183 research outputs found
Evolved galaxies in high-density environments across using the ZFOURGE survey
To explore the role environment plays in influencing galaxy evolution at high
redshifts, we study environments using the FourStar Galaxy
Evolution (ZFOURGE) survey. Using galaxies from the COSMOS legacy field with
, we use a seventh nearest neighbour density
estimator to quantify galaxy environment, dividing this into bins of low,
intermediate and high density. We discover new high density environment
candidates across and . We analyse the quiescent
fraction, stellar mass and specific star formation rate (sSFR) of our galaxies
to understand how these vary with redshift and environment. Our results reveal
that, across , the high density environments are the most
significant regions, which consist of elevated quiescent fractions, massive galaxies and suppressed star formation
activity. At , we find that high density regions consist of
elevated stellar masses but require more complete samples of quiescent and sSFR
data to study the effects of environment in more detail at these higher
redshifts. Overall, our results suggest that well-evolved, passive galaxies are
already in place in high density environments at , and that the
Butcher-Oemler effect and SFR-density relation may not reverse towards higher
redshifts as previously thought.Comment: 11 pages, 5 figures, final version published in PAS
ZFIRE: A KECK/MOSFIRE Spectroscopic Survey of Galaxies in Rich Environments at z~2
We present an overview and the first data release of ZFIRE, a spectroscopic
redshift survey of star-forming galaxies that utilizes the MOSFIRE instrument
on Keck-I to study galaxy properties in rich environments at . ZFIRE
measures accurate spectroscopic redshifts and basic galaxy properties derived
from multiple emission lines. The galaxies are selected from a stellar mass
limited sample based on deep near infra-red imaging () and
precise photometric redshifts from the ZFOURGE and UKIDSS surveys as well as
grism redshifts from 3DHST. Between 2013--2015 ZFIRE has observed the COSMOS
and UDS legacy fields over 13 nights and has obtained 211 galaxy redshifts over
from a combination of nebular emission lines (such as \Halpha,
\NII, \Hbeta, \OII, \OIII, \SII) observed at 1--2\micron. Based on our
medium-band NIR photometry, we are able to spectrophotometrically flux
calibrate our spectra to \around10\% accuracy. ZFIRE reaches emission
line flux limits of \around with a
resolving power of and reaches masses down to \around10\msol. We
confirm that the primary input survey, ZFOURGE, has produced photometric
redshifts for star-forming galaxies (including highly attenuated ones) accurate
to with outliers. We measure a
slight redshift bias of , and we note that the redshift bias tends to
be larger at higher masses. We also examine the role of redshift on the
derivation of rest-frame colours and stellar population parameters from SED
fitting techniques. The ZFIRE survey extends spectroscopically-confirmed samples across a richer range of environments, here we make available the
first public release of the data for use by the
community.\footnote{\url{http://zfire.swinburne.edu.au}}Comment: Published in ApJ. Data available at http://zfire.swinburne.edu.au,
Code for figures at https://github.com/themiyan/zfire_survey, 31 pages, 24
figure
Acquisition and loss of CTX-M plasmids in Shigella species associated with MSM transmission in the UK
Shigellosis in men who have sex with men (MSM) is caused by multidrug resistant Shigellae, exhibiting resistance to antimicrobials including azithromycin, ciprofloxacin and more recently the third-generation cephalosporins. We sequenced four bla (CTX-M-27)-positive MSM Shigella isolates (2018–20) using Oxford Nanopore Technologies; three S. sonnei (identified as two MSM clade 2, one MSM clade 5) and one S. flexneri 3a, to explore AMR context. All S. sonnei isolates harboured Tn7/Int2 chromosomal integrons, whereas S. flexneri 3a contained the Shigella Resistance Locus. All strains harboured IncFII pKSR100-like plasmids (67-83kbp); where present bla (CTX-M-27) was located on these plasmids flanked by IS26 and IS903B, however bla (CTX-M-27) was lost in S. flexneri 3a during storage between Illumina and Nanopore sequencing. IncFII AMR regions were mosaic and likely reorganised by IS26; three of the four plasmids contained azithromycin-resistance genes erm(B) and mph(A) and one harboured the pKSR100 integron. Additionally, all S. sonnei isolates possessed a large IncB/O/K/Z plasmid, two of which carried aph(3’)-Ib/aph(6)-Id/sul2 and tet(A). Monitoring the transmission of mobile genetic elements with co-located AMR determinants is necessary to inform empirical treatment guidance and clinical management of MSM-associated shigellosis
ZFOURGE: Using Composite Spectral Energy Distributions to Characterize Galaxy Populations at 1<z<4
We investigate the properties of galaxies as they shut off star formation
over the 4 billion years surrounding peak cosmic star formation. To do this we
categorize galaxies from into groups based on the shape
of their spectral energy distributions (SEDs) and build composite SEDs with
resolution. These composite SEDs show a variety of spectral shapes
and also show trends in parameters such as color, mass, star formation rate,
and emission line equivalent width. Using emission line equivalent widths and
strength of the 4000\AA\ break, , we categorize the composite SEDs
into five classes: extreme emission line, star-forming, transitioning,
post-starburst, and quiescent galaxies. The transitioning population of
galaxies show modest H emission (\AA) compared to
more typical star-forming composite SEDs at
(\AA). Together with their smaller sizes (3 kpc vs. 4 kpc)
and higher S\'ersic indices (2.7 vs. 1.5), this indicates that morphological
changes initiate before the cessation of star formation. The transitional group
shows a strong increase of over one dex in number density from to
, similar to the growth in the quiescent population, while
post-starburst galaxies become rarer at . We calculate average
quenching timescales of 1.6 Gyr at and 0.9 Gyr at and
conclude that a fast quenching mechanism producing post-starbursts dominated
the quenching of galaxies at early times, while a slower process has become
more common since .Comment: Accepted for publication in The Astrophysical Journa
'Focusing' in motivational interviewing: development of a training tool for practitioners
Rationale, aims and objectives: Motivational Interviewing (MI) is an individual-level approach to behaviour change that has been evaluated in over 600 randomised clinical trials across multiple settings. Increasingly, research efforts focus on how MI works and how it can best be integrated into public health and clinical programmes. As the application of MI expands, a key integration challenge involves specifying the focus of a conversation such that a practitioner might ignite and intensify a patient’s internal motivation for change related to that focus. At present, this challenge is poorly conceptualised. We aimed to clarify the construct of “focusing” and to develop a practical tool that can be used to develop and assess practitioner competence.
Method: First we reviewed validated MI measures to elucidate current conceptualisations of focusing. Second, we identified practitioner speech acts that led to topic transitions. We then drafted the first version of MIFI. A gold standard rater, together with one expert MI and 3 non-expert MI raters, each used MIFI to coded 20 audio recordings from a feasibility study of MI and breastfeeding maintenance (n=170 observations). Internal consistency and inter-rater reliability analyses were conducted.
Results: Published MI measures include ‘focusing’ as a strategy to agree a target change or to hold attention on that change target. We observed practitioners create or shift focus using 4 skills: questions, listening statements, giving information or meta-statements. Moderate to strong correlations were demonstrated between 4 of 5 global measures on the MIFI. Reliability estimates were good to excellent overall (5 coder ICCs>0.65), fair to excellent for the non-expert coding group (ICCs>0.55) and for the best coding pair (MI expert and non-expert ICCs >0.52).
Conclusion: We offer conceptual clarity about focusing in MI and have developed a tool to train practitioners in “focusing” when integrating MI into healthcare and public health interventions
Tracking counterpart signatures in Saturn's auroras and ENA imagery during large-scale plasma injection events
Saturn's morningside auroras consist mainly of rotating, transient emission patches, following periodic reconnection in the magnetotail. Simultaneous responses in global energetic neutral atom (ENA) emissions have been observed at similar local times, suggesting a link between the auroras and large‐scale injections of hot ions in the outer magnetosphere. In this study, we use Cassini's remote sensing instruments to observe multiple plasma injection signatures within coincident auroral and ENA imagery, captured during 9 April 2014. Kilometric radio emissions also indicate clear injection activity. We track the motion of rotating signatures in the auroras and ENAs to test their local time relationship. Two successive auroral signatures—separated by ~4 hr UT—form postmidnight before rotating to the dayside while moving equatorward. The first has a clear ENA counterpart, maintaining a similar local time mapping throughout ~9 hr observation. Mapping of the ionospheric equatorward motion post‐dawn indicates a factor ~5 reduction of the magnetospheric source region's radial speed at a distance of ~14‐20 RS, possibly a plasma or magnetic boundary. The second auroral signature has no clear ENA counterpart; viewing geometry was relatively unchanged, so the ENAs were likely too weak to detect by this time. A third, older injection signature, seen in both auroral and ENA imagery on the nightside, may have been sustained by field‐aligned currents linked with the southern planetary period oscillation system, or the re‐energization of ENAs around midnight local times. The ENA injection signatures form near magnetic longitudes associated with magnetotail thinning
Epigenetic control of alternative mRNA processing at the imprinted Herc3/Nap1l5 locus
Alternative polyadenylation increases transcriptome diversity by generating multiple transcript isoforms from a single gene. It is thought that this process can be subject to epigenetic regulation, but few specific examples of this have been reported. We previously showed that the Mcts2/H13 locus is subject to genomic imprinting and that alternative polyadenylation of H13 transcripts occurs in an allele-specific manner, regulated by epigenetic mechanisms. Here, we demonstrate that allele-specific polyadenylation occurs at another im-printed locus with similar features. Nap1l5 is a retrogene expressed from the paternally inherited allele, is situated within an intron of a ‘host ’ gene Herc3, and overlaps a CpG island that is differen-tially methylated between the parental alleles. In mouse brain, internal Herc3 polyadenylation sites upstream of Nap1l5 are used on the pater-nally derived chromosome, from which Nap1l5 is expressed, whereas a downstream site is used more frequently on the maternally derived chromo-some. Ablating DNA methylation on the maternal allele at the Nap1l5 promoter increases the use of an internal Herc3 polyadenylation site and alters exon splicing. These changes demonstrate the influ-ence of epigenetic mechanisms in regulating Herc3 alternative mRNA processing. Internal Herc3 polyadenylation correlates with expression levels of Nap1l5, suggesting a possible role for transcrip-tional interference. Similar mechanisms may regulate alternative polyadenylation elsewhere in the genome
Northern grazing carbon farming – integrating production and greenhouse gas outcomes 1 : Climate Clever Beef Final Report
This project targeted three large and diverse regions across northern Australia: the Queensland Gulf, the Queensland Fitzroy Basin and the Northern Territory (Victoria River District, Douglas Daly and Barkly Tableland regions). Eleven grazing businesses across three broad regions were engaged as case studies to undertake demonstrations and evaluations within their businesses. These businesses manage more than 1,281,000 ha and 97,600 cattle.
The project provided an excellent opportunity to capitalize on established networks and genuine producer interest and participation built up in recent initiatives (e.g. CCRP Climate Clever Beef (Bray et al. 2014), Northern Grazing Systems project (Phelps et al. 2014), RELRP, SCaRP, SavannaPlan, CQ Beef).
The project team included research and extension professionals with decades of combined experience working with northern beef producers. The knowledge and analytical tools developed during previous projects identified practices to: reduce the greenhouse gas emissions impact of beef businesses, manage climate variability, improve land condition and increase business profitability
Northern grazing carbon farming – integrating production and greenhouse gas outcomes 1 : Climate Clever Beef Final Report
This project targeted three large and diverse regions across northern Australia: the Queensland Gulf, the Queensland Fitzroy Basin and the Northern Territory (Victoria River District, Douglas Daly and Barkly Tableland regions). Eleven grazing businesses across three broad regions were engaged as case studies to undertake demonstrations and evaluations within their businesses. These businesses manage more than 1,281,000 ha and 97,600 cattle.
The project provided an excellent opportunity to capitalize on established networks and genuine producer interest and participation built up in recent initiatives (e.g. CCRP Climate Clever Beef (Bray et al. 2014), Northern Grazing Systems project (Phelps et al. 2014), RELRP, SCaRP, SavannaPlan, CQ Beef).
The project team included research and extension professionals with decades of combined experience working with northern beef producers. The knowledge and analytical tools developed during previous projects identified practices to: reduce the greenhouse gas emissions impact of beef businesses, manage climate variability, improve land condition and increase business profitability
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