Modeling Differentiated Quality Standards in the Agri-Food Sector: The Case of Meat Trade in the EU

This paper looks at trade impacts of quality related standards from the supply side of the exporting country. We argue that food quality standards imposed by an importing country have profound effects on the market structure of the exporting industry, and hence a significant impact on the supply response. For our analysis, we develop a stylized oligopoly model that allows for the co-existence of complying and non-complying suppliers. The model is applied to two alternative policy options to explore different mechanisms an importing county may use to enhance the quality of its imports. We take the Polish meat sector as an empirical example, since after Poland's accession to the EU the tight EU food quality standards indeed apply but the process of adjusting to them is far from complete - particularly in Polish meat production/processing. The simulations show that a subsidy scheme, such as the EU's SAPARD program in Poland, can be an effective instrument to promote the compliance with standards and to upgrade the industry in the exporting country.food quality standards, trade, market structure, Poland, meat sector, oligopoly, International Relations/Trade, Livestock Production/Industries, Q17, Q18, L1,

Field-dependent exciton dissociation in organic heterojunction solar cells

In organic heterojunction solar cells, the generation of free charge carriers takes place in a multistep process which involves charge transfer (CT) states, that is, bound electron-hole pairs at the interface between donor and acceptor molecules. Past efforts to model the CT-state dissociation during solar cell operation were not able to consistently reproduce the experimentally observed field and temperature dependence. This discrepancy between model and experiment was partly due to the field-dependent free charge carrier collection process, which plays an important role in the widely used bulk heterojunction cell configuration and superimposes a possible field-dependent charge carrier generation process. In order to distinguish between generation and collection of free charge carriers, we propose the planar heterojunction cell configuration as a model system to study the field-dependent charge carrier generation process in organic heterojunction solar cells. We apply this model system to check current CT-state dissociation models against experimental data. Although the models can quantitatively account for the photocurrent's dependence on the applied voltage and the device thickness, they fail to account for the virtually negligible temperature dependence of the field-dependent charge-generation process. This discrepancy is traced back to a common feature of the models: an Arrhenius-like temperature dependence, distinctive of all processes involving a thermally activated jump over an energy barrier. As a solution to the problem, we introduce an exciton dissociation model based on a field-dependent tunnel process and demonstrate its consistency with the experimental observations. Our results indicate that the current microscopic picture of the charge-generation process in organic heterojunction solar cells being limited by the CT-state dissociation process needs to be reconsidered

Ermittlung der Kosten und Nutzen von Verkehr in Sachsen – Hauptstudie: Abschlussbericht, Im Auftrag des Freistaates Sachsen vertreten durch das Sächsische Landesamt für Umwelt und Geologie (LfUG)

Gegenstand der Studie ist die Analyse der externen Kosten von Verkehr im Freistaat Sachsen. Die relevanten Daten wurden zusammengestellt, monetarisiert und im GIS visualisiert, so dass als Ergebnis die externen Kosten für den Straßen-, Schienen- und Luftverkehr sowie die Binnenschifffahrt für das Jahr 1999 gemeindefein vorliegen. Die Summe der absoluten externen Kosten des Verkehrs in Sachsen beträgt für das Jahr 1999 ca. 8,7 Mrd. €, woraus sich pro Einwohner ein Wert von ca. 2.000 € pro Jahr ergibt. Einen Teil dieser Kosten trägt die Gesellschaft als Ganzes, aber auch andere Regionen und künftige Generationen werden damit belastet. Mit Abstand für den größten Teil der externen Kosten ist der Straßen- und hier der Pkw-Verkehr verantwortlich mit 95 Prozent der gesamten Kosten. Der Schienenverkehr verursacht ca. vier Prozent der externen Kosten, die Anteile des Flugverkehrs und der Binnenschifffahrt mit je ca. einem halben Prozent sind vernachlässigbar (auf Grund der Inlandsbetrachtung). Betrachtet man die einzelnen Kostenkomponenten, so sind die externen Unfallkosten am größten, gefolgt von den Kosten der Luftverschmutzung und der Klimafolgen. Der zweite Schwerpunkt der vorliegenden Studie lag auf der Erarbeitung eines Überblicks über Strategien zur Internalisierung der externen Kosten. Zu diesem Zweck wurden für jede Kostenkomponente auf den Ebenen Bund/EU, Land und Kommune Maßnahmen zusammengestellt, welche die einzelnen Akteure zur Verringerung der externen Kosten ergreifen können

X-ray detection of a nova in the fireball phase

Novae are caused by runaway thermonuclear burning in the hydrogen-rich envelopes of accreting white dwarfs, which leads to a rapid expansion of the envelope and the ejection of most of its mass1,2. Theory has predicted the existence of a ‘fireball’ phase following directly on from the runaway fusion, which should be observable as a short, bright and soft X-ray flash before the nova becomes visible in the optical3,4,5. Here we report observations of a bright and soft X-ray flash associated with the classical Galactic nova YZ Reticuli 11¿h before its 9¿mag optical brightening. No X-ray source was detected 4¿h before and after the event, constraining the duration of the flash to shorter than 8¿h. In agreement with theoretical predictions4,6,7,8, the source’s spectral shape is consistent with a black-body of 3.27+0.11-0.33¿×¿105¿K (28.2+0.9-2.8¿eV), or a white dwarf atmosphere, radiating at the Eddington luminosity, with a photosphere that is only slightly larger than a typical white dwarf.Peer ReviewedPostprint (author's final draft

The metrology system of the VLTI instrument GRAVITY

The VLTI instrument GRAVITY combines the beams from four telescopes and provides phase-referenced imaging as well as precision-astrometry of order 10 microarcseconds by observing two celestial objects in dual-field mode. Their angular separation can be determined from their differential OPD (dOPD) when the internal dOPDs in the interferometer are known. Here, we present the general overview of the novel metrology system which performs these measurements. The metrology consists of a three-beam laser system and a homodyne detection scheme for three-beam interference using phase-shifting interferometry in combination with lock-in amplifiers. Via this approach the metrology system measures dOPDs on a nanometer-level.Comment: 9 pages, 5 figure

Multiwavelength spectral evolution during the 2011 outburst of the very faint X-ray transient Swift J1357.2-0933

We report our multiwavelength study of the 2011 outburst evolution of the newly discovered black hole candidate X-ray binary Swift J1357.2-0933. We analysed the Swift X-ray telescope and Ultraviolet/Optical telescope (UVOT) data taken during the ~7 months duration of the outburst. It displayed a 2-10 keV X-ray peak luminosity of ~1E35(D/1.5 kpc)^2 erg s-1 which classifies the source as a very faint X-ray transient. We found that the X-ray spectrum at the peak was consistent with the source being in the hard state, but it softened with decreasing luminosity, a common behaviour of black holes at low luminosities or returning to quiescence from the hard state. The correlations between the simultaneous X-ray and ultraviolet/optical data suggest a system with a black hole accreting from a viscous disc that is not irradiated. The UVOT filters provide the opportunity to study these correlations up to ultraviolet wavelengths a regime so far unexplored. If the black hole nature is confirmed, Swift J1357.2-0933 would be one of the very few established black hole very-faint X-ray transients.Comment: 6 pages, 2 tables, 5 figures. Accepted by MNRA

study protocol for a randomized controlled trial

Background Osteoarthritis (OA) is a heterogeneous group of conditions with disturbed integrity of articular cartilage and changes in the underlying bone. The pathogenesis of OA is multifactorial and not just a disease of older people. Hydroxychloroquine (HCQ) is a disease-modifying anti-rheumatic drug (DMARD) typically used for the treatment of various rheumatic and dermatologic diseases. Three studies of HCQ in OA, including one abstract and one letter, are available and use a wide variety of outcome measures in small patient populations. Despite initial evidence for good efficacy of HCQ, there has been no randomized, double-blind, and placebo-controlled trial in a larger patient group. In the European League Against Rheumatism (EULAR), evidence-based recommendations for the management of hand OA, HCQ was not included as a therapeutic option because of the current lack of randomized clinical trials. Methods/Design OA TREAT is an investigator-initiated, multicenter, randomized, double-blind, placebo-controlled trial. A total of 510 subjects with inflammatory and erosive hand OA, according to the classification criteria of the American College of Rheumatology (ACR), with recent X-ray will be recruited across outpatient sites, hospitals and universities in Germany. Patients are randomized 1:1 to active treatment (HCQ 200 to 400 mg per day) or placebo for 52 weeks. Both groups receive standard therapy (non-steroidal anti-inflammatory drugs [NSAID], coxibs) for OA treatment, taken steadily two weeks before enrollment and continued further afterwards. If disease activity increases, the dose of NSAID/coxibs can be increased according to the drug recommendation. The co-primary clinical endpoints are the changes in Australian-Canadian OA Index (AUSCAN, German version) dimensions for pain and hand disability at week 52. The co-primary radiographic endpoint is the radiographic progression from baseline to week 52. A multiple endpoint test and analysis of covariance will be used to compare changes between groups. All analyses will be conducted on an intention-to-treat basis. Discussion The OA TREAT trial will examine the clinical and radiological efficacy and safety of HCQ as a treatment option for inflammatory and erosive OA over 12 months. OA TREAT focuses on erosive hand OA in contrast to other current studies on symptomatic hand OA, for example, HERO [Trials 14:64, 2013]

A distributed tree data structure for real-time OLAP on cloud architectures

In contrast to queries for on-line transaction processing (OLTP) systems that typically access only a small portion of a database, OLAP queries may need to aggregate large portions of a database which often leads to performance issues. In this paper we introduce CR-OLAP, a Cloud based Real-time OLAP system based on a new distributed index structure for OLAP, the distributed PDCR tree, that utilizes a cloud infrastructure consisting of (m + 1) multi-core processors. With increasing database size, CR-OLAP dynamically increases m to maintain performance. Our distributed PDCR tree data structure supports multiple dimension hierarchies and efficient query processing on the elaborate dimension hierarchies which are so central to OLAP systems. It is particularly efficient for complex OLAP queries that need to aggregate large portions of the data warehouse, such as 'report the total sales in all stores located in California and New York during the months February-May of all years'. We evaluated CR-OLAP on the Amazon EC2 cloud, using the TPC-DS benchmark data set. The tests demonstrate that CR-OLAP scales well with increasing number of processors, even for complex queries. For example, on an Amazon EC2 cloud instance with eight processors, for a TPC-DS OLAP query stream on a data warehouse with 80 million tuples where every OLAP query aggregates more than 50% of the database, CR-OLAP achieved a query latency of 0.3 seconds which can be considered a real time response

Occurrence of the leucine-to-phenylalanine knockdown resistance (kdr) mutation in Anopheles arabiensis populations in Tanzania, detected by a simplified high-throughput SSOP-ELISA method

BACKGROUND: Molecular markers of insecticide resistance can provide sensitive indicators of resistance development in malaria vector populations. Monitoring of insecticide resistance in vector populations is an important component of current malaria control programmes. Knockdown resistance (kdr) confers resistance to the pyrethroid class of insecticides with cross-resistance to DDT through single nucleotide polymorphisms (SNPs) in the voltage-gated sodium channel gene. METHODS: To enable detection of kdr mutations at low frequency a method was developed that uses polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay (ELISA)-based technology, allowing rapid, reliable and cost-effective testing of large numbers of individual mosquitoes. This was used to assay mosquitoes from sites in lower Moshi, Tanzania. RESULTS: Sequence-specific oligonucleotide probes (SSOP) were used for simultaneous detection of both East and West African kdr mutations with high specificity and sensitivity. Application of the SSOP-ELISA method to 1,620 field-collected Anopheles arabiensis from Tanzania identified the West African leucine-phenylalanine kdr mutation in two heterozygous individuals, indicating the potential for resistance development that requires close monitoring. CONCLUSION: The presence of the West African kdr mutation at low frequency in this East African population of An. arabiensis has implications for the spread of the kdr gene across the African continent