732 research outputs found
Estimating Trail Use and Visitor Spatial Distribution Using Mobile Device Data: An Example From the Nature Reserve of Orange County, California USA
Monitoring visitor use in parks and protected areas (PPAs) provides essential information for managers of PPAs to evaluate aspects of the visitor experience and balance the ecological disturbance that use creates. Traditional methods for quantifying visitation and spatial use of PPAs are resource intensive and thus are conducted infrequently or at cost-effective intervals which may fail to capture the dynamic nature of modern visitor use trends. This paper provides an addition to a growing literature using mobile-device data to quantify visitation and spatial density of use of urban-proximate PPAs in Orange County, California, USA using the analysis platform Streetlight, Inc. The results of our analysis compared favorably with well-established automatic trail counting and GPS-based monitoring methods, and illustrate several advantages of mobile device data to inform the management of PPAs. Mobile device data provide reliable estimates of visitation and spatial density of use and can augment and compliment existing social and resource monitoring for PPA management and planning
JMJD5 is a human arginyl C-3 hydroxylase.
Oxygenase-catalysed post-translational modifications of basic protein residues, including lysyl hydroxylations and NĪµ-methyl lysyl demethylations, have important cellular roles. Jumonji-C (JmjC) domain-containing protein 5 (JMJD5), which genetic studies reveal is essential in animal development, is reported as a histone NĪµ-methyl lysine demethylase (KDM). Here we report how extensive screening with peptides based on JMJD5 interacting proteins led to the finding that JMJD5 catalyses stereoselective C-3 hydroxylation of arginine residues in sequences from human regulator of chromosome condensation domain-containing protein 1 (RCCD1) and ribosomal protein S6 (RPS6). High-resolution crystallographic analyses reveal overall fold, active site and substrate binding/product release features supporting the assignment of JMJD5 as an arginine hydroxylase rather than a KDM. The results will be useful in the development of selective oxygenase inhibitors for the treatment of cancer and genetic diseases
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Enrichment of CpG island shore region hypermethylation in epigenetic breast field cancerization
While changes in DNA methylation are known to occur early in breast carcinogenesis and the landscape of breast tumour DNA methylation is profoundly altered compared with normal tissue, there have been limited efforts to identify DNA methylation field cancerization effects in histologically normal breast tissue adjacent to tumour. Matched tumour, histologically normal tissue of the ipsilateral breast (ipsilateral-normal), and histologically normal tissue of the contralateral breast (contralateral-normal) were obtained from nine women undergoing bilateral mastectomy. Laser capture microdissection was used to select epithelial cells from normal tissue, and neoplastic cells from tumour for genome-scale measures of DNA methylation with the Illumina HumanMethylationEPIC array. We identified substantially more CpG loci that were differentially methylated between contralateral-normal and tumour (63,271 CpG loci q \u3c 0.01), than between ipsilateral-normal and tumour (38,346 CpG loci q \u3c 0.01). We identified differential methylation in ipsilateral-normal relative to contralateral-normal tissue (9,562 CpG loci p \u3c 0.01). In this comparison, hypomethylated loci were significantly enriched for breast cancer-relevant transcription factor binding sites including those for ESR1, FoxA1, and GATA3 and hypermethylated loci were significantly enriched for CpG island shore regions. In addition, progression of shore hypermethylation was observed in tumours compared to matched ipsilateral normal tissue, and these alterations tracked to several well-established tumour suppressor genes. Our results indicate an epigenetic field effect in surrounding histologically normal tissue. This work offers an opportunity to focus investigations of early DNA methylation alterations in breast carcinogenesis and potentially develop epigenetic biomarkers of disease risk
A Deep Probe of the Galaxy Stellar Mass Functions at z~1-3 with the GOODS NICMOS Survey
We use a sample of 8298 galaxies observed in the HST GOODS NICMOS Survey
(GNS) to construct the galaxy stellar mass function as a function of both
redshift and stellar mass up to z=3.5 and down to masses of Mstar=10^8.5 Msun
at z~1. We discover that a significant fraction of all massive Mstar>10^11 Msun
galaxies are in place up to the highest redshifts we probe, with a decreasing
fraction of lower mass galaxies present at all redshifts. This is an example of
`galaxy mass downsizing', and is the result of massive galaxies forming before
lower mass ones, and not just simply ending their star formation earlier as in
traditional downsizing scenarios. We find that the faint end slope is
significantly steeper than what is found in previous investigations. We
demonstrate that this steeper mass function better matches the stellar mass
added due to star formation, thereby alleviating some of the mismatch between
these two measures of the evolution of galaxy mass. We furthermore examine the
stellar mass function divided into blue/red systems, as well as for star
forming and non-star forming galaxies. We find a similar mass downsizing
present for both blue/red and star-forming/non-star forming galaxies, and that
the low mass galaxies are mostly all blue, and are therefore creating the steep
mass functions. We furthermore show that, although there is a downsizing such
that high mass galaxies are nearer their z=0 values at high redshift, this
turns over at masses Mstar~10^10 Msun, such that the lowest mass galaxies are
more common than galaxies at slight higher masses, creating a `dip' in the
observed galaxy mass function. We argue that the galaxy assembly process may be
driven by different mechanisms at low and high masses, and that the efficiency
of the galaxy formation process is lowest at masses Mstar~10^10 Msun at 1<z<3.
(Abridged)Comment: 16 pages, 11 figures, MNRAS, accepte
Heteroepitaxial growth of ferromagnetic MnSb(0001) films on Ge/Si(111) virtual substrates
Molecular beam epitaxial growth of ferromagnetic MnSb(0001) has been achieved on high quality, fully relaxed Ge(111)/Si(111) virtual substrates grown by reduced pressure chemical vapor deposition. The epilayers were characterized using reflection high energy electron diffraction, synchrotron hard X-ray diffraction, X-ray photoemission spectroscopy, and magnetometry. The surface reconstructions, magnetic properties, crystalline quality, and strain relaxation behavior of the MnSb films are similar to those of MnSb grown on GaAs(111). In contrast to GaAs substrates, segregation of substrate atoms through the MnSb film does not occur, and alternative polymorphs of MnSb are absent
Optimal translational termination requires C4 lysyl hydroxylation of eRF1
Efficient stop codon recognition and peptidyl-tRNA hydrolysis are essential in order to terminate translational elongation and maintain protein sequence fidelity. Eukaryotic translational termination is mediated by a release factor complex that includes eukaryotic release factor 1 (eRF1) and eRF3. The N terminus of eRF1 contains highly conserved sequence motifs that couple stop codon recognition at the ribosomal A site to peptidyl-tRNA hydrolysis. We reveal that Jumonji domain-containing 4 (Jmjd4), a 2-oxoglutarate- and Fe(II)-dependent oxygenase, catalyzes carbon 4 (C4) lysyl hydroxylation of eRF1. This posttranslational modification takes place at an invariant lysine within the eRF1 NIKS motif and is required for optimal translational termination efficiency. These findings further highlight the role of 2-oxoglutarate/Fe(II) oxygenases in fundamental cellular processes and provide additional evidence that ensuring fidelity of protein translation is a major role of hydroxylation
The Interaction of Ī±B-Crystallin with Mature Ī±-Synuclein Amyloid Fibrils Inhibits Their Elongation
Ī±B-Crystallin is a small heat-shock protein (sHsp) that is colocalized
with Ī±-synuclein (Ī±Syn) in
Lewy bodiesāthe pathological hallmarks of Parkinson's
diseaseāand is an inhibitor of Ī±Syn amyloid
fibril formation in an ATP-independent manner inĀ vitro. We have
investigated the mechanism underlying the inhibitory action of sHsps, and here
we establish, by means of a variety of biophysical techniques including
immunogold labeling and nuclear magnetic resonance spectroscopy, that
Ī±B-crystallin interacts with
Ī±Syn, binding along the length of mature amyloid
fibrils. By measurement of seeded fibril elongation kinetics, both in solution
and on a surface using a quartz crystal microbalance, this binding is shown to
strongly inhibit further growth of the fibrils. The binding is also demonstrated
to shift the monomer-fibril equilibrium in favor of dissociation. We believe
that this mechanism, by which a sHsp interacts with mature amyloid fibrils,
could represent an additional and potentially generic means by which at least
some chaperones protect against amyloid aggregation and limit the onset of
misfolding diseases
Cosmic Evolution Early Release Science (CEERS) survey: The colour evolution of galaxies in the distant Universe
The wavelength-coverage and sensitivity of JWST now enables us to probe the
rest-frame UV - optical spectral energy distributions (SEDs) of galaxies at
high-redshift (). From these SEDs it is, in principle, through SED fitting
possible to infer key physical properties, including stellar masses, star
formation rates, and dust attenuation. These in turn can be compared with the
predictions of galaxy formation simulations allowing us to validate and refine
the incorporated physics. However, the inference of physical properties,
particularly from photometry alone, can lead to large uncertainties and
potential biases. Instead, it is now possible, and common, for simulations to
be \emph{forward-modelled} to yield synthetic observations that can be compared
directly to real observations. In this work, we measure the JWST broadband
fluxes and colours of a robust sample of galaxies using the Cosmic
Evolution Early Release Science (CEERS) Survey. We then analyse predictions
from a variety of models using the same methodology and compare the
NIRCam/F277W magnitude distribution and NIRCam colours with observations. We
find that the predicted and observed magnitude distributions are similar, at
least at the distributions differ somewhat, though our
observed sample size is small and thus susceptible to statistical fluctuations.
Likewise, the predicted and observed colour evolution show broad agreement, at
least at . There is however some disagreement between the observed and
modelled strength of the strong line contribution. In particular all the models
fails to reproduce the F410M-F444W colour at , though, again, the sample
size is small here.Comment: 11 pages, 10 figures, submitted to MNRA
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