Dynamic sea level changes following changes in the thermohaline circulation

Using the coupled climate model CLIMBER-3α, we investigate changes in sea surface elevation due to a weakening of the thermohaline circulation (THC). In addition to a global sea level rise due to a warming of the deep sea, this leads to a regional dynamic sea level change which follows quasi-instantaneously any change in the ocean circulation. We show that the magnitude of this dynamic effect can locally reach up to ~1m, depending on the initial THC strength. In some regions the rate of change can be up to 20-25 mm/yr. The emerging patterns are discussed with respect to the oceanic circulation changes. Most prominent is a south-north gradient reflecting the changes in geostrophic surface currents. Our results suggest that an analysis of observed sea level change patterns could be useful for monitoring the THC strength.

Estudo da topologia de motores de fluxo axial de excitação híbrida com foco na utilização em tração elétrica.

Os motores de corrente contínua convencionais são muito bem conhecidos pela sua robustez e pelo seu alto nível de controlabilidade, alem do fato de possibilitarem a operação na região de enfraquecimento de campo (modo motor), quando esta situação se fizer necessária. Por estas características, as máquinas de corrente contínua ainda são empregadas nos dias atuais em nichos específicos de utilização. Não obstante, a máquina c.c. apresenta algumas desvantagens, principalmente a intensiva e dispendiosa manutenção eletromecânica necessária para sua operação. Como opção de sanar este problema, surgiram na década de 60, as máquinas elétricas de corrente contínua sem escovas (brushless) com excitação por ímãs permanentes de fluxo trapezoidal. O problema destas máquinas se deve justamente a impossibilidade da variação de fluxo de excitação uma vez que são produzidos puramente pelos ímãs. Sendo assim, este trabalho tem como propósito, o estudo de topologias diferenciadas da máquina elétrica, através de um circuito magnético não convencional para aplicação e utilização em sistemas de tração elétrica para operação na região de enfraquecimento de campo através da variação do fluxo resultante no entreferro. Como objeto de estudo, foi focada a topologia de fluxo axial com excitação híbrida, ou seja, dupla excitação (excitação a ímãs permanentes e excitação elétrica). Para o projeto da topologia proposta, nesta tese, adicionalmente ao método analítico, foram realizadas simulações computacionais para a comparação e refinamento dos resultados das grandezas eletromagnéticas da máquina.

Populismos y democracias defectuosas en El Ecuador (1996-2012): continuidades y diferencia

From 1995 to 2015, Ecuador experienced one of its longest periods of deep political, social and economic crisis. During this interval, three democratically elected governments (Bucaram, 1997; Mahuad, 2000 and Gutiérrez, 2005) were overthrown and a critical juncture arose in 2006 as a result. Since 2007, and as a consequence of these chaotic circumstances, new populist strongmen ascended and, amid the biggest bonanza of oil revenues in Ecuadorian history, established a defective democracy. The gradual escalation of authoritarian tendencies during the three consecutive terms in which Rafael Correa has acted as President, have resulted in the severe weakening of the country’s democratic institutions, since Correa’s has strived to perpetuate himself in power through continual re-election into office, instead of building an institutional quality-democracy. This study aims to clarify the historical foundations of the recurrence of caudillistas, populist and authoritarian governments in Ecuador, revealing the basis of the specific path dependence of Ecuadorian politics. We also explore the Jungian theory, specifically the “pseudo-hero myth”, as the political narrative which Correa’s regime successfully employed to establish its hegemony. Additionally, we perform a psychological-political case analysis by examining the social psychology components underlying the Ecuadorian path dependence towards authoritarian and populist caudillos: Specifically, our case study is framed within historical institutionalism, which focuses on methodological individualism to attend various political science and psychological-political theories...

Towards the Consideration of the U.S. Community College Model to Address the Need for Higher Education Reforms in Ghana

ABSTRACT The higher education systems throughout the continent of Africa are undergoing unprecedented challenges and are considered in crisis. African countries, including Ghana, all have in common ties to their colonial legacy whereby they are confronted with weak policies put in place by their colonizers. Having gained their independence, Africans should now take responsibility for the task of reforming their higher education system. To date, nothing substantial has been accomplished, with serious implications for weakening and damaging the structures of the foundation of their educational systems. This qualitative, single case study utilized a postcolonial theory-critical pedagogy framework, providing guidance for coming to grips with the mindset posed by Ghana's colonial heritage in the postcolonial era, especially in terms of its damaging effects on Ghana's higher education system. The study explores alternative pathways for secondary school students to transition to tertiary education--a problematic transition that currently hinders open access to all and equality in educational opportunity, resulting in a tremendous pool of discontinued students. This transitional problem is directly related to Ghana's crisis in higher education with far reaching consequences. The alternative pathway considered in this study is an adaptation of the U.S. community college model or an integration of its applicable aspects into the current structures of the higher education system already in place. In-depth interviews were conducted with 5 Ghanaian professors teaching at community colleges in the United States, 5 Ghanaian professors teaching at universities in Ghana, and 2 educational consultants from the Ghanaian Ministry of Education. Based on their perspectives of the current state of Ghanaian higher education, analyzed in terms of pedagogy, structure/infrastructure, and curriculum, the participants provided their perceptions of salient aspects of the U.S. community college model that would be applicable to Ghana's situation, along with other recommendations. Access to all, including equality of educational opportunity, was considered essential, followed by adaptability, affordability, practicality, and quality of curriculum content and delivery. Canada's successful adaptation of the U.S. model was also discussed. Findings can help guide consideration of alternative pathways to higher education in Ghana and Africa as a whole.

É possível determinar a maturidade fisiológica das sementes de milho (Zea mays) utilizando o sal de tetrazólio?

Nessa pesquisa foi avaliada a utilização do sal de tetrazólio para determinar a maturidade fisiológica das sementes de milho. As sementes utilizadas foram dos híbridos Pioneer 4285 e Dow 2B587, semeadas em 03/10/2014 e 05/12/2014 respectivamente, e colhidas a partir dos 40 dias após o florescimento (DAF), com intervalos de 4 dias até os 68 DAF. As sementes colhidas foram avaliadas quanto à viabilidade e ao vigor (testes de germinação, de emergência da plântula, de condutividade elétrica, de envelhecimento acelerado e determinações do comprimento da plântula). Os parâmetros utilizados para determinar o ponto de maturidade fisiológica das sementes foram a camada preta, a linha de leite, a massa de matéria seca, o teor de água e a avaliação dos tecidos da semente utilizando o sal de tetrazólio, utilizando o método descrito para avaliar a viabilidade, complementado pela avaliação da atividade das células da chalaza e da zona de transferência do endosperma para o embrião. Para as sementes de milho dos dois híbridos a germinação foi superior a 95% e não houve diferença entre as épocas de colheita, somente nas últimas colheitas das sementes do híbrido Dow 2B587 houve redução da germinação e do vigor. O ponto de maturidade fisiológica (PM) foi identificado aos 56 DAF para as sementes de milho do híbrido P4285 e aos 48 DAF para as do híbrido Dow 2B587 e correspondeu ao estádio 4 da linha de leite e ao máximo de acúmulo da matéria seca. O máximo de vigor foi detectado por meio do resultado do teste de envelhecimento acelerado oito dias antes do (PM) para os dois híbridos. A atividade das células do endosperma está relacionada com os demais indicadores do PM (linha de leite, camada preta, massa de matéria seca e teor de água). O transporte de fotoassimilados da planta mãe para a semente cessa no ponto de maturidade fisiológica da semente, desativando o transporte no qual atuam as células da chalaza e da região basal do endosperma. A utilização do sal de tetrazólio possibilita identificar a morte das células da região basal do endosperma, uma vez que a partir desse momento não há mais a reação dessas células com o sal de tetrazólio, indicando que não têm atividade celular. Dessa forma, é possível caracterizar o ponto de maturidade fisiológica da semente de milho, por meio da atividade do sal de tetrazólio; essa caracterização é confirmada pela expressão das enzimas CAT e MDH.

Automatic Abdominal Aortic Aneurysm segmentation in MR images

Abdominal Aortic Aneurism is a disease related to a weakening in the aortic wall that can cause a break in the aorta and the death. The detection of an unusual dilatation of a section of the aorta is an indicative of this disease. However, it is difficult to diagnose because it is necessary image diagnosis using computed tomography or magnetic resonance. An automatic diagnosis system would allow to analyze abdominal magnetic resonance images and to warn doctors if any anomaly is detected. We focus our research in magnetic resonance images because of the absence of ionizing radiation. Although there are proposals to identify this disease in magnetic resonance images, they need an intervention from clinicians to be precise and some of them are computationally hard. In this paper we develop a novel approach to analyze magnetic resonance abdominal images and detect the lumen and the aortic wall. The method combines different algorithms in two stages to improve the detection and the segmentation so it can be applied to similar problems with other type of images or structures. In a first stage, we use a spatial fuzzy C-means algorithm with morphological image analysis to detect and segment the lumen; and subsequently, in a second stage, we apply a graph cut algorithm to segment the aortic wall. The obtained results in the analyzed images are pretty successful obtaining an average of 79% of overlapping between the automatic segmentation provided by our method and the aortic wall identified by a medical specialist. The main impact of the proposed method is that it works in a completely automatic way with a low computational cost, which is of great significance for any expert and intelligent system.

Complaint of Harvard President and Tutors against Nathan Prince, submitted to Governor William Shirley and the Board of Overseers on Jan. 29, 1741

President Edward Holyoke and Tutors Henry Flynt, Joseph Mayhew, and Thomas Marsh accused Prince of "sundry crimes & misdemeanors" and "sundry evil actions," including weakening and undermining the College government, showing contempt towards his fellow Tutors and towards Hollis Professor John Winthrop (who he claimed "knew no more of Philosophy than a Brute"), and making insulting remarks on numerous occasions. Prince was accused of calling others "Fool, Rogue, Rascal, Puppy &c." and of calling Col. Brattle "a Devilish Lyar." He was also accused of "appearing often times, to be what is commonly stil'd the worse for Drink" and of neglecting his duties towards his students.

Simulating Granite Emplacement and Deformation with Centrifuge Analogue Modelling

The Greater Himalayan leucogranites are a discontinuous suite of intrusions emplaced in a thickened crust during the Miocene southward ductile extrusion of the Himalayan metamorphic core. Melt-induced weakening is thought to have played a critical role in strain localization that facilitated the extrusion. Recent advancements in centrifuge analogue modelling techniques allow for the replication of a broader range of crustal deformation behaviors, enhancing our understanding of large hot orogens. Polydimethylsiloxane (PDMS) is commonly used in centrifuge experiments to model weak melt zones. Difficulties in handling PDMS had, until now, limited its emplacement in models prior to any deformation. A new modelling technique has been developed where PDMS is emplaced into models that have been subjected to some shortening. This technique aims to better understand the effects of melt on strain localization and potential decoupling between structural levels within an evolving orogenic system. Models are subjected to an early stage of shortening, followed by the introduction of PDMS, and then a final stage of shortening. Theoretical percentages of partial melt and their effect on rock strength are considered when adding a specific percentage of PDMS in each model. Due to the limited size of the models, only PDMS sheets of 3 mm thickness were used, which varied in length and width. Within undeformed packages, minimal surface and internal deformation occurred when PDMS is emplaced in the lower layer of the model, showing a vertical volume increase of ~20% within the package; whereas the emplacement of PDMS into the middle layer showed internal dragging of the middle laminations into the lower layer and a vertical volume increase ~30%. Emplacement of PDMS results in ~7% shortening for undeformed and deformed models. Deformed models undergo ~20% additional shortening after two rounds of deformation. Strain localization and decoupling between units occur in deformed models where the degree of deformation changes based on the amount of partial melt present. Surface deformation visible by the formation of a bulge, mode 1 extension cracks and varying surface strain ellipses varies depending if PDMS is present. Better control during emplacement is exhibited when PDMS is added into cooler models, resulting in reduced internal deformation within the middle layer.

Transforming Power Relationships: Leadership, Risk, and Hope. IHS Political Science Series No. 135, May 2013

Chronic communal conflicts resemble the prisoner’s dilemma. Both communities prefer peace to war. But neither trusts the other, viewing the other’s gain as its own loss, so potentially shared interests often go unrealized. Achieving positive-sum outcomes from apparently zero-sum struggles requires a kind of riskembracing leadership. To succeed leaders must: a) see power relations as potentially positive-sum; b) strengthen negotiating adversaries instead of weakening them; and c) demonstrate hope for a positive future and take great personal risks to achieve it. Such leadership is exemplified by Nelson Mandela and F.W. de Klerk in the South African democratic transition. To illuminate the strategic dilemmas Mandela and de Klerk faced, we examine the work of Robert Axelrod, Thomas Schelling, and Josep Colomer, who highlight important dimensions of the problem but underplay the role of risk-embracing leadership. Finally we discuss leadership successes and failures in the Northern Ireland settlement and the Israeli-Palestinian conflict.

Emerging Markets' Euro Nemesis. CEPS Commentary, 9 September 2013

In this new commentary, CEPS Director Daniel Gros argues that the weakening of European demand triggered by austerity is the real cause behind the recent deterioration of emerging markets’ current accounts. As a consequence, unless the US resumes its role as consumer of last resort, the latest bout of financial-market jitters will weaken the global economy again.

Helpless and lonely: Turkey's attitude towards the war in Syria. OSW Commentary No. 136, 09.05.2014

The conflict in Syria, which has lasted since 2011, has become the most significant test of the efficiency of Turkey’s foreign policy and the biggest challenge to Turkey’s security in recent decades. The lack of a clear prospect of an end to the war does not allow us to come to a final conclusion regarding the Syrian civil war’s importance for Turkey. However, it can be said today that with the exception of the initial phase of the conflict, Ankara’s influence over the course of events in Syria has been limited, and the war itself is evolving in a direction that is unfavourable for Turkey: the hostile regime of Bashar al-Assad is still in power, the opposition has proved to be an unreliable or even a dangerous ally, and in northern Syria militant jihadist groups and Kurds are gaining importance. It is also quite unlikely that the West will take any greater responsibility for stabilising the situation in the region. In response to such an unfortunate situation, and out of fear of risking deeper involvement in the conflict, during the past year Turkey’s policy towards Syria has been restrained, reactive and focused mainly on defending Turkey’s territory. However, this policy offers no security guarantees and does not prevent the country’s regional position from weakening, especially in the context of the reinforcement of the jihadist militants and the Kurdish autonomy in northern Syria. The arguments for Turkey continuing its defensive policy are strong: the country fears the possible results of an open confrontation with Assad’s forces; most probably it could not count on support for such actions from within its own society or its Western allies. It also does not have enough acceptance within the anti-Assad opposition circles. On the other hand, though, the risk of uncontrolled development of events is still present; the risk of confrontations with armed jihadist militants is growing; and the potential operation of Turkish forces, either against the jihadists or against Assad’s army, could be considered as a method of diverting attention from the political problems with which the AKP government has been struggling at home.

Lukashenka has to choose: reforms or concessions to Russia. OSW Commentary No. 42, 2010-10-27

The most serious crisis in the history of Russian-Belarusian relations has been taking place over the past few months. In 2007 Russia started the process of depriving Belarus of subsidies in the form of supplies of fuels at low prices, which have for more than a decade guaranteed the stability of the Belarusian economic model, and is continuing this process now at an accelerated rate. At the same time, the Russian media started attacks on Alyaksandr Lukashenka from the middle of this year. This toughening up of Russia’s measures indicates that the Kremlin is determined to implement its goals regarding Belarus, including first of all taking over its strategic economic assets, which would result in a significant weakening of Lukashenka’s position. The Belarusian government has been consistently avoiding meeting Russian demands, while at the same time insisting on the reinstatement of preferential conditions of co-operation. If the Belarusian leader continues resisting Russian demands, the crisis in Russian- -Belarusian relations will be aggravated, and a conflict over energy issues around the turn of 2011 cannot be ruled out. The reduction in preferences offered by Russia in the energy sector has significantly impaired the condition of the Belarusian economy, and may lead to its breakdown in a year or two. As his country comes under increasing pressure from Russia, Alyaksandr Lukashenka will soon have to make a strategic choice between yielding to the Kremlin’s demands and embarking upon an at least partial restructuring of the economy.

The bear watches the dragon. The Russian debate on China. OSW Point of View Number 31, February 2013

Most participants in the Russian public debate seem to agree in their evaluation of the present condition of Russian-Chinese relations. There is awareness of increasing inequality between these two powers and Russia’s weakening position as compared to China.Those who share the optimistic view see co-operation with China as an opportunity for the Russian economy and a key element of Russia’s multi-directional foreign policy, an opportunity for Russia to avoid unilateral dependence on the West. The pessimists view the deepening co-operation with China through the prism of threats resulting from the increasing imbalance in bilateral relations. The greatest source of concern is the model of economic relations, which is often referred to as neo-colonial, where Russia’s role is reduced to that of a supplier of raw materials to China. The possible consequences are evaluated in different ways, ranging from the political subordination of Russian interests the Chinese ones to real loss of control over the Russian Far East. Those who share such views believe that Moscow should slow down its rapprochement with China and search for other partners in Eastern Asia, relations with whom could counterbalance the Chinese influence.

Turbulence ahead: disputes within the Russian ruling elite are gathering force. OSW Commentary No. 91, 2012-09-27

The last month has seen a public confrontation between Igor Sechin, the president of Rosneft, and Arkady Dvorkovich, the deputy prime minister, concerning the consolidation of the energy sector. This is the latest in a series of disputes between the Kremlin & businessmen from Putin’s inner circle on one side, and the government & Prime Minister Medvedev on the other. These disputes have been wide-ranging in nature, concerning economic policy, the scope of competency of individual members of the elite, but also the ‘tough line’ adopted by the Kremlin since Vladimir Putin’s return to the presidency. The Kremlin, which is still the main decision-making centre in Russia, has been effectively forcing its opinions through in its short-term disputes with the government. However, a new element in the ongoing conflicts, which is unfavourable to President Putin, is their exceptional strength, their much more public nature, and their wide range (which has included criticism of the president himself) and ever-changing context, especially the worsening socio-economic situation. These conflicts have been overlapping with signs of dissent among Putin’s business supporters, and their declining political willingness to support the leader unconditionally. The Kremlin’s response to the unrest consists of intensifying efforts to discipline the elite and weakening those groups in which Vladimir Putin has limited confidence. The elite’s support is crucial to the stability of his government; to maintain this support, the Kremlin is ready to introduce restrictive and repressive actions against both parliamentarians and government officials. In the short term, such a policy will force the Kremlin’s supporters back into obedience, but fears of a further increase in repression are also starting to be expressed on the sidelines.

Ukrainian economy on the verge of recession. OSW Commentary No. 96, 2012-11-21

In the third quarter of 2012, Ukraine’s economy recorded negative growth (-1.3%) for the first time since its 2009 economic crisis. Q4 GDP is projected to suffer a further decline, bringing Ukraine into formal recession. In addition to the worsening macroeconomic indicators, Ukraine is also facing a series of concomitant economic problems: a growing trade deficit, industrial decline, shrinking foreign exchange reserves, and the weakening of the hryvnia. Poor economic growth is expected to result in lower than projected budget revenues, which in turn could lead to the sequestration of the budget in December. The decline evident across the key economic indicators in the second half of 2012 brings to a close a period of relative economic stability and two years of economic growth, which had been seen as a significant personal achievement of President Viktor Yanukovych and the ruling Party of Regions. The health of the Ukrainian economy largely depends on the state of the country’s export- -oriented industries. The current economic forecasts for foreign markets are not very optimistic. It is impossible to determine whether the current economic downturn is likely to be merely temporary or whether it heralds the onset of a prolonged economic crisis. The limited capacity to deal with the growing economic problems may mean that Kiev will need to seek financial support from abroad. This is particularly significant with regard to external debt servicing, since in 2013 Ukraine will need to pay back around 9 billion USD, including over 5.5 billion USD to the International Monetary Fund. In order to overcome the recession and stabilise public finances, the government may be forced to take a series of unpopular measures, including raising the price of natural gas and utilities. These measures have been stipulated by the IMF as a condition of further financial assistance and the disbursement of the 12 billion USD stabilisation loan granted to Ukraine in July 2010. The only alternative for Western loans and economic reforms appears to be financial support from Russia. The price for Moscow’s help might however turn out to be very high, and precipitate a turn in Kiev’s foreign policy towards a gradual re-integration of former Soviet republics under Moscow-led geopolitical projects.