TY - CHAP A1 - Proeller, Isabella A1 - Siegel, John ED - Schedler, Kuno T1 - 'Tools' in public management BT - how efficiency and effectiveness are thought to be controlled T2 - Elgar encyclopedia of public management N2 - Tools are methods or procedures, and thus operational patterns of action, applied in public administrations to solve standard problems. It is also possible to consider them as structured communication according to professional standards aiming at complexity reduction. Regularly, tools in management stem on a deductive-synoptic rationale offering a seemingly ‘objective’ decision basis. They have a strong formative influence on the organization, regularly also beyond the intended effects. The prominence of tools is sometimes confused with management as such, e.g. introducing tools is mistaken as equivalent to managing for a particular purpose. However, tools have to be closely and carefully managed regarding the objectives and purposes they should serve. KW - cost cutting KW - instruments KW - methods KW - tools KW - zero-based budgeting Y1 - 2022 SN - 978-1-80037-548-2 SN - 978-1-80037-549-9 U6 - https://doi.org/10.4337/9781800375499.tools SP - 186 EP - 190 PB - Edward Elgar Publishing CY - Cheltenham ER - TY - JOUR A1 - Hamm, Maximilian A1 - Pelivan, Ivanka A1 - Grott, Matthias A1 - de Wiljes, Jana T1 - Thermophysical modelling and parameter estimation of small solar system bodies via data assimilation JF - Monthly notices of the Royal Astronomical Society N2 - Deriving thermophysical properties such as thermal inertia from thermal infrared observations provides useful insights into the structure of the surface material on planetary bodies. The estimation of these properties is usually done by fitting temperature variations calculated by thermophysical models to infrared observations. For multiple free model parameters, traditional methods such as least-squares fitting or Markov chain Monte Carlo methods become computationally too expensive. Consequently, the simultaneous estimation of several thermophysical parameters, together with their corresponding uncertainties and correlations, is often not computationally feasible and the analysis is usually reduced to fitting one or two parameters. Data assimilation (DA) methods have been shown to be robust while sufficiently accurate and computationally affordable even for a large number of parameters. This paper will introduce a standard sequential DA method, the ensemble square root filter, for thermophysical modelling of asteroid surfaces. This method is used to re-analyse infrared observations of the MARA instrument, which measured the diurnal temperature variation of a single boulder on the surface of near-Earth asteroid (162173) Ryugu. The thermal inertia is estimated to be 295 +/- 18 Jm(-2) K-1 s(-1/2), while all five free parameters of the initial analysis are varied and estimated simultaneously. Based on this thermal inertia estimate the thermal conductivity of the boulder is estimated to be between 0.07 and 0.12,Wm(-1) K-1 and the porosity to be between 0.30 and 0.52. For the first time in thermophysical parameter derivation, correlations and uncertainties of all free model parameters are incorporated in the estimation procedure that is more than 5000 times more efficient than a comparable parameter sweep. KW - radiation mechanisms: thermal KW - methods: data analysis KW - methods KW - statistical KW - minor planets, asteroids: individual: (162173) Ryugu Y1 - 2020 U6 - https://doi.org/10.1093/mnras/staa1755 SN - 0035-8711 SN - 1365-2966 VL - 496 IS - 3 SP - 2776 EP - 2785 PB - Oxford Univ. Press CY - Oxford ER - TY - JOUR A1 - Freitas da Cruz, Harry A1 - Pfahringer, Boris A1 - Martensen, Tom A1 - Schneider, Frederic A1 - Meyer, Alexander A1 - Böttinger, Erwin A1 - Schapranow, Matthieu-Patrick T1 - Using interpretability approaches to update "black-box" clinical prediction models BT - an external validation study in nephrology JF - Artificial intelligence in medicine : AIM N2 - Despite advances in machine learning-based clinical prediction models, only few of such models are actually deployed in clinical contexts. Among other reasons, this is due to a lack of validation studies. In this paper, we present and discuss the validation results of a machine learning model for the prediction of acute kidney injury in cardiac surgery patients initially developed on the MIMIC-III dataset when applied to an external cohort of an American research hospital. To help account for the performance differences observed, we utilized interpretability methods based on feature importance, which allowed experts to scrutinize model behavior both at the global and local level, making it possible to gain further insights into why it did not behave as expected on the validation cohort. The knowledge gleaned upon derivation can be potentially useful to assist model update during validation for more generalizable and simpler models. We argue that interpretability methods should be considered by practitioners as a further tool to help explain performance differences and inform model update in validation studies. KW - Clinical predictive modeling KW - Nephrology KW - Validation KW - Interpretability KW - methods Y1 - 2021 U6 - https://doi.org/10.1016/j.artmed.2020.101982 SN - 0933-3657 SN - 1873-2860 VL - 111 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Dineva, Ekaterina Ivanova A1 - Pearson, Jeniveve A1 - Ilyin, Ilya A1 - Verma, Meetu A1 - Diercke, Andrea A1 - Strassmeier, Klaus A1 - Denker, Carsten T1 - Characterization of chromospheric activity based on Sun-as-a-star spectral and disk-resolved activity indices JF - Astronomische Nachrichten = Astronomical notes N2 - The strong chromospheric absorption lines Ca ii H & K are tightly connected to stellar surface magnetic fields. Only for the Sun, spectral activity indices can be related to evolving magnetic features on the solar disk. The Solar Disk-Integrated (SDI) telescope feeds the Potsdam Echelle Polarimetric and Spectroscopic Instrument (PEPSI) of the Large Binocular Telescope (LBT) at Mt. Graham International Observatory, Arizona, U.S.A. We present high-resolution, high-fidelity spectra that were recorded on 184 & 82 days in 2018 & 2019 and derive the Ca ii H & K emission ratio, that is, the S-index. In addition, we compile excess brightness and area indices based on full-disk Ca ii K-line-core filtergrams of the Chromospheric Telescope (ChroTel) at Observatorio del Teide, Tenerife, Spain and full-disk ultraviolet (UV) 1600 angstrom images of the Atmospheric Imaging Assembly (AIA) onboard the Solar Dynamics Observatory (SDO). Thus, Sun-as-a-star spectral indices are related to their counterparts derived from resolved images of the solar chromosphere. All indices display signatures of rotational modulation, even during the very low magnetic activity in the minimum of Solar Cycle 24. Bringing together different types of activity indices has the potential to join disparate chromospheric datasets yielding a comprehensive description of chromospheric activity across many solar cycles. KW - astronomical databases KW - miscellaneous KW - methods KW - data analysis KW - activity KW - Sun KW - atmosphere KW - chromosphere KW - techniques KW - spectroscopic Y1 - 2022 U6 - https://doi.org/10.1002/asna.20223996 SN - 0004-6337 SN - 1521-3994 VL - 343 IS - 5 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Cvetković, Nada A1 - Conrad, Tim A1 - Lie, Han Cheng T1 - A convergent discretization method for transition path theory for diffusion processes JF - Multiscale modeling & simulation : a SIAM interdisciplinary journal N2 - Transition path theory (TPT) for diffusion processes is a framework for analyzing the transitions of multiscale ergodic diffusion processes between disjoint metastable subsets of state space. Most methods for applying TPT involve the construction of a Markov state model on a discretization of state space that approximates the underlying diffusion process. However, the assumption of Markovianity is difficult to verify in practice, and there are to date no known error bounds or convergence results for these methods. We propose a Monte Carlo method for approximating the forward committor, probability current, and streamlines from TPT for diffusion processes. Our method uses only sample trajectory data and partitions of state space based on Voronoi tessellations. It does not require the construction of a Markovian approximating process. We rigorously prove error bounds for the approximate TPT objects and use these bounds to show convergence to their exact counterparts in the limit of arbitrarily fine discretization. We illustrate some features of our method by application to a process that solves the Smoluchowski equation on a triple-well potential. KW - ergodic diffusion processes KW - transition paths KW - rare events KW - Monte Carlo KW - methods Y1 - 2021 U6 - https://doi.org/10.1137/20M1329354 SN - 1540-3459 SN - 1540-3467 VL - 19 IS - 1 SP - 242 EP - 266 PB - Society for Industrial and Applied Mathematics CY - Philadelphia ER - TY - THES A1 - Brandt-Kobele, Oda-Christina T1 - Comprehension of verb inflection in German-speaking children T1 - Das Verständnis von Verbflexionsendungen bei deutschsprachigen Kindern N2 - Previous studies on the acquisition of verb inflection in normally developing children have revealed an astonishing pattern: children use correctly inflected verbs in their own speech but fail to make use of verb inflections when comprehending sentences uttered by others. Thus, a three-year old might well be able to say something like ‘The cat sleeps on the bed’, but fails to understand that the same sentence, when uttered by another person, refers to only one sleeping cat but not more than one. The previous studies that have examined children's comprehension of verb inflections have employed a variant of a picture selection task in which the child was asked to explicitly indicate (via pointing) what semantic meaning she had inferred from the test sentence. Recent research on other linguistic structures, such as pronouns or focus particles, has indicated that earlier comprehension abilities can be found when methods are used that do not require an explicit reaction, like preferential looking tasks. This dissertation aimed to examine whether children are truly not able to understand the connection the the verb form and the meaning of the sentence subject until the age of five years or whether earlier comprehension can be found when a different measure, preferential looking, is used. Additionally, children's processing of subject-verb agreement violations was examined. The three experiments of this thesis that examined children's comprehension of verb inflections revealed the following: German-speaking three- to four-year old children looked more to a picture showing one actor when hearing a sentence with a singular inflected verb but only when their eye gaze was tracked and they did not have to perform a picture selection task. When they were asked to point to the matching picture, they performed at chance-level. This pattern indicates asymmetries in children's language performance even within the receptive modality. The fourth experiment examined sensitivity to subject-verb agreement violations and did not reveal evidence for sensitivity toward agreement violations in three- and four-year old children, but only found that children's looking patterns were influenced by the grammatical violations at the age of five. The results from these experiments are discussed in relation to the existence of a production-comprehension asymmetry in the use of verb inflections and children's underlying grammatical knowledge. N2 - Experimentelle Studien zum Erwerb der Verbflexion bei sprachunauffälligen Kindern haben ein überraschendes Muster aufgezeigt. Kinder im Alter von drei und vier Jahren verwenden Verbflexionsendungen anscheinend korrekt in ihrer eigenen Sprachproduktion, aber sie scheinen unfähig zu sein, Verbflexionen in den Äußerungen anderer zu verstehen. Ein Kind ist also problemlos in der Lage “Sie schläft auf dem Bett.” zu sagen, wenn es die Position von z. B. einer Katze beschreiben möchte. Gleichzeitig scheint es nicht zu verstehen, dass sich ein Satz wie “Sie schläft auf dem Bett” auf nur eine schlafende Katze und nicht mehrere bezieht. Das Verständnis von Sätzen, in denen der einzige Hinweis auf die Anzahl der Handelnden (den Numerus des Subjekts) die Verbflexion ist, wurde bislang nur mit ‘Zeige-Experimenten’ untersucht. In solchen Sprachtests soll das Kind durch eine Zeigegeste auf eines von zwei vorgegebenen Bildern explizit anzeigen wie es den vorgegebenen Satz verstanden hat. Aktuelle Studien, die das Verständnis von sprachlichen Elementen wie Pronomen und Fokuspartikeln bei Kindern untersucht haben, lassen erkennen, dass die Testmethodik einen erheblichen Einfluss auf die kindlichen Sprachverständnisfähigkeiten zu haben scheint. Wenn man Methoden verwendet, die keine explizite Reaktion von Seiten der Kinder verlangen, findet man korrektes Verständnis schon bei jüngeren Kindern. Das Ziel dieser Dissertation war es zu untersuchen, ob drei- und vierjährige Kinder tatsächlich nicht in der Lage sind die Beziehung zwischen Verbform (Art der Verbflexion) und Subjektbedeutung (Numerus des Subjekts) zu verstehen oder ob man korrektes Sprachverständnis in jüngeren Populationen finden kann, wenn eine alternative Testmethode, die Messung der Augenbewegungen, verwendet wird. Zusätzlich wurde untersucht ob Kinder im gleichen Alter Verletzungen der Subjekt-Verb-Kongruenz in auditiv präsentierten Sätzen entdecken. Drei Experimente dieser Dissertation, die das kindliche Sprachverständnis in Bezug auf Verbflexion untersucht haben bringen folgendes Muster zum Vorschein: Deutsch-sprachige Kinder im Alter von drei bis vier Jahren schauten mehr zu einem Bild, auf dem nur ein Akteur zu sehen war, wenn sie einen Satz mit einem singular flektierten Verb hörten (Sie streichelt eine Katze). Andererseits schauten sie mehr zu einem Bild, auf dem zwei Akteure zu sehen waren, wenn sie einen Satz mit einem plural flektierten Verb hörten (Sie streicheln eine Katze). Wenn sie hingegen gebeten wurden, auf das korrekte Bild zu zeigen, reagierten sie nicht besser als es der Zufall erwartet hätte, d.h.~sie waren nicht in der Lage einen Satz einem entsprechenden Bild zuzuordnen. Dieses Ergebnismuster deutet auf die Existenz von (methoden-abhängigen) Asymmetrien innerhalb einer sprachlichen Modalität, dem Sprach\-verständnis, hin. Das vierte Experiment untersuchte die kindliche Sensitivität gegenüber der Verletzung von Subjekt-Verb-Kongruenz. Hier zeigte sich, dass das Blickverhalten von fünfjährigen Kindern von der Grammatikalität der Testsätze beeinflusst war, während keine Evidenz für das Erkennen von Grammatikalitätsverletzungen bei jüngeren Kindern gefunden werden konnte. Das asymmetrische Performanzmuster innerhalb der rezeptiven Modalität, das in dieser Arbeit gefunden wurde, erlaubt Rückschlüsse auf die Annahme einer Produktions-Verständnis-Aymmetrie und somit auch auf Theorien zur grammatischen Entwicklung bei Kindern. T3 - Spektrum Patholinguistik - Schriften - 6 KW - Spracherwerb KW - Verbflexion KW - Blickbewegungsmessung KW - Methoden KW - Sprachverständnis KW - Language acquisition KW - verb inflection KW - eye-tracking KW - methods KW - language comprehension Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-62046 SN - 978-3-86956-216-2 SN - 1869-3822 SN - 1869-3830 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Brand, Ralf A1 - Nosrat, Sanaz A1 - Späth, Constantin A1 - Timme, Sinika T1 - Using COVID-19 Pandemic as a Prism: A Systematic Review of Methodological Approaches and the Quality of Empirical Studies on Physical Activity Behavior Change JF - Frontiers in Sports and Active Living N2 - Background: The COVID-19 pandemic has highlighted the importance of scientific endeavors. The goal of this systematic review is to evaluate the quality of the research on physical activity (PA) behavior change and its potential to contribute to policy-making processes in the early days of COVID-19 related restrictions. Methods: We conducted a systematic review of methodological quality of current research according to PRISMA guidelines using Pubmed and Web of Science, of articles on PA behavior change that were published within 365 days after COVID-19 was declared a pandemic by the World Health Organization (WHO). Items from the JBI checklist and the AXIS tool were used for additional risk of bias assessment. Evidence mapping is used for better visualization of the main results. Conclusions about the significance of published articles are based on hypotheses on PA behavior change in the light of the COVID-19 pandemic. Results: Among the 1,903 identified articles, there were 36% opinion pieces, 53% empirical studies, and 9% reviews. Of the 332 studies included in the systematic review, 213 used self-report measures to recollect prepandemic behavior in often small convenience samples. Most focused changes in PA volume, whereas changes in PA types were rarely measured. The majority had methodological reporting flaws. Few had very large samples with objective measures using repeated measure design (pre and during the pandemic). In addition to the expected decline in PA duration, these studies show that many of those who were active prepandemic, continued to be active during the pandemic. Conclusions: Research responded quickly at the onset of the pandemic. However, most of the studies lacked robust methodology, and PA behavior change data lacked the accuracy needed to guide policy makers. To improve the field, we propose the implementation of longitudinal cohort studies by larger organizations such as WHO to ease access to data on PA behavior, and suggest those institutions set clear standards for this research. Researchers need to ensure a better fit between the measurement method and the construct being measured, and use both objective and subjective measures where appropriate to complement each other and provide a comprehensive picture of PA behavior. KW - meta-science KW - exercise KW - methods KW - quality KW - study designs KW - standards Y1 - 2022 U6 - https://doi.org/10.3389/fspor.2022.864468 SN - 2624-9367 VL - 4 SP - 1 EP - 17 PB - Frontiers CY - Lausanne, Schweiz ER - TY - GEN A1 - Brand, Ralf A1 - Nosrat, Sanaz A1 - Späth, Constantin A1 - Timme, Sinika T1 - Using COVID-19 Pandemic as a Prism: A Systematic Review of Methodological Approaches and the Quality of Empirical Studies on Physical Activity Behavior Change T2 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe N2 - Background: The COVID-19 pandemic has highlighted the importance of scientific endeavors. The goal of this systematic review is to evaluate the quality of the research on physical activity (PA) behavior change and its potential to contribute to policy-making processes in the early days of COVID-19 related restrictions. Methods: We conducted a systematic review of methodological quality of current research according to PRISMA guidelines using Pubmed and Web of Science, of articles on PA behavior change that were published within 365 days after COVID-19 was declared a pandemic by the World Health Organization (WHO). Items from the JBI checklist and the AXIS tool were used for additional risk of bias assessment. Evidence mapping is used for better visualization of the main results. Conclusions about the significance of published articles are based on hypotheses on PA behavior change in the light of the COVID-19 pandemic. Results: Among the 1,903 identified articles, there were 36% opinion pieces, 53% empirical studies, and 9% reviews. Of the 332 studies included in the systematic review, 213 used self-report measures to recollect prepandemic behavior in often small convenience samples. Most focused changes in PA volume, whereas changes in PA types were rarely measured. The majority had methodological reporting flaws. Few had very large samples with objective measures using repeated measure design (pre and during the pandemic). In addition to the expected decline in PA duration, these studies show that many of those who were active prepandemic, continued to be active during the pandemic. Conclusions: Research responded quickly at the onset of the pandemic. However, most of the studies lacked robust methodology, and PA behavior change data lacked the accuracy needed to guide policy makers. To improve the field, we propose the implementation of longitudinal cohort studies by larger organizations such as WHO to ease access to data on PA behavior, and suggest those institutions set clear standards for this research. Researchers need to ensure a better fit between the measurement method and the construct being measured, and use both objective and subjective measures where appropriate to complement each other and provide a comprehensive picture of PA behavior. T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 790 KW - meta-science KW - exercise KW - methods KW - quality KW - study designs KW - standards Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-563625 SN - 1866-8364 SP - 1 EP - 17 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Beisner, Beatrix E. A1 - Grossart, Hans-Peter A1 - Gasol, Josep M. T1 - A guide to methods for estimating phago-mixotrophy in nanophytoplankton JF - Journal of plankton research N2 - Growing attention to phytoplankton mixotrophy as a trophic strategy has led to significant revisions of traditional pelagic food web models and ecosystem functioning. Although some empirical estimates of mixotrophy do exist, a much broader set of in situ measurements are required to (i) identify which organisms are acting as mixotrophs in real time and to (ii) assess the contribution of their heterotrophy to biogeochemical cycling. Estimates are needed through time and across space to evaluate which environmental conditions or habitats favour mixotrophy: conditions still largely unknown. We review methodologies currently available to plankton ecologists to undertake estimates of plankton mixotrophy, in particular nanophytoplankton phago-mixotrophy. Methods are based largely on fluorescent or isotopic tracers, but also take advantage of genomics to identify phylotypes and function. We also suggest novel methods on the cusp of use for phago-mixotrophy assessment, including single-cell measurements improving our capacity to estimate mixotrophic activity and rates in wild plankton communities down to the single-cell level. Future methods will benefit from advances in nanotechnology, micromanipulation and microscopy combined with stable isotope and genomic methodologies. Improved estimates of mixotrophy will enable more reliable models to predict changes in food web structure and biogeochemical flows in a rapidly changing world. KW - flow cytometry KW - phagotrophy KW - phytoplankton KW - methods KW - fluorescence KW - microscopy KW - FISH KW - isotopic methods KW - phylotypes KW - carbon flows KW - gene sequencing Y1 - 2019 U6 - https://doi.org/10.1093/plankt/fbz008 SN - 0142-7873 SN - 1464-3774 VL - 41 IS - 2 SP - 77 EP - 89 PB - Oxford Univ. Press CY - Oxford ER -