Dissecting a neuron network: FIB-SEM-based 3D-reconstruction of the visual neuropils in the sea spider Achelia langi (Dohrn, 1881) (Pycnogonida)

Background: The research field of connectomics arose just recently with the development of new three-dimensional- electron microscopy (EM) techniques and increasing computing power. So far, only a few model species (for example, mouse, the nematode Caenorhabditis elegans, and the fruit fly Drosophila melanogaster) have been studied using this approach. Here, we present a first attempt to expand this circle to include pycnogonids, which hold a key position for the understanding of arthropod evolution. The visual neuropils in Achelia langi are studied using a focused ion beam-scanning electron microscope (FIB-SEM) crossbeam-workstation, and a three-dimensional serial reconstruction of the connectome is presented. Results: The two eyes of each hemisphere of the sea spider's eye tubercle are connected to a first and a second visual neuropil. The first visual neuropil is subdivided in two hemineuropils, each responsible for one eye and stratified into three layers. Six different neuron types postsynaptic to the retinula (R-cells) axons are characterized by their morphology: five types of descending unipolar neurons and one type of ascending neurons. These cell types are also identified by Golgi impregnations. Mapping of all identifiable chemical synapses indicates that the descending unipolar neurons are postsynaptic to the R-cells and, hence, are second-order neurons. The ascending neurons are predominantly presynaptic and sometimes postsynaptic to the R-cells and may play a feedback role. Conclusions: Comparing these results with the compound eye visual system of crustaceans and insects - the only arthropod visual system studied so far in such detail - we found striking similarities in the morphology and synaptic organization of the different neuron types. Hence, the visual system of pycnogonids shows features of both chelicerate median and mandibulate lateral eyes

Die (innere) Logik des Entscheidens: Zur neurobiologischen Fundierung ökonomischer Entscheidungen

Ziel des Beitrages ist es, die neueren Erkenntnisse der Neurobiologie zum Entscheidungsverhalten von Menschen für die Entwicklung eines idealtypischen Ablaufplans ökonomischer Entscheidungsvorgänge einzusetzen, indem die Logik deutlich gemacht wird, die den Aufbau des menschlichen Gehirns bestimmt. Ein solcher Ablaufplan kann dazu beitragen, ökonomische Modelle realitätsnäher als bisher formulieren zu können, und ökonomische Modelle, die bisher eher getrennt voneinander gesehen wurden, als Teil eines größeren Ganzen einzuordnen. Es zeigt sich, dass wesentliche Komponenten einiger viel verwendeter Mo-delle der Ökonomik Parallelen in der neurobiologischen und physiologischen Arbeitsweise des Gehirns finden. Dies kann einen Beitrag dazu leisten, Modelle zielgerichteter als bisher zur Lösung ökonomischer Probleme einzusetzen. --Neuroeeconomics,Behavioural Economics,Entscheidungsverhalten,Validierung ökonomischer Modelle

Gesamtwirtschaftliche Effekte verminderter Transferzahlungen für die ostdeutschen Bundesländer

Die regionale Wirtschaftskraft, gemessen als Bruttoinlandsprodukt je Einwohner in Kaufkraftstandards, dürfte aller Voraussicht nach auch in der kommenden EU-Strukturfondsperiode 2014–2020 als Kriterium für die Vergabe des Förderstatus dienen. tatsächlich dürfte dieser Indikator aber die Wirtschaftskraft in den ostdeutschen Regionen überzeichnen, da diese in hohem Maße von Transferzahlungen abhängig sind. Die Frage, inwieweit eine Kürzung der Ausgleichszahlungen zu einem Rückgang der wirtschaftlichen Leistungsfähigkeit der ostdeutschen Bundesländer führt, kann mit Hilfe eines makroökonomischen Simulationsmodells beantwortet werden. Rechnungen mit Hilfe des HERMIN-Modells zeigen, dass das Bruttoinlandsprodukt gegenüber einem Szenario ohne Rückführungen der Transferleistungen um bis zu 2 % niedriger liegen dürfte. Der Grenzwert für die Abgrenzung der Strukturfonds-Förderregionen wird damit jedoch aller Wahrscheinlichkeit nach nicht unterschritten werden.Investitionspolitik; Wirtschaftspolitische Wirkungsanalyse; Neue Bundesländer; Alte Bundesländer; Öffentlicher Finanztransfer

Entwicklung der Grundlagen für eine Laboranlage zur kontinuierlichen Herstellung von PET-Recyclingpolyolen - Darstellung des Standes der Arbeiten im InnoRegio-Projekt

Die vorliegende Arbeit hat die Entwicklung der Grundlagen für eine Anlage zum Ziel, mit der aus Polyethylenterephthalat (PET), insbesondere aus Produktionsabfällen von PET-Verarbeitern, durch Umesterungen in Gegenwart von Diolen in einem kontinuierlichen Prozess aromatische Polyesterpolyole (APP) hergestellt werden können, die als Rohstoffe für Polyurethane (PUR) verwendet werden

Dissecting a neuron network: FIB-SEM-based 3D-reconstruction of the visual neuropils in the sea spider Achelia langi (Dohrn, 1881) (Pycnogonida)

Background: The research field of connectomics arose just recently with the development of new three-dimensional- electron microscopy (EM) techniques and increasing computing power. So far, only a few model species (for example, mouse, the nematode Caenorhabditis elegans, and the fruit fly Drosophila melanogaster) have been studied using this approach. Here, we present a first attempt to expand this circle to include pycnogonids, which hold a key position for the understanding of arthropod evolution. The visual neuropils in Achelia langi are studied using a focused ion beam-scanning electron microscope (FIB-SEM) crossbeam-workstation, and a three-dimensional serial reconstruction of the connectome is presented. Results: The two eyes of each hemisphere of the sea spider's eye tubercle are connected to a first and a second visual neuropil. The first visual neuropil is subdivided in two hemineuropils, each responsible for one eye and stratified into three layers. Six different neuron types postsynaptic to the retinula (R-cells) axons are characterized by their morphology: five types of descending unipolar neurons and one type of ascending neurons. These cell types are also identified by Golgi impregnations. Mapping of all identifiable chemical synapses indicates that the descending unipolar neurons are postsynaptic to the R-cells and, hence, are second-order neurons. The ascending neurons are predominantly presynaptic and sometimes postsynaptic to the R-cells and may play a feedback role. Conclusions: Comparing these results with the compound eye visual system of crustaceans and insects - the only arthropod visual system studied so far in such detail - we found striking similarities in the morphology and synaptic organization of the different neuron types. Hence, the visual system of pycnogonids shows features of both chelicerate median and mandibulate lateral eyes

Multiple electromagnetic electron positron pair production in relativistic heavy ion collisions

We calculate the cross sections for the production of one and more electron-positron pairs due to the strong electromagnetic fields in relativistic heavy ion collisions. Using the generating functional of fermions in an external field we derive the N-pair amplitude. Neglecting the antisymmetrisation in the final state we find that the total probability to produce N pairs is a Poisson distribution. We calculate total cross sections for the production of one pair in lowest order and also include higher-order corrections from the Poisson distribution up to third order. Furthermore we calculate cross sections for the production of up to five pairs including corrections from the Poisson distribution.Comment: 13 pages REVTeX, 4 Postscript figures, This and related papers may also be obtained from http://www.phys.washington.edu/~hencken

The ChildPoeDE Corpus: 1082 German Children’s Poems for Computational and Experimental Studies on Poetry Reception

We introduce childPoeDE: the first corpus of German poetry for children comprising poems which are still read today and cover a wide range of topics and authors. ChildPoeDE contains poem texts and both poem-level and token-level metadata. Poem-level metadata includes information about the anthologies and authors, quantitative text features, rhyme and lexical richness. Token-level metadata covers word length, position and frequency, parts-of-speech, onomatopoeia and sonority. This corpus can be used for computational text analysis, but also as a source for stimulus material in experimental studies. The corpus metadata is freely accessible via Zenodo. The poem texts are protected by copyright

Standards – An important step for the (public) use of lidars

Lidar standards are needed to ensure quality and lidar product control at the interface between lidar manufacturers and lidar users. Meanwhile three lidar standards have been published by German and international standardization organizations. This paper describes the cooperation between the lidar technique inventors, lidar instrument constructors, and lidar product users to establish useful standards. Presently a backscatter lidar standard is elaborated in Germany. Key points of this standard are presented here. Two German standards were already accepted as international standards by the International Organization for Standardization (ISO). Hence, German and international organizations for the establishment of lidar standards are introduced to encourage a cooperative work on lidar standards by lidar scientists