459 research outputs found
Optimal Vessel Quotas and Capacity of a Danish Trawler Fleet Segment: A Dual Approach
In the period of investigation, 1995–2000, the Danish fishery for species meant for human consumption was managed by individual non-transferable vessel quotas, while the fishery for species meant for fishmeal and fish oil was subject to a total quota. The revenues of the fishermen targeting species for human consumption are therefore fixed on the assumption that they are price takers, and that they will maximize profits by minimizing their costs. To model the economic behaviour of the fishermen in terms of the optimal quota size per vessel and optimal fleet size, a dual cost-function approach is an appropriate choice. This method is applied using a generalized Leontief cost function to model the behaviour of the Danish fleet of trawlers below 50 GRT, targeting species for human consumption solely. The estimated cost function is used to determine the optimal quotas yielding: (i) minimum average cost and (ii) maximum profit. The results of the estimations show that the optimal quotas per vessel should be increased by more than 2.5 times and consequently that the fleet should be reduced by more than 60%. As this has not been the case, a probable explanation is that non-transferable quotas leave the fishermen with the option of quitting the fishery only if a decommissioning programme is in place. There is no option to transfer the quota to another vessel.Cost function, dual approach, economic behaviour, Leontief cost function, long-run equilibrium, maximum profit, minimum average cost., Institutional and Behavioral Economics, Research Methods/ Statistical Methods, Resource /Energy Economics and Policy, B41, C13, C61, C67,
Modelling economic response to harvest and effort control in North Sea cod fishery
A number of European fishing fleets have been regulated through a
combination of quota and effort (sea days) controls since 2004. These two
regulation schemes are, however, interrelated, i.e. a given quota limit will
necessarily determine the effort used and vice versa. A bioeconomic feedback
model is presented which takes this causality between effort and harvest
control into account, and switches back and forth between these two
regulation schemes depending on which is the binding rule. The model is
based on biological stock projection, and quotas are set using the Pope
approximation while an economic production function is used to estimate the
harvest when the effort is binding. The economic response of the fleet is
modelled through a dynamic investment/disinvestment module which evaluates
the change in the fleet capacity given the economic outcome of the fishery.
A simple example is presented for the Danish seiners catching cod in the
North Sea. The model has been constructed as part of the 6th framework
project “Operational Evaluation Tools for Fisheries Management Options
(EFIMAS)”
Was uns das Fernsehen bietet – zwischen Beobachtung und Voyeurismus
Massive Kritik am Fernsehen übt der Fernsehkritiker Hans Hoff aus Düsseldorf. Es würden Show und Unterhaltung statt Information geboten. Der Autor verdeutlicht seine Aussagen mit Beispielen der privaten Fernsehsender, der Kriegsberichterstattung aus dem Irak und anhand von Talkshows im öffentlich-rechtlichen Rundfunk. Auch bei ARD und ZDF würden Boulevard-Magazine immer mehr Sendeplatz einnehmen. Für Hoff liegt das "Grundproblem" des Fernsehens darin, dass je echter Fernsehen wirke, desto unechter sei es. Das Fernsehen gaukele zunehmend eine Welt vor, die es so nur im Fernsehen und artverwandten Medien gebe und in der Realität mit Fiktion verwechselt werde. Die Grenzen würden verschwimmen, wenn die reale Welt der fiktionalen immer ähnlicher werde. Es gebe allerdings immer noch sehr gute Sendungen im deutschen Fernsehen, und es lohne, sich diese gezielt herauszusuchen. EnglishHans Hoff: What TV offers us – between watching and voyarism In this vividly and emotionally presented speech the author critisizes television for favoring shows and entertainment programs over information. To confirm his thesis he gives examples such as reports on the war in Iraq aired by German private TV stations and talk-shows aired by German public TV. Today even the two German public TV stations ARD and ZDF are favoring entertainment programms. The author regards it as the main problern of television programms in these days that the more realistic they appear the less real they are.Television leads viewers to believe in a world which is only real in itself and in which fiction is taken for reality. And if the real world is continually transformed into fiction, all boundaries are disappearing. At the end of his article, the author confirms, however, that in German TV a lot of excellent programs can still be found - but you have to look out for them.
Linking effort and fishing mortality in a mixed fisheries model:comparing linear versus non-linear assumptions
Beträge zur Geschichte des freien Rhythmus in der deutschen Dichtung : Goethe, Heine, Mörike, Liliencron und Holz
Thesis (PhD)--University of Illinois, 1908.Typescript.Vita.Includes bibliographical references
Hvilken verdi har et venterom? Om verdsetting av kvaliteten på stasjoner og knutepunkter.
I transportplanlegging brukes ofte samfunnsøkonomiske metoder for å prioritere mellom ulike tiltak. Et omfattende verktøy er utviklet for å vurdere effektene av investeringer. Imidlertid er det i Norge ikke etablert praksis for å inkludere verdien av kvalitetsforbedringer på stasjoner i slike analyser, i alle fall ikke i uttrykt i tids- eller pengeverdi. Det er imidlertid gjort undersøkelser i andre land, og i artikkelen presenteres funn fra Nederland og England. Begge disse bygger på tidligere analyser og peker på at det er mulig å beregne og forsvare en oppnådd pengeverdi som følger av bedringer i stasjonskomfort og standard. Følgelig er det sannsynligvis en større feil å utelukke verdsetting av slike elementer, enn å inkludere verdier. Jernbaneverket har gjort en pilot/kvalitativ undersøkelse av passasjerenes verdsetting av standard på stasjoner, og vil videreføre denne med en kvantitativ undersøkelse (betinget verdsetting). Det kan argumenteres for at slike komfortelementer eller kvalitetsnivåer kan uttrykkes som en faktor i forhold til tidsverdier
Spectroscopic characterization of reaction centers of the (M)Y210W mutant of the photosynthetic bacterium Rhodobacter sphaeroides
The tyrosine-(M)210 of the reaction center of Rhodobacter sphaeroides 2.4.1 has been changed to a tryptophan using site-directed mutagenesis. The reaction center of this mutant has been characterized by low-temperature absorption and fluorescence spectroscopy, time-resolved sub-picosecond spectroscopy, and magnetic resonance spectroscopy. The charge separation process showed bi-exponential kinetics at room temperature, with a main time constant of 36 ps and an additional fast time constant of 5.1 ps. Temperature dependent fluorescence measurements predict that the lifetime of P* becomes 4–5 times slower at cryogenic temperatures. From EPR and absorbance-detected magnetic resonance (ADMR, LD-ADMR) we conclude that the dimeric structure of P is not significantly changed upon mutation. In contrast, the interaction of the accessory bacteriochlorophyll BA with its environment appears to be altered, possibly because of a change in its position
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