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Spiral galaxies undergo strong ram-pressure effects when they fall into the galaxy cluster potential. As a consequence, their gas is stripped to form extended tails within which star formation can happen, giving them the typical jellyfish appearance. The ultraviolet imaging observations of jellyfish galaxies provide an opportunity to understand ongoing star formation in the stripped tails. We report the ultraviolet observations of the jellyfish galaxies JW39, JO60, JO194 and compare with observations in optical continuum and Hα. We detect knots of star formation in the disc and tails of the galaxies and find that their UV and Hα flux are well correlated. The optical emission line ratio maps of these galaxies are used to identify for every region the emission mechanism, due to either star formation, LINER or a mix of the two phenomena. The star-forming regions in the emission line maps match very well with the regions having significant UV flux. The central regions of two galaxies (JW39, JO194) show a reduction in UV flux which coincides with composite or LINER regions in the emission line maps. The galaxies studied here demonstrate significant star formation in the stripped tails, suppressed star formation in the central regions and present a possible case of accelerated quenching happening in jellyfish galaxies. [ABSTRACT FROM AUTHOR]

We present a dynamical study of the narrow-line regions in two nearby type 2 quasars (QSO2s). We construct dynamical models based on detailed photoionization models of the emission-line gas, including the effects of internal dust, to apply to observations of large-scale outflows from these active galactic nuclei (AGNs). We use Mrk 477 and Mrk 34 in order to test our models against recent Hubble Space Telescope (HST) Space Telescope Imaging Spectrograph (STIS) observations of [O  iii ] emission-line kinematics, since these AGNs possess more energetic outflows than found in Seyfert galaxies. We find that the outflows within 500 pc are consistent with radiative acceleration of dusty gas, however the outflows in Mrk 34 are significantly more extended and may not be directly accelerated by radiation. We characterize the properties of X-ray winds found from the expansion of [O  iii ]-emitting gas close to the black hole. We show that such winds possess the kinetic energy density to disturb [O  iii ] gas at ∼1.8 kpc, and have sufficient energy to entrain the [O  iii ] clouds at ∼1.2 kpc. Assuming that the X-ray wind possesses the same radial mass distribution as the [O  iii ] gas, we find that the peak kinetic luminosity for this wind is 2 per cent of Mrk 34's bolometric luminosity, which is in the 0.5–5 per cent range required by some models for efficient feedback. Our work shows that, although the kinetic luminosity as measured from [O  iii ]-emitting gas is frequently low, X-ray winds may provide more than one order of magnitude higher kinetic power. [ABSTRACT FROM AUTHOR]

We use Hubble Space Telescope /Space Telescope Imaging Spectrograph long-slit G430M and G750M spectra to analyse the extended [O  iii ] λ5007 emission in a sample of 12 nearby (z < 0.12) luminous (L bol > 1.6 × 1045 erg s−1) QSO2s. The purpose of the study is to determine the properties of the mass outflows of ionized gas and their role in active galactic nucleus feedback. We measure fluxes and velocities as functions of radial distances. Using cloudy models and ionizing luminosities derived from [O  iii ] λ5007, we are able to estimate the densities for the emission-line gas. From these results, we derive masses of [O  iii ]-emitting gas, mass outflow rates, kinetic energies, kinetic luminosities, momenta, and momentum flow rates as a function of radial distance for each of the targets. For the sample, masses are several times |$10^{3}$| – |$10^{7}\, {\rm M_{\odot }}$| and peak outflow rates are from 9.3 × 10−3 to |$10.3\, {\rm M_{\odot }}\, {\rm yr^{-1}}$|⁠. The peak kinetic luminosities are (3.4 × 10−8)–(4.9 × 10−4) of the bolometric luminosity, which does not approach the (5.0 × 10−3)–(5.0 × 10−2) range required by some models for efficient feedback. For Mrk 34, which has the largest kinetic luminosity of our sample, in order to produce efficient feedback there would have to be 10 times more [O  iii ]-emitting gas than that we detected at its position of maximum kinetic luminosity. Three targets show extended [O  iii ] emission, but compact outflow regions. This may be due to different mass profiles or different evolutionary histories. [ABSTRACT FROM AUTHOR]

Iteroparity is a bet-hedging strategy where individuals spread the risk of reproductive failure over time. The occurrence of iteroparity (i.e. proportion of repeat spawners in annual returns) varies among Atlantic salmon (Salmo salar) populations, yet information on its ecological importance is limited. We compiled multi-decadal time series on the spawning history composition of Atlantic salmon annual returns across ten populations of the northwest Atlantic and West Greenland mixed-stock fishery landings to: (i) describe spatio-temporal patterns of iteroparity at the continental scale; (ii) quantify the reproductive contributions of repeat spawners; and (iii) test the hypothesis that iteroparity acts as a population safeguard during periods of low recruitment through repeat spawners' contributions. Despite high variability in the representation of repeat spawners among populations and years (range: 0–24.7%; average: 5.0%), we identified broad-scale spatio-temporal shifts in iteroparity, with increases in mid-latitudinal and northern populations (from 3.1% to 7.6%) and declines in southern areas (from 4.1% to 2.7%), between the 1971–1992 and 1993–2017 periods. Our findings highlight the potential for increased prevalence of iteroparity when threats are mitigated (e.g. fishing pressure), with measurable benefits to population processes manifested by the high reproductive contributions of repeat spawners, especially in years of low maiden spawner abundance. [ABSTRACT FROM AUTHOR]

Abstract To examine constraints on evolution of larger body size in two stunted populations of brook charr (Salvelinus fontinalis ) from a single river in Cape Race, Newfoundland, Canada, we measured viability selection acting on length-at-age traits, and estimated quantitative genetic parameters in situ (following reconstruction of pedigree information from microsatellite data). Furthermore we tested for phenotypic differentiation between the populations, and for association of high juvenile growth with early maturity that is predicted by life history theory. Within each population, selection differentials and estimates of heritabilities for length-at-age traits suggested that evolution of larger size is prevented by both selective and genetic constraints. Between the populations, phenotypic differentiation was found in length-at-age and age of maturation traits, whereas early maturation was associated with increased juvenile growth (relative to adult growth) both within and between populations. The results suggest an adaptive plastic response in age of maturation to juvenile growth rates that have a largely environmental basis of determination. [ABSTRACT FROM AUTHOR]

Objective: The objective of this study was to determine whether anthrax vaccine resulted in adverse health effects in Canadian Forces members 8 months after vaccination.Methods: A quasi-experimental, retrospective chart review was undertaken for two groups within the Canadian Forces, one group that received anthrax vaccination and another that did not. Information on symptoms, diagnoses, and injuries for 848 persons for which there were approximately 35,000 chart entries was abstracted from charts over a 4.5-year period and was coded using the International Statistical Classification of Diseases and Related Health Problems, 10th edition.Results: The chart retrieval rate was 84%. The mean number of chart entries per person was higher in the comparison group (43.4) than in the vaccine group (38.2). No statistically significant differences were seen in the percent change before and after vaccination in the number of chart entries for specific diagnoses and symptoms for the vaccine group compared with the comparison group. Visual inspection of the time trend in rates showed no unexplained increases in the rate of diagnosis and symptoms in the vaccine group after vaccination.Conclusion: This study found no evidence that the anthrax vaccination resulted in an increase in adverse health effects in the 8-month period after vaccination. [ABSTRACT FROM AUTHOR]