Estimating Bat and Bird Mortality Occurring at Wind Energy Turbines from Covariates and Carcass Searches Using Mixture Models

Environmental impacts of wind energy facilities increasingly cause concern, a central issue being bats and birds killed by rotor blades. Two approaches have been employed to assess collision rates: carcass searches and surveys of animals prone to collisions. Carcass searches can provide an estimate for the actual number of animals being killed but they offer little information on the relation between collision rates and, for example, weather parameters due to the time of death not being precisely known. In contrast, a density index of animals exposed to collision is sufficient to analyse the parameters influencing the collision rate. However, quantification of the collision rate from animal density indices (e.g. acoustic bat activity or bird migration traffic rates) remains difficult. We combine carcass search data with animal density indices in a mixture model to investigate collision rates. In a simulation study we show that the collision rates estimated by our model were at least as precise as conventional estimates based solely on carcass search data. Furthermore, if certain conditions are met, the model can be used to predict the collision rate from density indices alone, without data from carcass searches. This can reduce the time and effort required to estimate collision rates. We applied the model to bat carcass search data obtained at 30 wind turbines in 15 wind facilities in Germany. We used acoustic bat activity and wind speed as predictors for the collision rate. The model estimates correlated well with conventional estimators. Our model can be used to predict the average collision rate. It enables an analysis of the effect of parameters such as rotor diameter or turbine type on the collision rate. The model can also be used in turbine-specific curtailment algorithms that predict the collision rate and reduce this rate with a minimal loss of energy production.German Federal Ministry for the Environment, Nature Conservation and Nuclear Safety/FKZ 0327638 A,

Multifluid flows with weak and strong discontinuous interfaces using an elemental enriched space

In a previous paper, the authors presented an elemental enriched space to be used in a finite-element framework (EFEM) capable of reproducing kinks and jumps in an unknown function using a fixed mesh in which the jumps and kinks do not coincide with the interelement boundaries. In this previous publication, only scalar transport problems were solved (thermal problems). In the present work, these ideas are generalized to vectorial unknowns, in particular, the incompressible Navier-Stokes equations for multifluid flows presenting internal moving interfaces. The advantage of the EFEM compared with global enrichment is the significant reduction in computing time when the internal interface is moving. In the EFEM, the matrix to be solved at each time step has not only the same amount of degrees of freedom (DOFs) but also the same connectivity between the DOFs. This frozen matrix graph enormously improves the efficiency of the solver. Another characteristic of the elemental enriched space presented here is that it allows a linear variation of the jump, thus improving the convergence rate, compared with other enriched spaces that have a constant variation of the jump. Furthermore, the implementation in any existing finite-element code is extremely easy with the version presented here because the new shape functions are based on the usual finite-element method shape functions for triangles or tetrahedrals, and once the internal DOFs are statically condensed, the resulting elements have exactly the same number of unknowns as the nonenriched finite elements.Peer ReviewedPreprin

Ultrapure sinewave generation by combining Josephson systems

Peer Reviewe

Territorial songs indicate male quality in the sac-winged bat Saccopteryx bilineata (Chiroptera, Emballonuridae)

Defense of territories in many animal species involves the advertisement of territory holder quality by acoustic signaling. In the sac-winged bat Saccopteryx bilineata, males engage in territorial countersinging when reoccupying their day-roost territories in the morning and in the evening before abandoning the roost for the night. Females roost mainly in male territories, and territory holders are reproductively more successful than nonterritorial males. In territorial songs of male S. bilineata, we distinguished 6 syllable types and parameterized their acoustic properties. The analysis of 11 microsatellite loci allowed assignments of juveniles to their parents. Males had a higher reproductive success both when they uttered more territorial songs per day and when their long buzz syllables had a lower end frequency of the fundamental harmonic. Long buzzes had a harsh quality due to a pulsation of the fundamental frequency at the syllable onset and also had the highest sound pressure level of all syllable types in most territorial songs. Territorial songs and especially long buzz syllables are thus likely to advertise territory holder quality and competitive abilit

Fetal trans-apical stent delivery into the pulmonary artery: prospects for prenatal heart-valve implantation

OBJECTIVE The purpose of this study was to assess the technical feasibility of a fetal trans-apical stent delivery into the pulmonary artery using a novel hybrid-intervention technique as a possible route for prenatal minimally invasive heart-valve-implantation approaches. METHODS Pregnant Pre-Alp sheep between 122 and 128 days' gestation (n=3) underwent a midline laparotomy. The fetus was left in utero or partially externalized and its chest was opened via a left-sided minithoracotomy. The fetal heart was cannulated and a guide wire was introduced through the ductus arteriosus into the aorta. A 14-French delivery system was then mounted onto the guide wire and advanced to the landing zone in the pulmonary artery, where the stent was deployed. The position of the stent was confirmed using echocardiography, angiography as well as computed tomography. RESULTS The trans-apical implantation was successful in all animals. However, at necropsy in one animal, the stent was found to partly occlude one of the pulmonary valvular leaflets. Bleeding at the antero-apical incision occurred in all animals but could be managed without fetal demise. No fetal cardiopulmonary bypass was performed. In all animals, contrast angiography displayed normal perfusion of the pulmonary vasculature as well as the ductus arteriosus. CONCLUSIONS Our study demonstrates the principal technical feasibility of a prenatal stent delivery into the pulmonary artery using a novel trans-apical hybrid-intervention technique. This approach demonstrates the first step towards possible future minimally invasive prenatal heart-valve-implantation procedure

Reduktion des Kollisionsrisikos von Fledermäusen an Onshore-Windenergieanlagen (RENEBAT II)

Fledermausschlagopfer an Windenergieanlagen (WEA) treten an vielen Standorten und teilweise in erheblichen Zahlen auf. Eine Reduktion der Schlagopferzahlen ist aus artenschutzrechtlichen Gründen unverzichtbar und auch für die Akzeptanz des Ausbaus der Windenergie wichtig. Im vorangegangenen Forschungsvorhaben RENEBAT I wurde eine Methode entwickelt, mit der das Schlagrisiko für Fledermäuse an WEA quantifiziert und über anlagenspezifische Betriebsalgorithmen reduziert werden kann. Zentrale Ziele des Forschungsvorhabens RENEBAT II waren die Validierung und Weiterentwicklung der fledermausfreundlichen Betriebsalgorithmen. Getestet wurde der fledermausfreundliche Betrieb an 16 WEA in 8 Windparks (2 WEA je Windpark) in mehreren Naturräumen im Bundesgebiet. Dieser Praxistest konnte zeigen, dass die in RENEBAT I entwickelten statistischen Modelle die Schlagopferzahlen an den untersuchten Anlagen mit hoher Genauigkeit voraussagen können und, dass der fledermausfreundliche Betriebsalgorithmus dazu geeignet ist, das Schlagrisiko mit hoher Präzision auf einen festgelegten Wert des verbleibenden Kollisionsrisikos zu reduzieren. Die Kosten für dieses Vorgehen konnten beispielhaft ermittelt werden. Ein weiteres wichtiges Ziel war die Integration der Forschungsergebnisse in die Planungspraxis. Als Handreichungen für die Praxis wurden daher ein Leitfaden für eine akustische Gondelerfassung an WEA und ein Statistiktool zur Berechnung der tatsächlichen Schlagopferzahl aus der Anzahl gefundener toter Fledermäuse entwickelt. Außerdem wurden die Regelwerke und Empfehlungen einzelner Bundesländer zur Berücksichtigung von Fledermäusen beim Bau und Betrieb von WEA zusammengefasst. Darüber hinaus wurden neue Ansätze zur Verbesserung und Vereinfachung der Erfassung von Fledermäusen an WEA entwickelt und erprobt. Ein Detektorsystem wurde neu entwickelt, das sich als wenig anfällig gegenüber Störgeräuschen erwies und in der Lage war mit hoher Empfindlichkeit und sehr selektiv Fledermausrufe aufzuzeichnen. Um mit verschiedenen Detektorsystemen erfasste Daten miteinander vergleichen zu können, wurde ein Laboraufbau entwickelt, mit dem verschiedene Aspekte der Detektortechnik standardisiert und reproduzierbar untersucht werden können. Der Einsatz eines Helligkeitssensors konnte keine eindeutige Korrelation zwischen der Helligkeit in der Nacht und der Aktivität von Fledermäusen an WEA zeigen. Durch die Messung der Fledermausaktivität mittels 3D-Wärmebilderfassung konnte der erste überzeugende Nachweis geführt werden, dass WEA einen anziehenden Effekt auf Fledermäuse haben. Dies ermöglichte auch die Berechnung von Skalierungsfaktoren für die Berechnung des Schlagrisikos an WEA mit verschiedenen Rotordurchmessern.Bundesministerium für Umwelt, Naturschutz und Reaktorsicherheit/0327638C+

Dynamics of urinary and respiratory shedding of Severe acute respiratory syndrome virus 2 (SARS-CoV-2) RNA excludes urine as a relevant source of viral transmission

PURPOSE To investigate the expression of the receptor protein ACE-2 alongside the urinary tract, urinary shedding and urinary stability of SARS-CoV-2 RNA. METHODS Immunohistochemical staining was performed on tissue from urological surgery of 10 patients. Further, patients treated for coronavirus disease (COVID-19) at specialized care-units of a university hospital were assessed for detection of SARS-CoV-2 RNA in urinary samples via PCR, disease severity (WHO score), inflammatory response of patients. Finally, the stability of SARS-CoV-2 RNA in urine was analyzed. RESULTS High ACE-2 expression (3/3) was observed in the tubules of the kidney and prostate glands, moderate expression in urothelial cells of the bladder (0-2/3) and no expression in kidney glomeruli, muscularis of the bladder and stroma of the prostate (0/3). SARS-CoV-2 RNA was detected in 5/199 urine samples from 64 patients. Viral RNA was detected in the first urinary sample of sequential samples. Viral RNA load from other specimen as nasopharyngeal swabs (NPS) or endotracheal aspirates revealed higher levels than from urine. Detection of SARS-CoV-2 RNA in urine was not associated with impaired WHO score (median 5, range 3-8 vs median 4, range 1-8, p = 0.314), peak white blood cell count (median 24.1 × 1000/ml, range 5.19-48.1 versus median 11.9 × 1000/ml, range 2.9-60.3, p = 0.307), peak CRP (median 20.7~mg/dl, 4.2-40.2 versus median 11.9~mg/dl, range 0.1-51.9, p = 0.316) or peak IL-6 levels (median: 1442~ng/ml, range 26.7-3918 versus median 140~ng/ml, range 3.0-11,041, p = 0.099). SARS-CoV-2 RNA was stable under different storage conditions and after freeze-thaw cycles. CONCLUSIONS SARS-CoV-2 RNA in the urine of COVID-19 patients occurs infrequently. The viral RNA load and dynamics of SARS-CoV-2 RNA shedding suggest no relevant route of transmission through the urinary tract