545 research outputs found

    Reversal of density dependence of juvenile Littorina littorea (Gastropoda) growth in response to periphyton nutrient status

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    Experimental periphyton communities were grown in aquaria receiving media of differently enriched seawater (fully enriched, without Si enrichment, without N and P enrichment) and supplied differently with medium (batch and weekly replacement). Periphyton was subject to grazing by 1-6 individuals of juvenile Littorina littorea. Periphyton biomass was higher in the replacement aquaria than in the batch aquaria and higher in the full and the -Si medium than in the -NP medium. The N:C ratio of the periphyton increased with Littorina number in the batch aquaria and was unaffected by Littorina number in the replacement aquaria. Diatoms were most dominant in the -NP treatments and rarest in the -Si treatments. Chlorophytes were dominant in the -Si and the fully enriched treatments, but also Cyanobacteria contributed significantly to periphyton biomass in those treatments under nutrient replacement. Somatic growth of Littorina was negatively correlated to Littorina density in the replacement aquaria and positively density dependent in the batch aquaria. The latter is explained by improved food quality under stronger grazing pressure

    Charmonium - Pion Cross Section from QCD Sum Rules

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    The J/ψπDˉD,DˉDJ/\psi \pi\to \bar{D} D^*, \bar{D} D, DˉD{\bar D}^* D^* and DˉD{\bar D} D^* cross sections as a function of s\sqrt{s} are evaluated in a QCD sum rule calculation. We study the Borel sum rule for the four point function involving pseudoscalar and vector meson currents, up to dimension four in the operator product expansion. We find that our results are smaller than the J/ψπcharmedmesonsJ/\psi \pi\to {charmed mesons} cross sections obtained with models based on meson exchange, but are close to those obtained with quark exchange models.Comment: revised version accepted for publication in Phys. Lett.

    Late Eocene to middle Miocene (33 to 13 million years ago) vegetation and climate development on the North American Atlantic Coastal Plain (IODP Expedition 313, Site M0027)

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    ArticleWe investigated the palynology of sediment cores from Site M0027 of IODP (Integrated Ocean Drilling Program) Expedition 313 on the New Jersey shallow shelf to examine vegetation and climate dynamics on the east coast of North America between 33 and 13 million years ago and to assess the impact of over-regional climate events on the region. Palynological results are complemented with pollen-based quantitative climate reconstructions. Our results indicate that the hinterland vegetation of the New Jersey shelf was characterized by oak–hickory forests in the lowlands and conifer-dominated vegetation in the highlands from the early Oligocene to the middle Miocene. The Oligocene witnessed several expansions of conifer forest, probably related to cooling events. The pollen-based climate data imply an increase in annual temperatures from ∼11.5 °C to more than 16 °C during the Oligocene. The Mi-1 cooling event at the onset of the Miocene is reflected by an expansion of conifers and mean annual temperature decrease of ∼4 °C, from ∼16 °C to ∼12 °C around 23 million years before present. Relatively low annual temperatures are also recorded for several samples during an interval around ∼20 million years before present, which may reflect the Mi-1a and the Mi-1aa cooling events. Generally, the Miocene ecosystem and climate conditions were very similar to those of the Oligocene. Miocene grasslands, as known from other areas in the USA during that time period, are not evident for the hinterland of the New Jersey shelf, possibly reflecting moisture from the proto-Gulf Stream. The palaeovegetation data reveal stable conditions during the mid-Miocene climatic optimum at ∼15 million years before present, with only a minor increase in deciduous–evergreen mixed forest taxa and a decrease in swamp forest taxa. Pollen-based annual temperature reconstructions show average annual temperatures of ∼14 °C during the mid-Miocene climatic optimum, ∼2 °C higher than today, but ∼1.5 °C lower than preceding and following phases of the Miocene. We conclude that vegetation and regional climate in the hinterland of the New Jersey shelf did not react as sensitively to Oligocene and Miocene climate changes as other regions in North America or Europe due to the moderating effects of the North Atlantic. An additional explanation for the relatively low regional temperatures reconstructed for the mid-Miocene climatic optimum could be an uplift of the Appalachian Mountains during the Miocene, which would also have influenced the catchment area of our pollen record.We thank the entire IODP Expedition 313 Scientific Party for input, and the IODP staff for support. We thank M. Drljepan, R. Zanatta, V. Menke, K. Reichel, and S. Namyslo for their assistance with preparing and processing the samples, and during photographing. Discussions with C. Bjerrum, J. Browning, T. Donders, L. Fang, M. Katz, Y. Milker, K. Miller, and P. Sugarman are gratefully acknowledged. Input from K. Dybkjær and anonymous reviewers was very much appreciated and contributed to a significant condensing of the manuscript. The German Science Foundation supported the research (DFG project KO 3944/3-1 to U. Kotthoff). Funding was also provided by NSERC Discovery Grants to F. M. G. McCarthy and to D. R. Greenwood respectively. NERC supported work by S. P. Hesselbo. This research used samples and/or data provided by the Integrated Ocean Drilling Program (IODP)

    PENGARUH PERILAKU PEMERIKSA PAJAK DAN PROFESIONALISME PEMERIKSA PAJAK TERHADAP KINERJA PEMERIKSA PAJAK (Studi Pada KPP Pratama Bandung Karees )

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    ABSTRAK Penelitian ini bertujuan untuk mengetahui seberapa besar pengaruh perilaku pemeriksa pajak terhadap profesionalisme pemeriksa pajak dampaknya pada kinerja pemeriksa pajak dan untuk mengetahui seberapa besar pengaruh perilaku pemeriksa pajak dan profesionalisme pemeriksa pajak terhadap kinerja pemeriksa pajak . Metode penelitian yang digunakan adalah analisis deskriptif dan verifikatif. Populasi dari penelitian ini adalah pemeriksa pajak di KPP Pratama Bandung Karees yang berjumlah 30 responden. Te knik sampling yang digunakan adalah teknik sampling jenuh yaitu keseluruhan populasi dijadikan sampel penelitian. Analisis data dilakukan dengan menggunakan analisis path dan analisis regresi linier berganda. Hasil penelitian menunju k kan bahwa Perilaku Pemeriksa Pajak masuk ke dalam Kriteria cukup baik karena nilai rata - rata sebesar 33,77 berada pada interval 26,1 s/d 34. Secara parsial Perilaku Pemeriksa Pajak berpengaruh signifikan terhadap Kinerja Pemeriksa Pajak dengan kontribusi pengaruh sebesar 21, 6%. Profesionalisme Pemeriksa Pajak masuk ke dalam Kriteria cukup tinggi karena nilai rata - rata sebesar 47,8 berada pada interval 36,6 s/d 47,8 . Secara parsial Profesionalisme Pemeriksa Pajak berpengaruh signifikan terhadap Kinerja Pemeriksa Pajak dengan k ontribusi pengaruh sebesar 37,2%. Secara simultan Pengaruh Perilaku Pemeriksa Pajak dan Profesionalisme Pemeriksa Pajak terhadap Kinerja Pemeriksa Pajak adalah Perilaku Pemeriksa Pajak dan Profesionalisme Pemeriksa Pajak berpengaruh signifikan terhadap K inerja Pemeriksa Pajak dengan kontribusi pengaruh sebesar 59%. Pengaruh tidak langsung Perilaku Pemeriksa Pajak terhadap Kinerja Pemeriksa Pajak melalui Profesionalisme Pemeriksa Pajak sebesar 26,3%. Total pengaruh Perilaku Pemeriksa Pajak, Profesionalism e Pemeriksa Pajak terhadap Kinerja Pemeriksa Pajak sebesar 47,9%. Kata kunci : Perilaku Pemeriksa Pajak , Profesionalisme Pemeriksa Pajak dan Kinerja Pemeriksa Pajak

    Simple assessment of spatio-temporal evolution of salt marshes ecological services

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    A number of previous research studies have addressed the enormous role played by biodiversity and ecosystems in human well-being and have placed particular emphasis on the consequences of the reduction or loss of these services. A handful of studies have implemented practical methodologies to quantify the variability of limiting factors leading to reductions in these ecological services. The aim of this article is to document the limited number of studies that have analyzed coastal ecosystem services and acknowledge the impacts of physical changes in habitat provision. In one example, it is clear that the maintenance of salt marshes depends on sedimentary supply and consequent morphological variability in spite of the fact that there is usually no recurrent integration of habitat time-space dynamics (sediment availability) during the quantification and monetization of marsh services (i.e., monetary valuation of salt marsh services). This means that one key challenge facing the analysis of salt marsh (or other ecosystem) services in a global climate context is to predict future value, based on past trends, while at the same time guaranteeing conservation. Research in this field has been very broad and so the use of long-term evolutionary datasets is proposed here to explain future habitat provision. An empirical approximation is also presented here that accounts for service provision and enables time-space analysis. Although improvements will be required, the equation presented here represents a key first step to enable managers to cope with the constraints of resource limitations and is also applicable to other habitats.PTDC/MAR-EST/1031/2014info:eu-repo/semantics/publishedVersio

    Two- and Three-photon Fusion in Relativistic Heavy ion Collisions

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    The production of mesons in ultra-peripheral collisions of relativistic heavy ions is re-analyzed using a projection technique to calculate the amplitudes for the appropriate Feynman diagrams. The virtuality of the exchanged photons is fully accounted for in this approach. In the case of two-photon fusion, it is explicitly shown that the inclusion of nuclear form factors validates the equivalent photon approximation. However, this does not apply to three-photon fusion cross sections. The cross section of J/\psi production in ultra-peripheral collisions at RHIC and LHC are shown to be much smaller than the cross sections for the production of C=even mesons of similar masses.Comment: Version to be published in Nuclear Physics

    Cruise Report ALKOR 438 [AL438] - Foraminiferal biomonitoring in the North Sea, May 29 - May 31, 2014, Kiel (Germany) - Kiel (Germany)

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    The aim of R/V Alkor cruise AL438 was to investigate the assemblage composition, population density and distribution of Recent benthic foraminifera in the Elbe estuary and southern North Sea. We focused on an assessment of the present state of the ecosystems and a comparison with data from former decades. Our work resumed investigations of the Geologisch-Paläontologisches Institut of Kiel University and the Federal Hydrographic Office from 1960s till the 1980s, as well as topical studies to the west of Helgoland. We revisited the same stations and took sediment samples with historical and modern grab samplers, box corer, Minicorer and a gravity corer. These samples were accomplished with samples from new stations in order to describe the relationships of foraminiferal faunas living in the Helgoland mud area with those inhabiting the surrounding sands. The sampling was accompanied with hydrographical measurements and water sampling to document relevant environmental parameters. The foraminiferal sampling was carried out for the first time following of the FOraminiferal BIoMOnitoring group (FOBIMO) recommendations as much as possible, in order to test the practicability of the guidelines. In total, 109 deployments at 37 stations were successfully accomplished

    Modelling the extreme storm surge in the western Baltic Sea on November 13, 1872, revisited

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    Die Küste, 92 - Online First - 1872 - An exceptional storm surge in the Balti
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