scholarly journals Effects of Exposure to Low Concentrations of Oil on the Expression of Cytochrome P4501a and Routine Swimming Speed of Atlantic Haddock (Melanogrammus aeglefinus) Larvae In Situ

2020 ◽  
Vol 54 (21) ◽  
pp. 13879-13887 ◽  
Author(s):  
Alessandro Cresci ◽  
Claire B. Paris ◽  
Howard I. Browman ◽  
Anne Berit Skiftesvik ◽  
Steven Shema ◽  
...  
2004 ◽  
Vol 61 (7) ◽  
pp. 1071-1079 ◽  
Author(s):  
Mike Breen ◽  
Jamie Dyson ◽  
Finbarr G. O'Neill ◽  
Emma Jones ◽  
Michael Haigh

Abstract This paper describes an experiment to determine the swimming endurance of haddock (Melanogrammus aeglefinus) at prolonged swimming speeds. Fish were stimulated to swim in a circular path around an annular tank, using a moving light pattern to trigger the optomotor response. Individually tagged haddock (length range 16.0–40.2 cm) swam in groups over a range of speeds (0.3–0.9 m s−1) and at a constant temperature (9.85 ± 0.07°C). Endurance of individual fish was shown to be related to their swimming speed and length. However, there was also significant variation (p < 0.05) in the performance of fish of approximately equal length. Distinct behaviours and swimming gaits were also identified and associated with the performance of individual fish. The inverse-linear model is introduced, as an alternative to the log-linear model, for describing the relationship between swimming speed and endurance, and estimating maximum sustainable swimming speed (Ums). Estimates of Ums ranged from 0.38 ± 0.03 m s−1 and 3.16 ± 0.02 BL s−1 (for a 16.0-cm fish) to 0.62 ± 0.04 m s−1 and 1.51 ± 0.07 BL s−1 (for a 42.0-cm fish). Ums represents an important threshold in the behavioural physiology of fish, marking the upper limit of aerobic swimming. The relevance of these results and Ums to the fish capture process is discussed.


1992 ◽  
Vol 49 (1) ◽  
pp. 91-98 ◽  
Author(s):  
D. J. Wildish ◽  
A. J. Wilson ◽  
B. Frost

A first quantitative description is provided of the drifting or swimming macrofauna present within the benthic boundary layer (BBL) over the hard sediments of Browns Bank in the northwest Atlantic. Major categories of identified animals include drift epi- or infauna, zooplankters, fish larvae and eggs, and suprabenthic animals. Suprabenthic amphipods were good indicators of the type of sediment/flow environment that they were associated with. Although zooplanktonic copepods were by far the most abundant and suprabenthos the most diverse group of the BBL macrofauna, they appear to be ignored as a source of food by juvenile haddock (Melanogrammus aeglefinus), which are known to feed on prey classified herein either as in situ, or drifted, epi- or infauna. Unfortunately, the BBL sled used in our study could not sample animals at < 33 cm from the sediment–water interface. Our results imply that juvenile haddock feed either directly on animals living in, or at the sediment interface, or on drifting animals present within the BBL at heights < 33 cm above the bottom


Sensors ◽  
2021 ◽  
Vol 21 (9) ◽  
pp. 3147
Author(s):  
Ilaria Frau ◽  
Stephen Wylie ◽  
Patrick Byrne ◽  
Patrizia Onnis ◽  
Jeff Cullen ◽  
...  

Thousands of pollutants are threatening our water supply, putting at risk human and environmental health. Between them, trace metals are of significant concern, due to their high toxicity at low concentrations. Abandoned mining areas are globally one of the major sources of toxic metals. Nowadays, no method can guarantee an immediate response for quantifying these pollutants. In this work, a novel technique based on microwave spectroscopy and planar sensors for in situ real-time monitoring of water quality is described. The sensors were developed to directly probe water samples, and in situ trial measurements were performed in freshwater in four polluted mining areas in the UK. Planar microwave sensors were able detect the water pollution level with an immediate response specifically depicted at three resonant peaks in the GHz range. To the authors’ best knowledge, this is the first time that planar microwave sensors were tested in situ, demonstrating the ability to use this method for classifying more and less polluted water using a multiple-peak approach.


1989 ◽  
Vol 157 ◽  
Author(s):  
Young-Jin Jeon ◽  
M.F. Becker ◽  
R.M. Walser

ABSTRACTThis work was concerned with comparing the relative effects of boron and phosphorus impurities on the solid phase epitaxial (SPE) regrowth rate of self-ion amorphized layers in silicon wafers with (100) orientation. We used previously reported data measured by in situ, high precision, cw laser interferometry during isothermal annealing for temperatures from 450°C to 590°C, and concentrations in the range from 7.8×1018 cm-3 to 5×l020 cm-3 for boron (NB), and from 5×l017 cm-3 to 3×1020 cm-3 for phosphorus (Np) impurities. The basis for the comparison was a recently developed model that extends the Spaepen-Turnbull model for silicon recrystallization to include ionization enhanced processes.The experimental data for bom boron and phosphorus exhibited the linear variation in regrowth rate expected for low concentrations of implanted hydrogenic impurities having a concentration-independent fractional ionization in amorphous silicon. In the linear range the relative enhanced regrowth rate produced by these impurities can be expressed as a product of their, relative fractional ionizations, and the relative amount the rate constant for reconstruction is altered by localizing an electron, or a hole, at the reconstruction site. Assuming that a localized hole and electron equally softened the potential barrier for reconstruction, the experimental results indicated that boron had an ?40 meV lower barrier to ionization in amorphous silicon than phosphorus.The variations in the SPE regrowth rates with higher concentrations of both implanted boron and phosphorus were well fit by quadratic equations, but with different curvatures (+ and - for B and P respectively). This result was interpreted to indicate that SPE regrowth was further enhanced by localized hole pairs, but retarded by localized electron pairs.


1999 ◽  
Vol 160 (1) ◽  
pp. 21-33 ◽  
Author(s):  
RS Robinson ◽  
GE Mann ◽  
GE Lamming ◽  
DC Wathes

The expression of oxytocin receptor (OTR) in the uterine endometrium plays an important role in the initiation of luteolysis. During early pregnancy, the conceptus secretes interferon tau (IFN|gt) which inhibits OTR up-regulation and luteolysis. In this study, uterine horn cross sections were collected on day 16 from 15 pregnant cows (PREG), 9 uninseminated controls and 5 inseminated cows with no embryo present. The latter two groups had similar results and were combined to form a single non-pregnant (NP) group. The animals were given an oxytocin challenge shortly before tissue collection to assess prostaglandin F2alpha (PGF2alpha) release through the measurement of the metabolite 13,14-dihydro-15-keto PGF2alpha (PGFM). The mRNAs for OTR, oestrogen receptor (ER) and progesterone receptor (PR) were localised by in situ hybridisation. The results were quantified by optical density (OD) measurements from autoradiographs using image analysis. OTR protein was measured by autoradiography with iodinated oxytocin antagonist and ER and PR protein was detected by immunocytochemistry. The release of PGFM after the oxytocin challenge was significantly higher in the 14 NP cows (187%+/-15%) compared with the PREG group (131%+/-11%) (P<0.01). Low concentrations of OTR mRNA were localised to the luminal epithelium (LE) in 6 out of the 14 NP cows, of which 2 also expressed OTR protein, while OTR mRNA and protein were undetectable in all the pregnant animals. These results indicated that the sampling time coincided with the onset of the luteolytic mechanism in the NP cows. On day 16 ER mRNA was detectable in both the LE and glands of both PREG and NP animals. There were no differences in either ER mRNA or protein between NP and PREG samples. PR mRNA was moderately expressed in the caruncular stroma, with lower levels in the dense caruncular-like stroma and glands. There were no differences between PREG and NP animals. The expression of PR mRNA and protein in the deep glands was variable between animals. These results suggested that, in cows, the presence of an embryo suppressed the expression of OTR, but had no effect on the expression of the transcriptionally regulated ER on day 16.


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