Division of labor between M and P visual pathways: different visual pathways minimize joint entropy differently

Visual perception and action are strongly linked with parallel processing channels connecting the retina, the lateral geniculate nucleus, and the input layers of the primary visual cortex. Achromatic vision is provided by at least two of such channels formed by the M and P neurons. These cell pathways are similarly organized in primates having different lifestyles, including species that are diurnal, nocturnal, and which exhibit a variety of color vision phenotypes. We describe the M and P cell properties by 3D Gábor functions and their 3D Fourier transform. The M and P cells occupy different loci in the Gábor information diagram or Fourier Space. This separation allows the M and P pathways to transmit visual signals with distinct 6D joint entropy for space, spatial frequency, time, and temporal frequency. By combining the M and P impacts on the cortical neurons beyond V1 input layers, the cortical pathways are able to process aspects of visual stimuli with a better precision than it would be possible using the M or P pathway alone. This performance fulfils the requirements of different behavioral tasks.

A visão através dos contrastes

O primeiro estágio de processamento da informação do estímulo visual consiste na contagem de fótons pelas células fotorreceptoras. Nos estágios pós-receptorais a informação de intensidade absoluta do estímulo é transformada em comparações de informações provindas de áreas adjacentes da retina e momentos sucessivos. Essa métrica implementada pelo sistema visual para quantificar o estímulo é chamada de contraste - contraste espacial ou simultâneo e contraste temporal ou sucessivo. A presença de contraste é essencial para a geração de percepção visual consciente no domínio do espaço e do tempo e em três dimensões ortogonais de cores - branca e preta; azul e amarela; verde e vermelha. Uma curva em forma de sinodelimita os limiares de detecção de contraste em função da frequência especial ou temporal do estímulo. Ela é chamada função de sensibilidade ao contraste e é afetada por uma série de fatores ópticos e neurais. Neurônios de diferentes classes contribuem para regiões diferentes da função de sensibilidade ao contraste e suas atividades representam as ações de vias de processamento visual que se estendem da retina ao córtex visual. Investigações básicas e clínicas têm dado suporte à importância do estudo da sensibilidade ao contraste espacial de luminância (branco e preta) como uma ferramenta indicadora da função visual em sujeitos normais e afetados por disfunções neuro-oftalmológicas.

Uma análise da ascensão chinesa a partir da Teoria do Imperialismo

Pós-graduação em Ciências Sociais - FFC

ロシアの中東政策 -- プーチン大統領のシリア政策を通じて

The active initiative taken by Russian President Vladamir Putin by bombarding the antigovernment forces in Syria at the end of September 2015 startled the world by its precalculated boldness. Russian intervention has radically changed the dynamic of the war by empowering the Syrian government of Bashar Assad, and has resulted in a ceasefire agreement which starts on 27th February 2016, led by Russia and the US. No one can predict at present the next stage of conflicts in Syria or whether it will result in a positive solution to the tragic wars there. However, there is no denying the fact that Russia has played an important role in the development of the game. This paper analyzes the motivations of Putin in intervening in the Syrian crisis and the factors which have enabled Russia to play an enlarged role in the Middle East, seemingly beyond its objective capabilities. Legacies of international networks built during the Soviet period; shrewd tactics in making use of the inconsistency and vacillation of US policies, particularly towards the Middle East; its historical experience of interaction with the Muslim cultures, including domestic ones; its geopolitical perception of world politics, and the export of energy resources and military weapons as tools of diplomacy are some of the factors which explain Russian behavior. At the same time, the personal leadership and accumulated experience of President Putin in formulating Russian diplomacy and in manipulating different issues in a combined policy should be taken into account. His initiative in Syria succeeded to some extent in turning world attention away from the Ukrainian issue, aimed at changing the present sanctions imposed by the West. Another phenomenon to be noted in the international arena is the newly developed mutual interaction between Russia and the Arab countries in the Gulf. Frequent visits to Russia by autocratic leaders, including kings, emirsand princes do not always reflect a shared common interest between Russia and the Arab leaders. On the contrary, in spite of sharp and fundamental differences in their attitude toward the issues related to Syria, Iran and Yemen, the Arab leaders find it necessary to communicate with Russia and to know Russia’s expected strategies and intentions towards the Middle East, apart from its oil and gas policies. The Iran deal on the nuclear issue in July 2015 may have been a factor behind the phenomena.

Putin’s grand design to destroy the EU’s Eastern Partnership and replace it with a disastrous neighbourhood policy of his own. CEPS Commentary, 17 September 2013

This new Commentary by Michael Emerson and Hrant Kostanyan shows how the pressure exerted by President Putin on Armenia to withdraw from the Deep and Comprehensive Free Trade Agreement it had negotiated with the EU and to join the Belarus, Kazakhstan and Russia customs union is but the most recent in a long series of ongoing moves by Russia to destroy the Eastern Partnership. In their view, the message to be hammered home to those unsure of the economic arguments is that you do not have to have an exclusive customs union to enjoy deep integration for goods, services, people and capital, and of course even less for hard security relationships. High-quality free trade agreements are the logical instrument for those who want excellent relations with more than one big neighbour.

The EU and Syria – Time to Play behind Closed Doors. Jean Monnet/Robert Schuman Paper Series Special Issue, September 13, 2013

From the Introduction. Since the – presumed – utilization of chemical weapons against civilians by the Assad regime late August, the members of the Euro-Atlantic community have been building the case for a military intervention, a punishing mission against Bashar al-Assad. Despite evidences that sarin gas was used, the UK and Germany seem to be out of the race – for a similar reason: domestic politics –, leaving the US and France in the starting blocks. French President Hollande has expressed his commitment to go to war. The world is now on hold waiting for the US as President Obama, after asking US Congress to postpone a vote on a military intervention, is working on a possible diplomatic solution with Russian President Putin. Since Kerry’s comments in London earlier this week, Russian President Putin has been seeking for a diplomatic solution that would put all Syrian chemical arsenals under international supervision.

How should the EU respond to Russia's war in Ukraine? CEPS Commentary, 3 September 2014

President Putin has chosen to escalate the conflict in south-eastern Ukraine, thereby ignoring both the sanctions and the diplomatic advances of the EU and its partners in response to Russia’s belligerence towards its neighbour over the last six months. Ahead of the NATO Summit in Wales on September 4-5, calls are growing for EU member states to provide arms and more intelligence to Ukraine’s beleaguered army. But it is far from certain that the EU will summon up the collective courage to do so. Beyond sanctions, what other options does the EU have to alter the Kremlin’s calculus?

Russia’s Punitive Trade Policy Measures towards Ukraine, Moldova and Georgia. CEPS Working Document No. 400, September 2014

While EU and US sanctions against Russia over its aggression in Ukraine, and Russia’s counter-sanctions, are much discussed due to their evident political significance, less attention has been given to Russia’s punitive sanctions against the three Eastern European states – Ukraine, Moldova and Georgia – that have signed with the EU Association Agreements (AA), which include Deep and Comprehensive Free Trade Area (DCFTA) provisions. This paper therefore documents these trade policy restrictions and embargoes imposed by Russia, and provides some first indications of their impact. The immediate impact on trade flows, especially for agri-food products, has been substantial, albeit with some leakage through Belarus. The main instrument for the Russian measures has been allegations of non-conformity with Russian technical standards, although the correlation of these allegations with movements in Russia’s geopolitical postures makes it obvious that the Russian technical agencies are following political guidelines dressed up as scientific evidence. These measures also push the three states into diversifying their trade marketing efforts in favour of the EU and other world markets, with Georgia already having taken significant steps in this direction, since in its case the Russian sanctions date back to 2006. In the case of Ukraine, Russia’s threat to cancel CIS free trade preferences infiltrated trilateral talks between the EU, Ukraine and Russia, leading on 12 September to their proposed postponement until the end of 2015 of the ‘provisional’ implementation of a large part of the AA/DCFTA. This was immediately followed on 16 September by ratification of the AA/DCFTA by both the Rada in Kyiv and the European Parliament, which will lead to its full and definitive entry into force when the 28 EU member states have also ratified it. However Putin followed the day after with a letter to Poroshenko making an abusive interpretation of the 12 September understanding.

Why the EU must reengage with Turkey. EPC Commentary, 29 September 2014

Democratic values and basic rights in Turkey are hanging by a thread. Over the past eighteen months the rule of law, civil liberties and freedoms have been eroded which has left many Turks anxious over the direction in which their country is heading. With Turkey’s accession negotiations de facto frozen, the EU finds itself with little leverage over Ankara. Calls of concern have fallen on deaf ears as Turkey’s leadership has become increasingly belligerent, with its EU related narrative overflowing with resentment. Because Turkey’s accession negotiations are irreversibly intertwined with Turkey-EU cooperation in other areas, this has had a negative impact on the broader relationship between both sides. Recent examples include the issue of foreign fighters traveling from Europe to Syria via Turkey. Each side has accused the other of not doing enough to stem the flow. Likewise, following the decision of Russian President, Vladimir Putin, to ban the import of agricultural goods from countries that have placed sanctions on Moscow, the EU asked Turkey to demonstrate solidarity, as a “candidate country”, and not to increase exports of agricultural products to Russia. Turkey rejected this request and is reportedly working on strengthening trade ties with Moscow. Turkey remains an important partner in a number of key areas including trade, energy, foreign and security policy and migration. At a time when the EU faces crises in both its Eastern and Southern neighbourhoods, a reliable and predictable Turkey, with which it can cooperate in the Black Sea and Middle East neighbourhoods is crucial. Hence the vision and plans of the EU’s new leadership, in particular new Foreign Policy Chief, Federica Mogherini, and Commissioner for European Neighbourhood Policy and Enlargement Negotiations, Johannes Hahn, how to shape relations with Ankara is particularly significant. The Union’s current policy is counterproductive and is further eroding trust and cooperation rather than enhancing it. It needs to be turned around.

Germany on Russia. Yes to links, no to rapprochement. OSW Point of View Number 39, March 2014

The German media have been correctly describing the atmosphere between the Chancellor's Office and the Kremlin as the chilliest in years. Various factors have laid bare the fact that the strategic partnership between Germany and Russia is at best currently undergoing a 'technical pause’: the underwhelming outcomes of the German-Russian intergovernmental consultations in the autumn of 2012 and of Chancellor Merkel's meeting with President Putin during the Hanover fair in the spring of 2013, as well as the way in which the EU dealt with the Cyprus debt issue and, finally, the support that Germany has extended to the anti-presidential protests in Ukraine. Meanwhile, the priorities of Germany's foreign and economic policy have changed considerably, not only as a result of the eurozone crisis, but also, even more importantly, because the attention of German business and politics has been shifting to the so-called neue Gestaltungsmächte, or new regional powers. German politicians increasingly believe that Russia should not be offered new methods or mechanisms of co-operation. Firstly, because the existing ones have not been fully utilised, and secondly, because Germany at this stage seems to have no idea of what the long-term strategy of co-operation with Putin's Russia should be.

An Asian alternative? Russia's chances of making Asia an alternative to relations with the West. OSW Point of View, June 2008

Under Vladimir Putin's rule, Russia consistently and systematically expanded its activity in Asia, establishing closer political contacts with key countries in the region, rebuilding relations with former allies from Soviet times, and strengthening its presence in the Asian markets, in the energy sphere also. These activities were accompanied by intensive Russian propaganda, the message of which was that relations with the West can be restricted in favour of developing closer relations with Asian states. A justified question concerning the Russian Federation's realistic possibilities arises in this context: To what extent can it make Asia an alternative to theWest in geopolitical, economic and energy terms? Can Russia build an anti-Western alliance with Asian states? Is it able to reduce its dependence on the European market by developing its trade with Asia? Is it possible to redirect a substantial portion of Russian energy resource exports onto Asian markets? A presentation of the existing ties between Russia and theWest (here considered as the USA and the EU) will serve as a starting point for answering these questions. The following chapters will analyse Russia's opportunities in Asia in terms of geopolitical issues, the economy and energy

The Pro-Western Turn in Russia's Foreign Policy: Causes, Consequences and Prospects. OSW Point of View, September 2002

From Europe and Poland's point of view, one of the most important recent developments in international politics was the re-orientation of Russia's foreign policy. This paper aims to answer three important questions relating to this issue: 4. When and why did the "pro-Western turn" in the Russian Federation's policy take place? 5. Has it been profitable for Russia? 6. What goals will the Russian policy pursue in the future? An analysis of the last two years in Russia's foreign policy leads to the several conclusions, including those: 5. Clearly, the Russian leaders realise that in the longer term, Russia - in its desire for more influence in the world - will not be able to survive as an independent pole of power in international politics and it will have to join forces with the West (most likely, the European Union). 6. September 11 was not the cause of Russia's pro-Western turn, but rather a catalyst that put the process which started when Vladimir Putin took his office in sharp focus. 7. In the nearest future, this new direction of Russia's foreign policy seems not be challenged by internal opposition in Russia. 8. The "pro-Western turn" proved to be beneficial for Russia, although: d. Russia has not become a strategic ally of the US e. There has been no breakthrough in the relations between Russia and the European Union, and Moscow has not gained any real influence on NATO's important decisions. f. Russia has not become a major decision-maker of international politics. 5. Russia's closing to the West is in Poland's and Europe's interest.

Eurasian integration. Russia's attempt at the economic unification of the post-Soviet area. OSW Study 44/2013

In 2009, Vladimir Putin, the then Russian prime minister, gave impetus to the establishment of closer relations within what was then a still narrow group of three countries: Russia, Kazakhstan and Belarus. Russia was determined in embarking on the implementation of the principles of the Customs Union among these three states and, since 2012, within the Common Economic Space as well. This process of integration is intended to bring about the introduction of ‘four freedoms’ in this area: the free movement of goods, services, capital and labour. From Moscow’s point of view, building up such integration structures is especially necessary in order to counteract the economic expansion of the European Union and China. It also feels it is important to take measures against the loosening of the bonds between the CIS countries and Russia. At the same time, close co-operation is expected to guarantee for Russia that the strong politico-economic influences in this area will be maintained. Despite the numerous limitations of the integration process, such as the small number of the participating states or limited progress in implementing the CES, this is still the most advanced integration programme in the region seen since the collapse of the USSR. Progress in putting the rules of the Customs Union into practice can be seen as a success for Moscow. In turn, the formation of the CES is still at an early stage, and it is difficult to determine at this point to what extent the three countries will harmonise their markets.