The Impact of Coffee Production on the Economy of Colombia

This senior thesis seeks to determine the impact that the level of coffee production in Colombia has on economic wellbeing in the country. As a proxy for economic wellbeing in different arenas, I look at the income, health, and education variables of GDP, infant mortality rate, and secondary education enrollment. I use a Two-Stage Least Squares regression model to estimate this impact, with lagged international coffee prices and the occurrence of the fungal plant disease coffee leaf rust as instruments to account for endogeneity. The data which I use in this project include country-level indicators from the World Bank and monthly coffee production quantities from Colombia’s National Federation of Coffee Growers. I find that a 10 percent increase in coffee production is significantly associated with a roughly 3.4% increase in GDP. I find the estimated effect of coffee production on the infant mortality rate, given a 10 percent increase in coffee production, to be a decrease of .6 deaths per thousand live births, but this result is not statistically significant. Lastly, I find that a 10 percent increase in coffee production is associated with a statistically significant decrease in the ratio of secondary educational enrollment by 2.4 points, while the current baseline is around 40 points

Individual differences in good manners rather than compassion predict fair allocations of wealth in the dictator game

Objective. One of the most common tools for studying prosociality is the dictator game, in which allocations to one’s partner are often described in terms of altruism. However, there is less consensus regarding the motivations driving these allocations, which may represent either emotional concern for others (compassion), adherence to social norms regarding fairness (politeness), or both. Method. In this paper, we apply personality psychology to the study of behavior in the dictator game, in which we examine the discriminant validity of distinct prosocial constructs from the Big Five and HEXACO models in relation to allocations of wealth. Results. Across four studies (combined N = 798) utilizing both hypothetical and incentivized designs, we found that the politeness—but not compassion—aspect of Big Five agreeableness, as well as HEXACO honesty-humility, uniquely predicted dictator allocations within their respective personality models. Conclusions. These findings contribute to a growing literature indicating that the standard dictator game measures “good manners” or adherence to norms concerning fairness, rather than pure emotional concern or compassionate motives, which have important implications for how this paradigm is used and interpreted in psychological research

Brachial artery characteristics and micro-vascular filtration capacity in rock climbers

Rock climbers perform repeated isometric forearm muscle contractions subjecting the vasculature to repeated ischaemia and distorted haemodynamic signals. This study investigated forearm vascular characteristics in rock climbers compared to healthy untrained controls. Eight climbers (CLIMB) (BMI; 22.3, s = 2.0 kg/m2, isometric handgrip strength; 46, s = 8 kg) were compared against eight untrained controls (CON) (BMI; 23.8, s = 2.6 kg/m2, isometric handgrip strength; 37, s = 9 kg). Brachial artery diameter and blood flow were measured, using Doppler ultrasound, at rest and following 5-mins ischaemia (peak diameter) and ischaemic exercise (maximal dilation) to calculate flow mediated dilation (FMD) and dilatory capacity (DC). Capillary filtration capacity was assessed using venous occlusion plethysmography. Resting (4.30, s = 0.26 vs. 3.79, s = 0.39 mm), peak (4.67, s = 0.31 vs. 4.12, s = 0.45 mm) and maximal (5.14, s = 0.42 vs. 4.35, s = 0.47 mm) diameters were greater (P < 0.05) in CLIMB than CON, respectively, despite no difference in FMD (9.2, s = 2.6 vs. 8.7, s = 2.9%). Peak reactive hyperaemic blood flow (1136, s = 504 vs. 651, s = 221 ml/min) and capillary filtration capacity (3.8, s = 0.9 vs. 5.2, s = 0.7 ml.min−1.mmHg−1.100 ml tissue−1 × 10−3) were greater (P < 0.05) in CLIMB compared to CON, respectively. Rock climbers exhibit structural vascular adaptation compared to untrained control participants but have similar vascular function. This may contribute to the enhanced ability of climbers to perform repeated isometric contractions

Does sexual selection explain the courtship song of field crickets (Gryllus bimaculatus)?

This study evaluates the factors that may potentially affect the courtship songs of Gryllus bimaculatus, (including: wing morphology, male body size and the male’s current nutritional condition) and whether female crickets assess male courtship song.This paper was initially delivered at the Annual Congress of the Biological Sciences Division of the South African Academy for Science and Art, ARC-Plant Protection Research Institute, Roodeplaat, Pretoria, South Africa on 01 October 2010.http://www.satnt.ac.zaam2014ab201

Costless and Costly Prosociality: Correspondence Among Personality Traits, Economic Preferences, and Real-World Prosociality

Prosociality can either be costly (e.g., donating to charity) or costless (e.g., posthumous organ donation). Whereas links between personality and costly prosociality have been explored, links with costless prosociality and personality are at present unknown. We address this in two studies: Study 1 (N ¼ 200) confirms the distinction between costless and costly prosociality based on willingness to engage with health and nonhealth prosociality. Study 2, using data from four samples (student and community; N ¼ 733), shows that across incentivized and hypothetical economic games to assess costless (generosity game) and costly (dictator game) prosociality, that organ donor behavior was linked to greater allocations in the GG and charity/volunteering behavior in the DG. Costless and costly prosocialities are associated with different personality traits (e.g., costly with politeness and compassion and costless with intellect). Implications for cooperative phenotypes and recruiting organ donors are discussed

Vector species-specific association between natural Wolbachia infections and avian malaria in black fly populations

Thanks to the Institute of Biodiversity Animal Health and Comparative Medicine (University of Glasgow) for funding vector traps.Artificial infection of mosquitoes with the endosymbiont bacteria Wolbachia can interfere with malaria parasite development. Therefore, the release of Wolbachia-infected mosquitoes has been proposed as a malaria control strategy. However, Wolbachia effects on vector competence are only partly understood, as indicated by inconsistent effects on malaria infection reported under laboratory conditions. Studies of naturally-occurring Wolbachia infections in wild vector populations could be useful to identify the ecological and evolutionary conditions under which these endosymbionts can block malaria transmission. Here we demonstrate the occurrence of natural Wolbachia infections in three species of black fly (genus Simulium), which is a main vector of the avian malaria parasite Leucocytozoon. Prevalence of Leucocytozoon was high (25%), but the nature and magnitude of its association with Wolbachia differed between black fly species. Wolbachia infection was positively associated with avian malaria infection in S. cryophilum, negatively associated in S. aureum, and unrelated in S. vernum. These differences suggest that Wolbachia interacts with the parasite in a vector host species-specific manner. This provides a useful model system for further study of how Wolbachia influences vector competence. Such knowledge, including the possibility of undesirable positive association, is required to guide endosymbiont based control methods.Publisher PDFPeer reviewe

Are high elevation crag lizards sensitive to climate change?

Crag lizards are restricted to montane areas where biota are strongly exposed to the effects of climate change. We investigated the factors shaping the distribution of Drakensberg crag lizards (Pseudocordylus melanotus melanotus; Cordylidae) by quantifying their elevational ranges, availability of shelter and prey as well as the thermal environment at three elevations. We recorded expected body temperatures using copper models of the lizards at each elevation in the field and in the laboratory, estimating the duration for which lizards must shelter from high temperatures. This correlated strongly with field observations of lizard activity during winter, spring and summer. Our models predicted that at lower elevations, lizards would shelter for longer periods each day, resulting in a marked reduction in time available for essential activities such as feeding and breeding, possibly explaining why these animals do not occur at lower elevations. The distribution and survival of these animals therefore appear to be impacted by the degree to which daytime temperatures limit their activity. Modelling future climate change scenarios at the high elevation site indicates that crag lizards would be resilient against small to moderate warming reflected by RCP4.5 climate change predictions, but populations are unlikely to persist under conditions predicted in the RCP8.5 scenario. This study is important as, unlike broader-scope studies that cannot quantify climate change impacts on individual species, we combine detailed field data with laboratory measurements and modelling of a single species to assess the ecological constraints to which crag lizards are exposed.The University of Pretoria and the National Research Foundation.https://onlinelibrary.wiley.com/journal/14429993hj2022Geography, Geoinformatics and MeteorologyPhysicsZoology and Entomolog

Doing Biopolitics Differently? Radical Potential in the Post-2015 MDG and SDG Debates

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