Behavioural adaptive variation in the striped mouse Rhabdomys

A thesis submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Doctor of Philosophy, 2017Under current and previous global climate change, environments are changing and have changed at a rapid rate. Species with the potential to undergo adaptive radiation are likely to survive environmental change. The genus Rhabdomys is widespread in southern Africa, occurring along the east-west rainfall gradient in South Africa. Rhabdomys may have undergone adaptive radiations in the past, which may have resulted in the current suite of species in various habitats of different aridity. Some Rhabdomys species also occur in sympatry in some locations in South Africa. The aim of my study was to investigate adaptive variation in Rhabdomys by studying the behaviour of 5 populations, representing 3 Rhabdomys species, across South Africa. Using selected taxa, my approach was, firstly, to describe variation in two traits, personality and spatial cogntion, well known for showing environmentally-linked (i.e. adaptive) variation. Secondly, I manipulated the development of exploratory and anxiety behaviour to assess the limits of the adaptive variation (i.e. test the nature of the reaction norm of the characters measured). I first established the taxon-level personality of 4 taxa (2 sympatric) in 5 standard behavioural tests. Generally, the semi-desert living R. pumilio was the boldest together, surprisingly, with R. d. dilectus occurring in grasslands of central South Africa, contradicting previously published results. Comparatively, R. bechuanae from central South Africa and R. dilectus from far north-eastern South Africa, also occurring in grasslands were less bold, even though R. bechuanae is sympatric with R. dilectus in central South Africa. My data indicate adaptive variation at the extreme populations and possibly character displacement in the sympatric populations. In the next chapter, I investigated whether early rearing environment shapes exploratory behaviour and anxiety responses of R. pumilio and R. bechuanae. I predicted that using an interspecies cross-fostering protocol would reveal a gene x environment interaction on behaviour, so that fostered offspring would display an intermediate behaviour phenotype compared to their non-fostered siblings. I showed that a novel rearing environment mostly did not influence the adult behaviour of cross-fostered inidividuals. This indicates genetic constraints on exploratory behaviour and anxiety responses. Next, I tested whether physical rearing environment shapes exploratory behaviour and anxiety responses. I reared semidesert R. pumilio, sympatric R. bechuanae and R. dilectus and allopatric R. bechuanae under either no cover or high cover for 2 generations. The taxa were mostly similar and altering the phyical housing condition did not alter behaviour, but there were small differences between the taxa in exploratory behaviour. In the final experimental chapter, I established whether the environment predicts the spatial cognition in semi-desert R. pumilio, sympatric R. bechuanae and R. dilectus and an allopatric population of R. dilectus from far north-eastern South Africa. The populations showed very similar performance in a modified Barnes maze, indicating a possible phylogenetic constraint on spatial cognition. Overall, my study suggests that there is adaptive variation in personality but not spatial cognition. In contrast to previous studies in the genus, alterations to the social and physical environments failed to separate out genetic and environmental effects (i.e. reaction norm) that would potentially provide the mechanisms for adaptive variation within and between species. The similarity in spatial cognition between taxa and similar responses to environmental modification indicate phylogenetic constraints on traits that were predicted to vary geographically.XL201

Property Rights in Celestial Bodies: A Question of Pressing Concern to All Mankind

Commercial interest in outer space is increasing, thanks in part to technological developments and private sector investment. Major spacefaring nations—including the United States, China, and Russia—are suddenly having to grapple with issues of space law that have not been so hotly debated since the Cold War. Unfortunately, the foundational document governing the use of outer space and its resources is the Outer Space Treaty from 1967. Written from the perspective of an earlier era and intentionally nonspecific in much of its phrasing, this agreement has stymied the economic development of space resources by its ambiguously worded prohibition on the appropriation of certain extraterrestrial objects

The behaviour of two sub-species of the striped mouse Rhabdomys: the role of phylogeny and the environment

MSc., Faculty of Science, University of the Witwatersrand, 2011The role of phylogeny and environmental influences on behaviour were investigated in two sub-species of Rhabdomys dilectus: R. d. chakae and R. d. dilectus. I compared populations of the two sub-species that occur about 70 km apart in superficially similar grasslands, south of Johannesburg (Walkers Fruit Farms) and at Irene in Gauteng Province, South Africa. The vegetation characteristics of the localities were assessed by measuring aerial cover, cover density, amount of dead material, and the maximum and minimum plant height. I studied the maintenance (non-social) and social behaviour of the sub-species in captivity. Three maintenance behaviours were studied: diel activity in an open arena, activity in an enclosed maze and in a modified plus maze. Social behaviour was studied by investigating the stress response of juvenile males after removal from their family groups and being placed in a plus maze, and the tolerance of unfamiliar same-sex consub-specifics in staged dyadic encounters. My results indicate that there were differences in the vegetation at the localities, most notably in the level of cover, which was greater at Irene (R. d. dilectus) than at Walkers Fruit Farms (R. d. chakae). Both sub-species displayed similar activity profiles (diurnal and crepuscular) and similar levels of activity in an enclosed maze. However, R. d. dilectus showed high levels of anxiety in an open arena and in a plus maze. The sub-species showed similar social behaviours: males of both sub-species that were removed from their family groups at the onset of weaning showed a lower stress response compared to the social sister species R. pumilio. Social interactions of same-sex intra-sub-specifics were mostly similar between the sub-species but there were slight discrepancies in behaviour associated with mating. Surprisingly, there were higher levels of amicability in all dyads than predicted by the solitary lifestyle of the two sub-species in nature. Behavioural differences (anxiety response) may be due to divergence in allopatry because of differences in vegetation characteristics. The similarities in activity profile and social behaviours could be explained by phylogenetic inertia or by similar selection pressures in similar environments

The health of working dogs in conservation in Africa

IntroductionDogs are increasingly being employed for conservation purposes worldwide. In Africa, they work in challenging environments with unique health risks which have not been investigated until now.MethodsTo understand the health challenges faced by the dogs, semi-structured interviews were conducted with participants from 14 organisations that used working dogs in their conservation programmes. The data was qualitatively analysed by thematic analysis.ResultsFive themes were generated. Three affective themes influenced how participants responded to the challenges associated with having a successful conservation dog programme. A strong handler-dog attachment, proficient handler training, and the acknowledgement of the challenging environment were pivotal to maintaining dog health. Two themes related to the difficulties in managing these programmes and how veterinary support interacts with the management choices being made.DiscussionTo have healthy conservation dogs, current and future programmes should focus on fostering the handler-dog relationship and provide continuous handler training. The management of conservation dogs’ health should adopt an evidence-based approach. Future research should focus on areas where the evidence base is lacking, particularly in the areas of prevention and treatment of African canine trypanosomiasis. Programmes should develop a good working relationship with a veterinarian that has access to evidence-based veterinary medical information

Safe and just operating spaces for regional social-ecological systems

Humanity faces a major global challenge in achieving wellbeing for all, while simultaneously ensuring that the biophysical processes and ecosystem services that underpin wellbeing are exploited within scientifically informed boundaries of sustainability. We propose a framework for defining the safe and just operating space for humanity that integrates social wellbeing into the original planetary boundaries concept (Rockström et al., 2009a,b) for application at regional scales. We argue that such a framework can: (1) increase the policy impact of the boundaries concept as most governance takes place at the regional rather than planetary scale; (2) contribute to the understanding and dissemination of complexity thinking throughout governance and policy-making; (3) act as a powerful metaphor and communication tool for regional equity and sustainability. We demonstrate the approach in two rural Chinese localities where we define the safe and just operating space that lies between an environmental ceiling and a social foundation from analysis of time series drawn from monitored and palaeoecological data, and from social survey statistics respectively. Agricultural intensification has led to poverty reduction, though not eradicated it, but at the expense of environmental degradation. Currently, the environmental ceiling is exceeded for degraded water quality at both localities even though the least well-met social standards are for available piped water and sanitation. The conjunction of these social needs and environmental constraints around the issue of water access and quality illustrates the broader value of the safe and just operating space approach for sustainable development

HER2 Testing and Clinical Decision Making in Gastroesophageal Adenocarcinoma

CONTEXT: ERBB2 (erb-b2 receptor tyrosine kinase 2 or HER2) is currently the only biomarker established for selection of a specific therapy for patients with advanced gastroesophageal adenocarcinoma (GEA). However, there are no comprehensive guidelines for the assessment of HER2 in patients with GEA. OBJECTIVES: To establish an evidence-based guideline for HER2 testing in patients with GEA, to formalize the algorithms for methods to improve the accuracy of HER2 testing while addressing which patients and tumor specimens are appropriate, and to provide guidance on clinical decision making. DESIGN: The College of American Pathologists, American Society for Clinical Pathology, and American Society of Clinical Oncology convened an expert panel to conduct a systematic review of the literature to develop an evidence-based guideline with recommendations for optimal HER2 testing in patients with GEA. RESULTS: The panel is proposing 11 recommendations with strong agreement from the open-comment participants. RECOMMENDATIONS: The panel recommends that tumor specimen(s) from all patients with advanced GEA, who are candidates for HER2-targeted therapy, should be assessed for HER2 status before the initiation of HER2-targeted therapy. Clinicians should offer combination chemotherapy and a HER2-targeted agent as initial therapy for all patients with HER2-positive advanced GEA. For pathologists, guidance is provided for morphologic selection of neoplastic tissue, testing algorithms, scoring methods, interpretation and reporting of results, and laboratory quality assurance. CONCLUSIONS: This guideline provides specific recommendations for assessment of HER2 in patients with advanced GEA while addressing pertinent technical issues and clinical implications of the results