn and spring. In addition, the oryx exhibited inter- and intra-seasonal variations in the temporal budgeting of 24 h activity patterns. Strong relationships with both photoperiod and ambient temperatures were found and in some instances suggested that increasing ambient temperatures are a primary driving force behind seasonal shifts in activity patterns. These adaptive patterns may be dictated by the availability of food and water, which in turn are strongly influenced by seasonal climate variations. Overall, the adaptive responses of free-roaming Arabian oryx in such harsh and non-laboratorial conditions provide a framework for comparing wild populations as well as aiding conservation efforts.

The Arabian oryx, Oryx leucoryx, is a member of the superorder Cetartiodactyla and is native to the Arabian Desert. The desert environment can be considered extreme in which to sleep, as the ranges of temperatures experienced are beyond what most mammals encounter. The current study describes the nuclear organization and neuronal morphology of the systems that have been implicated in sleep control in other mammals for the Arabian oryx. The nuclei delineated include those revealed immunohistochemically as belonging to the cholinergic, catecholaminergic, serotonergic and orexinergic systems within the basal forebrain, hypothalamus, midbrain and pons. In addition, we examined the GABAergic neurons and their terminal networks surrounding or within these nuclei. The majority of the neuronal systems examined followed the typical mammalian organizational plan, but some differences were observed: (1) the neuronal morphology of the cholinergic laterodorsal tegmental (LDT) and pedunculopontine tegmental (PPT) nuclei, as well as the parvocellular subdivision of the orexinergic main cluster, exhibited Cetartiodactyl-specific features; (2) the dorsal division of the catecholaminergic anterior hypothalamic group (A15d), which has not been reported in any member of the Artiodactyla studied to date, was present in the brain of the Arabian oryx; and (3) the catecholaminergic tuberal cell group (A12) was notably more expansive than previously seen in any other mammal. The A12 nucleus has been associated functionally to osmoregulation in other mammals, and thus its expansion could potentially be a species specific feature of the Arabian oryx given their native desert environment and the need for extreme water conservation.

The Arabian oryx inhabits an environment where summer ambient
temperatures can exceed 40 °C for extended periods of time. While the oryx uses a suite of adaptations that aid survival, the effects of this extreme environment on inactivity are unknown. To determine how the oryx manages inactivity seasonally, we measured the daily rhythm of body temperature and used fine-grain actigraphy, in 10 animals, to reveal when the animals were inactive in relation to ambient temperature and photoperiod. We demonstrate that during the cooler winter months, the oryx was inactive during the cooler parts of the 24-h day (predawn hours), showing a nighttime (nocturnal) inactivity pattern. In contrast,
in the warmer summer months, the oryx displayed a bimodal inactivity
pattern, with major inactivity bouts (those greater than 1 h) occurring equally during both the coolest part of the night (predawn hours) and the warmest part of the day (afternoon hours). Of note, the timing of the daily rhythm of body temperature did not vary seasonally, although the amplitude did change, leading to a seasonal alteration in the phase relationship between inactivity and the body temperature rhythm. Because during periods of inactivity the oryx were presumably asleep for much of the time, we speculate that the daytime shift in inactivity may allow the oryx to take advantage of the thermoregulatory physiology
of sleep, which likely occurs when the animal is inactive for more than 1
h, to mitigate environmentally induced increases in body temperature.

Introduction: The Arabian oryx, a large desert dwelling mammal, successfully inhabits the Arabian deserts in which climate undergoes extreme shifts throughout the seasons of the year. Summer ambient temperatures often exceed general mammalian thermoneutral zones for prolonged periods. The Arabian oryx are known to employ multiple behavioural and physiological adaptations in order to survive such extreme environments; however, the effects on inactivity and sleep are so far unknown. Methods: To investigate how oryx successfully sleep and manage inactivity throughout the year both fine and coarse-grain actigraphy was utilized in 16 male, free-roaming oryx. Inactivity/ sleep variations were determined in relation to ambient temperature and light levels in the Saudi Arabian Desert. Results: The results demonstrate that oryx show typical diurnal Artiodactyl patterns of inactivity/ sleep during the cooler winter months with the major sleep/ inactivity occurring pre-dawn (coldest part of night). In contrast, during the hotter summer months the oryx shift to a crepuscular activity pattern with the major sleep/ inactive bouts now split between pre-dawn hours (coldest part of night) and the afternoon (hottest part of day). No seasonal shifts were observed for daily rhythm of core body temperature alongside the shifts in sleep/ inactivity throughout the year. It appears the transitional periods from winter diurnal activity to summer crepuscular activity occur in May and then reverse in September. Discussion: By diverting half the major summer sleep bouts to the afternoon, the oryx appear able to employ standard sleep thermoregulatory processes to circumvent major core body temperature increases. This possibly novel thermoregulatory mechanism in response to the desynchronization of circadian rhythms (core body temperature, sleep timing and daily activity patterns) during summer seems indicative of more than one primary zeitgeber. This study possibly establishes the first naturally occurring desynchronization of circadian rhythms and possible occurrence of both light and temperature as primary zeitgebers entraining different daily rhythms.

Arabian oryx, Oryx leucoryx, are members of the superorder Cetartiodactyla and belong within the family Bovidae. They are native to the Arabian Desert and are currently listed as “vulnerable” on the IUCN red data list. The current study describes the nuclear organization and neuronal morphology of the systems involved in the generation and control of the sleep-wake cycle in the Arabian oryx. The systems examined included the cholinergic, catecholaminergic, serotonergic and orexinergic as well as the GABAergic neurons associated with these nuclei. The aim of the study was to identify these neural systems and to compare the results to that reported for other members of Cetartiodactyla and mammals in general. The majority of the neuronal systems examined followed the typical mammalian organizational plan; however, some differences were observed: (1) the neuronal morphology of the cholinergic laterodorsal tegmental (LDT) and pedunculopontine tegmental (PPT) nuclei as well as the parvocellular subdivision of the orexinergic main cluster exhibited Cetartiodactyl-specific features; (2) the dorsal division of the catecholaminergic anterior hypothalamic group (A15d), which has not been reported in any member of the Cetartiodactyla studied to date, was present in the brain of the Arabian oryx; and (3) the catecholaminergic tuberal cell group (A12) was notably more expansive than previously seen in any other mammal. The A12 nucleus has been associated functionally to osmoregulation in other mammals, and thus its expansion could potentially be a species specific feature of the Arabian oryx given their native desert environment and the need for water conservation.

Introduction: The Arabian oryx, a large mammal, successfully inhabits the Arabian deserts where climate undergoes extreme shifts seasonally. It is known the oryx employ multiple physiological and behavioural adaptions in order to survive: however, it is currently unknown whether such harsh conditions have led to the evolution of any neural adaptations within the sleep system neuroanatomy or have any effects on inactivity and sleep patterns. Methods: Sleep/ inactivity throughout the summer and winter season was examined by fine-grain actigraphy in free-roaming oryx (n=9). Sleep neuroanatomy was examined by immunohistochemistry of the cholinergic, catecholaminergic, serotonergic and orexinergic systems within the basal forebrain, hypothalamus and pons (n=3). Inactivity/ sleep variations and core body temperature (Tc) were determined in relation to ambient temperature and light levels in the Mahazat as-Sayd Protected Area, Saudi Arabia. Results: The sleep system neuroanatomy follows the typical mammalian organization with only minor differences. The oryx show typical diurnal Artiodactyl patterns of inactivity/ sleep during winter with the major sleep/ inactivity occurring predawn. In contrast, during the hotter summer month the oryx shift to a crepuscular activity pattern with the major sleep/ inactive bouts now split between predawn hours (coldest part of night) and the afternoon (hottest part of day). No seasonal differences were observed for daily rhythm of Tc alongside sleep/ inactivity patterns. Conclusion: Through dual-phasing between seasons, the oryx appear able to employ standard sleep thermoregulatory processes to circumvent major Tc increases. This possibly represents a novel thermoregulatory mechanism considering the sleep neuroanatomy appears typical and unspecialized in contrast to the unique sleep/ inactivity patterns. The results present a desynchronization of circadian rhythms (Tc, sleep timing and daily activity patterns) during summer and it seems indicative of more than one primary zeitgeber (light & temperature). The summer-based natural desynchronization of circadian rhythms and seasonal dual-phasing seen in free-roaming Arabian oryx appears novel and unreported thus far. Support (If Any): Funding by the National Plan for Science, Technology and Innovation, Deanship of Scientific Research at the King Saud University, Vice Deanship of Research Chairs, the South African National Research Foundation (NRF) and German Academic Exchange Service (DAAD) and lastly the South Africa Research Chair for Mammal Behavioural Ecology.

The evolution and function of sleep remains an enigma in modern science. Significant variation can be observed within species and across taxa. Little is understood about how sleep exists, or presents itself in species surviving in extreme conditions. For example, harsh desert ecosystems with notably lower survival rates for resident species. It has been hypothesized that specialized sleep-related behaviours impact thermoregulation to promote survival advantage. The threatened Arabian oryx (Oryx leucoryx), a member of the Cetartiodactyl superorder, is a large desert dwelling ungulate species successfully residing in the arid zones of the Middle East. Arabian Oryx exhibit numerous morphophysiological adaptations and capabilities to cope with their harsh environment. The current thesis provides an examination of the neuroanatomy, physiology and behavioural patterns related to sleep in wild, free-roaming Arabian oryx under natural conditions. It was our objective to determine whether the extreme conditions and climate of the Arabian Desert has led to novelties within the organization of the oryx’s sleep related neuronal architecture, seasonal behaviour patterns and sleep physiology. Using immunohistochemistry and stereology our results indicate the sleep related nuclei in the brain of the oryx exhibit a typical mammalian organizational plan with additional order-specific and novel, species- specific features. Actigraphy revealed that oryx exhibit temporal niche switching patterns seasonally presenting with winter diurnal- and summer nocturnal activity and intermittent patterns during the transitional periods of spring and autumn. Polysomnography results indicate novel sleep patterns between seasons and physiologically confirm activity-based temporal niche switching at a seasonal level. Our work covers the first examination of the Arabian oryx brain sleep centers as well as its year-long activity patterns. Importantly, it is the first examination of physiological
sleep in wild mammals within a desert environment. Our results suggest that ambient temperature acts a dominant driving force for the adaptive behavioural and physiological features described. The Arabian oryx is a remarkable species, well adapted to such an extreme environment and its highly plastic survival mechanisms appear unique. Considering the continual desertification of our planet and the predicted consequences of climate change, knowledge of such species and their continued conservation is of vital importance.