Garden floras interact with native biodiversity by providing resources for wildlife and by acting as a source of non-native species. Understanding the composition and richness of garden floras will ...help evaluate the relationships between these floras and the wider environment. The composition and richness of vascular plant floras were measured in a stratified sample of 61 urban, domestic gardens in Sheffield, UK, based on complete garden inventories. The entire garden flora contained 1166 species, of which 30% were native and 70% alien. Across gardens, aliens showed lower occupancy than natives, comprising 79% of the species recorded only once. The garden flora contained 146 plant families, which included 72% of the native, naturalised or recurrent casual families recorded in the wild in Britain and Ireland. Gardens contained on average 45% natives, irrespective of garden size. Garden area explained 30% of the variation in species richness within individual gardens. Doubling garden size led to an increase in species richness of 25%. The garden flora comprised 10% annuals, 63% biennial/perennials, 18% shrubs and 8% trees; shrubs were disproportionately composed of alien species. The floras of urban domestic gardens probably form the greatest source of potentially invasive alien plants. However, the plants found in domestic gardens have closer affinities with the uncultivated flora than is often perceived, and their role for wildlife in gardens deserves reassessment. Declines in garden size that result from recommendations on the density of new housing are unlikely to have major consequences for plant richness in gardens.
► There is much utility in the use of TCD to assess cerebrovascular function. ► TCD is an efficient tool to access blood velocities within the cerebral vessels. ► TCD is an effective method to assess ...cerebrovascular function.
There is considerable utility in the use of transcranial Doppler ultrasound (TCD) to assess cerebrovascular function. The brain is unique in its high energy and oxygen demand but limited capacity for energy storage that necessitates an effective means of regional blood delivery. The relative low cost, ease-of-use, non-invasiveness, and excellent temporal resolution of TCD make it an ideal tool for the examination of cerebrovascular function in both research and clinical settings. TCD is an efficient tool to access blood velocities within the cerebral vessels, cerebral autoregulation, cerebrovascular reactivity to CO
2, and neurovascular coupling, in both physiological states and in pathological conditions such as stroke and head trauma. In this review, we provide: (1) an overview of TCD methodology with respect to other techniques; (2) a methodological synopsis of the cerebrovascular exam using TCD; (3) an overview of the physiological mechanisms involved in regulation of the cerebral blood flow; (4) the utility of TCD for assessment of cerebrovascular pathology; and (5) recommendations for the assessment of four critical and complimentary aspects of cerebrovascular function: intra-cranial blood flow velocity, cerebral autoregulation, cerebral reactivity, and neurovascular coupling. The integration of these regulatory mechanisms from an integrated systems perspective is discussed, and future research directions are explored.
High-redshift quasars (
z
> 5) that also shine brightly at radio wavelengths are unique signposts of supermassive black hole activity in the early universe. However, bright radio sources at
z
≥ 5 ...are extremely rare and therefore we have started a campaign to search for new high-
z
quasars by combining an optical dropout selection driven by the
g
,
r
, and
z
bands from the Dark Energy Spectroscopic Instrument (DESI) Legacy Imaging Surveys with low-frequency radio observations from the LOFAR Two-metre Sky Survey (LoTSS). Currently, LoTSS covers a large fraction of the northern sky (∼5720 deg
2
) to such a depth (median noise level ∼83 μJy beam
−1
) that about 30% of the general quasar population is detected − which is a factor of 5–10 more than previous large sky radio surveys such as NVSS and FIRST, respectively. In this paper, we present the discovery of 20 new quasars (and the independent confirmation of four) between 4.9 ≤
z
≤ 6.6. Out of the 24 quasars, 21 satisfy the traditional radio-loudness criterion of
R
=
f
5 GHz
/
f
4400 Å
> 10, with the full sample spanning
R
∼ 6–1000, thereby more than doubling the sample of known radio-loud quasars at
z
≥ 5. Our radio detection requirement strongly decreases the contamination of stellar sources and allows one to select these quasars in a broad redshift range. Despite selecting our quasar candidates using fewer and less conservative colour restrictions, both the optical and near-infrared colours, Ly
α
emission line properties, and dust reddening,
E
(
B
−
V
), measurements of our quasar sample do not deviate from the known radio-quiet quasar population, suggesting similar optical quasar properties of the radio-loud and radio-quiet quasar population at high-
z
. Our campaign demonstrates the potential for discovering new high-
z
quasar populations through next generation radio continuum surveys.
▶ Fisheries can impact species, habitats and ecological communities. ▶ We describe a risk-based framework to assess these impacts. ▶ Novel features include a hierarchical structure and a ...precautionary approach. ▶ This framework has applicability in a wide range of fisheries.
Management of fisheries around the world is challenged by fishing impacts on habitats, bycatch species, threatened and endangered species, and even associated ecological communities. One response to these other factors has been a call for ecosystem-based fisheries management (EBFM), which demands consideration of the above non-target interactions. A challenge with implementation of EBFM is the scale and range of issues to be considered, all of which cannot be addressed at the same level of detail as for target species, due to data or time constraints. We developed an approach to progress the EBFM mandate in Australia, using a new ecological risk assessment framework applied to fisheries, termed Ecological Risk Assessment for the Effects of Fishing (ERAEF). Novel features of this framework include its hierarchical structure and its precautionary approach to uncertainty. The amount of information required increases through the hierarchy, and allows application in data-limited situations. The ERAEF framework has been applied to over 30 fisheries in Australia and elsewhere. The efficiencies in application of the hierarchical approach are illustrated by the south-east otter trawl fishery, where following Level 1 assessment of all components, an initial set of 600 species and 158 habitats was reduced to a group of concern of 159 species and 46 habitats using the Level 2 analysis, with the number of species of concern further reduced to 25 following Level 3 analysis. As a result of the assessments in Australia, management actions have been enacted for a range of the high risk species. Overall, the ERAEF approach offers a realistic method to assess ecological risk in an EBFM context, and has applicability in a wide range of fisheries. The interactive and inclusive nature of the approach also has the advantage of bringing stakeholders, scientists and managers together to develop management solutions.
In a phase III trial in patients with advanced, well-differentiated, progressive pancreatic neuroendocrine tumors, sunitinib 37.5 mg/day improved investigator-assessed progression-free survival (PFS) ...versus placebo (11.4 versus 5.5 months; HR, 0.42; P < 0.001). Here, we present PFS using retrospective blinded independent central review (BICR) and final median overall survival (OS), including an assessment highlighting the impact of patient crossover from placebo to sunitinib.
In this randomized, double-blind, placebo-controlled study, cross-sectional imaging from patients was evaluated retrospectively by blinded third-party radiologists using a two-reader, two-time-point lock, followed by a sequential locked-read, batch-mode paradigm. OS was summarized using the Kaplan–Meier method and Cox proportional hazards model. Crossover-adjusted OS effect was derived using rank-preserving structural failure time (RPSFT) analyses.
Of 171 randomized patients (sunitinib, n = 86; placebo, n = 85), 160 (94%) had complete scan sets/time points. By BICR, median (95% confidence interval CI) PFS was 12.6 (11.1–20.6) months for sunitinib and 5.8 (3.8–7.2) months for placebo (HR, 0.32; 95% CI 0.18–0.55; P = 0.000015). Five years after study closure, median (95% CI) OS was 38.6 (25.6–56.4) months for sunitinib and 29.1 (16.4–36.8) months for placebo (HR, 0.73; 95% CI 0.50–1.06; P = 0.094), with 69% of placebo patients having crossed over to sunitinib. RPSFT analysis confirmed an OS benefit for sunitinib.
BICR confirmed the doubling of PFS with sunitinib compared with placebo. Although the observed median OS improved by nearly 10 months, the effect estimate did not reach statistical significance, potentially due to crossover from placebo to sunitinib.
NCT00428597.
Abstract
We present panchromatic observations and modeling of calcium-strong supernovae (SNe) 2021gno in the star-forming host-galaxy NGC 4165 and 2021inl in the outskirts of elliptical galaxy NGC ...4923, both monitored through the Young Supernova Experiment transient survey. The light curves of both, SNe show two peaks, the former peak being derived from shock cooling emission (SCE) and/or shock interaction with circumstellar material (CSM). The primary peak in SN 2021gno is coincident with luminous, rapidly decaying X-ray emission (
L
x
= 5 × 10
41
erg s
−1
) detected by Swift-XRT at
δ
t
= 1 day after explosion, this observation being the second-ever detection of X-rays from a calcium-strong transient. We interpret the X-ray emission in the context of shock interaction with CSM that extends to
r
< 3 × 10
14
cm. Based on X-ray modeling, we calculate a CSM mass
M
CSM
= (0.3−1.6) × 10
−3
M
⊙
and density
n
= (1−4) × 10
10
cm
−3
. Radio nondetections indicate a low-density environment at larger radii (
r
> 10
16
cm) and mass-loss rate of
M
̇
<
10
−
4
M
⊙
yr
−1
. SCE modeling of both primary light-curve peaks indicates an extended-progenitor envelope mass
M
e
= 0.02−0.05
M
⊙
and radius
R
e
= 30−230
R
⊙
. The explosion properties suggest progenitor systems containing either a low-mass massive star or a white dwarf (WD), the former being unlikely given the lack of local star formation. Furthermore, the environments of both SNe are consistent with low-mass hybrid He/C/O WD + C/O WD mergers.
ABSTRACT
We present a detailed study of the cosmic star formation history over 90 per cent of cosmic time (0 ≲ z ≲ 4), using deep, radio continuum observations that probe star formation activity ...independent of dust. The Low Frequency Array Two Metre Sky Survey has imaged three well-studied extragalactic fields, Elais-N1, Boötes, and the Lockman Hole, reaching $\sim 20\, \mu \rm {Jy\,beam^{-1}}$ rms sensitivity at $150\, \rm {MHz}$. The availability of high-quality ancillary data from ultraviolet to far-infrared wavelengths has enabled accurate photometric redshifts and the robust separation of radio-bright AGN from their star-forming counterparts. We capitalize on this unique combination of deep, wide fields and robustly selected star-forming galaxies to construct radio luminosity functions and derive the cosmic star formation rate density. We carefully constrain and correct for scatter in the $L_{150\, \rm {MHz}}-\rm {SFR}$ relation, which we find to be $\sim 0.3\, \rm {dex}$. Our derived star formation rate density lies between previous measurements at all redshifts studied. We derive higher star formation rate densities between z ∼ 0 and z ∼ 3 than are typically inferred from short wavelength emission; at earlier times, this discrepancy is reduced. Our measurements are generally in good agreement with far-infrared and radio-based studies, with small offsets resulting from differing star formation rate calibrations.
LUX-ZEPLIN (LZ) is a second-generation direct dark matter experiment with spin-independent WIMP-nucleon scattering sensitivity above
1.4
×
10
-
48
cm
2
for a WIMP mass of
40
GeV
/
c
2
and a
1000
days
...exposure. LZ achieves this sensitivity through a combination of a large
5.6
t
fiducial volume, active inner and outer veto systems, and radio-pure construction using materials with inherently low radioactivity content. The LZ collaboration performed an extensive radioassay campaign over a period of six years to inform material selection for construction and provide an input to the experimental background model against which any possible signal excess may be evaluated. The campaign and its results are described in this paper. We present assays of dust and radon daughters depositing on the surface of components as well as cleanliness controls necessary to maintain background expectations through detector construction and assembly. Finally, examples from the campaign to highlight fixed contaminant radioassays for the LZ photomultiplier tubes, quality control and quality assurance procedures through fabrication, radon emanation measurements of major sub-systems, and bespoke detector systems to assay scintillator are presented.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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