Seasonality, resource stress, and food sharing in so-called "egalitarian" foraging societies

Most discussions of food sharing among so-called "egalitarian" hunters and gatherers implicitly assume that, because all adult members of a group participate in the network of sharing, all must therefore be receiving portions of more or less equivalent nutritional worth. This assumption is questioned and five basic points are raised: (1) because fat is not uniformly distributed over the carcass of an animal and because it is depleted sequentially when an animal is stressed, certain individuals may receive nutritionally inferior portions of meat, with potentially serious health consequences for the recipients during seasonal or interannual periods when other food resources are in short supply; (2) even when sharing is quantitatively and nutritionally equitable, food taboos may block certain individuals from access to meat and/or fat, particularly children, women at critical stages in their reproductive life, and the elderly (however, in the case of pregnant women, such food taboos and seemingly inequitable sharing practices may have positive as well as negative consequences for the health and survivorship of the fetus or newborn infant by keeping maternal protein consumption below about 20% of total calories and by reducing the mother's risk of exposure to potentially teratogenic substances that may accumulate in animal tissues); (3) skilled hunters may acquire nutritionally more valuable parts than do other males by "snacking" at kill sites and through differential sharing; (4) food-sharing practices and food taboos vary widely among foragers, and this diversity may contribute to observed differences among groups in fertility and infant mortality patterns; and (5) the focus of anthropologists on the sharing of food, especially meat, as opposed to the sharing of a broad spectrum of social, political, economic, and sexual rights and privileges, is an overly narrow and potentially misleading perspective. In closing, the paper briefly discusses the utility of the term "egalitarian," concluding that the concept, by conflating ideology with actual behavior, may obscure rather than enhance our understanding of the origins and adaptations of foraging societies.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/28530/1/0000327.pd

Methods for visualising complex water quality data

Includes abstract.Includes bibliographical references (leaves 157-173).The quality of South Africa’s over-stretched water resources is a matter of concern for all who depend on them for their survival and prosperity, so access to the relevant monitoring data is essential. Visualisation is a powerful method for analysing these data and communicating the results, because it unloads complex cognitive processes from the fairly restricted human numerical processing structures onto the highly developed visual perception system. Developments in the field of visualisation during the past two decades have yielded many practical methods that are applicable to the analysis and presentation of water quality data. Judicious use of visualisation aids aquatic scientists, water resource managers and ordinary consumers in assessing the quality of their water and deciding on remedial measures. To provide some insight into the possibilities of visualisation techniques, I analyse and discuss five visual methods that I have developed or contributed to: multivariate time-series inventory plots; multivariate map symbols; spatially-referenced inventory of water quality data; mass transfer summary plots; and the use of visual methods in communicating the ecological status of rivers to a wide audience

Device therapy for the management of symptoms in atrial fibrillation

Atrial fibrillation is the commonest clinical arrhythmia and places a considerable burden on health services, patient wellbeing and survival. Many strategies have been implemented to treat this condition using such diverse approaches as pharmacological, device, ablative and hybrid therapies. However, as yet there is no panacea for this heterogeneous condition and thus there is active on-going research in each of these fields. The aim of this thesis is to investigate the potential benefits of selected device therapies in the management of symptoms in patients with atrial fibrillation. This thesis commences with a historical review of device therapy for atrial fibrillation. A methodological chapter discusses pacemaker analytical processes and the development of echocardiographic tools for assessing ventricular synchrony during exercise. Original work using third generation anti-AF preventive pacIng algorithms and their impact on disea'se and symptoms is examined. This IS followed by an assessment of the sensing accuracy of modern pacemakers. The device-derived electrophysiological factors are then compared to patient symptoms to isolate predictors of symptomatic status for individual atrial fibrillation episodes. The confounding problem of ventricular pacing is examined for an adverse effect on paroxysmal atrial fibrillation. The next chapter examines the use of an impedance-based rate response sensor in the right ventricular high septum. The final study describes an assessment of right ventricular apical versus high septal pacing in 'ablate and pace' patients with persistent AF uSIng cardiopulmonary and symptomatic assessments. The thesis concludes with the principal findings and a discussion on directions for future research in this field.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Successful Non-fluoroscopic Radiofrequency Ablation of Incessant Atrial Tachycardia in a High Risk Twin Pregnancy

We describe a patient presenting with incessant ectopic atrial tachycardia during a high risk twin pregnancy. Tachycardia was resistant to escalating doses of beta-blockade with digoxin. Because of increasing left ventricular dysfunction early in the third trimester, catheter ablation was performed successfully at 30 weeks gestation. Electro-anatomic mapping permitted the entire procedure to be conducted without the use of ionizing radiation. The pregnancy proceeded to successful delivery near term and after three years the patient remains recurrence free with normal left ventricular function, off all medication