Hydrological model calibration for derived flood frequency analysis using stochastic rainfall and probability distributions of peak flows

Derived flood frequency analysis allows the estimation of design floods with hydrological modeling for poorly observed basins considering change and taking into account flood protection measures. There are several possible choices regarding precipitation input, discharge output and consequently the calibration of the model. The objective of this study is to compare different calibration strategies for a hydrological model considering various types of rainfall input and runoff output data sets and to propose the most suitable approach. Event based and continuous, observed hourly rainfall data as well as disaggregated daily rainfall and stochastically generated hourly rainfall data are used as input for the model. As output, short hourly and longer daily continuous flow time series as well as probability distributions of annual maximum peak flow series are employed. The performance of the strategies is evaluated using the obtained different model parameter sets for continuous simulation of discharge in an independent validation period and by comparing the model derived flood frequency distributions with the observed one. The investigations are carried out for three mesoscale catchments in northern Germany with the hydrological model HEC-HMS (Hydrologic Engineering Center's Hydrologic Modeling System). The results show that (I) the same type of precipitation input data should be used for calibration and application of the hydrological model, (II) a model calibrated using a small sample of extreme values works quite well for the simulation of continuous time series with moderate length but not vice versa, and (III) the best performance with small uncertainty is obtained when stochastic precipitation data and the observed probability distribution of peak flows are used for model calibration. This outcome suggests to calibrate a hydrological model directly on probability distributions of observed peak flows using stochastic rainfall as input if its purpose is the application for derived flood frequency analysis

Notch and cancer: a double-edged sword

Abstract.: The highly conserved Notch signaling pathway plays pleiotropic roles during embryonic development and is important for the regulation of selfrenewing tissues. The physiological functions of this signaling cascade range from stem cell maintenance and influencing cell fate decisions of barely differentiated progenitor cells, to the induction of terminal differentiation processes, all of which have been found to be recapitulated in different forms of cancers. Although Notch signaling has mostly been associated with oncogenic and growth-promoting roles, depending on the tissue type it can also function as a tumor suppressor. Here we describe recent findings on Notch signaling in cancer and tumor angiogenesis, and highlight some of the therapeutic approaches that are currently being developed to interfere with tumor growth and progressio

Exchange Instabilities in Semiconductor Double Quantum Well Systems

We consider various exchange-driven electronic instabilities in semiconductor double-layer systems in the absence of any external magnetic field. We establish that there is no exchange-driven bilayer to monolayer charge transfer instability in the double-layer systems. We show that, within the unrestricted Hartree-Fock approximation, the low density stable phase (even in the absence of any interlayer tunneling) is a quantum ``pseudospin rotated'' spontaneous interlayer phase coherent spin-polarized symmetric state rather than the classical Ising-like charge-transfer phase. The U(1) symmetry of the double quantum well system is broken spontaneously at this low density quantum phase transition, and the layer density develops quantum fluctuations even in the absence of any interlayer tunneling. The phase diagram for the double quantum well system is calculated in the carrier density--layer separation space, and the possibility of experimentally observing various quantum phases is discussed. The situation in the presence of an external electric field is investigated in some detail using the spin-polarized-local-density-approximation-based self-consistent technique and good agreement with existing experimental results is obtained.Comment: 24 pages, figures included. Also available at http://www-cmg.physics.umd.edu/~lzheng/preprint/ct.uu/ . Revised final version to appear in PR

A cluster randomized controlled trial comparing the effectiveness of an individual planning intervention with collaborative planning in adolescent friendship dyads to enhance physical activity (TWOgether)

Abstract Background Most adolescents do not meet the recommendations for physical activity (PA) of at least 1 h per day. Individual planning (IP) interventions, including forming plans for when, where and how (action planning) to engage in a behavior, as well as the planning for how to deal with arising barriers (coping planning), are effective to enhance PA in adults. Collaborative planning (CP) is conjoint planning of two individuals regarding a behavior which is performed together. It is assumed that CP stimulates social exchange processes between the planning partners. However, it remains unclear whether planning interventions of PA in adolescents are successful and which planning intervention is more effective. Thus, this cluster randomized controlled trial (RCT) examines changes in daily moderate-to-vigorous PA in adolescents’ friendship dyads resulting from planning. Individual self-regulating mechanism and social exchange processes are proposed as mediating mechanisms of the effects of planning for health behavior change. Methods A single-blind four-arm parallel-group cluster-RCT is used. The sample consists of 400 friendship dyads between 14 and 18 years of age. As the recruitment takes place in schools, a cluster randomization of the schools is used to enroll dyads to (a) an IP intervention, (b) a CP intervention or (c) one of the two no-planning control conditions. Devise-measured and self-reported PA as the primary outcomes, self-regulatory strategies, and social exchange processes as secondary outcomes are assessed at three or four time points. After baseline measurement, the baseline ecological momentary assessment of the main variables takes place for 8 days followed by the intervention and a 7-days diary phase. Follow-ups are 1 month and 6 months later. Subsequent to the six-month follow-up, another 7-days diary phase takes place. Discussion This is the first study examining IP in comparison to CP in adolescents applying a single-blind cluster RCT. Consequently, the study allows for understanding the efficacy of individual and collaborative planning and the underlying mechanisms in adolescent dyads. Trial registration This RCT was funded by the Swiss National Science Foundation (100019_169781/1) and was registered on 18/06/2018 at ClinicalTrials.gov: NCT03575559

Modelling the Seasonal Growth of the Brown Seaweed Fucus Vesiculosus in the Kiel Outdoor Benthocosms

Warming and acidification of the oceans as a consequence of increasing CO2-concentrations occur globally. In mesocosm experiments, the single and combined impact of elevated seawater temperature and pCO2 (1,100 ppm) on the brown alga Fucus vesiculosus together with its ssociated community (epiphytes and mesograzers) was studied in four consecutive experiments (from April 2013 to April 2014). Based on these experiments, a numerical boxmodel simulating the seasonal growth of F. vesiculosus in the Kiel Outdoor Benthocosms (KOBs) was developed. Nitrogen and carbon cycling in the KOBs were considered and relevant physiological and ecological processes were implemented. To run simulations under present and global change scenarios (e.g. warming, ocean acidification) the model was forced with atmospheric and hydrographic data of the Kiel fjord. DIN and DIC concentration in the water and Fucus growth as carbon and nitrogen increase were explicitly modelled. For instance, the following processes were implemented: (1) Storage of carbon and nitrogen assimilates by Fucus, leading to a temporal decoupling of assimilation and growth. (2) Shading effects of epiphytes. (3) Grazing by Idotea, Gammarus and Littorina on both Fucus and epiphytes, but with species-specific rates and preferences. At present, the model is a suitable scientific tool capable of integrating our knowledge about macroalgal processes, their growth and productivity in coastal areas. It further facilitates the communication of complex knowledge to lay persons. Ultimately, the development of a predictive model, which can be coupled to a 3D-high resolution western Baltic Sea model, is anticipated. This will allow observations on the consequences of global change for the wellbeing and distribution of F. vesiculosus in the western Baltic Sea. Understanding responses of macroalgae and of the associated community is important because changing global temperatures and elevated CO2 may affect the ecological role of Fucus as primary producer, carbon sink, water purifier, and ecosystem engineer in the coastal ecosystem of the Baltic Sea

Transfer or Compensation? An experiment testing the effects of actual and imagined exercise on eating.

This study tested the effects of exercise on eating. The transfer hypothesis proposes that exercise leads to generalization of healthy behavior and therefore improved diet. The compensation hypothesis assumes that exercise leads to increased calorie intake to "compensate" for the energy expenditure. We tested these hypotheses both for actual and imagined exercise. Female University members (N=227) were randomized to three experimental groups: actual exercise vs. imagined exercise vs. control. After baseline, participants engaged in a 5-minute experimental task. Thereafter, they were left alone with unhealthy snacks. Participants who imagined themselves exercising (M=101, SD=128 kcal) consumed significantly fewer calories than controls (M=129, SD=142 kcal), consistent with a transfer effect. Participants who engaged in actual exercise but were distracted from thinking about exercise consumed similar quantities (M=127, SD=111 kcal) as controls. This study suggests that transfer effects are underpinned by psychological processes, such as goal activation, which should be investigated in the future

A multi-analytical approach to gold in Ancient Egypt: studies on provenance and corrosion

Recent results from a three-year multi-disciplinary project on Ancient Egyptian gold jewellery revealed that items of jewellery from the Middle Kingdom to the New Kingdom were manufactured using a variety of alluvial gold alloys. These alloys cover a wide range of colours and the majority contain Platinum Group Elements inclusions. However, in all the gold foils analysed, these inclusions were found to be absent. In this work a selection of gilded wood and leather items and gold foil fragments, all from the excavations by John Garstang at Abydos (primarily from Middle Kingdom graves), were examined using Scanning Electron Microscopy-Energy Disperse Spectroscopy (SEM-EDS), X-Ray Fluorescence (µXRF), Particle Induced X-Ray Emission (µPIXE) and Double Dispersive X-Ray Fluorescence (D2XRF). The work allowed us to characterise the composition of the base-alloys and also to reveal the presence of Pt at trace levels, confirming the use of alluvial gold deposits. Corrosion products were also investigated in the foils where surface tarnish was visually observed. Results showed that the differences in the colour of corrosion observed for the foils are related not only to the thickness of the corrosion layer but also to a multi-layer structure containing the various corrosion products

Investigation of short range structural order in Zr69.5Cu12Ni11Al7.5 and Zr41.5Ti41.5Ni17 glasses, using X ray absorption spectroscopy and ab initio molecular dynamics simulations

Short-range order has been investigated in Zr69.5Cu12Ni11Al7.5and Zr41.5Ti41.5Ni17metallic glasses using X-ray absorption spectroscopy andab initiomolecular dynamics simulations. While both of these alloys are good glass formers, there is a difference in their glass-forming abilities (Zr41.5Ti41.5Ni17&gt; Zr69.5Cu12Ni11Al7.5). This difference is explained by inciting the relative importance of strong chemical order, icosahedral content, cluster symmetry and configuration diversity.</jats:p