979 research outputs found

    The Advisory System for Fertilizer Application in the German Democratic Republic Emphasizing the Minimization of Nitrogen Pollution

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    This paper describes one of three operational state computer systems used to give advice on agricultural problems in the GDR. The system, employed nationwide, is oriented to providing advice about fertilizer application on farms or even single fields. Of the other two computer systems, one is described in IIASA CP-79-18, "Environmental Problems of Agriculture II: Pest and Weed Management: Monitoring and Forecasting in the German Democratic Republic." The remaining operational system is applied to irrigation. At IIASA's request, the present paper emphasizes the methods of the system for determining the optimal amount of fertilizer to apply which allows for maximum agricultural production without wasting resources or harming the environment. The paper thus offers another contribution to the solution of nonpoint source chemical pollution problems which have been intensively studied at IIASA both in-house and in cooperation with other institutions

    Direct primer walking on P1 plasmid DNA

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    Energy Scaling of Minimum-Bias Tunes

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    We propose that the flexibility offered by modern event-generator tuning tools allows for more than just obtaining "best fits" to a collection of data. In particular, we argue that the universality of the underlying physics model can be tested by performing several, mutually independent, optimizations of the generator parameters in different physical regions. For regions in which these optimizations return similar and self-consistent parameter values, the model can be considered universal. Deviations from this behavior can be associated with a breakdown of the modeling, with the nature of the deviations giving clues as to the nature of the breakdown. We apply this procedure to study the energy scaling of a class of minimum-bias models based on multiple parton interactions (MPI) and pT-ordered showers, implemented in the Pythia 6.4 generator. We find that a parameter controlling the strength of color reconnections in the final state is the most important source of non-universality in this model.Comment: 17 pages, 3 figures, 4 table

    Electrophysiological activation by masked primes: Independence of prime-related and target-related activities

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    Visual stimuli that are made invisible by metacontrast masking (primes) have a marked influence on behavioral and psychophysiological measures such as reaction time (RT) and the lateralized readiness potential (LRP). 4 experiments are reported that shed light on the effects that masked primes have on the LRP. Participants had a go-nogo task in which the prime was associated with 1 of 2 responses even if the target required participants to refrain from responding. To analyze the electrophysiological responses, we computed the LRP and applied an averaging method separating the activation due to the prime and the target. The results demonstrated that (a) masked primes activate responses even in a nogo situation, (b) this prime-related activation is independent of masking, (c) and is also independent of whether prime and target require the same responses (congruent condition) or different responses (incongruent condition)

    Top-down contingent feature-specific orienting with and without awareness of the visual input

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    In the present article, the role of endogenous feature-specific orienting for conscious and unconscious vision is reviewed. We start with an overview of orienting. We proceed with a review of masking research, and the definition of the criteria of experimental protocols that demonstrate endogenous and exogenous orienting, respectively. Against this background of criteria, we assess studies of unconscious orienting and come to the conclusion that so far studies of unconscious orienting demonstrated endogenous feature-specific orienting. The review closes with a discussion of the role of unconscious orienting in action control

    Beaver Research in the Uvs Nuur Region

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    In 1985, 1988, and 2002 Castor fiber birulai was introduced to the Tes Gol of the Uvs Nuur basin in North-western Mongolia. The beavers migrated through the Republic of Tyva and settled in the middle part of Tes Gol near the Tyvinian-Mongolian border. About 10 colonies were recorded in this region in 2002. Strict protection of Castor fiber birulai has to be ensured in Mongolia and the Republic of Tyva in future

    Questions and Remarks About Clans in Multiparticle Dynamics

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    The fact that several important effects in multiparticle dynamics, on which QCD has not yet satisfactory predictions, have been interpreted in terms of the validity of negative binomial (Pascal) regularity and related clan properties at the level of simpler substructures, raises intriguing questions on clan properties in all classes of collisions, the main one being whether clans are observable objects or merely a mathematical concept. We approach this problem by studying clan masses and rapidity distributions in each substructure for e+e- annihilation and hh collisions, and find that such properties can indeed characterise the different components. These results support the idea that clans could be observable, a challenging problem for future experiments.Comment: 11 pages; 3 figures; latex 2e and amsmat

    Ocean warming, a rapid distributional shift, and the hybridization of a coastal fish species

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    Despite increasing awareness of large-scale climate-driven distribution shifts in the marine environment, no study has linked rapid ocean warming to a shift in distribution and consequent hybridization of a marine fish species. This study describes rapid warming (0.8 °C per decade) in the coastal waters of the Angola-Benguela Frontal Zone over the last three decades and a concomitant shift by a temperature sensitive coastal fish species (Argyrosomus coronus) southward from Angola into Namibia. In this context, rapid shifts in distribution across Economic Exclusive Zones will complicate the management of fishes, particularly when there is a lack of congruence in the fisheries policy between nations. Evidence for recent hybridization between A. coronus and a congener, A. inodorus, indicate that the rapid shift in distribution of A. coronus has placed adults of the two species in contact during their spawning events. Ocean warming may therefore revert established species isolation mechanisms and alter the evolutionary history of fishes. While the consequences of the hybridization on the production of the resource remain unclear, this will most likely introduce additional layers of complexity to their management
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