Data-driven Distributionally Robust Optimization over Time

Stochastic Optimization (SO) is a classical approach for optimization under uncertainty that typically requires knowledge about the probability distribution of uncertain parameters. As the latter is often unknown, Distributionally Robust Optimization (DRO) provides a strong alternative that determines the best guaranteed solution over a set of distributions (ambiguity set). In this work, we present an approach for DRO over time that uses online learning and scenario observations arriving as a data stream to learn more about the uncertainty. Our robust solutions adapt over time and reduce the cost of protection with shrinking ambiguity. For various kinds of ambiguity sets, the robust solutions converge to the SO solution. Our algorithm achieves the optimization and learning goals without solving the DRO problem exactly at any step. We also provide a regret bound for the quality of the online strategy which converges at a rate of $\mathcal{O}(\log T / \sqrt{T})$, where $T$ is the number of iterations. Furthermore, we illustrate the effectiveness of our procedure by numerical experiments on mixed-integer optimization instances from popular benchmark libraries and give practical examples stemming from telecommunications and routing. Our algorithm is able to solve the DRO over time problem significantly faster than standard reformulations

The function of tcf3 in medaka embryos: efficient knockdown with pePNAs

Background: The application of antisense molecules, such as morpholino oligonucleotides, is an efficient method of gene inactivation in vivo. We recently introduced phosphonic ester modified peptide nucleic acids (PNA) for in vivo loss-of-function experiments in medaka embryos. Here we tested novel modifications of the PNA backbone to knockdown the medaka tcf3 gene. Results: A single tcf3 gene exists in the medaka genome and its inactivation strongly affected eye development of the embryos, leading to size reduction and anophthalmia in severe cases. The function of Tcf3 strongly depends on co-repressor interactions. We found interactions with Groucho/Tle proteins to be most important for eye development. Using a dominant negative approach for combined inactivation of all groucho/tle genes also resulted in eye phenotypes, as did interference with three individual tle genes. Conclusions: Our results show that side chain modified PNAs come close to the knockdown efficiency of morpholino oligonucleotides in vivo. A single medaka tcf3 gene combines the function of the two zebrafish paralogs hdl and tcf3b. In combination with Groucho/Tle corepressor proteins Tcf3 acts in anterior development and is critical for eye formation

Kooperativer Bericht vom 7. Deutschen Bibliothekskongress: „Bibliotheken verändern“ (Leipzig, 18.–21. März 2019)

Der 7. Deutsche Bibliothekskongress hat von 18. bis 21. März 2019 in Leipzig stattgefunden. Das Motto der Konferenz, an der über 4.000 Personen (darunter 95 aus Österreich) teilgenommen haben, lautete „Bibliotheken verändern“. Im vorliegenden kooperativen Bericht werden folgende Themen behandelt: Förderprogramm Fachinformationsdienste für die Wissenschaft, Langzeitarchivierung, Repositorien, Forschungsdaten und Forschungsdatenmanagement, Open Access, NS-Provenienzforschung, Qualitätsmanagement und Barrierefreiheit

Cooperative report of the 7th German Librarians’ Congress: „Libraries For Change“ (Leipzig, March 18-21, 2019)

Der 7. Deutsche Bibliothekskongress hat von 18. bis 21. März 2019 in Leipzig stattgefunden. Das Motto der Konferenz, an der über 4.000 Personen (darunter 95 aus Österreich) teilgenommen haben, lautete „Bibliotheken verändern“. Im vorliegenden kooperativen Bericht werden folgende Themen behandelt: Förderprogramm Fachinformationsdienste für die Wissenschaft, Langzeitarchivierung, Repositorien, Forschungsdaten und Forschungsdatenmanagement, Open Access, NS-Provenienzforschung, Qualitätsmanagement und Barrierefreiheit.The 7th German Librarians’ Congress took place from 18 to 21 March 2019 in Leipzig. The motto of the conference, which was attended by more than 4.000 people (including 95 from Austria), was „Libraries for change“. This cooperative report covers the following topics: Specialised Information Services programme, long-term archiving, repositories, research data and research data management, open access, NS provenance research, quality management and accessibility

Direct Potential Modulation of Neurogenic Differentiation Markers by Granulocyte-Colony Stimulating Factor (G-CSF) in the Rodent Brain

The hematopoietic granulocyte-colony stimulating growth factor (G-CSF, filgrastim) is an approved drug in hematology and oncology. Filgrastim’s potential in neurodegenerative disorders is gaining increasingly more attention, as preclinical and early clinical studies suggest it could be a promising treatment option. G-CSF has had a tremendous record as a safe drug for more than three decades; however, its effects upon the central nervous system (CNS) are still not fully understood. In contrast to conceptual long-term clinical application with lower dosing, our present pilot study intends to give a first insight into the molecular effects of a single subcutaneous (s.c.) high-dose G-CSF application upon different regions of the rodent brain. We analyzed mRNA—and in some instances—protein data of neurogenic and non-neurogenic differentiation markers in different regions of rat brains five days after G-CSF (1.3 mg/kg) or physiological saline. We found a continuous downregulation of several markers in most brain regions. Remarkably, cerebellum and hypothalamus showed an upregulation of different markers. In conclusion, our study reveals minor suppressive or stimulatory effects of a single exceptional high G-CSF dose upon neurogenic and non-neurogenic differentiation markers in relevant brain regions, excluding unregulated responses or unexpected patterns of marker expression

Strengthening of Reinforced Concrete Beams with Externally Mounted Sequentially Activated Iron-Based Shape Memory Alloys

Iron based shape memory alloys (Fe-SMA) have recently been used as active flexural strengthening material for reinforced concrete (RC) beams. Fe-SMAs are characterized by a shape memory effect (SME) which allows the recovery of previously induced plastic deformations through heating. If these deformations are restrained a recovery stress is generated by the SME. This recovery stress can be used to prestress a SMA applied as a strengthening material. This paper investigates the performance and the load deformation behavior of RC beams strengthened with mechanical end anchored unbonded Fe-SMA strips activated by sequentially infrared heating. The performance of a single loop loaded and a double loop loaded SMA strengthened RC beam are compared to an un-strengthened beam and a reference beam strengthened with commercially available structural steel. In these tests the SMA strengthened beam had the highest cracking load and the highest ultimate load. It is shown that the serviceability behavior of a concrete beam can be improved by a second thermal activation. The sequential heating procedure causes different temperature and stress states during activation along the SMA strip that have not been researched previously. The possible effect of this different temperature and stress states on metal lattice phase transformation is modeled and discussed. Moreover the role of the martensitic transformation during the cooling process on leveling the inhomogeneity of phase state in the overheated section is pointed out

Absorption Imaging of Ultracold Atoms on Atom Chips

Imaging ultracold atomic gases close to surfaces is an important tool for the detailed analysis of experiments carried out using atom chips. We describe the critical factors that need be considered, especially when the imaging beam is purposely reflected from the surface. In particular we present methods to measure the atom-surface distance, which is a prerequisite for magnetic field imaging and studies of atom surface-interactions.Comment: 12 pages, 8 figures. v2 contains updated figures, modifications to tex