Not going anywhere? Migration as a social practice in the early Neolithic Linearbandkeramik

Under embargo until: 2022-04-15This paper argues that personal and group migration (as a subset of mobility) was a central feature of Linearbandkeramik (c. 5500-4900 cal BC) life, and not confined to short-term events along the agricultural frontier. The first part summarises the data currently available on individual migration (mostly interpreted as female exogamy) and the migration of households or groups of households. It is noted that in current models, migratory behaviour is often seen as pertaining to lower-status groups or that it constitutes a crisis response. In the second part of the paper, I outline the evidence, both isotopic and archaeological, for migration as a constant behaviour and show where this has opened up avenues for new research, notably concerning the use of non-loess areas. In turn, narratives suggesting an increase in hierarchical differences throughout the LBK as a whole are challenged. It is argued that migration was an accepted social strategy that could be used to gain status, and counteracted the creation of hereditary and durable social stratification in established settlement sites. Seeing migration as a constant in LBK life can thus lead to a reinterpretation of other aspects of this early farming society.acceptedVersio

Learning vector quantization for proximity data

Hofmann D. Learning vector quantization for proximity data. Bielefeld: Universität Bielefeld; 2016.Prototype-based classifiers such as learning vector quantization (LVQ) often display intuitive and flexible classification and learning rules. However, classical techniques are restricted to vectorial data only, and hence not suited for more complex data structures. Therefore, a few extensions of diverse LVQ variants to more general data which are characterized based on pairwise similarities or dissimilarities only have been proposed recently in the literature. In this contribution, we propose a novel extension of LVQ to similarity data which is based on the kernelization of an underlying probabilistic model: kernel robust soft LVQ (KRSLVQ). Relying on the notion of a pseudo-Euclidean embedding of proximity data, we put this specific approach as well as existing alternatives into a general framework which characterizes different fundamental possibilities how to extend LVQ towards proximity data: the main characteristics are given by the choice of the cost function, the interface to the data in terms of similarities or dissimilarities, and the way in which optimization takes place. In particular the latter strategy highlights the difference of popular kernel approaches versus so-called relational approaches. While KRSLVQ and alternatives lead to state of the art results, these extensions have two drawbacks as compared to their vectorial counterparts: (i) a quadratic training complexity is encountered due to the dependency of the methods on the full proximity matrix; (ii) prototypes are no longer given by vectors but they are represented in terms of an implicit linear combination of data, i.e. interpretability of the prototypes is lost. We investigate different techniques to deal with these challenges: We consider a speed-up of training by means of low rank approximations of the Gram matrix by its Nyström approximation. In benchmarks, this strategy is successful if the considered data are intrinsically low-dimensional. We propose a quick check to efficiently test this property prior to training. We extend KRSLVQ by sparse approximations of the prototypes: instead of the full coefficient vectors, few exemplars which represent the prototypes can be directly inspected by practitioners in the same way as data. We compare different paradigms based on which to infer a sparse approximation: sparsity priors while training, geometric approaches including orthogonal matching pursuit and core techniques, and heuristic approximations based on the coefficients or proximities. We demonstrate the performance of these LVQ techniques for benchmark data, reaching state of the art results. We discuss the behavior of the methods to enhance performance and interpretability as concerns quality, sparsity, and representativity, and we propose different measures how to quantitatively evaluate the performance of the approaches. We would like to point out that we had the possibility to present our findings in international publication organs including three journal articles [6, 9, 2], four conference papers [8, 5, 7, 1] and two workshop contributions [4, 3]. References [1] A. Gisbrecht, D. Hofmann, and B. Hammer. Discriminative dimensionality reduction mappings. Advances in Intelligent Data Analysis, 7619: 126–138, 2012. [2] B. Hammer, D. Hofmann, F.-M. Schleif, and X. Zhu. Learning vector quantization for (dis-)similarities. Neurocomputing, 131: 43–51, 2014. [3] D. Hofmann. Sparse approximations for kernel robust soft lvq. Mittweida Workshop on Computational Intelligence, 2013. [4] D. Hofmann, A. Gisbrecht, and B. Hammer. Discriminative probabilistic prototype based models in kernel space. New Challenges in Neural Computation, TR Machine Learning Reports, 2012. [5] D. Hofmann, A. Gisbrecht, and B. Hammer. Efficient approximations of kernel robust soft lvq. Workshop on Self-Organizing Maps, 198: 183–192, 2012. [6] D. Hofmann, A. Gisbrecht, and B. Hammer. Efficient approximations of robust soft learning vector quantization for non-vectorial data. Neurocomputing, 147: 96–106, 2015. [7] D. Hofmann and B. Hammer. Kernel robust soft learning vector quantization. Artificial Neural Networks in Pattern Recognition, 7477: 14–23, 2012. [8] D. Hofmann and B. Hammer. Sparse approximations for kernel learning vector quantization. European Symposium on Artificial Neural Networks, 549–554, 2013. [9] D. Hofmann, F.-M. Schleif, B. Paaßen, and B. Hammer. Learning interpretable kernelized prototype-based models. Neurocomputing, 141: 84–96, 2014

Endstation Friedhof? Bestattung und materielle Kultur im Wandel

Der vorliegende Band ist das Ergebnis einer Ringvorlesung, die im Wintersemester 2015/2016 an der Universität Hamburg abgehalten wurde1, um ein erstes interdisziplinäres Forum zum Themenbereich Tod, Bestattung, Trauerund Erinnerung zu bieten

Endstation Friedhof? Bestattung und materielle Kultur im Wandel

Der vorliegende Band ist das Ergebnis einer Ringvorlesung, die im Wintersemester 2015/2016 an der Universität Hamburg abgehalten wurde1, um ein erstes interdisziplinäres Forum zum Themenbereich Tod, Bestattung, Trauer und Erinnerung zu bieten

Endstation Friedhof? Bestattung und materielle Kultur im Wandel

Der vorliegende Band ist das Ergebnis einer Ringvorlesung, die im Wintersemester 2015/2016 an der Universität Hamburg abgehalten wurde1, um ein erstes interdisziplinäres Forum zum Themenbereich Tod, Bestattung, Trauerund Erinnerung zu bieten

Sugar-to-base correlation in nucleic acids with a 5D APSY-HCNCH or two 3D APSY-HCN experiments

A five-dimensional (5D) APSY (automated projection spectroscopy) HCNCH experiment is presented, which allows unambiguous correlation of sugar to base nuclei in nucleic acids. The pulse sequence uses multiple quantum (MQ) evolution which enables long constant-time evolution periods in all dimensions, an improvement that can also benefit non-APSY applications. Applied with an RNA with 23 nucleotides the 5D APSY-HCNCH experiment produced a complete and highly precise 5D chemical shift list within 1.5h. Alternatively, and for molecules where the out-and-stay 5D experiment sensitivity is not sufficient, a set of out-and-back 3D APSY-HCN experiments is proposed: an intra-base (3D APSY-b-HCN) experiment in an MQ or in a TROSY version, and an MQ sugar-to-base (3D APSY-s-HCN) experiment. The two 3D peak lists require subsequent matching via the N1/9 chemical shift values to one 5D peak list. Optimization of the 3D APSY experiments for maximal precision in the N1/9 dimension allowed matching of all 15N chemical shift values contained in both 3D peak lists. The precise 5D chemical shift correlation lists resulting from the 5D experiment or a pair of 3D experiments also provide a valuable basis for subsequent connection to chemical shifts derived with other experiment

No time out: scaling material diversity and change in the Alpine foreland Neolithic

Within a project exploring the difference which high-precision chronologies make for narratives of the European Neolithic, this paper examines the place of material culture in the flow of social existence. In contrast to approaches based on imprecise chronologies and stressing gradual change, we examine increasingly high-resolution dendrochronological data in the Neolithic of the northern Alpine foreland, where sharp boundaries between material styles were not in evidence. While 60-year filters allow a more differentiated analysis of the relative distribution of Cortaillod and Pfyn pottery, higher-resolution dendrochronology enables a very detailed narrative of the rapid introduction of Corded Ware in the Lake Zürich area, highlighting significant differences between eastern and western Switzerland. At the scale of individual sites, Concise shows continuity of the local potting tradition, despite repeated episodes of outside influence. At the short-lived site Arbon Bleiche 3, pottery changes much less than diet. This reveals a complex pattern of exactly contemporary diversity, seen even more sharply at the very briefly occupied settlement of Bad Buchau Torwiesen II. To get at agency within the flow of social life, we need as much temporal and spatial detail as possible, close attention to the material, and approaches that allow for nuanced narratives

Calcium dependent protein kinases as regulators of developmental processes in Arabidopsis thaliana

Während ihres Lebenszyklus müssen sich Pflanzen konstant an sich verändernde äußere Bedingungen, wie Verfügbarkeit von Licht und Nährstoffen oder auch an abiotische und biotische Stresse anpasen. Der ubiquitäre second messenger Ca2+ spielt eine zentrale Rolle in der Transduktion externer Signale in molekulare Antworten. Die Vielzahl der räumlich-zeitlichen Ca2+ Wellenmuster ermöglicht die Spezifität der einzelnen Signale und wird durch zwei große Familien von Signaltransduktionsmolekülen, den Calcineurin B-like Protein interagierenden Proteinkinasen (CBL/CIPKs) und den Calcium-abhängigen Proteinkinasen (CDPKs) in die endogenen Netzwerke der metabolischen und Entwicklungsprozesse integriert. Diese Arbeit konzentrierte sich auf die Calcium-abhängige Proteinkinase CPK3 aus Arabidopsis thaliana. Im ersten Teil wurden CPK3 Knockout- und Überexpressor-Linien auf Transkriptebene charakterisiert und phänotypische Differenzen unter bestimmten Wachstumsbedingungen analysiert. Von früheren Arbeiten war bekannt, dass CPK3 als positiver Regulator in Salzstressantwort wirkt. Hier wurde die Rolle von CPK3 in der transkriptionellen Regulation bekannter Salzstressantwortgene mittels RT-PCR analysiert. Der CPK3 Gehalt in den untersuchten Pflanzen hatte keinen Einfluss auf das transkriptionelle Induktionsmuster unter Salzstress. Daher wurde vermutet, dass CPK3 Salzstressantwort hauptsächlich auf post-transkriptioneller Ebene reguliert, ähnlich wie es bereits für Mitglieder der CBL/CIPK Familie gezeigt worden war, die den Plasmamembran Na+/H+ antiporter Salt overly sensitive (SOS) 1 oder den high-affinity K+ Transporter AKT1 durch Ca2+-abhängige Phosphorylierung aktivieren. Um den Einfluss von CPK3 auf die K+-Homöostase durch Regulation von K+-Kanälen zu evaluieren, wurden die CPK3-Linien auf Medium mit verschiedenen K+-Konzentrationen angebaut. Ein weiteres Experiment wurde begonnen, um mögliche Kompensation der CPK3- Funktion in CPK3 Knockout Pflanzen durch CDPK-Redundanz zu untersuchen. Spezifische RTPCR Primer wurden für alle übrigen Arabidopsis CDPKs designed um Transkript-Levels in Wildtyp und Knockout in verschiedenen Geweben und Entwicklungsstadien zu vergleichen, sowie um in silenced CPK3 Überexpressor Pflanzen mitausgeschaltete homologe Gene zu identifizieren. Im zweiten Teil wurde die Interaktion von CPK3 mit Basic Leucine Zipper Transkriptionsfaktoren (bZIPs) weiter untersucht. C-Gruppen bZIPs, bZIP9 und 63 waren bereits in einem früheren Yeast-2-Hybrid Screen als Interaktionspartner von CPK3, sowie als in vitro Phosphorylierungsargets identifiziert worden. Transiente Expression von bZIP9 und 63 als YFP-Fusionen zeigte deren ausschließliche Lokalisierung im Zellkern. Mit Hilfe von in vitro Kinase-Assays and MS Analyse konnten multiple CPK3-Phosphorylierungsstellen in beiden bZIPs nachgewiesen werden. Der Vergleich von Ergebnissen über Interaktion von CPK3 mit bZIP9 und 63 aus Yeast-2-Hybrid und Kinase-Assay zeigte, dass Yeast-2-Hybrid eine sub-optimale Methode für die Untersuchung der Interaktionen einer Proteinkinase ist. Die Analyse von bZIP Knockout- Linien zeigte einen möglicher Früh-Blüh-Phänotyp in bzip63.During their life cycle, plants constantly have to adapt their metabolism and development to varying external conditions, such as availability of light and nutrients as well as abiotic and biotic stresses. The ubiquitous second messenger Ca2+ plays a central role in transduction of external signals into molecular responses. The multitude of spatio-temporal Ca2+ wave patterns creates specificity for each signal and is integrated into the endogenous metabolic and developmental networks by two major families of signal transduction molecules, the Calcineurin B-like protein interacting protein kinases (CBL/CIPKs) and the Calcium dependent protein kinases (CDPKs). This work focused on the calcium dependent protein kinase CPK3 of Arabidopsis thaliana. In the first part CPK3 mutant and overexpressor lines were characterized on transcript-level and analyzed on phenotypic differences under specific growth conditions. From previous works, CPK3 was known to act as positive regulator in salt stress response. Here, the role of CPK3 in transcriptional regulation of known salt stress response genes was analyzed via RT-PCR. CPK3 levels in the analyzed plants had no influence on the transcriptional induction pattern under salt stress. Therefore it was presumed that CPK3 mainly regulates salt stress response on the post-transcriptional level, similar to as it had been shown for members of the CBL/CIPK family, which activate the plasmamembrane Na+/H+ antiporter Salt overly sensitive (SOS) 1 or the high-affinity K+ transporter AKT1 by Ca2+-dependent phosphorylation. To evaluate the influence of CPK3 on K+ homeostasis via regulation of K+ channels, the CPK3 lines were grown on medium with different K+ concentrations. An additional experiment was started to investigate possible compensation of CPK3 function in CPK3 knock out plants through CDPK redundancy. Specific RT-PCR primers were designed for all remaining Arabidopsis CDPKs to compare transcript levels in wild type and knock out in different tissues and developmental stages, as well as in silenced CPK3 over-expressor plants to identify co-knocked down homologous genes. In the second part, interaction with target proteins identified in a previous yeast-2-hybrid screen, the basic leucine zipper transcription factors (bZIPs) was further investigated. The C-group bZIPs, bZIP9 and 63, had already been identified as in vitro phosphorylation targets of CPK3. Transient expression of bZIP9 and 63 YFP-fusions revealed their exclusive localization to the nucleus. Using in vitro kinase assays and MS analysis, multiple CPK3 phosphorylation sites in both bZIPs were identified. Comparing results on interaction of CPK3 with bZIP9 and 63 in yeast-2-hybrid and kinase assay, it became evident that yeast-2-hybrid is a sub-optimal method for the analysis of protein kinase interaction. Analysis of bZIP knock out lines uncovered a possible early-flowering phenotype in bzip63

Individual and organizational resilience—Insights from healthcare providers in Germany during the COVID-19 pandemic

We explored the effects of resilience in the healthcare setting during the COVID-19 pandemic in Germany. Our study sheds light on the cross-level effects of resilience in hospitals and thus responds to calls to research this empirically. In a cross-sectional study design, the perceptions of resilience of employees in hospitals and of transformations at the individual, team, and organizational level were analyzed. An online survey was conducted in summer 2020 in Germany in which 1,710 healthcare workers completed a self-report questionnaire. Results indicate that resilience is both a highly interrelated construct on the individual and organizational level and also positively linked to perceptions of transformation as an indicator for demonstration of resilience. We also found a partial mediation effect of organizational resilience and team efficacy, respectively, on the relationship between individual resilience and perceived transformation on the individual and organizational level as well as a full mediation on the team level. The study highlights the interdependence of individual and organizational resilience (which is mediated by team efficacy) and its impact on perceived transformation in German hospitals during the COVID-19 pandemic. Whereas team efficacy is crucial for performance in regular work operations, during a pandemic the organizational level becomes more relevant. Theoretical and practical implications are discussed