176 research outputs found

    Factors Determining the Susceptibility of Fish to Effects of Human Pharmaceuticals

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    This is the final version. Available on open access from the American Chemical Society via the DOI in this recordThe increasing levels and frequencies at which active pharmaceutical ingredients (APIs) are being detected in the environment are of significant concern, especially considering the potential adverse effects they may have on nontarget species such as fish. With many pharmaceuticals lacking environmental risk assessments, there is a need to better define and understand the potential risks that APIs and their biotransformation products pose to fish, while still minimizing the use of experimental animals. There are both extrinsic (environment- and drug-related) and intrinsic (fish-related) factors that make fish potentially vulnerable to the effects of human drugs, but which are not necessarily captured in nonfish tests. This critical review explores these factors, particularly focusing on the distinctive physiological processes in fish that underlie drug absorption, distribution, metabolism, excretion and toxicity (ADMET). Focal points include the impact of fish life stage and species on drug absorption (A) via multiple routes; the potential implications of fish’s unique blood pH and plasma composition on the distribution (D) of drug molecules throughout the body; how fish’s endothermic nature and the varied expression and activity of drug-metabolizing enzymes in their tissues may affect drug metabolism (M); and how their distinctive physiologies may impact the relative contribution of different excretory organs to the excretion (E) of APIs and metabolites. These discussions give insight into where existing data on drug properties, pharmacokinetics and pharmacodynamics from mammalian and clinical studies may or may not help to inform on environmental risks of APIs in fish.ServierEuropean Union Horizon 2020European Federation of Pharmaceutical Industries and Association

    Equivalent widths of Lyman α\alpha emitters in MUSE-Wide and MUSE-Deep

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    The aim of this study is to better understand the connection between the Lyman α\alpha rest-frame equivalent width (EW0_0) and spectral properties as well as ultraviolet (UV) continuum morphology by obtaining reliable EW0_0 histograms for a statistical sample of galaxies and by assessing the fraction of objects with large equivalent widths. We used integral field spectroscopy from MUSE combined with broad-band data from the Hubble Space Telescope (HST) to measure EW0_0. We analysed the emission lines of 19201920 Lyman α\alpha emitters (LAEs) detected in the full MUSE-Wide (one hour exposure time) and MUSE-Deep (ten hour exposure time) surveys and found UV continuum counterparts in archival HST data. We fitted the UV continuum photometric images using the Galfit software to gain morphological information on the rest-UV emission and fitted the spectra obtained from MUSE to determine the double peak fraction, asymmetry, full-width at half maximum, and flux of the Lyman α\alpha line. The two surveys show different histograms of Lyman α\alpha EW0_0. In MUSE-Wide, 20%20\% of objects have EW0>240_0 > 240 \r{A}, while this fraction is only 11%11\% in MUSE-Deep and 16%\approx 16\% for the full sample. This includes objects without HST continuum counterparts (one-third of our sample), for which we give lower limits for EW0_0. The object with the highest securely measured EW0_0 has EW0=589±193_0=589 \pm 193 \r{A} (the highest lower limit being EW0=4464_0=4464 \r{A}). We investigate the connection between EW0_0 and Lyman α\alpha spectral or UV continuum morphological properties. The survey depth has to be taken into account when studying EW0_0 distributions. We find that in general, high EW0_0 objects can have a wide range of spectral and UV morphological properties, which might reflect that the underlying causes for high EW0_0 values are equally varied. (abridged)Comment: 28 pages, 21 + 1 figures, 7 + 1 tables, accepted for publication in A&

    Comparative phylogeography of parasitic Laelaps mites contribute new insights into the specialist-generalist variation hypothesis (SGVH)

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    BACKGROUND: The specialist-generalist variation hypothesis (SGVH) in parasites suggests that, due to patchiness in habitat (host availability), specialist species will show more subdivided population structure when compared to generalist species. In addition, since specialist species are more prone to local stochastic extinction events with their hosts, they will show lower levels of intraspecific genetic diversity when compared to more generalist. RESULTS: To test the wider applicability of the SGVH we compared 337 cytochrome oxidase I mitochondrial DNA and 268 nuclear tropomyosin DNA sequenced fragments derived from two co-distributed Laelaps mite species and compared the data to 294 COI mtDNA sequences derived from the respective hosts Rhabdomys dilectus, R. bechuanae, Mastomys coucha and M. natalensis. In support of the SGVH, the generalist L. muricola was characterized by a high mtDNA haplotypic diversity of 0.97 (±0.00) and a low level of population differentiation (mtDNA Fst= 0.56, p < 0.05; nuDNA Fst = 0.33, P < 0.05) while the specialist L. giganteus was overall characterized by a lower haplotypic diversity of 0.77 (±0.03) and comparatively higher levels of population differentiation (mtDNA Fst = 0.87, P < 0.05; nuDNA Fst = 0.48, P < 0.05). When the two specialist L. giganteus lineages, which occur on two different Rhabdomys species, are respectively compared to the generalist parasite, L. muricola, the SGVH is not fully supported. One of the specialist L. giganteus species occurring on R. dilectus shows similar low levels of population differentiation (mtDNA Fst= 0.53, P < 0. 05; nuDNA Fst= 0.12, P < 0.05) than that found for the generalist L. muricola. This finding can be correlated to differences in host dispersal: R. bechuanae populations are characterized by a differentiated mtDNA Fst of 0.79 (P < 0.05) while R. dilectus populations are less structured with a mtDNA Fst= 0.18 (P < 0.05). CONCLUSION: These findings suggest that in ectoparasites, host specificity and the vagility of the host are both important drivers for parasite dispersal. It is proposed that the SGHV hypothesis should also incorporate reference to host dispersal since in our case only the specialist species who occur on less mobile hosts showed more subdivided population structure when compared to generalist species

    The JWST FRESCO Survey:Legacy NIRCam/Grism Spectroscopy and Imaging in the two GOODS Fields

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    We present the JWST cycle 1 53.8 h medium program FRESCO, short for 'First Reionization Epoch Spectroscopically Complete Observations'. FRESCO covers 62 arcmin2 in each of the two GOODS/CANDELS fields for a total area of 124 arcmin2 exploiting JWST's powerful new grism spectroscopic capabilities at near-infrared wavelengths. By obtaining ∼2 h deep NIRCam/grism observations with the F444W filter, FRESCO yields unprecedented spectra at R ∼1600 covering 3.8-5.0 μm for most galaxies in the NIRCam field of view. This setup enables emission line measurements over most of cosmic history, from strong PAH lines at z ∼0.2-0.5, to Pa α and Pa β at z ∼1-3, He i and [S iii] at z ∼2.5-4.5, H α and [N ii] at z ∼5-6.5, up to [O iii] and H β for z ∼7-9 galaxies. FRESCO's grism observations provide total line fluxes for accurately estimating galaxy stellar masses and calibrating slit-loss corrections of NIRSpec/MSA spectra in the same field. Additionally, FRESCO results in a mosaic of F182M, F210M, and F444W imaging in the same fields to a depth of ∼28.2 mag (5σ in 032 diameter apertures). Here, we describe the overall survey design and the key science goals that can be addressed with FRESCO. We also highlight several, early science results, including: spectroscopic redshifts of Lyman break galaxies that were identified almost 20 yr ago, the discovery of broad-line active galactic nuclei at z &gt; 4, and resolved Pa α maps of galaxies at z ∼1.4. These results demonstrate the enormous power for serendipitous discovery of NIRCam/grism observations.</p

    The JWST FRESCO Survey: Legacy NIRCam/Grism Spectroscopy and Imaging in the two GOODS Fields

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    We present the JWST Cycle 1 53.8hr medium program FRESCO, short for "First Reionization Epoch Spectroscopically Complete Observations". FRESCO covers 62 arcmin2^2 in each of the two GOODS/CANDELS fields for a total area of 124 arcmin2^2 exploiting JWST's powerful new grism spectroscopic capabilities at near-infrared wavelengths. By obtaining ~2 hr deep NIRCam/grism observations with the F444W filter, FRESCO yields unprecedented spectra at R~1600 covering 3.8 to 5.0 μ\mum for most galaxies in the NIRCam field-of-view. This setup enables emission line measurements over most of cosmic history, from strong PAH lines at z~0.2-0.5, to Paα\alpha and Paβ\beta at z~1-3, HeI and [SIII] at z~2.5-4.5, Hα\alpha and [NII] at z~5-6.5, up to [OIII] and Hβ\beta for z~7-9 galaxies, and possibly even [OII] at z~10-12. FRESCO's grism observations provide total line fluxes for accurately estimating galaxy stellar masses and calibrating slit-loss corrections of NIRSpec/MSA spectra in the same field. Additionally, FRESCO results in a mosaic of F182M, F210M, and F444W imaging in the same fields to a depth of ~28.2 mag (5 σ\sigma in 0.32" diameter apertures). Together with this publication, the v1 imaging mosaics are released as high-level science products via MAST. Here, we describe the overall survey design and the key science goals that can be addressed with FRESCO. We also highlight several, early science results, including: spectroscopic redshifts of Lyman break galaxies that were identified almost 20 years ago, the discovery of broad-line active galactic nuclei at z>4, and resolved Paα\alpha maps of galaxies at z~1.4. These results demonstrate the enormous power for serendipitous discovery of NIRCam/grism observations. Given the wealth of ancillary data available in these fields, the zero-proprietary time FRESCO data is poised to enable a large amount of legacy science by the community.Comment: 11 pages, 11 figures; submitted to MNRAS; for more information on the survey and data releases, see http://jwst-fresco.astro.unige.ch

    The JWST FRESCO Survey: Legacy NIRCam/Grism Spectroscopy and Imaging in the two GOODS Fields

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    We present the JWST Cycle 1 53.8hr medium program FRESCO, short for “First Reionization Epoch Spectroscopically Complete Observations”. FRESCO covers 62 arcmin2 in each of the two GOODS/CANDELS fields for a total area of 124 arcmin2 exploiting JWST’s powerful new grism spectroscopic capabilities at near-infrared wavelengths. By obtaining ∼2hr deep NIRCam/grism observations with the F444W filter, FRESCO yields unprecedented spectra at R ∼ 1600 covering 3.8 to 5.0 μm for most galaxies in the NIRCam field-of-view. This setup enables emission line measurements over most of cosmic history, from strong PAH lines at z ∼ 0.2 − 0.5, to Paα and Paβ at z ∼ 1 − 3, HeI and [SIII] at z ∼ 2.5 − 4.5, Hα and [NII] at z ∼ 5 − 6.5, up to [OIII] and Hβ for z∼7-9 galaxies. FRESCO’s grism observations provide total line fluxes for accurately estimating galaxy stellar masses and calibrating slit-loss corrections of NIRSpec/MSA spectra in the same field. Additionally, FRESCO results in a mosaic of F182M, F210M, and F444W imaging in the same fields to a depth of ∼28.2 mag (5 σ in 0.{_{.}^{\prime\prime}}32 diameter apertures). Here, we describe the overall survey design and the key science goals that can be addressed with FRESCO. We also highlight several, early science results, including: spectroscopic redshifts of Lyman break galaxies that were identified almost 20 years ago, the discovery of broad-line active galactic nuclei at z &amp;gt; 4, and resolved Paα maps of galaxies at z ∼ 1.4. These results demonstrate the enormous power for serendipitous discovery of NIRCam/grism observations

    UNCOVER: Candidate Red Active Galactic Nuclei at 3<z<7 with JWST and ALMA

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    The James Webb Space Telescope (JWST) is revolutionizing our knowledge of z>5z>5 galaxies and their actively accreting black holes. Using the JWST Cycle 1 Treasury program Ultradeep NIRSpec and NIRCam ObserVations before the Epoch of Reionization (UNCOVER) in the lensing field Abell 2744, we report the identification of a sample of little red dots at 3<zphot<73 < z_{\rm{phot}} < 7 that likely contain highly-reddened accreting supermassive black holes. Using a NIRCam-only selection to F444W<27.7<27.7 mag, we find 26 sources over the 45\sim45 arcmin2^{2} field that are blue in F115W-F200W0\sim0 (or βUV2.0\beta_{\rm UV}\sim-2.0 for fλλβf_{\lambda} \propto \lambda^\beta), red in F200W-F444W = 141-4 (βopt+2.0\beta_{\rm opt} \sim +2.0), and are dominated by a point-source like central component. Of the 20 sources with deep ALMA 1.2-mm coverage, none are detected individually or in a stack. For the majority of the sample, SED fits to the JWST+ALMA observations prefer models with hot dust rather than obscured star-formation to reproduce the red NIRCam colors and ALMA 1.2-mm non-detections. While compact dusty star formation can not be ruled out, the combination of extremely small sizes (re50\langle r_e \rangle\approx50 pc after correction for magnification), red rest-frame optical slopes, and hot dust can by explained by reddened broad-line active galactic nuclei (AGNs). Our targets have faint M145014 to18M_{\rm 1450} \approx -14\ \, {\rm to} -18 mag but inferred bolometric luminosities of Lbol=10431046L_{\rm bol} = 10^{43}-10^{46} erg/s, reflecting their obscured nature. If the candidates are confirmed as AGNs with upcoming UNCOVER spectroscopy, then we have found an abundant population of reddened luminous AGN that are at least ten times more numerous than UV-luminous AGN at the same intrinsic bolometric luminosity.Comment: submitted to Ap
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