3,565 research outputs found
Intersections of Soundscapes and Conservation: Ecologies of Sound in Naturecultures
An ecosystem is a reflection of coupled human and natural systems. A key, and less understood, interaction is with sound. Paralleling development in landscape ecology, soundscape ecology provides a diversity of measures of spatial and temporal variation in sound. Here we bridge disciplines to describe variation in soundscape measures across a gradient of novel to natural landscapes. Soundscape measures studied varied as a function of forest area but not matrix type, and season but not time. Results suggest future directions and allow practitioners to better identify management options that mitigate the impacts of noise on natural and human systems.Un Ă©cosystĂšme est un reflet de lâappariement dâun systĂšme humain et dâun systĂšme naturel. Lâune des interactions essentielles, et des moins bien comprises, se fait au moyen du son. Se dĂ©veloppant parallĂšlement Ă lâĂ©cologie du paysage, lâĂ©cologie du paysage sonore procure une diversitĂ© de mesures de variations spatiales et temporelles du son. Ici nous Ă©tablissons un pont entre les disciplines pour dĂ©crire la variation dans les mesures du paysage sonore le long dâune graduation allant des paysages nouveaux aux paysages naturels. Les mesures du paysage sonore Ă©tudiĂ©es variaient en fonction de la rĂ©gion forestiĂšre, mais non du type matriciel, et de la saison mais non du temps. Les rĂ©sultats indiquent des orientations futures et permettent aux praticiens de mieux identifier les options de gestion qui attĂ©nuent les impacts du bruit sur les systĂšmes humains et naturels
J1420--0545: The radio galaxy larger than 3C236
We report the discovery of the largest giant radio galaxy, J1420-0545: a FR
type II radio source with an angular size of 17.4' identified with an optical
galaxy at z=0.3067. Thus, the projected linear size of the radio structure is
4.69 Mpc (if we assume that H_{0}=71 km\s\Mpc, Omega_{m}=0.27, and
Omega_{\Lambda}=0.73). This makes it larger than 3C236, which is the largest
double radio source known to date. New radio observations with the 100 m
Effelsberg telescope and the Giant Metrewave Radio Telescope, as well as
optical identification with a host galaxy and its optical spectroscopy with the
William Herschel Telescope are reported. The spectrum of J1420-0545 is typical
of elliptical galaxies in which continuum emission with the characteristic
4000A discontinuity and the H and K absorption lines are dominated by evolved
stars. The dynamical age of the source, its jets' power, the energy density,
and the equipartition magnetic field are calculated and compared with the
corresponding parameters of other giant and normal-sized radio galaxies from a
comparison sample. The source is characterized by the exceptionally low density
of the surrounding IGM and an unexpectedly high expansion speed of the source
along the jet axis. All of these may suggest a large inhomogeneity of the IGM.Comment: 20 pages, 5 figures, 3 table
Modeling of Wnt-mediated tissue patterning in vertebrate embryogenesis
During embryogenesis, morphogens form a concentration gradient in responsive tissue, which is then translated into a spatial cellular pattern. The mechanisms by which morphogens spread through a tissue to establish such a morphogenetic field remain elusive. Here, we investigate by mutually complementary simulations and in vivo experiments how Wnt morphogen transport by cytonemes differs from typically assumed diffusion-based transport for patterning of highly dynamic tissue such as the neural plate in zebrafish. Stochasticity strongly influences fate acquisition at the single cell level and results in fluctuating boundaries between pattern regions. Stable patterning can be achieved by sorting through concentration dependent cell migration and apoptosis, independent of the morphogen transport mechanism. We show that Wnt transport by cytonemes achieves distinct Wnt thresholds for the brain primordia earlier compared with diffusion-based transport. We conclude that a cytoneme-mediated morphogen transport together with directed cell sorting is a potentially favored mechanism to establish morphogen gradients in rapidly expanding developmental systems
Energetic Trade-Offs in Migration Decision-Making, Reproductive Effort and Subsequent Parental Care in a Long-Distance Migratory Bird
Migratory species trade-off long-distance movement with survival and reproduction, but the spatio-temporal scales at which these decisions occur are relatively unknown. Technological and statistical advances allow fine-scale study of animal decision-making, improving our understanding of possible causes and therefore conservation management. We quantified effects of reproductive preparation during spring migration on subsequent breeding outcomes, breeding outcomes on autumn migration characteristics and autumn migration characteristics on subsequent parental survival in Greenland white-fronted geese
Inferring transmission fitness advantage of SARS-CoV-2 variants of concern from wastewater samples using digital PCR, Switzerland, December 2020 through March 2021
BackgroundThroughout the COVID-19 pandemic, SARS-CoV-2 genetic variants of concern (VOCs) have repeatedly and independently arisen. VOCs are characterised by increased transmissibility, increased virulence or reduced neutralisation by antibodies obtained from prior infection or vaccination. Tracking the introduction and transmission of VOCs relies on sequencing, typically whole genome sequencing of clinical samples. Wastewater surveillance is increasingly used to track the introduction and spread of SARS-CoV-2 variants through sequencing approaches.AimHere, we adapt and apply a rapid, high-throughput method for detection and quantification of the relative frequency of two deletions characteristic of the Alpha, Beta, and Gamma VOCs in wastewater.MethodsWe developed drop-off RT-dPCR assays and an associated statistical approach implemented in the R package WWdPCR to analyse temporal dynamics of SARS-CoV-2 signature mutations (spike Î69-70 and ORF1a Î3675-3677) in wastewater and quantify transmission fitness advantage of the Alpha VOC.ResultsBased on analysis of Zurich wastewater samples, the estimated transmission fitness advantage of SARS-CoV-2 Alpha based on the spike Î69-70 was 0.34 (95% confidence interval (CI): 0.30-0.39) and based on ORF1a Î3675-3677 was 0.53 (95% CI: 0.49-0.57), aligning with the transmission fitness advantage of Alpha estimated by clinical sample sequencing in the surrounding canton of 0.49 (95% CI: 0.38-0.61).ConclusionDigital PCR assays targeting signature mutations in wastewater offer near real-time monitoring of SARS-CoV-2 VOCs and potentially earlier detection and inference on transmission fitness advantage than clinical sequencing. Keywords: B.1.1.7; SARS-CoV-2; digital PCR; drop-off assays; transmission fitness
Inter- and Intragranular Effects in Superconducting Compacted Platinum Powders
Compacted platinum powders exhibit a sharp onset of diamagnetic screening at
mK in zero magnetic field in all samples investigated. This
sharp onset is interpreted in terms of the intragranular transition into the
superconducting state. At lower temperatures, the magnetic ac susceptibility
strongly depends on the ac field amplitude and reflects the small intergranular
critical current density . This critical current density shows a strong
dependence on the packing fraction f of the granular samples. Surprisingly,
increases significantly with decreasing f ( A/cm for f = 0.67 and A/cm for f
= 0.50). The temperature dependence of shows strong positive curvature
over a wide temperature range for both samples. The phase diagrams of inter-
and intragranular superconductivity for different samples indicate that the
granular structure might play the key role for an understanding of the origin
of superconductivity in the platinum compacts.Comment: 11 pages including 9 figures. To appear in Phys. Rev. B in Nov. 0
Measurement of the Inclusive Semi-electronic Branching Fraction
Using the angular correlation between the emitted in a decay and the emitted in the subsequent decay, we have measured the branching fraction for the
inclusive semi-electronic decay of the meson to be: {\cal B}(D^0
\rightarrow X e^+ \nu) = [6.64 \pm 0.18 (stat.) \pm 0.29 (syst.)] \%. The
result is based on 1.7 fb of collisions recorded by the CLEO II
detector located at the Cornell Electron Storage Ring (CESR). Combining the
analysis presented in this paper with previous CLEO results we find,
\frac{{\cal B} (D^0 \rightarrow X e^+ \nu)}
{{\cal B} (D^0 \rightarrow K^- \pi^+)}
= 1.684 \pm 0.056 (stat.) \pm 0.093(syst.) and
\frac{{\cal B}(D\rightarrow K^-e^+\nu)}
{{\cal B}(D\rightarrow Xe^+\nu)}
= 0.581 \pm 0.023 (stat.) \pm 0.028(syst.).
The difference between the inclusive rate and the sum of the measured
exclusive branching fractions (measured at CLEO and other experiments) is of the inclusive rate.Comment: Latex file, 33pages, 4 figures Submitted to PR
Somatostatin-based radiotherapy with [90Y-DOTA]-TOC in neuroendocrine tumors: long-term outcome of a phase I dose escalation study
BACKGROUND
We describe the long-term outcome after clinical introduction and dose escalation of somatostatin receptor targeted therapy with [90Y-DOTA]-TOC in patients with metastasized neuroendocrine tumors.
METHODS
In a clinical phase I dose escalation study we treated patients with increasing [90Y-DOTA]-TOC activities. Multivariable Cox regression and competing risk regression were used to compare efficacy and toxicities of the different dosage protocols.
RESULTS
Overall, 359 patients were recruited; 60 patients were enrolled for low dose (median: 2.4âGBq/cycle, range 0.9-7.8âGBq/cycle), 77 patients were enrolled for intermediate dose (median: 3.3âGBq/cycle, range: 2.0-7.4âGBq/cycle) and 222 patients were enrolled for high dose (median: 6.7âGBq/cycle, range: 3.7-8.1âGBq/cycle) [90Y-DOTA]-TOC treatment. The incidences of hematotoxicities grade 1-4 were 65.0%, 64.9% and 74.8%; the incidences of grade 4/5 kidney toxicities were 8.4%, 6.5% and 14.0%, and the median survival was 39 (range: 1-158) months, 34 (range: 1-118) months and 29 (range: 1-113) months. The high dose protocol was associated with an increased risk of kidney toxicity (Hazard Ratio: 3.12 (1.13-8.59) vs. intermediate dose, pâ=â0.03) and a shorter overall survival (Hazard Ratio: 2.50 (1.08-5.79) vs. low dose, pâ=â0.03).
CONCLUSIONS
Increasing [90Y-DOTA]-TOC activities may be associated with increasing hematological toxicities. The dose related hematotoxicity profile of [90Y-DOTA]-TOC could facilitate tailoring [90Y-DOTA]-TOC in patients with preexisting hematotoxicities. The results of the long-term outcome suggest that fractionated [90Y-DOTA]-TOC treatment might allow to reduce renal toxicity and to improve overall survival. (ClinicalTrials.gov number NCT00978211)
Solitary waves in the Nonlinear Dirac Equation
In the present work, we consider the existence, stability, and dynamics of
solitary waves in the nonlinear Dirac equation. We start by introducing the
Soler model of self-interacting spinors, and discuss its localized waveforms in
one, two, and three spatial dimensions and the equations they satisfy. We
present the associated explicit solutions in one dimension and numerically
obtain their analogues in higher dimensions. The stability is subsequently
discussed from a theoretical perspective and then complemented with numerical
computations. Finally, the dynamics of the solutions is explored and compared
to its non-relativistic analogue, which is the nonlinear Schr{\"o}dinger
equation. A few special topics are also explored, including the discrete
variant of the nonlinear Dirac equation and its solitary wave properties, as
well as the PT-symmetric variant of the model
Glacier retreat creating new Pacific salmon habitat in western North America
Glacier retreat poses risks and benefits for species of cultural and economic importance. One
example is Pacific salmon (Oncorhynchus spp.), supporting subsistence harvests, and commercial and recreational fisheries worth billions of dollars annually. Although decreases in
summer streamflow and warming freshwater is reducing salmon habitat quality in parts of
their range, glacier retreat is creating new streams and lakes that salmon can colonize.
However, potential gains in future salmon habitat associated with glacier loss have yet to be
quantified across the range of Pacific salmon. Here we project future gains in Pacific salmon
freshwater habitat by linking a model of glacier mass change for 315 glaciers, forced by five
different Global Climate Models, with a simple model of salmon stream habitat potential
throughout the Pacific Mountain ranges of western North America. We project that by the
year 2100 glacier retreat will create 6,146 (±1,619) km of new streams accessible for colonization by Pacific salmon, of which 1,930 (±569) km have the potential to be used for
spawning and juvenile rearing, representing 0 to 27% gains within the 18 sub-regions we
studied. These findings can inform proactive management and conservation of Pacific salmon
in this era of rapid climate change.Ye
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