648 research outputs found

    Outcome-driven Service Provider Performance under Conditions of Complexity and Uncertainty

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    Proceedings Paper (for Acquisition Research Program)This paper describes applying ROI analysis principles for SOA performance management, creating Service-level Agreements (SLAs) to articulate agreements between the Government and external service providers, and managing SLAs through a governance framework (Hanf & Buck, 2009, March). This white paper highlights key findings of research undertaken by The MITRE Corporation (MITRE) and the resulting recommendations for (1) applying Return-on-Investment (ROI) analysis principles as the foundation for more effective performance management of Government Service-oriented Architecture (SOA), (2) creating comprehensive Service-level Agreements (SLAs) to articulate agreements between the Government and external service providers, and (3) managing SLAs through a governance framework (Oakley-Bogdewic & Buck, 2009; Hanf & Buck, 2009, March 25). As illustrated in Figure 1, MITRE''s recommendations address the additional managerial complexity and uncertainty that SOA objectives and proposed solutions often create.Naval Postgraduate School Acquisition Research ProgramApproved for public release; distribution is unlimited

    Quasiperiodicity and non-computability in tilings

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    We study tilings of the plane that combine strong properties of different nature: combinatorial and algorithmic. We prove existence of a tile set that accepts only quasiperiodic and non-recursive tilings. Our construction is based on the fixed point construction; we improve this general technique and make it enforce the property of local regularity of tilings needed for quasiperiodicity. We prove also a stronger result: any effectively closed set can be recursively transformed into a tile set so that the Turing degrees of the resulted tilings consists exactly of the upper cone based on the Turing degrees of the later.Comment: v3: the version accepted to MFCS 201

    In Situ Characterisation of Permanent Magnetic Quadrupoles for focussing proton beams

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    High intensity laser driven proton beams are at present receiving much attention. The reasons for this are many but high on the list is the potential to produce compact accelerators. However two of the limitations of this technology is that unlike conventional nuclear RF accelerators lasers produce diverging beams with an exponential energy distribution. A number of different approaches have been attempted to monochromise these beams but it has become obvious that magnetic spectrometer technology developed over many years by nuclear physicists to transport and focus proton beams could play an important role for this purpose. This paper deals with the design and characterisation of a magnetic quadrupole system which will attempt to focus and transport laser-accelerated proton beams.Comment: 20 pages, 42 figure

    Demographic characteristics of Australian humpback dolphins reveal important habitat toward the southwestern limit of their range

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    Open Access under Creative Commons by Attribution Licence. Use, distribution and reproduction are un-restricted. Authors and original publication must be credited.ABSTRACT: The paucity of information on the recently described Australian humpback dolphin Sousa sahulensis has hindered assessment of its conservation status. Here, we applied capture-recapture models to photo-identification data collected during boat-based surveys between 2013 and 2015 to estimate the abundance, site fidelity and residence patterns of Australian humpback dolphins around the North West Cape (NWC), Western Australia. Using Pollock’s closed robust design, abundance estimates varied from 65 to 102 individuals, and POPAN open modelling yielded a super-population size of 129 individuals in the 130 km2 study area. At approximately 1 humpback dolphin per km2, this density is the highest recorded for this species. Temporary emigration was Markovian, suggesting seasonal movement in and out of the study area. Hierarchical clustering showed that 63% of individuals identified exhibited high levels of site fidelity. Analysis of lagged identification rates indicated dolphins use the study area regularly, following a movement model characterised by emigration and re-immigration. These density, site fidelity and residence patterns indicate that the NWC is an important habitat toward the southwestern limit of this species’ range. Much of the NWC study area lies within a Marine Protected Area, offering a regulatory framework on which to base the management of human activities with the potential to impact this threatened species. Our methods provide a methodological framework to be used in future environmental impact assessments, and our findings represent a baseline from which to develop long-term studies to gain a more complete understanding of Australian humpback dolphin population dynamics

    Benefits of a marketing cooperative in transition agriculture: Mórakert purchasing and service co-operative

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    The paper analyses the potential benefits of marketing cooperatives in Hungary, employing a transaction cost economics framework. We found that the purchased quantity, the existence of contracts, flexibility and trust are the most important factors farmers consider when selling their products via a cooperative. The most striking result is that diversification has positive influences on the share of cooperatives in farmers’ sale. Furthermore, farmers with larger bargaining power have less willingness to sell their product to the cooperative. Surprisingly, asset specificity has rather negative effects on the share of cooperatives in members’ sales

    How Effective is the Invisible Hand? Agricultural and Food Markets in Central and Eastern Europe

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    Since the seminal work of Adam Smith, markets have been considered an efficient tool for co-ordinating the behaviour of economic agents. The basic characteristic of a market economy is that the complex system of interaction among individuals is not centrally coordinated. Under the assumption of profit and utility maximisation (and a whole set of assumptions about the institutional framework), relative prices and their change over time provide the signals that guide, like an invisible hand, the allocation of resources, i.e., the structure of production and the intensity of input use in the various production processes. They do this by co-ordinating the activities of economic agents, i.e., of resource owners, producers, intermediaries, traders, and consumers. After system change in the former Soviet Union and in Central and Eastern Europe (CEE) central economic planning had to be replaced by other forms of co-ordination. The general direction in all transition countries was towards a market economy, but the speed and depth of reforms towards an environment in which markets can evolve differed largely between countries, sectors and between different phases during the past 15 years. IAMO Forum 2005 focuses on this development and discusses the functioning of markets, the requirements for this, and the advantages and disadvantages of other co-ordination mechanisms under different environments in the agricultural and food sectors in Central and Eastern Europe. CEE agri-food markets deserve researchers' and policy makers' attention for several reasons. Two of them regard the high demand for support to policy decisions that aim to stimulate economic and social development in the region. In most CEE countries, the significance of the agricultural and food sector is relatively high with respect to income and employment. In particular, rural areas can benefit from the development of this branch of the economy. Also, there is marked indication that agri-food markets in CEE are not ensuring exchange as frictionless as possible. This means that large benefits can be expected if potential improvements of the economic environment are implemented and if individual agents adapt optimally to that environment. Another motivation for economic research on transition countries is that we are looking at a huge region that started almost as a vacuum with regard to institutional settings. This means that a wide range of substantially different settings were introduced in the respective countries, and were only weakly confined by political rigidities or path dependencies. From a distant perspective, the repeated fundamental shifts in recent economic policies almost evoke the impression of a trial and error approach. The consequences of distinctively different options (across countries and periods) can be observed in a way almost similar to a laboratory situation. Such unique opportunity has attracted economists, particularly those interested in institutional economics, to conduct research on CEE. However, this also means that the experiences made in CEEC can enhance the general understanding of what markets can do and what the limitations of market coordination are. This volume contains selected contributions presented at IAMO Forum 2005 and gives an overview of the major topics discussed there. Partial analyses of specific economic problems usually abstract from the general economic framework which is assumed to be more or less constant as expressed in ceteris paribus clauses. Oftentimes, the set of institutional conditions is even assumed to be sufficiently well-described by the framework used in neoclassical models. Particularly for transition countries, this has frequently led to spurious results because crucial aspects of the framework actually in place were not considered, and sometimes were not even thought of. An extreme and very obvious example is the neglect of the effects of the replacement of monetary by nonmonetary exchange in phases of a barter economy. There is no generic approach to avoid unintended omission of crucial framework conditions, but it must generally be emphasised that a broad look at the various interdependent markets and at the entire socioeconomic context of a country is needed before going into detail. Descriptive analyses of the situation in various markets form part of such a broad look. The contributions of POPP, FERTÃ et al., WILKIN et al., and HEIN in the chapter Selected analyses from CEEC provide excellent examples, and focus on market developments in new EU member countries. On the one hand, the papers show the heterogeneity of problems e.g. due to largely differing farm structures. On the other hand, several common patterns can be observed: The market shares and power of large processors and retailers (hypermarkets, etc.) are increasing. Also, international (especially intra-EU) trade in commodities has increased in response to CAP-induced price harmonisation. Both tendencies weaken the market position of farmers, particularly small entities which cannot supply in volumes sufficient for large processing and trade firms. Within the food industry concentration increased as many smaller firms could not comply with EU processing standards and had to quit the market. The increased size and specialization of large producers, as well as of large processors, made many of those firms co-ordinate business with each other through long-term contractual agreements rather than by relying on spot markets. This tendency is very distinct in the fruit and vegetable sector, as WILKINâs contribution describes. Two contributions draw attention to the institutional framework itself, mainly by looking at circumstances which prevent market allocation from leading to an optimal outcome. HOBBS describes factors that impede investment and growth by drawing on transaction cost economics. Situations typical for transition countries are highlighted where e.g. transparency is not sufficient or the existence and reliable enforcement of contract or corporate law are not guaranteed. NUPPENAU stresses the need for the appropriate and precise formulation of land property rights, which should evoke a balance between governance and exclusion. The importance of appropriate and reliable institutions to avoid flaws is emphasised. But even with suitable institutions, transaction costs cannot be reduced to zero. The main reason for this is that since agents may gain form a head start of information, incentives to reveal their knowledge are quite restricted. Furthermore, some of the information required to make correct decisions is not available. This especially concerns information regarding all future contingencies. An uncertain future and the asymmetric distribution of information impose special problems when decisions have long-term effects and agents are linked together through investment decisions. This offers possibilities for opportunistic behaviour, i.e., when an agent behaves in a way that allows him to extract rents from the partners' activities. The friction induced in such situations may result in a market outcome that is biased by transaction costs. Mitigating this bias should be a goal of public policy but it is also in the interest of (at least some of the) private agents involved. This issue is discussed in more detail in the papers dealing with alternative governance structures. A number of contributions to IAMO Forum highlight approaches for measuring the well-functioning of markets. While studies that aim to directly measure transaction costs are very rare and are necessarily limited to comparing only very specific portions of transaction costs, most studies focus on indirect indicators. These usually start from the idea that in a well-functioning, competitive market any supply or demand shocks are reflected in price changes, not only in the particular market where the shock occurs but also in other, related markets, i.e., in different locations or at different stages of the production and marketing chain. Consequently, an approach for assessing the functioning of markets is to compare price differentials with processing-, marketing- or transfer-costs, or â since these costs are usually difficult to quantify â to observe price differentials over time. Accepting the assumption that the costs reflected by price differentials are more or less constant (or stationary) over the observed time span, any additional price changes or a lack of price co-movement is interpreted as an indication for insufficiently connected or insufficiently functioning markets. Three contributions in the chapter Analytical approaches for measuring market efficiency describe analyses which mainly focus on the vertical dimension, i.e., between market stages. BOJNEC, in his descriptive price analysis for several agricultural products in Slovenia since 1991, finds a heterogeneous development of the farm gate/consumer price spread: The processing and marketing margins increased for wheat and beef while they declined for grapes (processed to wine), sugar and poultry. BRÃMMER and ZORYA, as well as BAKUCS and FERTÃ, use cointegration analysis to describe the degree and nature of vertical price integration in the Ukrainian wheat market and the Hungarian pork market, respectively. Both studies find that price changes are transmitted vertically, that there is a tendency to "correct" any deviations from some underlying equilibrium price-relationship. However, such error correction mechanisms are found not to be a constant, universal force. In the Hungarian paper, it could only be found for a sub-period of the observed time span, excluding the highly volatile early 1990s. Also, equilibrium was found to be achieved by adjustment of farm gate prices only while the retail prices were found to be exogenous, i.e., not responding to any disequilibrium. The paper on Ukraine shows that adjustment processes between wheat and wheat flour prices cannot be sufficiently described by a constant error correction mechanism for the period 2000 to 2004. In fact, four different regimes of adjustment processes were found to have been in force, reflecting particular phases of largely differing market situations and political interventions. The functioning of markets depends on several crucial conditions. One of these conditions concerns the availability of information. Only if agents have perfect and complete information will the exchange lead to an outcome in which no individual can be better off without reducing the welfare of others. However, in the real world this condition regarding information is not fulfilled. Information is not perfect, since the future cannot be predicted with certainty. Incomplete information results from, first, not all information being revealed, and second, individuals not possessing the mental capacity to collect and process all information. Moreover, because of its asymmetric distribution, information can be regarded as a resource that can be exploited by agents. This means that there are incentives to hamper the diffusion of information to the public domain. In general, the more uncertain the future is and the more information is tacit, the worse markets will function, and the more beneficial become alternative mechanisms of coordination. Three papers dealing with this issue of organisational choice. HANF focuses on governance structures within supply chain networks that are appropriate for allowing an optimal flow of information between the involved individuals while retaining the necessary hierarchy for efficient implementation of strategic decisions. MAACKâs analysis shows that there is strong mutual interest between producers and processors of berry fruits to reduce marketing and procurement risk, respectively. This can be achieved by switching from spot market exchange to contractual supply agreements. A prerequisite for such agreements is that a well-balanced distribution of risks and risk premiums between the farmer and processor is implemented. This means that processors, who â facing a multitude of small producers â are used to opportunities for exerting market power, have to agree to cover part of the production risk through appropriate contractual clauses. Finally, BALINT looks at the various marketing channels used by Romanian farmers and finds that a self-enforcing dualism exists. For commercially-oriented farmers who can supply large quantities, marketing directly to traders, wholesalers and processors is most favourable and involves relatively low transaction costs. Although this form of supply-relationship is usually not based on contractual agreements, it can still be characterised by a certain stability over time. In contrast, small farmers whose production does not considerably exceed the subsistence level incur relatively high (per unit) transaction costs in selling their produce on local markets and to other farmers. Another aspect of organisational choice is the question of whether ownership of production factors is transferred or only the right to use them temporarily. The uncertainty of future developments implies that the possession of resources cannot be only regarded from the point of view of income generation at a certain point in time. With perfect foresight, there is no difference whether a factor is rented or purchased, because the remuneration would be the same. This perfect substitutability is no longer given when the future is uncertain. Income generation, then, is only one feature of ownership. Additional aspects such as insurance, wealth, and speculation as motivations for possession affect the value of ownership and thus shift the demand and supply curves of the factor. HURRELMAN picks up this issue in her analysis of the Polish land market and shows the impact of additional grounds for valuing property on the decision to rent or to buy land. Uncertainty may also affect the specialization of factor use. Allocating a factor of production to different production activities reduces the risk of income instabilities, but at the cost of specialization gains through economics of scale. Moreover, the decision on income combination is â besides risk â affected by a complex interaction of other determinants. GLAUBEN et al., analyse these interactions for the case of part-time farming in China and show how the decision of income combination is affected by household characteristics, human capital and other variables. Incomplete and imperfect information not only causes individuals to choose optimal governance modes, often it is also understood as a call for government intervention. The selected papers in the chapter on policy intervention plead for careful selection and coherent implementation of policy instruments. BENNER, as well as KUHN, highlight the significance of information diffusion and argue in favour of government intervention in this area. However, both emphasise that these interferences should be used carefully and be adjusted to specific market failures. Both argue that setting up information systems would improve the functioning of markets. BENNER also discusses possible negative impacts if governments that engage in setting up and enforcing product and process standards try, at the same time, to foster a sector like agriculture through support in marketing. The latter activity affects the governmentâs (crucial) credibility in the first activity. KUHN points to negative welfare effects and budgetary requirements of an intervention system which is implemented to increase price stability. Moreover, when a government intervenes in market allocation or intends to provide rules that should facilitate the exchange on markets, it has to take into account that the new regulation has to be implemented in a coherent manner. This requires the various policy regulations and institutional settings to be complementary and not cause frictions which hamper the functioning of the system. LERMAN and SHAGAIDA highlight this aspect in their discussion of the Russian land market, where bureaucracy and high costs for the registration of property rights can be regarded as a major cause of the low number of land transactions. However, since economic activities take place in a dynamic environment, the comparative static point of view may lead to inappropriate policy formulation. WANDEL discusses this aspect in the context of competition policy. From a comparative static point of view, market power has to be assessed negatively because of the distortions of resource allocation. However, monopoly profits are an indicator of extra rents and thus provide incentives for market entry. On the one hand, this thread may lead to special pricing schemes and/or to the accelerated development of technological change so that a monopolist can consolidate its market position. But it is possible, on the other hand, that market entry may in fact happen. In this case, one would observe structural change, which would be accompanied by an improved use of resources. This in turn means that competition policy should not be oriented towards an optimal market structure but towards the facilitation of market entry so that competition can discover market opportunities and determine the optimal structure of the market. The present volume shows the wide range of interesting and controversial topics that are concerned when looking at co-ordination, particularly on markets in CEE agri-food sectors. It remains a hope that the heterogeneity and dynamics of the developments will decrease as successful constellations of framework conditions, organisational choices and individual behaviour become more and more obvious and widespread in the region. Conversion to sustainable, balanced patterns might take place, but this cannot be taken for granted. However, chances for such development are better the more stable and balanced political developments, as well as international co-operation, become. We hope that the academic community will contribute towards such goal.Agribusiness, Community/Rural/Urban Development, Industrial Organization, International Development, Labor and Human Capital, Land Economics/Use, Political Economy,

    Über die Verantwortung der Phytomediziner bei der Zulassung und Anwendung von Pflanzenschutzmitteln

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    Die Zulassung von Pflanzenschutzmitteln unterliegt in der BRD sehr strengen Bestimmungen. Eine zu enge Begrenzung der Zulassungsbereiche einzelner Pflanzenschutzmittel auf einzelne Schaderreger und einzelne Kulturen birgt die Gefahr, daß kleinere Kulturen - insbesondere bei selten auftretenden Schaderregern - nicht mehr genügend geschützt werden können. Es sollte auf jeden Fall eine Regelung angestrebt werden, die den in der Beratung tätigen Phytomediziner in die Lage versetzt, geeignete Mittel mit gewisser Eigenverantwortlichkeit zu empfehlen, wenn es zum Schutze von Kulturpflanzen erforderlich ist. Dies kann am besten durch Zulassungen für Einsatzgebiete und nicht für Einzelindikationen erreicht werden

    Aus der Praxis der Obstbaum-Winterspritzung.

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    Complex temporal climate signals drive the emergence of human water-borne disease

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    Predominantly occurring in developing parts of the world, Buruli ulcer is a severely disabling mycobacterium infection which often leads to extensive necrosis of the skin. While the exact route of transmission remains uncertain, like many tropical diseases, associations with climate have been previously observed and could help identify the causative agent's ecological niche. In this paper, links between changes in rainfall and outbreaks of Buruli ulcer in French Guiana, an ultraperipheral European territory in the northeast of South America, were identified using a combination of statistical tests based on singular spectrum analysis, empirical mode decomposition and cross-wavelet coherence analysis. From this, it was possible to postulate for the first time that outbreaks of Buruli ulcer can be triggered by combinations of rainfall patterns occurring on a long (i.e., several years) and short (i.e., seasonal) temporal scale, in addition to stochastic events driven by the El Nino-Southern Oscillation that may disrupt or interact with these patterns. Long-term forecasting of rainfall trends further suggests the possibility of an upcoming outbreak of Buruli ulcer in French Guiana
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