Latin American-United States Security Relations and the Power Asymmetry Divide

Security relations between Latin American and the United States are generally well explained by hegemonic stability theory. Succinctly stated, hegemonic stability theory explains that in systems with a hegemonic power there is a greater likelihood of security cooperation. This is because a hegemon provides public goods, such as a stable currency or security from outside interference, and in turn, the less powerful states acknowledge the leadership of the dominant state. When compared to other regions it is readily apparent that the U.S. and Latin America do not have major security issues on the level of East Asia, the Middle East, Africa, or even Europe. However, a review of the literature indicates a persistent gap between U.S. and Latin American responses to security related issues such as state sovereignty, arms trade, humanitarian intervention, the illegal narcotics trade, and technology transfer. Hegemonic stability explains the relatively peaceful relations between the U.S. and Latin America; however, it fails to explain the undercurrent of distrust. This study focuses on the degree of power asymmetry between the hegemon and weaker states in the system to explain why the same hegemonic system may create greater levels of cooperation during different periods. A hegemonic system by definition contains a certain level of power asymmetry, however this study asks the question: When power asymmetry becomes more extreme does it erode security cooperation between the U.S. and Latin America? To explore this issue empirical evidence is gathered from the last century of Latin American-U.S. security relations. The ebb and flow of security cooperation is analyzed and reveals that broad patterns in the system emerge over time demonstrating that as the power of the U.S. increases, the likelihood of U.S. leaders to commit to unilateral actions in Latin America increases. During the same time, the likelihood of Latin American leaders to be more sensitive to U.S. policies and search for alternatives to U.S. dominance also increases. Although U.S. hegemony contributes to greater security cooperation as hegemonic stability theory predicts, when U.S. power reaches higher levels compared to Latin American, the gains of hegemonic stability deteriorate and security cooperation becomes more difficult. The dissertation contributes to international relations scholarship in two important ways. First, it demands that when hegemonic stability theory is applied it cannot be assumed that all levels of power asymmetry create security cooperation equally. Second, it applies formal international relations theory to Latin American-U.S. relations, a geographical area in which comparative political theory is more commonly utilized

Solvent‐induced enantioselectivity reversal in a chiral metal organic framework

Solvent-induced enantioselectivity reversal is a rarely reported phenomenon in porous homochiral materials. Similar behavior has been studied in chiral high performance liquid chromatography, where minor modifications to the mobile phase can induce elution order reversal of two enantiomers on a chiral stationary phase column. We report the first instance of solvent-induced enantioselectivity reversal in a homochiral metal organic framework. Further, we highlight the complex enantioselectivity behavior of homochiral metal organic frameworks toward racemic mixtures in the presence of solvents through racemate-solvent enantioselectivity and loading experiments as well as enantiopure-solvent loading experiments. We hypothesize that this interesting selectivity reversal behavior is likely to be observed in other competitive adsorption, nonchiral selective processes involving a solvent

Price Discovery and the Accuracy of Consolidated Data Feeds in the U.S. Equity Markets

Both the scientific community and the popular press have paid much attention to the speed of the Securities Information Processor, the data feed consolidating all trades and quotes across the US stock market. Rather than the speed of the Securities Information Processor, or SIP, we focus here on its accuracy. Relying on Trade and Quote data, we provide various measures of SIP latency relative to high-speed data feeds between exchanges, known as direct feeds. We use first differences to highlight not only the divergence between the direct feeds and the SIP, but also the fundamental inaccuracy of the SIP. We find that as many as 60 percent or more of trades are reported out of sequence for stocks with high trade volume, therefore skewing simple measures such as returns. While not yet definitive, this analysis supports our preliminary conclusion that the underlying infrastructure of the SIP is currently unable to keep pace with the trading activity in today's stock market.Comment: 18 pages, 20 figures, 2 table

PinR mediates the generation of reversible population diversity in Streptococcus zooepidemicus

Opportunistic pathogens must adapt to and survive in a wide range of complex ecosystems. Streptococcus zooepidemicus is an opportunistic pathogen of horses and many other animals, including humans. The assembly of different surface architecture phenotypes from one genotype is likely to be crucial to the successful exploitation of such an opportunistic lifestyle. Construction of a series of mutants revealed that a serine recombinase, PinR, inverts 114 bp of the promoter of SZO_08560, which is bordered by GTAGACTTTA and TAAAGTCTAC inverted repeats. Inversion acts as a switch, controlling the transcription of this sortase-processed protein, which may enhance the attachment of S. zooepidemicus to equine trachea. The genome of a recently sequenced strain of S. zooepidemicus, 2329 (Sz2329), was found to contain a disruptive internal inversion of 7 kb of the FimIV pilus locus, which is bordered by TAGAAA and TTTCTA inverted repeats. This strain lacks pinR and this inversion may have become irreversible following the loss of this recombinase. Active inversion of FimIV was detected in three strains of S. zooepidemicus, 1770 (Sz1770), B260863 (SzB260863) and H050840501 (SzH050840501), all of which encoded pinR. A deletion mutant of Sz1770 that lacked pinR was no longer capable of inverting its internal region of FimIV. The data highlight redundancy in the PinR sequence recognition motif around a short TAGA consensus and suggest that PinR can reversibly influence the wider surface architecture of S. zooepidemicus, providing this organism with a bet-hedging solution to survival in fluctuating environments

An exploration of the organisational stressors encountered by international disability footballers

Presently, disability athletes remain under-represented in organisational stressor research. Our study sought to bring novel insights to this area by determining the organisational stressors experienced by international disability footballers. Twelve current international disability footballers (10 male, 2 female) from a range of UK impairment squads took part in the study. Semi-structured interviews were completed with each participant, and data were analysed by content analysis procedures. Organisational stressors data were abstracted into Arnold, Wagstaff, Steadman, and Pratt’s (2017) concepts, and Arnold and Fletcher’s (2012) four general dimensions: leadership and personnel issues, cultural and team issues, logistical and environmental issues, and performance and personal issues, revealing a series of football specific nuances. Our study is the first exploration of the prevalence of organisational stressors within international disability football. Our study also provides practitioners with an understanding of the common and unique organisational stressors faced by international disability footballers. Finally, we suggest a series of practical recommendations for policy development within disability football organisations to aid athletes to effective manage organisational stressors

Block-Diagonalization and f-electron Effects in Tight-Binding Theory

We extend a tight-binding total energy method to include f-electrons, and apply it to the study of the structural and elastic properties of a range of elements from Be to U. We find that the tight-binding parameters are as accurate and transferable for f-electron systems as they are for d-electron systems. In both cases we have found it essential to take great care in constraining the fitting procedure by using a block-diagonalization procedure, which we describe in detail.Comment: 9 pages, 6 figure

Electrochemically copper-doped bismuth tellurium selenide thin films

We report the first results of a study on electrochemically doped copper bismuth tellurium selenide thin films electrodeposited from aqueous nitric acid electrolytes containing up to 2 mM of Cu(NO3)2. The effect of Cu(NO3)2 concentration on the composition, structure and thermoelectric properties of the bismuth tellurium selenide films is investigated by scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction and Seebeck and Hall effect measurements. A Cu(NO3)2 concentration of 1.5 mM is found to offer a Seebeck coefficient of up to −390 μV K−1 at room temperature, which is the highest reported to date for an electrodeposited bismuth tellurium compound

Characterization of the acidic cold seep emplaced jarositic Golden Deposit, NWT, Canada, as an analogue for jarosite deposition on Mars

Surficial deposits of the OH-bearing iron sulfate mineral jarosite have been observed in several places on Mars, such as Meridiani Planum and Mawrth Vallis. The specific depositional conditions and mechanisms are not known, but by comparing martian sites to analogous locations on Earth, the conditions of formation and, thus, the martian depositional paleoenvironments may be postulated. Located in a cold semi-arid desert ~100 km east of Norman Wells, Northwest Territories, Canada, the Golden Deposit (GD) is visible from the air as a brilliant golden-yellow patch of unvegetated soil, approximately 140 m x 50 m. The GD is underlain by permafrost and consists of yellow sediment, which is precipitating from seeps of acidic, iron-bearing groundwater. On the surface, the GD appears as a patchwork of raised polygons, with acidic waters flowing from seeps in troughs between polygonal islands. Although UV-Vis-NIR spectral analysis detects only jarosite, mineralogy, as determined by X-Ray Diffraction and Inductively Coupled Plasma Emission Spectrometry, is predominantly natrojarosite and jarosite, with hydronium jarosite, goethite, quartz, clays, and small amounts of hematite. Water pH varies significantly over short distances depending on proximity to acid seeps, from 2.3 directly above seeps, to 5.7 several m downstream from seeps within the deposit, and up to 6.5 in ponds proximal to the deposit. Visual observations of microbial filament communities and phospholipid fatty acid analyses confirm that the GD is capable of supporting life for at least part of the year. Jarositic-bearing sediments extend beneath vegetation up to 70 m out from the deposit and are mixed with plant debris and minerals presumably weathered from bedrock and glacial till. This site is of particular interest because mineralogy (natrojarosite, jarosite, hematite, and goethite) and environmental conditions (permafrost and arid conditions) at the time of deposition are conceivably analogous to jarosite deposits on Mars. Most terrestrial analogues for Mars jarosites have been identified in temperate environments, where evaporation rates are very high and jarosites form along with other sulfates due to rapid evaporation (e.g. Rio Tinto, Spain; Western Australian acidic saline lake deposits). The GD is a rare example of an analogue site where jarosite precipitates under dominant freezing processes similar to those which could have prevailed on early Mars. Thus, the GD offers a new perspective on jarosite deposition by the upwelling of acidic waters through permafrost at Meridiani Planum and Mawrth Vallis, Mars. The GD also demonstrates that martian deposits may show considerably more chemical and mineral variability than indicated by the current remote sensing data sets