Money-based interest rate rules: lessons from German data

The paper derives the monetary policy reaction function implied by money growth targeting. It consists of an interest rate response to deviations of the inflation rate from target, to the change in the output gap, to money demand shocks and to the lagged interest rate. In the second part, it is shown that this type of inertial interest rate rule characterises the Bundesbank's monetary policy from 1979 to 1998 quite well. This result is robust to the use of real-time or ex post data and to the consideration of serially correlated errors. The main lesson is that, in addition to anchoring long-term inflation expectations, monetary targeting introduces inertia and history-dependence into the monetary policy rule. This is advantageous when private agents have forward-looking expectations and when the level of the output gap is subject to persistent measurement errors. --Monetary policy,Taylor rule,money growth targets,history dependence

Increasing the Interactivity in Software Engineering MOOCs - A Case Study

MOOCs differ from traditional university courses: instructors do not know the learners who have a diverse background and cannot talk to them in person due to the worldwide distribution. This has a decisive influence on the interactivity of teaching and the learning success in online courses. While typical online exercises such as multiple choice quizzes are interactive, they only stimulate basic cognitive skills and do not reflect software engineering working practices such as programming or testing. However, the application of knowledge in practical and realistic exercises is especially important in software engineering education. In this paper, we present an approach to increase the interactivity in software engineering MOOCs. Our interactive learning approach focuses on a variety of practical and realistic exercises, such as analyzing, designing, modeling, programming, testing, and delivering software stimulating all cognitive skills. Semi-automatic feedback provides guidance and allows reflection on the learned theory. We applied this approach in the MOOC software engineering essentials SEECx on the edX platform. Since the beginning of the course, more than 15,000 learners from more than 160 countries have enrolled. We describe the design of the course and explain how its interactivity affects the learning success

PYRO-NN: Python Reconstruction Operators in Neural Networks

Purpose: Recently, several attempts were conducted to transfer deep learning to medical image reconstruction. An increasingly number of publications follow the concept of embedding the CT reconstruction as a known operator into a neural network. However, most of the approaches presented lack an efficient CT reconstruction framework fully integrated into deep learning environments. As a result, many approaches are forced to use workarounds for mathematically unambiguously solvable problems. Methods: PYRO-NN is a generalized framework to embed known operators into the prevalent deep learning framework Tensorflow. The current status includes state-of-the-art parallel-, fan- and cone-beam projectors and back-projectors accelerated with CUDA provided as Tensorflow layers. On top, the framework provides a high level Python API to conduct FBP and iterative reconstruction experiments with data from real CT systems. Results: The framework provides all necessary algorithms and tools to design end-to-end neural network pipelines with integrated CT reconstruction algorithms. The high level Python API allows a simple use of the layers as known from Tensorflow. To demonstrate the capabilities of the layers, the framework comes with three baseline experiments showing a cone-beam short scan FDK reconstruction, a CT reconstruction filter learning setup, and a TV regularized iterative reconstruction. All algorithms and tools are referenced to a scientific publication and are compared to existing non deep learning reconstruction frameworks. The framework is available as open-source software at \url{https://github.com/csyben/PYRO-NN}. Conclusions: PYRO-NN comes with the prevalent deep learning framework Tensorflow and allows to setup end-to-end trainable neural networks in the medical image reconstruction context. We believe that the framework will be a step towards reproducible researchComment: V1: Submitted to Medical Physics, 11 pages, 7 figure

Effects of different acute stressors on the regulation of appetite genes in the carp (Cyprinus carpio L.) brain

Our understanding of the timing of stress responses and specific roles of different regulatory pathways that drive stress responses is incomplete. In particular, the regulation of appetite genes as a consequence of exposure to different stressors has not been studied in sufficient detail in fish. Therefore, a stress trial was conducted with koi carp, aiming at identifying typical effects of stress on regulation of appetite genes. The stressors tank manipulation, air exposure and feed rewarding were chosen. The responses to these stressors were evaluated 10, 30 and 60 min after the stressors were applied. Orexigenic and anorexigenic genes were investigated in four different brain regions (telencephalon, hypothalamus, optic tectum and rhombencephalon). The results show that, apart from the typical appetite regulation in the hypothalamus, the different brain regions also display pronounced responses of appetite genes to the different stressors. In addition, several genes in the serotonergic, dopaminergic and gaba-related pathways were investigated. These genes revealed that rearing in pairs of two and opening of the tank lid affected anorexigenic genes, such as cart and cck, which were not changed by air exposure or feed rewarding. Moreover, distress and eustress led to limited, but distinguishable gene expression pattern changes in the investigated brain regions

Effect of feeding regime and light intensity on size heterogeneity, fin damage and growth performance of juvenile European perch (Perca fluviatilis) in aquaculture

Light and feeding regime are among the key factors that determine growth of farmed fish. Light is known to affect behaviour, which then, in turn can be matched with an adequate feeding regime to obtain best growth performance. A better understanding of the interplay between these two factors is of great interest to commercial perch farms due to the lack of information and the need to improve production efficiency. Here, we evaluated for the first time the combined effects of the factors light intensity and feeding regime (compromise between lower and upper levels currently applied in perch farms) on size heterogeneity, fin damage and growth performance of European perch, Perca fluviatilis. Two light intensities (15 lux and 100 lux) and three feeding regimes (5 and 24 feeding events per day and self-feeders) were applied in a factorial design with a four-fold replication of groups of 80 fish (initial body weight was 8.6 ± 1.7 g) that were reared for 42 days in a recirculating system. A light intensity of 15 lux improved growth and feed conversion when fish were fed with self-feeders. Size heterogeneity (CV) in all groups increased during the study with a tendency for lower CV in groups with 24 feeding events. No sexual growth dimorphism occurred, which, thus, did not influence size heterogeneity. Mortality and fin damage were low and were not affected by light intensity or feeding regime. Our results indicate that already marginal changes in light intensity alter the behaviour of perch when environmental factors permit fish to express their feeding preferences. The results contribute to the improvement of rearing conditions and production efficiency of commercial perch farms.Licht und Fütterungsregime gehören zu den Hauptfaktoren, die über das Wachstum von Zuchtfischen bestimmen. Es ist bekannt, dass Licht das Verhalten beeinflusst, welches dann mit einem angemessenen Fütterungsregime abgestimmt werden kann, um die beste Wachstumsleistung zu erzielen. Ein besseres Verständnis über das Zusammenspiel dieser beiden Faktoren ist für kommerzielle Barschfarmen von grossem Interesse, da es derzeit keine Informationen dazu gibt und die Notwendigkeit besteht, die Produktionseffizienz zu verbessern. Hier haben wir zum ersten Mal die kombinierten Auswirkungen der Faktoren Lichtintensität und Fütterungsregime (die Levels stellen ein Kompromiss zwischen dem unteren und oberen Niveau dar, das derzeit in Barschfarmen angewendet wird) auf die Grössenheterogenität, Flossenschäden und Wachstumsleistung des Flussbarschs, Perca fluviatilis, untersucht. In einem faktoriellen Design wurden zwei Lichtintensitäten (15 Lux und 100 Lux) und drei Fütterungsregime (5 und 24 Fütterungen pro Tag und Self-Feeder) angewendet. Die Gruppen, bestehend aus 80 Fischen (das anfängliche Körpergewicht betrug 8.6 ± 1.7 g), die während 42 Tagen in einem Kreislaufsystem gehalten wurden, wurden vierfach repliziert. Eine Lichtintensität von 15 Lux verbesserte das Wachstum und die Futterverwertung von Fischen, die mit Self-Feedern gefüttert wurden. Während der Studie nahm die Grössenheterogenität (CV) in allen Gruppen zu. Es zeigte sich aber eine Tendenz zu einem geringeren CV in den Gruppen, die 24 Fütterungen erhielten. Da kein sexueller Wachstumsdimorphismus auftrat, wurde die Grössenheterogenität dadurch nicht beeinflusst. Die Mortalität und die Flossenschäden waren gering und beide wurden weder durch die Lichtintensität noch durch das Fütterungsregime beeinflusst. Unsere Ergebnisse deuten darauf hin, dass bereits marginale Änderungen in der Lichtintensität das Verhalten von Barschen verändert, wenn es die Umweltfaktoren zulassen, dass die Fische ihre Fresspräferenzen auszudrücken können. Die Ergebnisse tragen zur Verbesserung der Haltungsbedingungen und der Produktionseffizienz von kommerziellen Barschzuchten bei

Einfluss von Mikroalgen-Fütterung auf das Wachstum und die Gesundheit von Tilapia (Oreochromis niloticus)

In aquaculture, different influences can affect the health of the fish. Histopathology is suitable to determine the fish’s health. Both the liver and the spleen fulfill essential functions in fish and can serve as indicator organs for fish health assessment. In the spleen, an important lymphatic organ, macrophage aggregates (MAs) occur. The frequency, as well as the conditions of the liver structure, react to various influences and fish farming conditions. The work presented examines the health of juvenile tilapia (Oreochromis niloticus) during a 9-week feeding trial. They were fed two feeds containing microalgae (Nanno/Porph and Iso/Nanno) as well as a control feed. This is done by means of a digital evaluation of histological preparations of the liver and the spleen. The obtained results are then compared with further data obtained from the feeding trial.In Aquakulturen können verschiedenste Einflüsse die Fischgesundheit beeinträchtigen, wobei sich die Histopathologie dazu eignet, den Gesundheitszustand von Fischen zu eruieren. Die Leber und die Milz erfüllen beide wichtige Funktionen in Fischen und können als Indikatororgane zur Erfassung der Fischgesundheit dienen. In der Milz, als wichtiges lymphatisches Organ, kommen Makrophagen-Aggregate (MAs) vor. Ihre Häufigkeit, ebenso wie der Zustand der Leberstruktur, reagieren auf verschiedenste Einflüsse und Haltungszustände. In der vorliegenden Arbeit soll der Gesundheitszustand von juvenilen Tilapias (Oreochromis niloticus), denen innerhalb eines 9-wöchigen Fütterungsexperiments zwei mikroalgenhaltige Futtermittel (Nanno/Porph und Iso/Nanno), sowie ein Kontrollfutter gefüttert wurde, erhoben werden. Dies geschieht anhand einer digitalen Auswertung von histologischen Präparaten der Leber und der Milz. Diese Resultate werden weiterhin mit weiteren Daten des Fütterungsexperiments verglichen

Mathematics Teachers Assess Instructional Methods Supporting Knowledge Processes

Answers to the questions of which instructional methods are suitable for school, what instructional methods should be applied in teaching individual subjects and how instructional methods support the act of learning represent challenges to general education and education in individual subjects. This article focuses on the empirical examination of instructional methods supporting knowledge processes in the act of learning. A survey was conducted in which mathematics teachers evaluated 20 instructional methods in regard to the following knowledge processes: build, process, apply, transfer, assess and integrate. The results of the study demonstrate that certain instructional methods are especially predestined for mathematics education: problem-based learning, direct instruction, learning at stations, learning tasks, project work and discovery learnin

Differential effects of acute eustress and distress on gene regulation patterns in the carp (Cyprinus carpio L.) brain

The activities of certain genes as a consequence of exposure to stressors related to typical handling procedures in aquaculture have not been studied in sufficient detail in fish. A stress trial with koi carp was, therefore, conducted, aiming at identifying relevant gene expression patterns in different brain regions during stress responses. The following stressors were selected: tank manipulation, distress caused by exposure to air and eustress due to feed rewards. Responses to these stressors were evaluated 10, 30 and 60 min after their application. The exact determination of gene expression profiles in the carp brain required the comparison of several suitable reference genes, which is also highly recommended for other studies focusing on the fish brain. Moreover, and as expected, the mRNA expression of a number of early immediate genes indicated activity in different brain regions as a response to changes in rearing and experimental conditions. In addition, the mRNA expression of metabolic genes was investigated, since increased brain activity may also increase the metabolic demands of certain brain areas. Furthermore, genes related to the stress axis were included in the study. The mRNA expression patterns of genes belonging to the stress axis revealed that negative stress caused by exposure to air had broad- ranging effects on the gene regulation patterns in the fish brain, even if the fish were only treated for 1 min. This parallels the effects that have been observed on blood cortisol and glucose. In contrast, a limited number of genes allows discrimination of eustress and distress, which indicates that further research is needed in the future. Finally, the use of different control groups is highly recommended for fish experiments to correct for typical experimental procedures such as lid openings or social isolation

Cross-Inhibition of Norrin and TGF-beta Signaling Modulates Development of Retinal and Choroidal Vasculature

PURPOSE. Norrin is essential for the formation of the retinal vasculature during development and promotes its repair after damage via activation of Wnt/beta-catenin signaling. Since retinal TGF-beta signaling has essentially opposite effects on the retinal vasculature we investigated if and how Norrin inhibits TGF-beta signaling, and vice versa. METHODS. Eyes from transgenic mice with an overexpression of Norrin (beta Bl-Norrin) and/or active TGF-beta (beta B1-TGF-beta 1) in the lens were generated and analyzed by light microscopy, immunohistochemistry, and TUNEL. Further on, protein as well as mRNA levels were investigated by Western blot analyses and real-time RT-PCR, respectively. RESULTS. In beta B1-TGF-beta l mice, the lack of retinal vascular development and choriocapillaris maintenance was rescued when transgenic Norrin was additionally overexpressed in the eye. In addition, retinal Wnt/beta-catenin signaling and the levels of SMAD7, an inhibitor of the canonical TGF-beta pathway, were substantially suppressed in retinae of beta B1-TGF-beta 1 mice. In contrast, Norrin normalized Wnt/beta-catenin signaling and SMAD7 levels in double transgenic mice. Moreover, in retinae of beta B1-TGF-beta 1 mice, the amounts of phosphorylated SMAD3, a downstream mediator of TGF-beta signaling, were increased compared to those of beta B1-Norrin/ beta B1-TGF-beta 1 mice. In vitro, Norrin substantially reduced the TGF-beta-mediated induction of target genes, an effect that was blocked by Dickkopf-1, a specific inhibitor of Wnt/beta-catenin signaling. CONCULSIONS. High amounts of TGF-beta in the eye cause a substantial reduction in the activity of Wnt/beta-catenin signaling. This effect is inhibited in the presence of high amounts of Norrin, which further induce the expression of SMAD7 to inhibit TGF-beta signaling