5,734 research outputs found

    Seals at sea: modelling seal distribution in the German bight based on aerial survey data

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    The Wadden Sea is an important habitat for harbour seals and grey seals. They regularly haul-out on sandbanks and islands along the coast. Comparably little is known about the time seals spend at sea and how they use the remainder of the North Sea. Yet, human activity in offshore waters is increasing and information on seal distribution in the North Sea is crucial for conservation and management. Aerial line transect surveys were conducted in the German bight from 2002 to 2007 to investigate the distribution and abundance of marine mammals. Distance sampling methodology was combined with density surface modelling for a spatially explicit analysis of seal distribution in the German North Sea. Depth and distance to coast were found to be relevant predictor variables for seal density. Density surface modelling allowed for a depiction of seal distribution in the study area as well as an abundance estimate. This is the first study to use aerial survey data to develop a density surface model (DSM) for a spatially explicit distribution estimate of seals at se

    A para-differential renormalization technique for nonlinear dispersive equations

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    For \alpha \in (1,2) we prove that the initial-value problem \partial_t u+D^\alpha\partial_x u+\partial_x(u^2/2)=0 on \mathbb{R}_x\times\mathbb{R}_t; u(0)=\phi, is globally well-posed in the space of real-valued L^2-functions. We use a frequency dependent renormalization method to control the strong low-high frequency interactions.Comment: 42 pages, no figure

    Hydrothermisch behandelte Lupinen zur Eiweißversorgung der Milchkuh

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    According to producer statements hydrothermal treatment of lupines increases the amount of rumen undegradable protein (UDP) from 20 % to 45 % and nXP values from 196 to 245 g/kg thus providing sufficient protein for dairy cows. To evaluate the effects of hydrothermal treatment on nutritive value of lupines, intestinal protein supply and lactation performance as well as economical and ecological efficiency, a nine months feeding trial was carried out at the Agricultural Centre Haus Riswick, Kleve. Two groups of 20 cows blocked by milk yield, parity and expected calving date were fed a forage diet of grass-clover and corn silage enriched with 3 kg of concentrates (46 % blue lupine, 41 % triticale, 10 % wheat bran, 2 % mineral feed, 1 % rape oil), sufficient for 25 kg ECM (DLG, 2001). Nutrient values per kg dry matter were as follows (control/experiment): 6,8 / 6,8 MJ NEL, 168 / 168 g XP, 144 / 148 g nXP, 3,9 / 3,2 g RNB. Nutritive value of lupines was determined by feeding wethers according to standard procedure (GfE, 1991). Protein fractions were analysed according to Shannak et al. (2000). Experimental groups varied only in lupine treatment (Börde Kraftkorn, Gröningen, GER). Yield of natural and energy corrected milk (ECM), milk fat and milk protein were higher in cows fed treated lupines (p <0,001). Urea nitrogen concentration was marginally lower compared to controls (p <0,001). Improvement of lactational performance was slightly higher during the first 100 days of lactation, but persisted during the whole lactational period. Body weight and condition were not affected by treatment. Improved lactational performance resulted in an overall better economic result

    Photonic chip based optical frequency comb using soliton induced Cherenkov radiation

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    By continuous wave pumping of a dispersion engineered, planar silicon nitride microresonator, continuously circulating, sub-30fs short temporal dissipative solitons are generated, that correspond to pulses of 6 optical cycles and constitute a coherent optical frequency comb in the spectral domain. Emission of soliton induced Cherenkov radiation caused by higher order dispersion broadens the spectral bandwidth to 2/3 of an octave, sufficient for self referencing, in excellent agreement with recent theoretical predictions and the broadest coherent microresonator frequency comb generated to date. In a further step, this frequency comb is fully phase stabilized. The ability to preserve coherence over a broad spectral bandwidth using soliton induced Cherenkov radiation marks a critical milestone in the development of planar optical frequency combs, enabling on one hand application in e.g. coherent communications, broadband dual comb spectroscopy and Raman spectral imaging, while on the other hand significantly relaxing dispersion requirements for broadband microresonator frequency combs and providing a path for their generation in the visible and UV. Our results underscore the utility and effectiveness of planar microresonator frequency comb technology, that offers the potential to make frequency metrology accessible beyond specialized laboratories.Comment: Changes: - Added data (new Fig.4) on the first full phase stabilization of a dissipative Kerr soliton (or dissipative cavity soliton) in a microresonator - Extended Fig. 8 in the SI - Introduced nomenclature of dissipative Kerr solitons - Minor other change

    Temporal Variability of Urinary Phthalate Metabolite Levels in Men of Reproductive Age

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    Phthalates are a family of multifunctional chemicals widely used in personal care and other consumer products. The ubiquitous use of phthalates results in human exposure through multiple sources and routes, including dietary ingestion, dermal absorption, inhalation, and parenteral exposure from medical devices containing phthalates. We explored the temporal variability over 3 months in urinary phthalate metabolite levels among 11 men who collected up to nine urine samples each during this time period. Eight phthalate metabolites were measured by solid-phase extraction–high-performance liquid chromatography–tandem mass spectrometry. Statistical analyses were performed to determine the between- and within-subject variance apportionment, and the sensitivity and specificity of a single urine sample to classify a subject’s 3-month average exposure. Five of the eight phthalates were frequently detected. Monoethyl phthalate (MEP) was detected in 100% of samples; monobutyl phthalate, monobenzyl phthalate, mono-2-ethylhexyl phthalate (MEHP), and monomethyl phthalate were detected in > 90% of samples. Although we found both substantial day-to-day and month-to-month variability in each individual’s urinary phthalate metabolite levels, a single urine sample was moderately predictive of each subject’s exposure over 3 months. The sensitivities ranged from 0.56 to 0.74. Both the degree of between- and within-subject variance and the predictive ability of a single urine sample differed among phthalate metabolites. In particular, a single urine sample was most predictive for MEP and least predictive for MEHP. These results suggest that the most efficient exposure assessment strategy for a particular study may depend on the phthalates of interest

    First evidence for fin whale migration into the Pacific from Antarctic feeding grounds at Elephant Island

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    Funding: This work was funded by IWC-SORP and by the DFG within the priority programme SPP 1158 ‘Antarctic Research with comparative investigations in Arctic ice areas’ by grant HE5696/3-1. Additional funding from National Geographic / Disney+ supported field efforts by Hickmott.This study presents the first long-distance tracks of fin whales (Balaenoptera physalus) equipped with satellite transmitters off the Antarctic Peninsula. Southern Hemisphere fin whales were severely depleted by twentieth century industrial whaling, yet recently, they have returned to historical feeding grounds off the northern Antarctic Peninsula, forming large aggregations in austral summers. To date, our knowledge only extended to summer behaviour, while information regarding migration routes and the location of breeding and wintering grounds are lacking. During the austral autumn of 2021, we deployed nsatellite transmitters on four fin whales at Elephant Island. Two transmitters stopped working while the animals were still at the feeding grounds, while two continued to transmit during the transition from feeding activity to migration. Both migrating animals left the feeding ground on 15 April 2021, travelling northward into the Pacific and up along the Chilean coast. The most northerly position received before all tags stopped transmitting on 1 May 2021 was at 48°S. These tracks provide initial evidence of seasonal migratory routes and a first indication toward possible locations of winter destinations. This information, even if preliminary, is critical for investigations of population connectivity, population structure and the identification of breeding grounds of Southern Hemisphere fin whales.Publisher PDFPeer reviewe

    Quantum Control of the Hyperfine Spin of a Cs Atom Ensemble

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    We demonstrate quantum control of a large spin-angular momentum associated with the F=3 hyperfine ground state of 133Cs. A combination of time dependent magnetic fields and a static tensor light shift is used to implement near-optimal controls and map a fiducial state to a broad range of target states, with yields in the range 0.8-0.9. Squeezed states are produced also by an adiabatic scheme that is more robust against errors. Universal control facilitates the encoding and manipulation of qubits and qudits in atomic ground states, and may lead to improvement of some precision measurements.Comment: 4 pages, 4 figures (color

    Molecular Identification of Lactic Acid Bacteria Occurring in Must and Wine

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    A specifically amplified polymorphic DNA-polymerase chain reaction (SAPD-PCR), a molecularfingerprinting method based on the amplification of specific gene sequences, was applied in order to allowa rapid identification of lactic acid bacteria (LAB) occurring in must and wine. The applicability of thismethod was confirmed with isolated strains from different wine samples from the German wine growingregion Palatinate. In addition, the formation of biogenic amines by the isolated strains was studied. Morethan half of the bacterial isolates from 50 red and white wine samples were able to produce biogenic amines.General health concerns related to biogenic amines in must and wine underline the need for an identificationof these species. The majority of the isolated strains were assigned to the species Lactobacillus brevis. Themajor biogenic amines in the investigated wines which were detected by thin-layer chromatography andHPLC were tyramine, histamine and ethylamine
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