273 research outputs found
Biologische Veränderungen im Versenkungsgebiet für schwach radioaktive Abfälle im Iberischen Tiefseebecken?
From 1979 to 2000, the site for the dumping of low-level radioactive wastes and an unaffected site in the North-east Atlantic were investigated to determine the biomass data of the benthopelagic nekton and the benthic organisms. The investigation shall demonstrate the influence on the biocoenosis of the so-called "artificial reef effect", caused by dumped waste drums. For sampling benthopelagic and benthic organisms, we used a modified Agassiz trawl, called the Deep-sea Closing Net. With the exception of the “Amperima event” in 1996 – a unique occurrence of a large number of sea-cucumbers – there was no change in the composition of benthopelagic and benthic organisms through the years. The biomass of the benthopelagic nekton was characterized by Macrouridae(rat-tailed fishes) and the main tax on of the benthos was Actiniaria (sea-anemones)
Entgiftungsstoffwechsel der Nordsee-Kliesche (Limanda limanda)
In the framework of monitoring programmes organized
under several sea protection conventions (HELSINKI Conv.,
OSPAR Conv.) the contracting parties are requested to
develop appropriate techniques for Biological-Effect-
Monitoring. In following these recommendations the Institut
for Fisheries Ecology studies the 7-ethoxyresorufin-
O-deethylase (EROD) activity in the liver of dab. EROD
represents one enzyme of the cytochrome P-450 species,
also called mixed function oxygenases (MFO), which is
induced by certain organic contaminants, e.g. PCBs. On
the other hand, an influence of natural factors like season,
temperature or spawning on the EROD activity may be
possible. The present study represents an insight into the
status of the EROD activity in North Sea dab. Ultimately,
we intend to decide if EROD activity is an appropriate tool
to detect effects of contaminants. The EROD activity in the
liver of 687 dabs, caught in the North Sea at different seasons in 1995 and 1996 with the fishery research vessel “Walther Herwig III”, has been determined and the data obtained have been statistically evaluated. The logarithmically transformed values of the EROD activity are following approximately a normal distribution. Due to the wide variation of the enzyme activities and due to the small
number of samples minor differences between samples are
not detectable. Nevertheless, comparing the enzyme
activities at different sites of the North Sea, some significant differences have been identified. A model for the discription of seasonal variations of EROD activity, developed at the Biologische Anstalt Helgoland, could be helpful for interpretation
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Congressional Careers, Committee Assignments, and Seniority Randomization in the US House of Representatives
This paper estimates the effects of initial committee seniority on the career histories of Democratic members of the House of Representatives from 1949 to 2006. When more than one freshman representative is assigned to a committee, positions in the seniority queue are established by lottery. Randomization ensures that queue positions are uncorrelated in expectation with other legislator characteristics within these groups. This natural experiment allows us to estimate the causal effect of seniority on a variety of career outcomes. Lower-ranked committee members areless likely to serve as subcommittee chairs on their initial committee; are more likely to transfer to other committees; and have fewer sponsored bills passed in the jurisdiction of their initial committee. On the other hand, there is little evidence that the seniority randomization has a net effect on reelection outcomes or noncommittee bills passed.GovernmentOther Research Uni
A Global 86GHz VLBI Survey of Compact Radio Sources
We present results from a large 86GHz global VLBI survey of compact radio
sources. The main goal of the survey is to increase by factors of 3--5 the
total number of objects accessible for future 3-mm VLBI imaging. The survey
observations reach the baseline sensitivity of 0.1Jy and image sensitivity of
better than 10 mJy/beam. The total of 127 compact radio sources have been
observed. The observations have yielded images for 109 sources, extending the
database of the sources imaged at 86GHz with VLBI observation by a factor of 5,
and only 6 sources have not been detected. The remaining 12 objects have been
detected but could not be imaged due to insufficient closure phase information.
Radio galaxies are less compact than quasars and BL Lacs on sub-milliarcsecond
scale. Flux densities and sizes of core and jet components of all imaged
sources have been estimated using Gaussian model fitting. From these
measurements, brightness temperatures have been calculated, taking into account
resolution limits of the data. The cores of 70% of the imaged sources are
resolved. The core brightness temperatures of the sources peak at K and only 1% have brightness temperatures higher than K.
Cores of Intraday Variable (IDV) sources are smaller in angular size than
non-IDV sources, and so yield higher brightness temperatures.Comment: 72 pages, 12 figures, accepted for publication in the Astronomical
Journa
Entweicht Radioaktivität aus den Abfallfässern im nordostatlantischen Versenkungsgebiet?
Radioactivity measured in samples from the NEA-Dumping-Site not only emanated from dumped barrels. Just as everywhere on the world also fallout from former nuclear weapon tests can be found there. Radionuclides which can emanate from different sources do not tell anything about their origin. To assess the fractions from various sources activity ratios from radionuclides can be used. There are different activity ratios for fallout and for waste from peaceful nuclear power engeneering. The comparison of the ratios of the plutonium isotopes Pu-238 and the sum of Pu-239 and Pu-240 (Pu-238/Pu-239,240) in benthic samples from the dumping site and from reference sites without waste dumping gives a clear hint. In the sampling period from 1980 to 2000 for samples from the dumping site this ratio increases significantly from 1986 on. Radioactivity emanating from the dumped barrels is regarded as causing this
Spatial Noise-Field Control With Online Secondary Path Modeling: A Wave-Domain Approach
Due to strong interchannel interference in multichannel active noise control (ANC), there are fundamental problems associated with the filter adaptation and online secondary path modeling remains a major challenge. This paper proposes a wave-domain adaptation algorithm for multichannel ANC with online secondary path modelling to cancel tonal noise over an extended region of two-dimensional plane in a reverberant room. The design is based on exploiting the diagonal-dominance property of the secondary path in the wave domain. The proposed wave-domain secondary path model is applicable to both concentric and nonconcentric circular loudspeakers and microphone array placement, and is also robust against array positioning errors. Normalized least mean squares-type algorithms are adopted for adaptive feedback control. Computational complexity is analyzed and compared with the conventional time-domain and frequency-domain multichannel ANCs. Through simulation-based verification in comparison with existing methods, the proposed algorithm demonstrates more efficient adaptation with low-level auxiliary noise.DP14010341
Pharmacokinetics and metabolism of eprinomectin in cats when administered in a novel topical combination of fipronil, (S)-methoprene, eprinomectin and praziquantel
AbstractFour studies were conducted to determine the pharmacokinetic characteristics and in vitro metabolism of eprinomectin, a semi-synthetic avermectin, in cats. Pharmacokinetic parameters including bioavailability of eprinomectin were determined in a parallel study design comprised of one group of eight cats which were treated once topically at 0.12mL/kg bodyweight with BROADLINE®, a novel combination product (fipronil 8.3% (w/v), (S)-methoprene 10% (w/v), eprinomectin 0.4% (w/v) and praziquantel 8.3% (w/v)), delivering a dose of 0.5mg eprinomectin per kg body weight, and a group of six cats which received 0.4% (w/v) eprinomectin at 0.4mg/kg bodyweight once by intravenous injection. For cats treated by topical application, the average eprinomectin (B1a component) maximum plasma concentration (Cmax) was 20ng/mL. The maximum concentrations were reached 24h after dosing in the majority of the animals (six of eight cats). The average terminal half-life was 114h due to slow absorption (‘flip-flop’ kinetics). Following intravenous administration the average Cmax was 503ng/mL at 5min post-dose, and the mean elimination half-life was 23h. Eprinomectin was widely distributed with a mean volume of distribution of 2390mL/kg, and the clearance rate was 81mL/h/kg. Mean areas under the plasma concentration versus time curves extrapolated to infinity were 2100ngh/mL and 5160ngh/mL for the topical and intravenous doses, respectively. Topical eprinomectin was absorbed with an average absolute bioavailability of 31%. In a second parallel design study, the dose proportionality of eprinomectin after single topical administration of BROADLINE® was studied. Four groups of eight cats each were treated once topically with 0.5, 1, 2 or 5 times the minimum recommended dose of the combination, 0.12mL/kg bodyweight. Based on comparison of areas under the plasma concentration versus time curves from the time of dosing to the last time point at which eprinomectin B1a was quantified, and Cmax, dose proportionality was established. In addition, the metabolic pathway of eprinomectin using cat liver microsomes, and plasma protein binding using cat, rat, and dog plasma were studied in vitro. Results of the analyses of eprinomectin B1a described here showed that it is metabolically stable and highly protein bound (>99%), and thus likely to be, as with other species, excreted mainly as unchanged parent drug in the feces of cats
Disorder-specific characteristics of borderline personality disorder with co-occurring depression and its comparison with major depression: An fMRI study with emotional interference task
AbstractBorderline personality disorder (BPD) and major depressive disorder (MDD) are both associated with abnormalities in the regulation of emotion, with BPD being highly comorbid with MDD. Disorder-specific dysfunctions in BPD, however, have hardly been addressed, hence the lack of knowledge pertaining to the specificity of emotion processing deficits and their commonality with MDD.24 healthy comparison subjects, 21 patients with MDD, and 13 patients with comorbid BPD and MDD (BPD+MDD group) were studied using functional MRI. The subjects were required to perform an emotional interference task that entailed categorizing facial affect while ignoring words that labeled the emotional contents of the external stimuli.Collapsing across emotional face types, we observed that participants with BPD+MDD uniquely displayed a greater involvement of the visual areas and the cerebellum. During emotional conflict processing, on the other hand, the lateral prefrontal cortex (LPFC) appeared to be affected in both patient groups. In comparison to the HC, the MDD group showed differences also in the posterior medial frontal cortex (pMFC) and the inferior parietal lobule (IPL).Thus, our data indicate dysfunctionality in the neural circuitry responsible for emotional conflict control in both disorders. The enhanced visual cortex activation in BPD+MDD suggests the visual system's hyperresponsiveness to faces at an early perceptual level. Not being associated with co-occurring depression, this effect in BPD+MDD appears to represent specific personality traits such as disturbed reactivity toward emotionally expressive facial stimuli
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