78 research outputs found
Climate Variability and Local Environmental Stressors Influencing Migration in Nang Rong, Thailand
Scholars point to climate change, often in the form of more frequent and
severe drought, as a potential driver of migration in the developing world,
particularly in populations that rely on agriculture for their livelihoods. To
date, however, there have been few large-scale, longitudinal studies that
explore the relationship between climate change and migration. This study
significantly extends current scholarship by evaluating distinctive effects of
slow onset climate change and short-term extreme events upon different
migration outcomes. Our analysis models the effect of the environment--as
measured by Normalized Difference Vegetation Index (NDVI) and the occurrence
of El Nino Southern Oscillation (ENSO) events—on migration out of Nang Rong.
Our preliminary findings indicate that predominantly dry El Niño periods of 24
months duration lead to outmigration, while predominantly wetter La Niña
periods of 12-month duration reduce outmigration. Clustered monthly patterns
of annual NDVI fluctuation indicate that villagers living in pixels that
exhibit early, consistently higher, and steep rising green-up are less likely
to migrate out in the subsequent year
Experimental evidence for convergent evolution of maternal care heuristics in industrialized and small-scale populations
Maternal care decision rules should evolve responsiveness to factors impinging on the fitness pay-offs of care. Because the caretaking environments common in industrialized and small-scale societies vary in predictable ways, we hypothesize that heuristics guiding maternal behaviour will also differ between these two types of populations. We used a factorial vignette experiment to elicit third-party judgements about likely caretaking decisions of a hypothetical mother and her child when various fitness-relevant factors (maternal age and access to resources, and offspring age, sex and quality) were varied systematically in seven populations—three industrialized and four small-scale. Despite considerable variation in responses, we found that three of five main effects, and the two severity effects, exhibited statistically significant industrialized/ small-scale population differences. All differences could be explained as adaptive solutions to industrialized versus small-scale caretaking environments. Further, we found gradients in the relationship between the population-specific estimates and national-level socio-economic indicators, further implicating important aspects of the variation in industrialized and small-scale caretaking environments in shaping heuristics. Although there is mounting evidence for a genetic component to human maternal behaviour, there is no current evidence for interpopulation variation in candidate genes. We nonetheless suggest that heuristics guiding maternal behaviour in diverse societies emerge via convergent evolution in response to similar selective pressures
Cooperation, collective action, and the archeology of large-scale societies
Archeologists investigating the emergence of large-scale societies in the past have renewed interest in examining the dynamics of cooperation as a means of understanding societal change and organizational variability within human groups over time. Unlike earlier approaches to these issues, which used models designated voluntaristic or managerial, contemporary research articulates more explicitly with frameworks for cooperation and collective action used in other fields, thereby facilitating empirical testing through better definition of the costs, benefits, and social mechanisms associated with success or failure in coordinated group action. Current scholarship is nevertheless bifurcated along lines of epistemology and scale, which is understandable but problematic for forging a broader, more transdisciplinary field of cooperation studies. Here, we point to some areas of potential overlap by reviewing archeological research that places the dynamics of social cooperation and competition in the foreground of the emergence of large-scale societies, which we define as those having larger populations, greater concentrations of political power, and higher degrees of social inequality. We focus on key issues involving the communal-resource management of subsistence and other economic goods, as well as the revenue flows that undergird political institutions. Drawing on archeological cases from across the globe, with greater detail from our area of expertise in Mesoamerica, we offer suggestions for strengthening analytical methods and generating more transdisciplinary research programs that address human societies across scalar and temporal spectra
Recommended from our members
Pulse oximetry in the oesophagus
Pulse oximetry has been one of the most significant technological advances in clinical monitoring in the last two decades. Pulse oximetry is a non-invasive photometric technique that provides information about the arterial blood oxygen saturation (SpO(2)) and heart rate, and has widespread clinical applications. When peripheral perfusion is poor, as in states of hypovolaemia, hypothermia and vasoconstriction, oxygenation readings become unreliable or cease. The problem arises because conventional pulse oximetry sensors must be attached to the most peripheral parts of the body, such as finger, ear or toe, where pulsatile flow is most easily compromised. Since central blood flow may be preferentially preserved, this review explores a new alternative site, the oesophagus, for monitoring blood oxygen saturation by pulse oximetry. This review article presents the basic physics, technology and applications of pulse oximetry including photoplethysmography. The limitations of this technique are also discussed leading to the proposed development of the oesophageal pulse oximeter. In the majority, the report will be focused on the description of a new oesophageal photoplethysmographic/SpO(2) probe, which was developed to investigate the suitability of the oesophagus as an alternative monitoring site for the continuous measurement of SpO(2) in cases of poor peripheral circulation. The article concludes with a review of reported clinical investigations of the oesophageal pulse oximeter
A Response to Margreta de Grazia, "Homonyms before and after Lexical Standardization"
A response to some of de Grazia's arguments in her Shakespeare-Jahrbuch article "Homonyms before and after Lexical Standardization.
Outcome from percutaneous nephrolithotomy in patients with spinal cord injury, using a single-stage dilator for access
- …