210 research outputs found
Zum Stellenwert von Fischmehl in der Aquakultur
The worldwide aquaculture production amounts to about one third of the world fishery catch. While the world fishery catch in the last years is stagnating and an increase is not to be expected, the aquaculture rose by about 10 % annually. This rate of growth is also predicted for the next years. Fish meal and oil forms a key position for the further development of aquaculture, specially for carnivorous fish species, of which the salmonids will gain an increasing economic importance, not only on the European, but also on the Japanese and American markets. Without an adequate supply of fish meal and oil for the production of these fish species, the expected product quality cannot be realized under economic conditions. Fish meal and oil are commonly produced from small pelagic fish species, which, at present and in the near future, have no importance for direct human consumption. Since December2000 the use of fish meal and oil in Germany is only allowed for use in aquaculture and petfood. However, conclusive arguments for a ban on the utilization for other animal feeds do not exist so far. The European Union continues to allows feeding of other animals – except ruminants – with fish meal under certain control measures
Sensibilität von Seefischen an Bord. Teil 3: Untersuchungen an demersalen Fischarten der Barentssee
In previous papers the sensibility of pelagic and demersal fishes caught at depth of up to 80 m was reported. This paper deals with the sensitiveness of flatfishes, gadids, and redfish caught at depth between 260 and 450 m and with trawling times between 1 and 6 h. The sensitiveness of the fishes was tested according to the method described in previous publications (Münkner et. al. 1998) after 10 min keeping in running sea water and after 1h bulk storage respectively. The sensitiveness of the fishes increased from cod to saithe to haddock. Surprisingly American plaice and Greenland halibut turned out to be very sensitive, far more sensitive than plaice and dab caught at lower depths in the North Sea. This was indicated by the high amount of animals showing rigor already after a trawling time of 2 hand 10 min of keeping in seawater. After 1 h of bulk storage and increasing trawling time sensitiveness of all fishes decreased, as expected, significantly. Besides mechanical encroachments the main problem for the fishes caught at greater depths was the gas supersaturation in the blood and tissue causing blockage of the gill capillary vessels, exophthalmus, visible gas bubbles in the skin and eyes, and in some cases protusion of the intestines through the snout due to rapid dilatation of the swimbladder
Sensibilität von Seefischen an Bord. Teil 2: Demersale und pelagische Fischarten aus Schleppnetzfängen in der Nord- und Ostsee
The sensitiveness of different demersal and pelagic fish
species of 70 hauls in the North and Baltic Sea in water
depths of 60 to 250 m and 15 to 80 m, respectively,
amount of catch of 100 to 3500 kg and trawling times of
0,5 to 6 h on board of the FRV “Walther Herwig III” was
investigated. Some demersal fish species , e.g. saithe
(Pollachius virens), were even still sensitive, when caught
at a water depth of 250 m at a trawling time of 1,5 h.
Generally the number of sensitive fishes was reduced
with increasing water depth, amount of catch, trawling
time and following storage of the catch on board. Among
demersal fishes the species without swimbladder and flat
fishes were clearly more resistent to mechanical stress.
On the contrary, pelagic fish species were generally less
robust. After trawling times of 2 h no sensitive animals
were observed. In some fisheries there are mixed catches
of demersal and pelagic fish species with different
sensitiveness. In commercial fisheries, there is therefore
– under animal welfare aspects – for the time being, no
prospect for an improvement of the catching and
slaughtering procedure on boar
Untersuchungen zur Sensibilität von Seefischen an Bord
First orientating investigations of the sensitiveness of the fish species dab (Limanda limanda), plaice (Pleuronectes platessa) and cod (Gadus morhua) immediately after catch and after different duration of bulk storage were carried out on board the fishing research vessel “Solea”. The aim of the investigations was to get an idea wether or not the central nervous system of the fishes was in function and the fishes could suffer pain. The proportion of sensitive dab, plaice and cod immediately after the catch was higher than 70, 80 and 95 %, respectively. After 30 min of bulk storage the percentage was reduced to 50, 60 and 70 % resp., after 90 minutes to 5, 15 % and 35 %. In cod it decreased further to 5 % after 120 min. An influence of trawling time (0,5 - 2 h) or size of the catch (100 to 1000 kg) on the number of sensitive
animals was not found. Although fishing parameters in commercial fishery will in most cases put a stronger mechanical stress on the animals during trawling and handling on board a certain number of sensitive fish can still be expected
Evaluation of renal Kt/V as a marker of renal function in predialysis patients
Evaluation of renal Kt/V as a marker of renal function in predialysis patients.BackgroundThe use of renal Kt/V (r-Kt/V) as an indicator for the need of dialysis initiation has been recommended in the NKF-DOQI guidelines. In analogy to clinical practice in peritoneal dialysis, a fall of r-Kt/V below a threshold of 2.0 per week may indicate inadequate renal toxin elimination. However, there are no studies linking r-Kt/V with other parameters of glomerular filtration rate (GFR) in predialysis patients, and the validity of r-Kt/V as parameter for timing of dialysis initiation is unknown.MethodsRenal function was assessed repeatedly in 125 patients (N = 465 measurements). In predialysis patients (r-Kt/V <2.5 per week) r-Kt/V was compared with creatinine [CCr], urea [CUr], averaged creatinine/urea clearance [CCr/Ur], Cockcroft-Gault formula [CCG], and MDRD prediction equation 6 (MDRD6-GFR). The diagnostic performance of r-Kt/V as a parameter for timing the initiation of dialysis was evaluated.ResultsRenal Kt/V <2.5 was prevalent in 24.9% of cases (N = 116, mean 1.92 ± 0.34). In this group mean CCr was 13.8 ± 4.9, mean CUr 6.7 ± 1.3, and CCr/Ur 10.2 ± 2.9mL/min/1.73m2. There was no correlation of r-Kt/V with serum creatinine and MDRD6-GFR, but a significantly positive correlation with CCr/Ur (r2 = 0.3382, P < 0.001). Sensitivity of r-Kt/V to detect CCr/Ur < 10.5mL/min/1.73m2, defined as the threshold for dialysis initiation, was 73.6% with a specificity of 91.9%.ConclusionsThese results suggest that r-Kt/V is a parameter of acceptable specificity but poor sensitivity for the timing of dialysis initiation. Additional measures of renal function, such as the average of measured creatinine and urea clearance, also should be taken into consideration when deciding on the timing of dialysis initiation prior to the development of clinical signs of uremia and malnutrition
Erosion, Erneuerung, Umnutzung: Arbeitgeberverbände und ihr Umgang mit dem Flächentarifvertrag am Beispiel der ERA-Einführung in der Metall- und Elektroindustrie
"Die in den letzten zwei Jahrzehnten anhaltende Erosion des Flächentarifvertragssystems in Deutschland gefährdet den ordnungspolitischen Anspruch der tarifvertraglichen Regelung von Arbeitsstandards. Mit den Entgeltrahmenabkommen (ERA) haben die Tarifparteien in der Metall- und Elektroindustrie einen ambitionierten Ansatz zur (Re-)Stabilisierung tariflicher Ordnungs- und Gestaltungsfunktion verfolgt. Der Beitrag arbeitet auf der Basis empirisch-soziologischer Begleitforschung in den Tarifregionen Baden-Württemberg und Niedersachsen heraus, wie die strategischen Zielsetzungen einer Modernisierung von Entgeltstrukturen von den Arbeitgeberverbänden regional unterschiedlich konzipiert, interpretiert und umgesetzt werden und wie sie dabei strategische Varianten des Umgangs mit dem Flächentarifvertrag begründen, die die Ausgestaltung der Tarifnormen sowie die Umsetzungsprozesse und -ergebnisse unterschiedlich prägen." (Autorenreferat)"The erosion of the German system of collective bargaining during the last two decades is threatening the effectiveness of collective regulation of wages and working standards. With the introduction of the new Single Status Pay Agreement (ERA), both sides, the employers' association and the trade union, initiated an ambitious attempt to (re)stabilize the system of collective bargaining in the metalworking industry. The article presents findings from an empirical sociological study of the implementation of ERA in two regions, Baden-Wurttemberg and Lower Saxony. The article shows that the strategic objectives of modernizing the pay system are conceptualized, interpreted and implemented quite differently by the regional employers' associations. Therefore, the article argues, the resulting differences of strategy lead to different collective standards, and shape the process and outcome of pay structure reform." (author's abstract
Magnetic properties of (VO)_2P_2O_7: two-plane structure and spin-phonon interactions
Detailed experiments on single-crystal (VO)_2P_2O_7 continue to reveal new
and unexpected features. We show that a model composed of two, independent
planes of spin chains with frustrated magnetic coupling is consistent with
nuclear magnetic resonance and inelastic neutron scattering measurements. The
pivotal role of PO_4 groups in mediating intrachain exchange interactions
explains both the presence of two chain types and their extreme sensitivity to
certain lattice vibrations, which results in the strong magnetoelastic coupling
observed by light scattering. We compute the respective modifications of the
spin and phonon dynamics due to this coupling, and illustrate their observable
consequences on the phonon frequencies, magnon dispersions, static
susceptibility and specific heat.Comment: 10 pages, 9 figure
Interannual differences in larval haddock survival : hypothesis testing with a 3D biophysical model of Georges Bank
Author Posting. © The Author(s), 2014. This is the author's version of the work. It is posted here by permission of John Wiley & Sons for personal use, not for redistribution. The definitive version was published in Fisheries Oceanography 23 (2014): 521–553, doi:10.1111/fog.12087.The ultimate goal of early life studies of fish over the past century has been to better understand recruitment variability. As evident in the Georges Bank haddock (Melanogrammus aeglefinus) population, there is a strong relationship between recruitment success and processes occurring during the planktonic larval stage. This research sought new insights into the mechanisms controlling the recruitment process in fish populations by using biological-physical modeling methods together with laboratory and field data sets. We created the first three-dimensional model of larval haddock on Georges Bank by coupling models of hydrodynamics, lower trophic levels, a single copepod species, and larval haddock. Interactions between feeding, metabolism, growth, vertical behavior, advection, predation, and the physical environment of larval haddock were quantitatively investigated using the coupled models. Particularly, the model was used to compare survival over the larval period and the sources of mortality in 1995 and 1998, two years of disparate haddock recruitment. The results of model simulations suggest that the increased egg hatching rates and higher food availability, which reduced starvation and predation, in 1998 contributed to its larger year-class. Additionally, the inclusion of temperature-dependent predation rates produced model results that better agreed with observations of the mean hatch date of survivors. The results from this biophysical model imply that food-limitation and its related losses to starvation and predation, especially from hatch to 7 mm, may be responsible for interannual variability in recruitment and larval survival outside of the years studied.Financial support was provided by a WHOI Watson Fellowship, a WHOI Coastal Ocean
Institute Student Research Proposal Award, and GLOBEC grants NA17RJ1223 (NOAA)
and OCE0815838 (NSF).2015-11-1
Recoil and Threshold Corrections in Short-distance Cross Sections
We identify and resum corrections associated with the kinematic recoil of the
hard scattering against soft-gluon emission in single-particle inclusive cross
sections. The method avoids double counting and conserves the flow of partonic
energy. It reproduces threshold resummation for high-p_T single-particle cross
sections, when recoil is neglected, and Q_T-resummation at low Q_T, when
higher-order threshold logarithms are suppressed. We exhibit explicit resummed
cross sections, accurate to next-to-leading logarithm, for electroweak
annihilation and prompt photon inclusive cross sections.Comment: minor modifications of the text, some references added. 51 pages,
LaTeX, 6 figures as eps file
The small RNA repertoire of Dictyostelium discoideum and its regulation by components of the RNAi pathway
Small RNAs play crucial roles in regulation of gene expression in many eukaryotes. Here, we report the cloning and characterization of 18–26 nt RNAs in the social amoeba Dictyostelium discoideum. This survey uncovered developmentally regulated microRNA candidates whose biogenesis, at least in one case, is dependent on a Dicer homolog, DrnB. Furthermore, we identified a large number of 21 nt RNAs originating from the DIRS-1 retrotransposon, clusters of which have been suggested to constitute centromeres. Small RNAs from another retrotransposon, Skipper, were significantly up-regulated in strains depleted of the second Dicer-like protein, DrnA, and a putative RNA-dependent RNA polymerase, RrpC. In contrast, the expression of DIRS-1 small RNAs was not altered in any of the analyzed strains. This suggests the presence of multiple RNAi pathways in D. discoideum. In addition, we isolated several small RNAs with antisense complementarity to mRNAs. Three of these mRNAs are developmentally regulated. Interestingly, all three corresponding genes express longer antisense RNAs from which the small RNAs may originate. In at least one case, the longer antisense RNA is complementary to the spliced but not the unspliced pre-mRNA, indicating synthesis by an RNA-dependent RNA polymerase
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