989 resultados para Power Laws (PL)
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Darwin observed that multiple, lowly organized, rudimentary, or exaggerated structures show increased relative variability. However, the cellular basis for these laws has never been investigated. Some animals, such as the nematode Caenorhabditis elegans, are famous for having organs that possess the same number of cells in all individuals, a property known as eutely. But for most multicellular creatures, the extent of cell number variability is unknown. Here we estimate variability in organ cell number for a variety of animals, plants, slime moulds, and volvocine algae. We find that the mean and variance in cell number obey a power law with an exponent of 2, comparable to Taylor's law in ecological processes. Relative cell number variability, as measured by the coefficient of variation, differs widely across taxa and tissues, but is generally independent of mean cell number among homologous tissues of closely related species. We show that the power law for cell number variability can be explained by stochastic branching process models based on the properties of cell lineages. We also identify taxa in which the precision of developmental control appears to have evolved. We propose that the scale independence of relative cell number variability is maintained by natural selection.
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The sport of rowing has become more popular in the past decade. While it is a relatively low impact sport, injuries can occur, specifically to the ribs (Karlson K. A., 1998) and more often in female athletes (Hickey, Fricker, & McDonald , 1997). It has been proposed that as the athlete rows, applying a cyclical load to the body, the mid trapezius fatigues and is unable to resist the force produced during the drive phase (Warden S. J., Gutschlag, Wajswelner, & Crossley, 2002). Once this happens, the scapulae are then pulled anterio-laterally which increases the compression force on the ribs, increasing the risk of injury. The rowing motion of 12 female varsity and club rowers was tracked as they completed a fatiguing rowing test on a rowing ergometer. Results showed that the curvature of thoracic spine changed throughout the rowing cycle but did not change with increasing power level. The transverse shoulder angle decreased (the upper back was less straight) as power level increased (R2=-0.69±19), suggesting that the scapula moved anterio-laterally. This may be that as it tired, the mid-trapezius was unable to hold the scapulae in position. The decreasing transverse shoulder angle when the power level is increased indirectly supports the fatiguing of the retractor muscles as a mechanism of injury. It would be valuable to understand the limitations of each athlete and to be able to prescribe the optimal training zone to reduce the risk of injury.
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Wireless sensor networks (WSNs) have shown wide applicability to many fields including monitoring of environmental, civil, and industrial settings. WSNs however are resource constrained by many competing factors that span their hardware, software, and networking. One of the central resource constrains is the charge consumption of WSN nodes. With finite energy supplies, low charge consumption is needed to ensure long lifetimes and success of WSNs. This thesis details the design of a power system to support long-term operation of WSNs. The power system’s development occurs in parallel with a custom WSN from the Queen’s MEMS Lab (QML-WSN), with the goal of supporting a 1+ year lifetime without sacrificing functionality. The final power system design utilizes a TPS62740 DC-DC converter with AA alkaline batteries to efficiently supply the nodes while providing battery monitoring functionality and an expansion slot for future development. Testing tools for measuring current draw and charge consumption were created along with analysis and processing software. Through their use charge consumption of the power system was drastically lowered and issues in QML-WSN were identified and resolved including the proper shutdown of accelerometers, and incorrect microcontroller unit (MCU) power pin connection. Controlled current profiling revealed unexpected behaviour of nodes and detailed current-voltage relationships. These relationships were utilized with a lifetime projection model to estimate a lifetime between 521-551 days, depending on the mode of operation. The power system and QML-WSN were tested over a long term trial lasting 272+ days in an industrial testbed to monitor an air compressor pump. Environmental factors were found to influence the behaviour of nodes leading to increased charge consumption, while a node in an office setting was still operating at the conclusion of the trail. This agrees with the lifetime projection and gives a strong indication that a 1+ year lifetime is achievable. Additionally, a light-weight charge consumption model was developed which allows charge consumption information of nodes in a distributed WSN to be monitored. This model was tested in a laboratory setting demonstrating +95% accuracy for high packet reception rate WSNs across varying data rates, battery supply capacities, and runtimes up to full battery depletion.
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Do realizacji niemieckich interesów w polityce zagranicznej, bezpieczeństwa i gospodarczej RFN wykorzystuje instrumenty soft power z obszaru dyplomacji publicznej, polityki rozwojowej, kulturalnej i naukowej. Budowanie sieci kontaktów i lobbing polityczny, programy współpracy rozwojowej oraz zagranicznej polityki kulturalnej i naukowej, mają służyć wspieraniu niemieckiej gospodarki uzależnionej od eksportu, uzyskaniu statusu europejskiego ośrodka technologii i innowacji oraz zwiększeniu wpływu RFN na działania zewnętrzne UE. Jednym z priorytetowych obszarów stosowania tych instrumentów są dla Niemiec państwa Europy Wschodniej, Kaukazu Południowego i Azji Centralnej. Decydują o tym bliskość geograficzna i otwierające się rynki zbytu, konieczność modernizacji gospodarek tych krajów, zagrożenia dla „miękkiego” bezpieczeństwa RFN oraz rozwój relacji UE z tymi państwami. Niemiecka aktywność jest w tych krajach niezależna od sytuacji politycznej i stanowi długofalową strategię ugruntowującą pozycję RFN jako ich najważniejszego europejskiego partnera gospodarczego i politycznego.
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Russian President Vladimir Putin’s visit to Serbia on 16 October has demonstrated Moscow’s willingness to secure its interests in the Balkans and use Belgrade in its confrontation with the West. It seems, however, that Russia does not have much to offer to Serbia’s authorities, which are reluctant to make more concessions towards Russia. However, Moscow has already gained a strong position in Serbia, which is due to the country’s dependence on Russian natural resources and, in particular, strong support for Russian policy on the part of Serbian elites and society. The traditional pro-Russian attitudes have been strengthened as a result of a series of Russia-inspired, wide-ranging soft power initiatives which have proved so successful that a large part of society has begun to believe that Russia’s interests are consistent with Serbia’s. Russia’s increasingly active policy towards Serbia and the Serbian minorities in the neighbouring countries – Bosnia and Herzegovina, Montenegro and Kosovo – has been part of a larger plan aimed at hampering the integration of the Balkan states with the Euro-Atlantic structures and maintaining an area of instability and frozen conflicts in the EU’s near neighbourhood. Russia’s policy is also becoming increasingly effective due to the EU states’ diminishing support for Balkan countries’ European integration.
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Since the Party of Regions took power in Ukraine, the process of strengthening the executive branch of government at the expense of the others, together with the instrumental use of the law, has been progressing steadily. By seeking to restrict criticism of the government, the ruling party is aiming at marginalisation of opposition groups and establishing informal control over the main media (largely by exerting pressure on their owners). The role of the Security Service of Ukraine (SBU) is growing, as it is used increasingly frequently to put pressure on Western-oriented NGOs. The government’s control over the judiciary is expanding. These trends had existed before the Party of Regions’ ascension to power, but they were much weaker, as the previous governments did not enjoy such a strong position or the ability to achieve their ends so efficiently. The Party of Regions is planning to take another step towards total power during the local elections scheduled for October 2010. The party is determined to establish control over the local self-governments; to this end, it has amended the legislation in a way which now undermines local civil initiatives. These changes not only illustrate the interests and political standpoint of the ruling elite; they also result from systemic reasons, and these are deeply rooted in the Soviet past. The present Ukrainian state has evolved through the evolutionary transformation of the Ukrainian Soviet Socialist Republic. As a result, the main features of the previous system have been sustained, including the weakness of the representative bodies and the instrumental use of the law. Twenty years into its independent development, Ukraine has developed a merely formal democracy, which is distant from EU standards.
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Even though the economic crisis proved harmful to the Russian economy and people's living standards, it has nonetheless failed to make the elite revise its policy. Despite some problems, the government has managed to sustain economic and political stability, thanks to the reserves it amassed in the times of prosperity, and to the propaganda campaign that protected it, above all Vladimir Putin. The crisis failed to force the elite to implement deeper structural and political reforms. Moreover, it has actually reinforced existing tendencies, such as state control over the economy and its oil-oriented character, the elite's economic expansion at the expense of private businesses, and the preservation of political power. Thus, the crisis has so far failed to dismantle Putinism, indeed quite the reverse - it has in fact contributed to its becoming 'set in stone'.
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The German government’s final decision to abandon nuclear power as of 2022 has been expected for months. However, instead of calming the waters, providing solutions and answering the question ‘What next?’, it has only fanned the flames. Even the adoption of legal amendments enforcing the government’s decision by the German parliament (both the Bundestag and the Bundesrat) in late June and early July has not calmed the situation. It is more than apparent that these decisions have been made under emotional pressure: there was not enough time for accurate calculations to be made and consideration to be given to the consequences of Germany abandoning nuclear power. Chancellor Angela Merkel has so far been unable to fully convince the public that the ‘energy shift is a huge opportunity’ and that this process will be carried out on condition that ‘the supplies remain secure, the climate protected and the whole process economically efficient’1. German economic associations have warned against a politically motivated, ill-judged and irreversible abandonment of nuclear energy. They are anxious about an increase in electricity prices, the instability of supplies and environmental damage. The government believes, however, that green technologies will become a new driving force for the German economy and its main export commodity. Before that happens the industry will have to increase its use of electricity produced from fossil fuels, mainly natural gas imported from Russia. This may be exploited by Gazprom which will try to strengthen its position on the German market, and thus in the entire EU.
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During Russian PM Dmitry Medvedev’s working visit to Minsk on 18 July, Russia and Belarus signed a general contract for the construction of a nuclear power plant in Belarus. The signature brought to an end the complex negotiations which had been underway since January 2009 involving the leadership in Minsk, the Russian government and Atomstroyexport, the Russian company that will be the main contractor of the investment. However, the power plant’s future ownership structure, management arrangements and terms and conditions of profit sharing remain unclear. The Belarusian leadership hopes that with the launch of the nuclear power plant, it will be able to reduce gas imports from Russia, gas being the main resource used in producing heat and electricity in Belarus. This should in turn reduce the costs of energy generation. In addition, Minsk expects that the new investment will allow it to export electricity surpluses to the European Union, including Poland. Agreements concerning the power plant have been concluded over the last year or so and, according to these, Russia has acquired partial control of the Belarusian electricity grid, especially with regard to the transmission of energy to foreign markets. Russia is also the sole creditor and contractor for the investment, and the sole future provider of nuclear fuel. Therefore, implementation of the project will exacerbate Minsk’s already significant dependence on Moscow in energy and political terms.
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The relations between Russia’s authorities and business circles are subordinated not so much to rational economic calculations as to the interests of political elites. The key interest in this case is maintaining the current model of government. The formal and informal supervision of business by law enforcement agencies is an important element of Russia’s economic reality. Despite the rhetoric of high-ranking officials, intended to suggest that the state is taking care of businesspeople’s interests, it is evident that there is no will to devise a systemic solution to the most urgent problems, including the state institutions’ disrespect for the rights of ownership.
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Printed for the use of the Temporary National Economic Committee.
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Bibliography: p. 256-259.
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Mode of access: Internet.
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Ancient history: Antediluvian history. Postdiluvian history. Monumental history. Egypt. Asia. Europe. Greece. Rome.--Modern history: Feudal system. Chivalry. Religions compared, rise of Christianity. Cities, growth and decay of their power. Revival of literature. Progress of regal authority, standing armies, balance of power. Reformation. Formation of English constitution. French revolution.
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Thesis (Ph.D.)--University of Washington, 2016-06