2,276 research outputs found
Taxonomy, biostratigraphy, and phylogeny of Oligocene Globigerinitidae (Dipsidripella, Globigerinita, and Tenuitella)
Full text linkThe taxonomy, biostratigraphy, and phylogeny of the
Oligocene Globigerinitidae (comprising the genera
Dipsidripella, Globigerinita and Tenuitella) is reviewed.
This family is here included in the Superfamily
Globigerinitoidea based on the distinctive wall
texture. The group is united by possessing a ‘radially
crystalline’ wall texture (the glutinata-type wall)
which typically bears pyramidal pustules and in
most species is microperforate (pores <1 µm in
diameter). The genus Dipsidripella is included in the family here for the first time. In Dipsidripella
the wall is often medioperforate (pores 1-2 µm
in diameter; danvillensis-subtype). The following
species are recognized as valid and occurring in
the Oligocene: Dipsidripella danvillensis (Howe and
Wallace), Dipsidripella liqianyui Huber and Pearson,
Globigerinita glutinata (Egger), Globigerinita uvula
(Ehrenberg), Tenuitella angustiumbilicata (Bolli),
Tenuitella gemma (Jenkins), Tenuitella munda
(Jenkins), and Tenuitella praegemma (Li)
The Role of Coordination and Cooperation for Bt-maize cultivation in Brandenburg, Germany
Full text linkSince 2006, several varieties of transgenic Bt-maize are approved for commercial cultivation in Germany. The German regulatory framework for growing these crops comprises ex-ante regulations as well as ex-post liability rules to protect conventional and organic farming from possible negative side effects of transgenic plants and to ensure co-existence. Public regulation is also suspected to impose additional costs to those farmers who intend to plant Bt-maize. We address the question how Bt-maize growing farmers perceive the additional costs of regulation and whether coordination or cooperation takes place in order to diminish these costs. In 2006, we carried out a case study in the Oderbruch region (Brandenburg, Germany) comprising eight Bt-maize growing farmers and six adjacent neighbours. The predominantly large farms chose intrafarm coordination to manage the construction of buffer zones within their own fields and to avoid the planting of Bt-maize close to their neighbours. Inter-farm coordination or cooperation with adjacent farmers was not regarded necessary to achieve co-existence.Coordination, Cooperation, Bt-maize, Crop Production/Industries,
The Diffusion of Bt Cotton and the Economic Impact on Producers
Full text linkThe objective is to present the economic impact of producers adopting Bt cotton and the rapid diffusion on the main producing countries: USA, China and India. The existing literature about this type of transgenic crop has been revised and the results of different research are presented. Bt cotton varieties have been quickly adopted by the countries in this study. Data show that this technology helps reduce production losses and significantly decrease the use of pesticides, thus saving their cost and the associated labour cost. But the total cost reduction is weak due to the high prices of the seeds incorporating this technology.Innovation diffusion, Bt cotton, Crop Production/Industries,
Liquid and solid scintillation: principles and applications
No full textPodeu consultar el llibre complet a: http://hdl.handle.net/2445/32166Scintillation counting is one of the most important developments in the application of radioisotopes to procedures needed by scientists, physicians, engineers, and technicians from many diverse discipline for the detection and quantitative measurement of radioactivity. In fact, Scintillation is the most sensitive and versatile technique for the detection and quantification of
radioactivity. Particularly, Solid and Liquid scintillation measurement are,
nowadays, standard laboratory methods in the life-sciences for measuring
radiation from gamma- and beta-emitting nuclides, respectively. This
methodology is used routinely in the vast majority of diagnostic and/or research
laboratories from those of biochemistry and biology to clinical departments
The practice of access pricing : telecommunications in the United Kingdom
Full text linkTelecommunications was the first network utility to be privatized in the United Kingdom. Drawing on 15 years'experience and discussion in the field, the author shows the economic principles of regulation in general and access pricing in particular that have been implemented. British Telecommunications (BT), formed as a public enterprise in 1980-81, was privatized in 1984. Since then the approaches to regulation have changed in three broad periods: the duoply, the transition to competition, and the recently introduced normalization phase. Dealing with each period, the author focuses on how the actual implementation of access charges are determined, at the same time providing background needed on regulatory intervention generally. Rather than follow the model of competition for a common infrastructure, Oftel [the Office of Telecommunications, the regulatory agency]has encouraged competition between alternative networks, which benefits customers but involves duplication of fixed costs. As a result of Oftel's approach, customers have seen their bills reduced 50 percent in real terms since privatization. It is difficult to know how much to attribute this remarkable result to technological progress (BT halved its workforce in the same period), to regulatory intervention (Oftel set string caps until 1997), or to competition (there are hundreds of players in the market). The author contends more weight should probably be given to the first two. Entrants have not achieved big market shares, if one considers the asymmetric regulation that has been in place for more than a decade. Indirectly, at least, competition benefited consumers by applying discipline to BT's behavior. Oftel's approach was interventionist until 1997, when it began trying to normalize the industry, as authority overseeing competition. The odds on complete deregulation are slight, and some controls on industry will remain. In the longer term, Oftel should especially monitor anticompetitive practices and collusive behavior among the bigger players (BT, CWC, and cellulator operators), The United Kingdom's interconnection experience demonstrates the complexity of the problem and its relationship to other topics, such as tariff rebalancing, access deficit, and universal service. Although a bit ad hoc, the recent incentive regulation, with a network cap based on proper accounting procedures and engineering models, may represent the best practice available today in the telecommunications industry, says the author.Public Sector Economics&Finance,Decentralization,Knowledge Economy,Economic Theory&Research,Payment Systems&Infrastructure,Public Sector Economics&Finance,Education for the Knowledge Economy,Knowledge Economy,Economic Theory&Research,ICT Policy and Strategies
Association of mouse mammary tumor virus superantigen with MHC class II during biosynthesis
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