Deep-sea predator niche segregation revealed by combined cetacean biologging and eDNA analysis of cephalopod prey

Fundamental insight on predator-prey dynamics in the deep sea is hampered by a lack of combined data on hunting behavior and prey spectra. Deep-sea niche segregation may evolve when predators target specific prey communities, but this hypothesis remains untested. We combined environmental DNA (eDNA) metabarcoding with biologging to assess cephalopod community composition in the deep-sea foraging habitat of two top predator cetaceans. Risso’s dolphin and Cuvier’s beaked whale selectively targeted distinct epi/meso- and bathypelagic foraging zones, holding eDNA of 39 cephalopod taxa, including 22 known prey. Contrary to expectation, extensive taxonomic overlap in prey spectra between foraging zones indicated that predator niche segregation was not driven by prey community composition alone. Instead, intraspecific prey spectrum differences may drive differentiation for hunting fewer, more calorific, mature cephalopods in deeper waters. The novel combination of methods presented here holds great promise to disclose elusive deep-sea predator-prey systems, aiding in their protection

Ein mehrkanaliges Biosensormesssystem zur Überwachung der Nitrifikation in Abwasserreinigungsanlagen

Bei der biologischen Abwasserreinigung treten häufig Störungen der Nitrifikationsstufe (biochemische Oxidation von Ammonium über Nitrit zu Nitrat) auf, die durch Hemmstoffe sowie durch Stossbelastungen hoher Stickstofffrachten (N-BSB) verursacht werden. Dadurch gelangen erhöhte Mengen an sauerstoffzehrenden reduzierten Stickstoffverbindungen in die Oberflächengewässer. Dies ist besonders kritisch bei Vorflutern mit einem bereits niedrigem Sauerstoffgehalt, da durch diese reduzierten Stickstoffverbindungen die Konzentration an gelöstem Sauerstoff in Folge mikrobieller Oxidation stark absinken kann und somit die Biocönose im Gewässer nachhaltig gestört wird. Da es sich bei Nitrit und Ammoniak zudem um starke Fischgifte handelt, ist die Elimination dieser Stickstoffverbindungen aus dem Abwasser nicht zuletzt auch gesetzlich vorgeschrieben. Zur Erfassung von Störungen der Nitrifikationsstufe wurde deswegen in den vergangenen Jahren am ISWA ein Nitrifikanten-Einzelbiosensor entwickelt. Dabei wird über den Sauerstoffverbrauch des Immobilisates die bakterielle Stoffwechselaktivität überwacht, wobei dies ein Maß für das Vorhandensein von Hemmstoffen bzw. Nitrifikationssubstraten in einer Probe ist. Der Vorteil dieses Systems ist vor allem darin zu sehen, dass die damit durchgeführten Messungen sowohl schnell als auch reproduzierbar durchführbar sind. So ist mit diesem Geräteprototyp über die Durchführung von ca. 10 – 15 Einzelmessungen verschiedener Probenverdünnungen die Quantifizierung der Hemmwirkung von einer Probe pro Messtag möglich. Schlussfolgerung und Ausblick Die Untersuchungen zur Bestimmung der nitrifikationshemmenden Wirkung von Standardhemmstoffen, Abwasserproben und des N-BSB ergaben, dass die neu entwickelten Nitrifikanten-Biosensoren schnell und mit hoher Signalstabilität auf sich ändernde Hemmstoff- und Substratkonzentrationen reagieren und somit für die Klärwerksüberwachung prinzipiell einsetzbar sind

Noise-induced switching between vortex states with different polarization in classical two-dimensional easy-plane magnets

In the 2-dimensional anisotropic Heisenberg model with XY-symmetry there are non-planar vortices which exhibit a localized structure of the z-components of the spins around the vortex center. We study how thermal noise induces a transition of this structure from one polarization to the opposite one. We describe the vortex core by a discrete Hamiltonian and consider a stationary solution of the Fokker-Planck equation. We find a bimodal distribution function and calculate the transition rate using Langer's instanton theory (1969). The result is compared with Langevin dynamics simulations for the full many-spin model.Comment: 15 pages, 4 figures, Phys. Rev. B., in pres

Lifeworld Inc. : and what to do about it

Can we detect changes in the way that the world turns up as they turn up? This paper makes such an attempt. The first part of the paper argues that a wide-ranging change is occurring in the ontological preconditions of Euro-American cultures, based in reworking what and how an event is produced. Driven by the security – entertainment complex, the aim is to mass produce phenomenological encounter: Lifeworld Inc as I call it. Swimming in a sea of data, such an aim requires the construction of just enough authenticity over and over again. In the second part of the paper, I go on to argue that this new world requires a different kind of social science, one that is experimental in its orientation—just as Lifeworld Inc is—but with a mission to provoke awareness in untoward ways in order to produce new means of association. Only thus, or so I argue, can social science add to the world we are now beginning to live in

Understanding Dwarf Galaxies in order to Understand Dark Matter

Much progress has been made in recent years by the galaxy simulation community in making realistic galaxies, mostly by more accurately capturing the effects of baryons on the structural evolution of dark matter halos at high resolutions. This progress has altered theoretical expectations for galaxy evolution within a Cold Dark Matter (CDM) model, reconciling many earlier discrepancies between theory and observations. Despite this reconciliation, CDM may not be an accurate model for our Universe. Much more work must be done to understand the predictions for galaxy formation within alternative dark matter models.Comment: Refereed contribution to the Proceedings of the Simons Symposium on Illuminating Dark Matter, to be published by Springe

Memorials to the victims of Nazism: the impact on tourists in Berlin

This qualitative study explores tourist responses to memorials to the victims of Nazism in Berlin and the impact they have on the tourist experience. The findings are located in the field of study known as dark tourism, of which visiting memorials is a part. The analysis shows that tourists increased their knowledge of the crimes committed by the Nazis, thus fulfilling the educational function of memorials. Tourists were also overwhelmed by their experience; they attested to feelings of sadness, shock, anger, despair and incomprehension. These feelings made it hard for them to resume the role of tourist after their exposure to a memorial. There was acknowledgement of the extent of commemoration practised in Germany

Introduction: Re-imagining Cities in Africa

The introduction presents the key concepts and core arguments of this special issue Re-Imagining African Cities: The Arts and Urban Politics that results from a workshop hosted by the Visual Culture Research Group at the Department of Anthropology, University of Basel, in 2016. Summarising and presenting the essays, it offers insights into how urban imagination and the physical cities interrelate in urban aesthetic practices. How do artists articulate their experiences and observations of the city? What position and relevance do the material city, the city image and the urban imagination have in the practice of these visual and performing artists? How does their work relate to the urban as a social space on the one hand and as an imagined entity on the other? The African and diasporic cities of Kinshasa, Paris, Cape Town, Lagos, Bamenda, Freetown, Johannesburg and Kampala are both the sites and research subjects of the authors and of the artists they present. The focus on visual and performative arts provides the vehicle and the critical means of observing, articulating and representing these entanglements of the material cities, their images and their societal as well as artistic imagination

Utility of arsenic-treated bird skins for DNA extraction

Background: Natural history museums receive a rapidly growing number of requests for tissue samples from preserved specimens for DNA-based studies. Traditionally, dried vertebrate specimens were treated with arsenic because of its toxicity and insect-repellent effect. Arsenic has negative effects on in vivo DNA repair enzymes and consequently may inhibit PCR performance. In bird collections, foot pad samples are often requested since the feet were not regularly treated with arsenic and because they are assumed to provide substantial amounts of DNA. However, the actual influence of arsenic on DNA analyses has never been tested. Findings: PCR success of both foot pad and body skin samples was significantly lower in arsenic-treated samples. In general, foot pads performed better than body skin samples. Moreover, PCR success depends on collection date in which younger samples yielded better results. While the addition of arsenic solution to the PCR mixture had a clear negative effect on PCR performance after the threshold of 5.4 μg/μl, such high doses of arsenic are highly unlikely to occur in dried zoological specimens. Conclusions: While lower PCR success in older samples might be due to age effects and/or DNA damage through arsenic treatment, our results show no inhibiting effect on DNA polymerase. We assume that DNA degradation proceeds more rapidly in thin tissue layers with low cell numbers that are susceptible to external abiotic influences. In contrast, in thicker parts of a specimen, such as foot pads, the outermost horny skin may act as an additional barrier. Since foot pads often performed better than body skin samples, the intention to preserve morphologically important structures of a specimen still conflicts with the aim to obtain optimal PCR success. Thus, body skin samples from recently collected specimens should be considered as alternative sources of DNA

The effects of traditional, superset, and tri-set resistance training structures on perceived intensity and physiological responses.

PURPOSE: Investigate the acute and short-term (i.e., 24 h) effects of traditional (TRAD), superset (SS), and tri-set (TRI) resistance training protocols on perceptions of intensity and physiological responses. METHODS: Fourteen male participants completed a familiarisation session and three resistance training protocols (i.e., TRAD, SS, and TRI) in a randomised-crossover design. Rating of perceived exertion, lactate concentration ([Lac]), creatine kinase concentration ([CK]), countermovement jump (CMJ), testosterone, and cortisol concentrations was measured pre, immediately, and 24-h post the resistance training sessions with magnitude-based inferences assessing changes/differences within/between protocols. RESULTS: TRI reported possible to almost certainly greater efficiency and rate of perceived exertion, although session perceived load was very likely lower. SS and TRI had very likely to almost certainly greater lactate responses during the protocols, with changes in [CK] being very likely and likely increased at 24 h, respectively. At 24-h post-training, CMJ variables in the TRAD protocol had returned to baseline; however, SS and TRI were still possibly to likely reduced. Possible increases in testosterone immediately post SS and TRI protocols were reported, with SS showing possible increases at 24-h post-training. TRAD and SS showed almost certain and likely decreases in cortisol immediately post, respectively, with TRAD reporting likely decreases at 24-h post-training. CONCLUSIONS: SS and TRI can enhance training efficiency and reduce training time. However, acute and short-term physiological responses differ between protocols. Athletes can utilise SS and TRI resistance training, but may require additional recovery post-training to minimise effects of fatigue

HEE-GER: a systematic review of German economic evaluations of health care published 1990–2004

BACKGROUND: Studies published in non-English languages are systematically missing in systematic reviews of growth and quality of economic evaluations of health care. The aims of this study were: to characterize German evaluations, published in English or German-language, in terms of various key parameters; to investigate methods to derive quality-of-life weights in cost-utility studies; and to examine changes in study characteristics over the years. METHODS: We conducted a country-specific systematic review of the German and English-language literature of German economic evaluations (assessment of or application to the German health care system) published 1990–2004. Generic and specialized health economic databases were searched. Two independent reviewers verified fulfillment of inclusion criteria and extracted study characteristics. RESULTS: The fulltexts of 730 articles were reviewed of which 283 fulfilled all entry criteria. 32% of included studies were published in German-language. 51% of studies evaluated pharmaceuticals and 63% were cost-effectiveness analyses. Economic appraisals concentrate on few disease categories and important health areas are strongly underrepresented. Declaration of sponsorship was associated with article language (49% English articles vs. 29% German articles, p < 0.001). The methodology used to obtain quality-of-life weights in published cost-utility studies was very diverse, poorly reported and most studies did not use German patients' or community health state valuations. CONCLUSION: Many of the German-language evaluations included in our study are likely to be missing in international reviews and may be systematically different from English-language reviews from Germany. Lack of transparency and adherence to recommended reporting practices constitute a serious problem in German economic evaluations