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A survey of the biodiversity of Tunicata with a focus on Ascidiacea in the waters of Heligoland Island, North Sea
Get PDFDuring a comprehensive study of the biodiversity of marine invertebrates on the island of Heligoland in September 2023, I identified 14 species of tunicates. I observed that some of these species occur only in specific locations on the island during this period and This agrees well with the results of previous studies on the distribution of species in different locations on the island. I suggest, that Molgula manhattensis is a relatively recently introduced species in this region.Peer Reviewe
Spatial biases in mental arithmetic
Get PDFEin bedeutender Effekt der numerischen Kognition, der Operational Momentum Effekt, beschreibt die Beobachtung, dass Proband*innen das Ergebnis von Additionen überschätzen und das Ergebnis von Subtraktionen unterschätzen. Diverse theoretische Modelle wurden vorgebracht, um diesen Effekt zu erklären. Diese Modelle unterscheiden sich in Bezug darauf, ob sie räumliche Prozesse während des Kopfrechnens annehmen. Einige Studien haben seitdem Belege für eine Verknüpfung zwischen räumlicher Verarbeitung und Kopfrechnen liefern können. Die vorliegende Dissertation zielt darauf ab, räumliche Aufmerksamkeitsverschiebungen beim Kopfrechnen in drei Studien (Studie 1, Studie 3, Studie 4) und einer Kontrollstudie (Studie 2) vertieft zu untersuchen. Studie 1 zeigt, dass zwei-stellige Additionen mit Aufmerksamkeitsverschiebungen nach rechts assoziiert sind, während zwei-stellige Subtraktionen nicht mit Verschiebungen nach links einhergehen. Studie 3 liefert Hinweise für Aufmerksamkeitsverschiebungen in der Antwortphase von approximativen Rechenprozessen. Jedoch wurden ich dieser Studie keine Verschiebungen im Zeitfenster zwischen der Aufgabenpräsentation und der Antwortselektion gefunden. In Studie 4 wurden mittels steady-state visuell evozierten Potenzialen keinerlei räumliche Verschiebungen, sowohl im arithmetischen Kontext als auch in der Kontrollaufgabe gefunden. Die Kontrollstudie (Studie 2) untersuchte den Einfluss von kognitiver Belastung auf räumliche Aufmerksamkeit, wobei jedoch kein solcher Einfluss nachweisbar war. Zusammen unterstützen die Ergebnisse der vorliegenden Dissertation die Hypothese, dass räumliche und arithmetische Verarbeitung funktionell assoziiert sind (Studie 1, Studie 3). Andere Ergebnisse sind jedoch nicht so einfach mit den bestehenden Theorien vereinbar. Die Nulleffekte von Studie 2 und 4 betonen die Rolle methodischer Aspekte bei der Untersuchung räumlicher Aufmerksamkeitsverschiebungen, wie zum Beispiel die Wahl geeigneter Baseline-Aufgaben.A hallmark effect of numerical cognition, the operational momentum effect, describes the finding that participants tend to overestimate the result of addition problems and underestimate the result of subtraction problems. Several theoretical accounts proposed to explain that effect differ with regard to whether they assume spatial contributions to mental arithmetic. Several studies have since then provided evidence for an association between spatial processing and mental arithmetic. The present dissertation aimed at further enlarging upon this knowledge by investigating spatial biases in mental arithmetic via several behavioural and neurophysiological experimental paradigms. This thesis comprises three studies (Study 1, Study 3, Study 4) and a control study (Study 2). Study 1 demonstrated that spatial biases to the right can be observed in the context of two-digit addition processing, while no biases to the left were observed for two-digit subtraction processing. Study 3 provided evidence for spatial biases during the response stage of approximate arithmetic processing. Yet, no biases were observed in the time window between the task presentation and response selection. In Study 4, no biases could be measured via steady-state visually evoked potentials, neither in an arithmetic context nor in a control task. The control study (Study 2) investigated the impact of cognitive load on spatial biases. Still, no such impact could be shown in Study 2. Together, the results of the present dissertation provide support for the notion of a functional association between spatial and arithmetic processing (Study 1, Study 3). Nevertheless, several other findings are difficult to reconcile with the existing theoretical accounts. This implies that other mechanisms might be involved. Finally, the null effects of Study 2 and 4 highlighted the role of methodological aspects, like the choice of appropriate baseline tasks, when investigating attentional biases
Hinweise für Lehrpersonen
Get PDFDer Einsatz von Dolmetscher*innen für deutsche Laut- und Gebärdensprache (GSD) im Unterricht stellt viele Lehrpersonen vor neue Chancen und Herausforderungen. Meist wurden die Lehrpersonen in der Ausbildung nicht auf ein solches Unterrichtssetting vorbereitet und der Umgang mit GSD und GSD nut-zenden Schüler*innen ist in der ersten Zeit ungewohnt. Um Lehrpersonen kompakt Hinweise für den Unterricht mit GSD an die Hand zu geben, wurde im Rahmen eines Projekts während des Referendariats der beiden Autorinnen an der Margarethe-von-Witzleben-Schule ein kurzes Merkblatt verfasst, das zehn wichtige Punkte (im Sinne des Best Practice) für den gemeinsamen Einsatz zusammenfasst.The use of interpreters for spoken German and German sign language in the classroom presents many teachers with new opportunities and challenges. In most cases, teachers have not been prepared for such a teaching setting during their training and dealing with the interpreters and pupils who use these is unfamiliar at first. In order to provide teachers with compact tips for teaching with interpreters present, a short leaflet was written as part of a project during the two authors' traineeship at Margarethe-von-Witzleben-Schule, which summarizes ten important points (in terms of best practice) for the collaborative work
Diglyme as a Promoter for the Electrochemical Formation of Quaternary Graphite Intercalation Compounds Containing two Different Types of Solvents
No full textCo-intercalation using ether-based electrolytes renders graphite as a promising anode material in sodium-ion batteries (SIBs). While most research on electrochemical solvent co-intercalation in graphite has focused on linear ethers such as mono-, di-, tri-, tetra-, and penta-glyme, we herein investigate the possibility of reversible electrochemical co-intercalation with alternative solvents, especially cyclic ethers tetrahydrofuran (THF) and 1,3-dioxolane (DOL), which show no signs of co-intercalation on their own. We demonstrate, however, that this reaction becomes feasible when incorporating diethylene glycol dimethyl ether (2G, diglyme) as an additive. Operando X-ray diffraction and ex-situ ss-NMR techniques are employed comprehensively to understand the co-intercalation reaction of these cyclic ethers, along with Na+-glymes, into graphite during cycling. When using these mixed electrolytes i. e., THF/2G and DOL/2G, the voltage profiles changes compared to the pure glyme-based electrolyte, while showing comparable specific capacities and good long-term durability. Overall, we propose that even trace amounts of diglyme prompt the co-intercalation of THF and DOL into graphite layers. This leads to the formation of quaternary graphite intercalation compounds (q-GICs), expanding beyond the realm of ternary graphite intercalation compounds (t-GICs).European Research Council (ERC)EIG Concert Japan programPeer Reviewe
Round table discussion: after the war – beginning life anew in the aftermath of violence
No full textHow neuronal morphology impacts the synchronisation state of neuronal networks
No full textThe biophysical properties of neurons not only affect how information is processed within cells, they can also impact the dynamical states of the network. Specifically, the cellular dynamics of action-potential generation have shown relevance for setting the (de)synchronisation state of the network. The dynamics of tonically spiking neurons typically fall into one of three qualitatively distinct types that arise from distinct mathematical bifurcations of voltage dynamics at the onset of spiking. Accordingly, changes in ion channel composition or even external factors, like temperature, have been demonstrated to switch network behaviour via changes in the spike onset bifurcation and hence its associated dynamical type. A thus far less addressed modulator of neuronal dynamics is cellular morphology. Based on simplified and anatomically realistic mathematical neuron models, we show here that the extent of dendritic arborisation has an influence on the neuronal dynamical spiking type and therefore on the (de)synchronisation state of the network. Specifically, larger dendritic trees prime neuronal dynamics for in-phase-synchronised or splayed-out activity in weakly coupled networks, in contrast to cells with otherwise identical properties yet smaller dendrites. Our biophysical insights hold for generic multicompartmental classes of spiking neuron models (from ball-and-stick-type to anatomically reconstructed models) and establish a connection between neuronal morphology and the susceptibility of neural tissue to synchronisation in health and disease
Ein Forschungsbericht zur Aufbereitung und Kommodifizierung radioaktiver Stoffe bei Auer in Oranienburg
No full textAusgangspunkt: Toxic heritage als interdisziplinäres Forschungsfeld In ihrem Buch Residues. Thinking through Chemical Environments schlagen Soraya Boudia et al. ein Forschungsprogramm vor, das die Geschichte(n) problematischer Reste zum Ausgangspunkt für einen „residual materialism“ nimmt: Wissenschafts- und Technikforschung müsse chemische Umwelten bzw. die Produktion, Nutzung, Entsorgung und Regulierung von Stoffen neu und anders denken.1 Denn Residuen sind nicht nur unvermeidlich. Sie sind auch persistent, kaum zu kontrollieren, und ihre problematischen Eigenschaften sind nur selten direkt wahrnehmbar. Diese Programmatik, verdichtet in der zentralen Aussage von „the past is always with us“,2 lässt sich am Beispiel der nuklearen Hinterlassenschaften in der Stadt Oranienburg nördlich von Berlin exemplifizieren. Das ‚Erbe‘ geht dabei im Wesentlichen auf die Auer-Werke und deren industrielle Verwertung Seltener Erden zurück. In einer Forschungs- und Lehrkooperation zwischen der Kulturwissenschaft an der Humboldt-Universität zu Berlin und der Technikgeschichte der Technischen Universität Berlin gehen wir der Geschichte der Aufbereitung und der Kommodifizierung radioaktiver Stoffe bei Auer nach, um lokalen Altlasten, die in Oranienburg das frühe 20. Jahrhundert mit dem Heute unmittelbar verbinden, zu rekonstruieren und zu problematisieren.Peer Reviewe
Towards holistic insect monitoring: species discovery, description, identification and traits for all insects
No full textHolistic insect monitoring needs scalable techniques to overcome taxon biases, determine species abundances, and gather functional traits for all species. This requires that we address taxonomic impediments and the paucity of data on abundance, biomass and functional traits. We here outline how these data deficiencies could be addressed at scale. The workflow starts with large-scale barcoding (megabarcoding) of all specimens from mass samples obtained at biomonitoring sites. The barcodes are then used to group the specimens into molecular operational taxonomic units that are subsequently tested/validated as species with a second data source (e.g. morphology). New species are described using barcodes, images and short diagnoses, and abundance data are collected for both new and described species. The specimen images used for species discovery then become the raw material for training artificial intelligence identification algorithms and collecting trait data such as body size, biomass and feeding modes. Additional trait data can be obtained from vouchers by using genomic tools developed by molecular ecologists. Applying this pipeline to a few samples per site will lead to greatly improved insect monitoring regardless of whether the species composition of a sample is determined with images, metabarcoding or megabarcoding.
This article is part of the theme issue ‘Towards a toolkit for global insect biodiversity monitoring’.Peer Reviewe
Multiple retinal isomerizations during the early phase of the bestrhodopsin photoreaction
No full textBestrhodopsins constitute a class of light-regulated pentameric ion channels that consist of one or two rhodopsins in tandem fused with bestrophin ion channel domains. Here, we report on the isomerization dynamics in the rhodopsin tandem domains of Phaeocystis antarctica bestrhodopsin, which binds all-trans retinal Schiff-base (RSB) absorbing at 661 nm and, upon illumination, converts to the meta-stable P540 state with an unusual 11-cis RSB. The primary photoproduct P682 corresponds to a mixture of highly distorted 11-cis and 13-cis RSB directly formed from the excited state in 1.4 ps. P673 evolves from P682 in 500 ps and contains highly distorted 13-cis RSB, indicating that the 11-cis fraction in P682 converts to 13-cis. Next, P673 establishes an equilibrium with P595 in 1.2 µs, during which RSB converts to 11-cis and then further proceeds to P560 in 48 µs and P540 in 1.0 ms while remaining 11-cis. Hence, extensive isomeric switching occurs on the early ground state potential energy surface (PES) on the hundreds of ps to µs timescale before finally settling on a metastable 11-cis photoproduct. We propose that P682 and P673 are trapped high up on the ground-state PES after passing through either of two closely located conical intersections that result in 11-cis and 13-cis RSB. Co-rotation of C11=C12 and C13=C14 bonds results in a constricted conformational landscape that allows thermal switching between 11-cis and 13-cis species of highly strained RSB chromophores. Protein relaxation may release RSB strain, allowing it to evolve to a stable 11-cis isomeric configuration in microseconds.Significance: The far-red absorbing rhodopsin modules (λmax = 661 nm) of bestrhodopsin are of high interest for a principle understanding of the photophysics and photochemistry of unusually far-red absorbing rhodopsins and optogenetic application in tissues that are more transparent to red light in comparison to blue or green light. Moreover, the identified light-induced isomeric switching processes on the ground state potential energy surface disclose a multi-isomerization activation mechanism that has so far remained unknown for rhodopsin.Peer Reviewe
Mapping opportunities and barriers for coexistence between people and pumas in the Argentine Dry Chaco
No full textThe article processing charge was funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) – 491192747 and the Open Access Publication Fund of Humboldt-Universität zu Berlin.Aim
The persistence of large carnivore populations depends on their survival outside protected areas, where they often impact local livelihoods through livestock depredation. Understanding the impacts of human behaviour on large carnivores in shared landscapes is thus important but is often overlooked in habitat assessments or conservation planning. We employed an integrated approach that considers human behaviour and landscape structure metrics to assess the potential for human-puma (Puma concolor) coexistence in the Chaco region, a global deforestation and defaunation hotspot.
Location
Argentine Dry Chaco (~490,000 km2).
Methods
We identified suitable puma habitat patches and movement areas using occupancy modelling and combined it with a spatial human-puma conflict risk model based on interview data to identify ‘safe’ and ‘unsafe’ habitat patches. We then used resistance surfaces to identify ‘safe’ and ‘unsafe’ movement areas, as well as ‘severed’ movement areas where anthropogenic land conversion inhibits movement.
Results
Safe puma habitat patches (i.e., suitable and safe) covered 29% of the region, whereas attractive sinks (i.e., suitable but risky) represented 12%. Movement areas corresponded to 60% of the region, while conflict risk and high landscape resistance undermined connectivity: unsafe and severed movement areas covered 10% and 11% of the region, respectively. Nearly 98% of safe habitat and movement areas occurred outside protected areas.
Main Conclusions
We provide an integrated conceptual framework and spatial explicit template for a three-pronged conservation strategy to (1) protect safe habitat and movement areas, (2) mitigate livestock depredation in attractive sinks and unsafe movement areas and (3) restore landscape in severed and matrix areas to improve ecological connectivity. This would allow pumas to maintain viable populations while reducing negative impacts on local people. More generally, we show how integrating habitat and conflict risk models can reveal opportunities and challenges for human-carnivore coexistence beyond protected areas.Fondo para la Investigación Científica y Tecnológica http://dx.doi.org/10.13039/501100006668Wild Felid Research and Management Association http://dx.doi.org/10.13039/100016553Wild Felid Association http://dx.doi.org/10.13039/100004450HORIZON EUROPE European Research Council http://dx.doi.org/10.13039/100019180Rufford Small Grant Foundation http://dx.doi.org/10.13039/100007463Peer Reviewe