A study of the anatomy and physiology of sleep in the rock hyrax, Procavia capensis

Ph.D., Faculty of Science, University of the Witwatersrand, 2011The rock hyrax, Procavia capensis, is a social diurnal mammal that typically lives in colonies on rocky outcrops and is found throughout most parts of Southern Africa. The aim of this thesis was to describe the sleep phenomenology of the rock hyrax. By means of immunohistochemistry the location and distribution of the cholinergic, catecholaminergic, serotonergic, orexinergic, histaminergic, and the GABAergic systems were described. For the most part these systems and their terminal network distributions followed the general mammalian organisational plan; however, several features, potentially unique to the rock hyrax, were found. These include the presence of cholinergic neurons in the AD and AV nuclei of the dorsal thalamus, parvo- and magnocellular divisions of the cholinergic LDT and PPT nuclei. A dense orexinergic terminal network distribution was noted in the regions coincident with the AD nucleus, a feature only observed in other diurnal mammals. Parvalbumin neurons did not show any association to the sleep related nuclei, whereas calbindin and calretinin neurons were found in all sleep related areas, though with differing densities and some homogeneities. The physiological measurable parameters of sleep were recorded continuously for 72 h under both solitary and social conditions and compared to determine whether differences existed. The results revealed that no major differences existed between the social and solitary conditions, but sleep intensity and REM duration (particularly REM0) was more pronounced in the social condition. REM was ambiguous in these animals, and led to its subdivision into REM1 and REM0. It is possible that REM1 could be a form of low voltage slow wave sleep, but further investigation is required. If REM1 is a form of NonREM sleep it would imply that the rock hyrax has the lowest amount of REM sleep of any terrestrial mammal studied to date

Sociality Affects REM Sleep Episode Duration Under Controlled Laboratory Conditions in the Rock Hyrax, Procavia capensis.

The rock hyrax, Procavia capensis, is a highly social, diurnal mammal. In the current study several physiologically measurable parameters of sleep, as well as the accompanying behavior, were recorded continuously from five rock hyraxes, for 72 h under solitary (experimental animal alone in the recording chamber), and social conditions (experimental animal with 1 or 2 additional, non-implanted animals in the recording chamber). The results revealed no significant differences between solitary and social conditions for total sleep times, number of episodes, episode duration or slow wave activity (SWA) for all states examined. The only significant difference observed between social and solitary conditions was the average duration of rapid eye movement (REM) sleep episodes. REM sleep episode duration was on average 20 s and 40 s longer under social conditions daily and during the dark period, respectively. It is hypothesized that the increase in REM sleep episode duration under social conditions could possibly be attributed to improved thermoregulation strategies, however considering the limited sample size and design of the current study further investigations are needed to confirm this finding. Whether the conclusions and the observations made in this study can be generalized to all naturally socially sleeping mammals remains an open question

Work-integrated learning and teaching schools : the University of Johannesburg teaching school experience

Abstract: In this chapter, we report on a study that employed a generic qualitative research design to explore how learning in and from practice, in a curriculum designed to achieve congruence between coursework and fieldwork, relates to student teachers’ learning at other schools they attend for WIL. When the University of Johannesburg (UJ), Faculty of Education established a ‘teaching school’ (TS) in 2010, the staff had no existing model based on which to plan. We worked from the idea that student teachers’ practicum in the TS could work in tandem with their WIL at other schools, in order to promote learning in and from practice, for practice. A shared vision of the kind of teacher we wished to produce was key, both within the programme itself and in terms of how coursework and practical experience/fieldwork were brought together. The central organising principle of child study not only brought cohesion to the programme but was also dependent on strong partnerships with expert teachers in the two settings who could operate as good mentors. Although such a vision is achievable at a TS, we found that building a relationship of equivalence demands a great deal of commitment and the willingness to compromise by both parties. This kind of relationship building was not possible at the WIL schools. However, we were motivated by the opportunity to combine practice in both TS and WIL schools for enabling student teachers to learn in and from practice at the TS to provide a solid foundation for learning during WIL at other schools. The data point to considerable congruence between student teachers learning in the TS and in coursework, but student teachers learning at WIL are more often a source of tension. We reasoned that if they have a vision of what good teaching is about from their experience at the TS, it would provide them with a benchmark of what to aspire for when placed in schools where this was absent

A University and School Working in Partnership to Develop Professional Practice Knowledge for Teaching

The article reports on the University of Johannesburg's (UJ) efforts at offering a practice-based teacher education program in partnership with a university-affiliated school (a “teaching school”) with a view to developing inquiry-oriented novice teachers. The research aimed at exploring what it takes to develop a “learningplace” (Conway et al., 2014) conducive to student teachers' development of professional practice knowledge and the role of mentoring in this regard. A two-phase process of generating data was used. In the first phase, the published research on the university-affiliated school was analyzed, using qualitative content analysis to look for patterns across the historical unfolding of the findings of these papers. In phase two a questionnaire was administered involving final year student teachers in the teacher education program. The research shows that a teaching school, if integrated into the program design and delivery, provides a rich practice learning site for student teachers. In addition, mentoring in cognitive apprenticeship mode could indeed be a powerful contributor to student teachers' professional development. However, the overall programme design is decisive. The preparation of teachers with strong professional practice knowledge requires attention to four interrelated aspects of program design, namely program identity, organizational structures, curriculum, and teacher education pedagogy. Addressing these aspects in an integrated manner would be difficult without working closely with one or more partnership schools

Inactivity/sleep in two wild free-roaming African elephant matriarchs - Does large body size make elephants the shortest mammalian sleepers?

The current study provides details of sleep (or inactivity) in two wild, free-roaming African elephant matriarchs studied in their natural habitat with remote monitoring using an actiwatch subcutaneously implanted in the trunk, a standard elephant collar equipped with a GPS system and gyroscope, and a portable weather station. We found that these two elephants were polyphasic sleepers, had an average daily total sleep time of 2 h, mostly between 02:00 and 06:00, and displayed the shortest daily sleep time of any mammal recorded to date. Moreover, these two elephants exhibited both standing and recumbent sleep, but only exhibited recumbent sleep every third or fourth day, potentially limiting their ability to enter REM sleep on a daily basis. In addition, we observed on five occasions that the elephants went without sleep for up to 46 h and traversed around 30 km in 10 h, possibly due to disturbances such as potential predation or poaching events, or a bull elephant in musth. They exhibited no form of sleep rebound following a night without sleep. Environmental conditions, especially ambient air temperature and relative humidity, analysed as wet-bulb globe temperature, reliably predict sleep onset and offset times. The elephants selected novel sleep sites each night and the amount of activity between sleep periods did not affect the amount of sleep. A number of similarities and differences to studies of elephant sleep in captivity are noted, and specific factors shaping sleep architecture in elephants, on various temporal scales, are discussed

Male blue wildebeest increase activity during the rut, but not at the expense of rest

Rest is a state of adaptive inactivity that increases the efficiency of activity by regulating its timing and reducing energy use when activity is not beneficial. Thus, animals can go without rest when specific demands, such as mating, favour being awake. Sexually active male blue wildebeest (bulls) are typically territorial, and it has been reported that when a bull is protecting a harem during the mating season (rut), he neither eats nor rests. We examined the daily activity and inactivity patterns of dominant bulls by means of actigraphy for 3 months, which included the rut. We also measured faecal androgen metabolite (fAM) levels and subcutaneous temperature, both of which have variances known to delineate the rut. During the rut, wildebeest bulls experienced higher levels of activity, fAM, and a greater daily range of subcutaneous temperature. Despite previous reports, the male blue wildebeest rested daily during the rut, and while the amount of rest was low, it was not substantially lower than prior to the rut. The amount of time spent inactive increased substantially after the rut. The timing of daily activity and inactivity patterns did not vary substantially across the recording period. Across the recording period, the average daily ambient temperatures decreased (seasonality), and the subcutaneous temperature followed this pattern, although it was not as marked. It appears that in the post-rut period a substantive increase in time spent at rest occurs, potentially allowing the wildebeest bulls time to recover following a period of intense activity.Grant Sponsors: South African National Research Foundation. Open access funding provided by University of the Witwatersrand.Open access funding provided by University of the Witwatersrand.https://link.springer.com/journal/360hj2023Anatomy and PhysiologyMammal Research InstituteZoology and Entomolog

Sleep and wake in rhythmic vs arrhythmic chronotypes of a microphthalmic species of African mole rat (Cryptomys mechowi)

The giant Zambian molerat (Cryptomys mechowi) is a subterranean African rodent noted for its regressed visual system and unusual patterns of circadian rhythmicity – within this species some individuals exhibit distinct regular circadian patterns while others have arrhythmic circadian patterns. The current study was aimed at understanding whether differences in circadian chronotypes in this species affects the patterns and proportions of the different phases of the sleep-wake cycle. Physiological parameters of sleep (EEG and EMG) and behaviour (video recording) were recorded continuously for 72 h from six mole rats (three rhythmic and three arrhythmic) using a telemetric system and a low light CCTV camera connected to a DVD recorder. The telemetric data was scored (in both 5 s and 1 min epochs) as wake, nonREM sleep (NREM) and rapid eye movement (REM) stages subject to the correlation between EEG, EMG and behaviour. Spectral power was calculated for EEG in each implanted individual, which assisted in understanding the sleep phases and the intensity of NREM between the chronotypes. In addition REM periodicity was calculated from which sleep cycle length was inferred. The results indicate that the arrhythmic individuals spend more time in waking with a longer average duration of a waking episode, less time in NREM with a shorter average duration of a NREM episode though a greater nonREM sleep intensity, and similar sleep cycle lengths. The time spent in REM and the average duration of a REM episode was similar between the chronotypes.http://content.karger.com/ProdukteDB/produkte.asp?Aktion=JournalHome&ProduktNr=223831ab201

Arabian oryx (Oryx leucoryx) respond to increased ambient temperatures with a seasonal shift in the timing of their daily inactivity patterns

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.National Plan for Science, Technology and Innovation (MAARIFAH), King Abdulaziz City for Science and Technology, Kingdom of Saudi Arabia, Award Number 11-ENV1918-02.http://jbr.sagepub.comhb2016Mammal Research Institut

Becoming a teacher

This book disseminates original research on learning in and from practice in pre-service teacher education. Authors such as Lederman and Lederman describe the student teaching practicum (or work-integrated learning [WIL]), which is an essential component of pre-service teacher education, as the ‘elephant in the room’. These authors note that 'the capstone experience in any teacher education programme is the student teaching practicum… [a]fter all, this is where the rubber hits the road'. However, many teacher educators will agree that this WIL component is sometimes very insufficient in assisting the student teacher to develop their own footing and voice as a teacher. This is the ‘gap’ that this research book addresses. Most of the chapters in the book report empirical data, with the exception of two chapters that can be categorized as systematic reviews. WIL is addressed from various angles in the chapters. Chapter 6 focuses on research related to what makes Finnish teacher education so effective, and in Chapter 4 researchers of the University of Johannesburg disseminate their findings on establishing a teaching school (based on Finnish insights) in Johannesburg. Chapter 3 highlights the challenges faced in open-and distance learning teacher education contexts. Several of the chapters disseminate research findings on alternative interventions to classic WIL, namely, where “safe spaces” or laboratories are created for student teachers to learn and grow professionally. These could either be simulations, such as software programmes and avatars in the intervention described in Chapter 2; student excursions, as the findings in chapters 5, 7 and 10 portray; or alternative approaches to WIL (e.g. Chapters 11 and 12). The book is devoted to scholarship in the field of pre-service teacher education. The target audience is scholars working in the fields of pre-service teacher education, work-integrated learning, and self-directed learning. The book makes a unique contribution in terms of firstly its extensive use of Cultural-Historical Activity Theory as a research lens, and secondly in drawing on various theoretical frameworks. Both quantitative and qualitative research informed the findings of the book

Priority areas for cannabis and cannabinoid product research in South Africa

No abstract available