176 research outputs found
Factors Determining the Susceptibility of Fish to Effects of Human Pharmaceuticals
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 emitters in MUSE-Wide and MUSE-Deep
The aim of this study is to better understand the connection between the
Lyman rest-frame equivalent width (EW) and spectral properties as
well as ultraviolet (UV) continuum morphology by obtaining reliable EW
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 EW. We analysed the emission lines of Lyman
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 line. The
two surveys show different histograms of Lyman EW. In MUSE-Wide,
of objects have EW \r{A}, while this fraction is only
in MUSE-Deep and for the full sample. This includes objects
without HST continuum counterparts (one-third of our sample), for which we give
lower limits for EW. The object with the highest securely measured EW
has EW \r{A} (the highest lower limit being EW \r{A}).
We investigate the connection between EW and Lyman spectral or UV
continuum morphological properties. The survey depth has to be taken into
account when studying EW distributions. We find that in general, high
EW objects can have a wide range of spectral and UV morphological
properties, which might reflect that the underlying causes for high EW
values are equally varied. (abridged)Comment: 28 pages, 21 + 1 figures, 7 + 1 tables, accepted for publication in
A&
Lineage Divergence and Historical Gene Flow in the Chinese Horseshoe Bat (Rhinolophus sinicus)
PMCID: PMC3581519This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
Comparative phylogeography of parasitic Laelaps mites contribute new insights into the specialist-generalist variation hypothesis (SGVH)
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
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 > 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
We present the JWST Cycle 1 53.8hr medium program FRESCO, short for "First
Reionization Epoch Spectroscopically Complete Observations". FRESCO covers 62
arcmin in each of the two GOODS/CANDELS fields for a total area of 124
arcmin 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 m 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 and Pa at z~1-3, HeI and [SIII] at
z~2.5-4.5, H and [NII] at z~5-6.5, up to [OIII] and H 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 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 Pa 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
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 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 years ago, the discovery of broad-line active galactic nuclei at z &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
The James Webb Space Telescope (JWST) is revolutionizing our knowledge of
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 that
likely contain highly-reddened accreting supermassive black holes. Using a
NIRCam-only selection to F444W mag, we find 26 sources over the
arcmin field that are blue in F115WF200W (or for ), red in F200WF444W =
(), 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 ( 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 mag but inferred
bolometric luminosities of 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
JWST/NIRSpec measurements of extremely low metallicities in high equivalent width Lyα emitters
Galaxie
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