First evidences of multiple breeding of Nuthatch Sitta europaea in the long-term population study around Braunschweig/North Germany

Im Braunschweiger Raum werden Daten von in künstlichen Nisthöhlen brütenden Kleibern in zahlreichen Untersuchungsgebieten bereits seit den frühen 1950er Jahren erfasst. 2004 gelangen erstmals für die Untersuchungsregion Zweitbrut-Nachweise. In beiden Fällen war der Ausfliegeerfolg in der ersten Brut nur gering. Zweitgelege folgten jeweils auf eine frühe Erstbrut.In numerous study areas near Braunschweig/Lower Saxony data of Nuthatches, breeding in artificial nestboxes, were recorded since the early 1950s. In 2004 the first evidences of second broods for this region could be established. In both cases of multiple breeding the number of fledged young in the first brood was only low. The second clutches followed on early first broods

Are tits Parus spp. and other hole-nesting passerines preferring at the choice of their breeding holes the weather-opposing side?

Von 1994 bis 2003 erfassten wir in einem Braunschweiger Untersuchungsgebiet die Brutbesiedlung von Nistkastenrondellen (jeweils 8 Höhlen rings um einen Eichenstamm). Wenn ein Rondell im selben Jahr von 2 Brutpaaren genutzt wurde, ging in die Auswertung nur die Wahl des Erstbesiedlers ein. Erstbesiedler waren 74 x Kohlmeisen Parus major, 7 x Blaumeisen Parus caerulus, 28 x Kleiber Sitta europaea, 34 x Trauerschnäpper Fidecula hypoleuca und 4 x Stare Sturnus vulgaris. Die meisten dieser Paare wählten Nisthöhlen, deren Eingang nach Osten (NE, E, SE) zeigte. Die stärkste Bevorzugung für den wetterabgewandten Ostsektor ließ sich bei Fidecula hypoleuca feststellen. Bei Nistkästen mit nach Osten weisendem Einflugloch dürfte das Risiko für Brutverluste durch Feuchtigkeit und/oder Überhitzung minimiert werden. Allerdings kann das Ergebnis der experimentellen Studie nicht auf die Situation von Naturhöhlen übertragen werden. Denn in benachbarten Waldparzellen waren die vom Star zur Brut genutzten Naturhöhlen (n = 72) bevorzugt in westliche Richtungen orientiert. Sekundäre Höhlenbrüter können ihre Präferenz hinsichtlich der Ausrichtung des Höhleneingangs unter natürlichen Verhältnissen offenbar nur eingeschränkt oder gar nicht realisieren, weil sich das Naturhöhlenangebot witterungsbedingt vor allem im S/SW-Sektor befindet.From 1994 until 2003 we recorded the settlement of hole-nesting passerines in nestbox-rondells (8 nestboxes around an oaktree, study area near Brunswick, Lower Saxony/Germany). Nearly all of the nestbox-rondells were used by at least one breeding pair per annum of great tit Parus major, blue tit Parus caeruleus, nuthatch Sitta europaea, pied flycatcher Ficedula hypoleuca, or starling Sturnus vulgaris. Most pairs used for their breeding holes easterly directions (NE, E, SE), the strongest preference was shown by Ficedula hypoleuca (at rondells with more than one breeding pair only the choice of “first settlers” were included). The east side is the weather-opposing side with less moisture and heat inside the hole and probably better breeding success. Breeding-hole choice in the nestbox-rondells are, however, not identical with the situation in natural holes. Our study showed that the majority of natural holes in which starlings are breeding are south-west orientated as a consequence of a higher offer of natural holes at the weather-facing side

Pricing Kernels and Risk Premia implied in Bitcoin Options

Bitcoin Pricing Kernels (PKs) are estimated using a novel data set from Deribit, the leading Bitcoin options exchange. The PKs, as the ratio between risk-neutral and physical density, dynamically reflect the change in investor preferences. Thus, the PKs improve the understanding of investor expectations and risk premiums in a new asset class. Bootstrap-based confidence bands are estimated in order to validate the results. Investors are heterogeneous in their risk profiles and preferences with respect to volatility and investment horizon. The empirical PKs turn out to be U-shaped for short-dated instruments and W-shaped for long-dated instruments. We find that investors are willing to pay a substantial risk premium to insure themselves against short-term price movements. The risk premium is smaller for longer-dated instruments and their traders are risk averse. The shape of the empirical PKs reveals the existence of a time-varying risk premium. The similarity between the shape of empirical PKs for Bitcoin and other markets that represent aggregate wealth shows that Bitcoin is becoming an established asset class.Deutsche ForschungsgemeinschaftCzech Science FoundationPeer Reviewe

Molecular genetic evidence for mixed maternity in broods of the Coal Tit Parus ater

Mittels molekulargenetischer Elternschaftsanalyse wurde eine niedrige Rate gemischter Mutterschaften in Bruten der sozial monogamen Tannenmeise nachgewiesen, einer Art, die sich durch hohe Fremdvaterschaftsraten auszeichnet. Gemischte Mutterschaften wurden in vier (= 0,8 %) von 483 Bruten entdeckt und nur für zehn (= 0,3 %) von 3563 erfolgreich genotypisierten Nachkommen wurde die Putativmutter von der genetischen Mutterschaft ausgeschlossen. In Anbetracht dieser sehr niedrigen Rate kann in evolutionsbiologischen Studien der soziale Fortpflanzungserfolg mit dem genetischen Fortpflanzungserfolg für Weibchen der Tannenmeise ohne weiteres gleichgesetzt werden. Die Putativväter wurden ebenfalls in allen Fällen von der genetischen Elternschaft ausgeschlossen, was Quasiparasitismus als Erklärung für gemischte Mutterschaften ausschließt. In einem Fall konnten die Partner eines Brutpaares, das zeitgleich in der Nähe eine eigene Brut aufzog, zweifelsfrei als die genetischen Eltern eines einzelnen Nachkommen identifiziert werden. Mögliche Ursachen für das Auftreten gemischter Mutterschaften bei der Tannenmeise schließen die Übernahme von Nistkästen samt begonnenen Gelegen nach dem Tod oder Abwandern der Vorbesitzer und innerartlichen Brutparasitismus ein.Molecular genetic analysis of parentage revealed a low frequency of mixed maternity in broods of the Coal Tit, a socially monogamous passerine with a high frequency of extra-pair paternity. Mixed maternity was detected in four (= 0.8 %) out of 483 analysed broods. For ten (= 0.3 %) out of 3563 successfully genotyped offspring the attending putative (social) mother was excluded from genetic parentage. Given the very low frequency of mixed maternity, social reproductive success can conveniently be equated with genetic reproductive success for female Coal Tits in evolutionary studies. Attending putative fathers were excluded from genetic parentage in all cases, too, ruling out quasi-parasitism as a mechanistic explanation for mixed maternity. In one case, the pair members from an adjacent territory were unequivocally identified as the genetic parents of a single offspring (they were simultaneously attending their own brood). Possible mechanisms leading to mixed maternity broods in the Coal Tit may include nest/clutch take-over and intraspecific brood parasitism and their respective relevance is briefly discussed

Quantinar: a blockchain p2p ecosystem for honest scientific research

Living in the Information Age, the power of data and correct statistical analysis has never been more prevalent. Academics, practitioners and many other professionals nowadays require an accurate application of quantitative methods. Though many branches are subject to a crisis of integrity, which is shown in improper use of statistical models, $p$-hacking, HARKing or failure to replicate results. We propose the use of a peer-to-peer education network, Quantinar, to spread quantitative analysis knowledge embedded with code in the form of Quantlets. The integration of blockchain technology makes Quantinar a decentralised autonomous organisation (DAO) that ensures fully transparent and reproducible scientific research

Onset of phase diffusion in high kinetic inductance granular aluminum micro-SQUIDs

Superconducting granular aluminum is attracting increasing interest due to its high kinetic inductance and low dissipation, favoring its use in kinetic inductance particle detectors, superconducting resonators or quantum bits. We perform switching current measurements on DC-SQUIDs, obtained by introducing two identical geometric constrictions in granular aluminum rings of various normal-state resistivities in the range from ρ n = 250–5550 μΩ cm. The relative high kinetic inductance of the SQUID loop, in the range of tens of nH, leads to a suppression of the modulation in the measured switching current versus magnetic flux, accompanied by a distortion towards a triangular shape. We observe a change in the temperature dependence of the switching current histograms with increasing normal-state film resistivity. This behavior suggests the onset of a diffusive motion of the superconducting phase across the constrictions in the two-dimensional washboard potential of the SQUIDs, which could be caused by a change of the local electromagnetic environment of films with increasing normal-state resistivities

Implementation of a Transmon Qubit Using Superconducting Granular Aluminum

The high kinetic inductance offered by granular aluminum (grAl) has recently been employed for linear inductors in superconducting high-impedance qubits and kinetic inductance detectors. Because of its large critical current density compared to typical Josephson junctions, its resilience to external magnetic fields, and its low dissipation, grAl may also provide a robust source of nonlinearity for strongly driven quantum circuits, topological superconductivity, and hybrid systems. Having said that, can the grAl nonlinearity be sufficient to build a qubit? Here we show that a small grAl volume (10×200×500  nm$^{3}$) shunted by a thin film aluminum capacitor results in a microwave oscillator with anharmonicity α two orders of magnitude larger than its spectral linewidth Γ$_{01}$, effectively forming a transmon qubit. With increasing drive power, we observe several multiphoton transitions starting from the ground state, from which we extract α=2$_{π}$×4.48  MHz. Resonance fluorescence measurements of the |0⟩→|1⟩ transition yield an intrinsic qubit linewidth γ=2$_{π}$×10  kHz, corresponding to a lifetime of 16  μs, as confirmed by pulsed time-domain measurements. This linewidth remains below 2$_{π}$×150  kHz for in-plane magnetic fields up to ∼70  mT