6,425 research outputs found

    Patient-Relativity and the Efficacy of Epicurean Therapy

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    According to Epicurus, philosophy’s sole task is to ensure the well-being of the soul. Human souls are often riddled with diseases; the most serious are the fear of the gods and the fear of death. Thus, the Epicureans offered several arguments designed to demonstrate that, for instance, “death is nothing to us,” and should therefore not be feared. Since their creation there has been much discussion, both in antiquity and by contemporary philosophers, about these arguments. In this thesis, I argue that Epicurean philosophical arguments are patient-relative; they necessarily adapt themselves so as to be therapeutically effective for their intended audience. The end result is that when we evaluate Epicurean philosophical arguments, we must do so in light of the audience for whom they were intended

    Heaping and its Consequences for Duration Analysis

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    This paper analyses the consequences of heaping in duration models. Heaping is a specific form of response error typical to retrospectively collected labor force status data. Respondents round-off the spell length, when duration data is collected by episode-based questionnaires. Calendar-based questionnaires instead may lead to abnormal concentrations of the start and/or end of spells at specific calendar months. The investigation concentrates on this latter type of heaping, which Kraus and Steiner [1995] identified for the unemployment spell data from the German Socio-Economic Panel (GSOEP). In the special case of an exponential model heaping with a symmetric zero-mean measurement error does not bias the parameter estimate. In the Weibull model with duration dependence, however, it is proven that even such a symmetric heaping would lead to inconsistent estimation. We discuss the bias for general heaping patterns and derive from this a proposal for bias correction. In a number of simulation studies we check the theoretical results. The Monte Carlo simulations also show that an amount of heaping, that characterizes the GSOEP-West does not lead to considerably biased parameter estimates of a Weibull model. However, it clearly leads to spurious seasonal effects. Finally, some directions of future work are indicated

    Restriction on the energy and luminosity of e+e- storage rings due to beamstrahlung

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    The role of beamstrahlung in high-energy e+e- storage-ring colliders (SRCs) is examined. Particle loss due to the emission of single energetic beamstrahlung photons is shown to impose a fundamental limit on SRC luminosities at energies 2E_0 >~ 140 GeV for head-on collisions and 2E_0 >~ 40 GeV for crab-waist collisions. With beamstrahlung taken into account, we explore the viability of SRCs in the E_0=240-500 GeV range, which is of interest in the precision study of the Higgs boson. At 2E_0=240 GeV, SRCs are found to be competitive with linear colliders; however, at 2E_0=400-500 GeV, the attainable SRC luminosity would be a factor 15-25 smaller than desired.Comment: Latex, 5 pages. v2 differs only by minor changes is abstract and introduction, one reference is added. v3 corresponds to the paper published in PR

    Sets of Priors Reflecting Prior-Data Conflict and Agreement

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    In Bayesian statistics, the choice of prior distribution is often debatable, especially if prior knowledge is limited or data are scarce. In imprecise probability, sets of priors are used to accurately model and reflect prior knowledge. This has the advantage that prior-data conflict sensitivity can be modelled: Ranges of posterior inferences should be larger when prior and data are in conflict. We propose a new method for generating prior sets which, in addition to prior-data conflict sensitivity, allows to reflect strong prior-data agreement by decreased posterior imprecision.Comment: 12 pages, 6 figures, In: Paulo Joao Carvalho et al. (eds.), IPMU 2016: Proceedings of the 16th International Conference on Information Processing and Management of Uncertainty in Knowledge-Based Systems, Eindhoven, The Netherland

    Detecting small-scale spatial heterogeneity and temporal dynamics of soil organic carbon (SOC) stocks: a comparison between automatic chamber-derived C budgets and repeated soil inventories

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    Carbon (C) sequestration in soils plays a key role in the global C cycle. It is therefore crucial to adequately monitor dynamics in soil organic carbon (∆SOC) stocks when aiming to reveal underlying processes and potential drivers. However, small-scale spatial (10-30 m) and temporal changes in SOC stocks, particularly pronounced on arable lands, are hard to assess. The main reasons for this are limitations of the well-established methods. On the one hand, repeated soil inventories, often used in long-term field trials, reveal spatial patterns and trends in ∆SOC but require a longer observation period and a sufficient number of repetitions. On the other hand, eddy covariance measurements of C fluxes towards a complete C budget of the soil-plant-atmosphere system may help to obtain temporal ∆SOC patterns but lack small-scale spatial resolution. To overcome these limitations, this study presents a reliable method to detect both short-term temporal dynamics as well as small-scale spatial differences of ΔSOC using measurements of the net ecosystem carbon balance (NECB) as a proxy. To estimate the NECB, a combination of automatic chamber (AC) measurements of CO2 exchange and empirically modeled aboveground biomass development (NPPshoot) were used. To verify our method, results were compared with ΔSOC observed by soil resampling. Soil resampling and AC measurements were performed from 2010 to 2014 at a colluvial depression located in the hummocky ground moraine landscape of NE Germany. The measurement site is characterized by a variable groundwater level (GWL) and pronounced small-scale spatial heterogeneity regarding SOC and nitrogen (Nt) stocks. Tendencies and magnitude of ∆SOC values derived by AC-measurements and repeated soil inventories corresponded well. The period of maximum plant growth was identified as being most important for the development of spatial differences in annual ΔSOC. Hence, we were able to confirm that AC-based C budgets are able to reveal small-scale spatial differences and short-term temporal dynamics of ∆SOC

    Restoration of peatlands and greenhouse gas balances

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    In this chapter the impact of peatland restoration on greenhouse gas fluxes is discussed based on a literature review. Casestudies are presented covering different peatland types, different regions and different starting conditions

    Measurement of the Blackbody Radiation Shift of the 133Cs Hyperfine Transition in an Atomic Fountain

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    We used a Cs atomic fountain frequency standard to measure the Stark shift on the ground state hyperfine transiton frequency in cesium (9.2 GHz) due to the electric field generated by the blackbody radiation. The measures relative shift at 300 K is -1.43(11)e-14 and agrees with our theoretical evaluation -1.49(07)e-14. This value differs from the currently accepted one -1.69(04)e-14. The difference has a significant implication on the accuracy of frequency standards, in clocks comparison, and in a variety of high precision physics tests such as the time stability of fundamental constants.Comment: 4 pages, 2 figures, 2 table

    Nitrogen mineralization and gaseous nitrogen losses from waterlogged and drained organic soils in a black alder (<i>Alnus glutinosa</i> (L.) Gaertn.) forest

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    Black alder (<i>Alnus glutinosa</i> (L.) Gaertn.) forests on peat soils have been reported to be hotspots for high nitrous oxide (N<sub>2</sub>O) losses. High emissions may be attributed to alternating water tables of peatlands and to the incorporation of high amounts of easily decomposable nitrogen (N) into the ecosystem by symbiotic dinitrogen (N<sub>2</sub>)-fixation of alder trees. Our study addressed the question to what extent drainage enhances the emissions of N<sub>2</sub>O from black alder forests and how N turnover processes and physical factors influence the production of N<sub>2</sub>O and total denitrification. The study was conducted in a drained black alder forest with variable groundwater tables at a southern German fen peatland. Fluxes of N<sub>2</sub>O were measured using the closed chamber method at two drained sites (D-1 and D-2) and one undrained site (U). Inorganic N contents and net N mineralization rates (NNM) were determined. Additionally a laboratory incubation experiment was carried out to investigate greenhouse gas and N<sub>2</sub> fluxes at different temperature and soil moisture conditions. Significantly different inorganic N contents and NNM rates were observed, which however did not result in significantly different N<sub>2</sub>O fluxes in the field but did in the laboratory experiment. N<sub>2</sub>O fluxes measured were low for all sites, with total annual emissions of 0.51 ± 0.07 (U), 0.97 ± 0.13 (D-1) and 0.93 ± 0.08 kg N<sub>2</sub>O–N ha<sup>−1</sup> yr<sup>&minus;1</sup> (D-2). Only 37% of the spatiotemporal variation in field N<sub>2</sub>O fluxes could be explained by peat temperature and groundwater level, demonstrating the complex interlinking of the controlling factors for N<sub>2</sub>O emissions. However, temperature was one of the key variables of N<sub>2</sub>O fluxes in the incubation experiment conducted. Increasing soil moisture content was found to enhance total denitrification losses during the incubation experiment, whereas N<sub>2</sub>O fluxes remained constant. At the undrained site, permanently high groundwater level was found to prevent net nitrification, resulting in a limitation of available nitrate (NO<sub>3</sub><sup>&minus;</sup>) and negligible gaseous N losses. N<sub>2</sub>O flux rates that were up to four times higher were measured in the incubation experiment. They reveal the potential of high N<sub>2</sub>O losses under changing soil physical conditions at the drained alder sites. The high net nitrification rates observed and high NO<sub>3</sub><sup>&minus;</sup> contents bear the risk of considerable NO<sub>3</sub><sup>&minus;</sup> leaching at the drained sites

    Drilling of shallow marine sulfide-sulfate mineralisation in south-eastern Tyrrhenian Sea, Italy; Seafloor sulfides, Tyrrhenian Sea, highsulfidation; hydrothermal systems, Palinuro

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    Semi-massive to massive sulfides with abundant late native sulfur were drilled in a shallowwater hydrothermal system in an island arc volcanic setting at the Palinuro volcanic complex in the Tyrrhenian Sea, Italy. Overall, 12.7 m of sulfide mineralisation were drilled in a sediment-filled depression at a water depth of 630 - 650 m using the lander-type Rockdrill I drill rig of the British Geological Survey. Polymetallic (Zn, Pb, Sb, As, Ag) sulfides overlie massive pyrite. The massive sulfide mineralisation contains a number of atypical minerals, including enargite-famatinite, tennantite-tetrahedrite, stibnite, bismuthinite, and Pb-,Sb-, and Ag-sulfosalts, that do not commonly occur in mid-ocean ridge massive sulfides. Analogous to subaerial epithermal deposits, the occurrence of these minerals and the presence of abundant native sulfur suggest an intermediate to high sulfidation and/or high oxididation state of the hydrothermal fluids in contrast to the near-neutral and reducing fluids from which base metal-rich massive sulfides along mid-ocean ridges typically form. Oxidised conditions during sulfide deposition are likely related to the presence of magmatic volatiles in the mineralising fluids that were derived from a degassing magma chamber below the Palinuro volcanic complex
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