2,223 research outputs found
Drought- Conditioning of Quaking Aspen (Populus tremuloides Michx.) Seedlings During Nursery Production Modifies Seedling Anatomy and Physiology
In the western US, quaking aspen (Populus tremuloides Michx.) regenerates primarily by root suckers after disturbances such as low to moderate severity fires. Planting aspen seedlings grown from seed may provide a mechanism to improve restoration success and genetic diversity on severely disturbed sites. However, few studies have examined the use of container-grown aspen seedlings for restoration purposes from both the outplanting and nursery production perspective. Thus, the purpose of this novel study was to examine how alterations in irrigation levels during nursery production across three seed sources would impact seedling performance attributes on harsh, dry outplanting sites. Irrigation treatments were based on three irrigation levels, determined gravimetrically: High = 90%, Medium = 80%, and Low = 70% of container capacity. The three seed sources represented a latitudinal gradient across the aspen range (New Mexico, Utah, and Alberta). Carbon isotope analysis indicated irrigation treatments were effective in creating higher levels of water stress for both the Low and Medium irrigation levels compared to seedlings under the High irrigation level. Seedlings subject to the Low irrigation level were found to induce greater height, higher photosynthetic rates, larger percentages of hydraulically active xylem, and faster xylem flow velocities compared to the High irrigation level. The lack of an interaction between irrigation treatments and seed source for nearly all response variables suggests that nursery conditioning via irrigation limitations may be effective for a range of aspen seed sources
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Bullous dermatoses secondary to anti-PD-L1 agents: a case report and review of the literature
Immune checkpoint inhibitors are used to treat numerous malignancies but may be associated with severe adverse events. Bullous dermatoses, chiefly bullous pemphigoid (BP), are potentially progressive adverse events that cause blistering skin lesions and may involve a significant body surface area. Herein, we report an 87-year-old man with urothelial cell carcinoma undergoing atezolizumab treatment who presented with an acute-onset blistering eruption. Biopsy revealed a subepidermal bulla, direct immunofluorescence revealed linear IgG and C3 deposits at the dermal-epidermal junction, and serum studies revealed elevated levels of antibodies to BP180 and BP230. Anti-PD-L1-induced BP was diagnosed, immunotherapy was withheld, and he was treated with oral doxycycline with niacinamide and clobetasol ointment. He restarted atezolizumab and has successfully received four cycles (every 3 weeks) while continuing this BP treatment regimen. A literature review revealed eight other cases of anti-PD-L1-induced bullous disorders. The incidence of bullous dermatoses with anti-PD-1/anti-PD-L1 agents combined is 1%, whereas the reported incidence for anti-PD-L1 agents alone ranges from 1.3-5%, raising concerns for a higher overall risk. In addition to our case, only one other case reported successful resumption of immunotherapy. Early control and management of immunotherapy-induced BP may reduce complications and prevent treatment discontinuation
Turbidimetric Determination of Anionic Polyacrylamide in Low Carbon Soil Extracts
Concerns over runoff water quality from agricultural lands and construction sites have led to the development of improved erosion control practices, including application of polyacrylamide (PAM). We developed a quick and reliable method for quantifying PAM in soil extracts at low carbon content by using a turbidimetric reagent, Hyamine 1622. Three high-molecular weight anionic PAMs differing in charge density (7, 20, and 50 mol%) and five water matrices, deionized (DI) water and extracts from four different soils, were used to construct PAM calibration curves by reacting PAM solutions with hyamine and measuring turbidity development from the PAMâhyamine complex. The PAM calibration curve with DI water showed a strong linear relationship (r2 = 0.99), and the sensitivity (slope) of calibration curves increased with increasing PAM charge density with a detection limit of 0.4 to 0.9 mg Lâ1. Identical tests with soil extracts showed the sensitivity of the hyamine method was dependent on the properties of the soil extract, primarily organic carbon concentration. Although the method was effective in mineral soils, the highest charge density PAM yielded a more reliable linear relationship (r2 \u3e 0.97) and lowest detection limit (0.3 to 1.2 mg Lâ1), compared with those of the lower charge density PAMs (0.7 to 23 mg Lâ1). Our results suggest that the hyamine test could be an efficient method for quantifying PAM in environmental soil water samples as long as the organic carbon in the sample is low, such as in subsurface soil material often exposed at construction sites
Variability in X-ray induced effects in [Rh(COD)Cl]â with changing experimental parameters
X-ray characterisation methods have undoubtedly enabled cutting-edge advances in all aspects of materials research. Despite the enormous breadth of information that can be extracted from these techniques, the challenge of radiation-induced sample change and damage remains prevalent. This is largely due to the emergence of modern, high-intensity X-ray source technologies and the growing potential to carry out more complex, longer duration in situ or in operando studies. The tunability of synchrotron beamlines enables the routine application of photon energy-dependent experiments. This work explores the structural stability of [Rh(COD)Cl]2, a widely used catalyst and precursor in the chemical industry, across a range of beamline parameters that target X-ray energies of 8 keV, 15 keV, 18 keV and 25 keV, on a powder X-ray diffraction synchrotron beamline at room temperature. Structural changes are discussed with respect to absorbed X-ray dose at each experimental setting associated with the respective photon energy. In addition, the X-ray radiation hardness of the catalyst is discussed, by utilising the diffraction data collected at the different energies to determine a dose limit, which is often considered in protein crystallography and typically overlooked in small molecule crystallography. This work not only gives fundamental insight into how damage manifests in this organometallic catalyst, but will encourage careful consideration of experimental X-ray parameters before conducting diffraction on similar radiation-sensitive organometallic materials
Automated eukaryotic gene structure annotation using EVidenceModeler and the Program to Assemble Spliced Alignments
EVidenceModeler (EVM) is an automated annotation tool that predicts protein-coding regions, alternatively spliced transcripts and untranslated regions of eukaryotic genes
Management of Persistent Pruritus and Lichenoid Reaction Secondary to Nivolumab With Narrowband Ultraviolet B Phototherapy
Immune checkpoint inhibitors targeting the programmed cell death receptor 1 (PD-1) are increasingly used to treat several malignancies, with the most common adverse event being cutaneous toxicity. We report the case of a 68-years-old man with stage IV non-small cell lung cancer treated with nivolumab who developed a pruritic, lichenoid eruption refractory to treatment with topical or systemic steroids, who was started on narrow band ultraviolet B therapy which resolved the reaction
Galaxy Cluster Environments of Radio Sources
Using the Sloan Digital Sky Survey (SDSS) and the FIRST (Faint Images of the
Radio Sky at Twenty Centimeters) catalogs, we examined the optical environments
around double-lobed radio sources. Previous studies have shown that
multi-component radio sources exhibiting some degree of bending between
components are likely to be found in galaxy clusters. Often this radio emission
is associated with a cD-type galaxy at the center of a cluster. We
cross-correlated the SDSS and FIRST catalogs and measured the richness of the
cluster environments surrounding both bent and straight multi-component radio
sources. This led to the discovery and classification of a large number of
galaxy clusters out to a redshift of z ~ 0.5. We divided our sample into
smaller subgroups based on their optical and radio properties. We find that FR
I radio sources are more likely to be found in galaxy clusters than FR II
sources. Further, we find that bent radio sources are more often found in
galaxy clusters than non-bent radio sources. We also examined the environments
around single-component radio sources and find that single-component radio
sources are less likely to be associated with galaxy clusters than extended,
multi-component radio sources. Bent, visually-selected sources are found in
clusters or rich groups ~78% of the time. Those without optical hosts in SDSS
are likely associated with clusters at even higher redshifts, most with
redshifts of z > 0.7.Comment: 47 pages, 24 figures. Accepted by A
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Inhibition of dual-specificity tyrosine phosphorylation-regulated kinase 2 perturbs 26S proteasome-addicted neoplastic progression
Dependence on the 26S proteasome is an Achilles' heel for triple-negative breast cancer (TNBC) and multiple myeloma (MM). The therapeutic proteasome inhibitor, bortezomib, successfully targets MM but often leads to drug-resistant disease relapse and fails in breast cancer. Here we show that a 26S proteasome-regulating kinase, DYRK2, is a therapeutic target for both MM and TNBC. Genome editing or small-molecule mediated inhibition of DYRK2 significantly reduces 26S proteasome activity, bypasses bortezomib resistance, and dramatically delays in vivo tumor growth in MM and TNBC thereby promoting survival. We further characterized the ability of LDN192960, a potent and selective DYRK2-inhibitor, to alleviate tumor burden in vivo. The drug docks into the active site of DYRK2 and partially inhibits all 3 core peptidase activities of the proteasome. Our results suggest that targeting 26S proteasome regulators will pave the way for therapeutic strategies in MM and TNBC
The intrinsic predictability of ecological time series and its potential to guide forecasting
Successfully predicting the future states of systems that are complex, stochastic, and potentially chaotic is a major challenge. Model forecasting error (FE) is the usual measure of success; however model predictions provide no insights into the potential for improvement. In short, the realized predictability of a specific model is uninformative about whether the system is inherently predictable or whether the chosen model is a poor match for the system and our observations thereof. Ideally, model proficiency would be judged with respect to the systemsâ intrinsic predictability, the highest achievable predictability given the degree to which system dynamics are the result of deterministic vs. stochastic processes. Intrinsic predictability may be quantified with permutation entropy (PE), a modelâfree, informationâtheoretic measure of the complexity of a time series. By means of simulations, we show that a correlation exists between estimated PE and FE and show how stochasticity, process error, and chaotic dynamics affect the relationship. This relationship is verified for a data set of 461 empirical ecological time series. We show how deviations from the expected PEâFE relationship are related to covariates of data quality and the nonlinearity of ecological dynamics. These results demonstrate a theoretically grounded basis for a modelâfree evaluation of a system's intrinsic predictability. Identifying the gap between the intrinsic and realized predictability of time series will enable researchers to understand whether forecasting proficiency is limited by the quality and quantity of their data or the ability of the chosen forecasting model to explain the data. Intrinsic predictability also provides a modelâfree baseline of forecasting proficiency against which modeling efforts can be evaluated
Weak Lensing with SDSS Commissioning Data: The Galaxy-Mass Correlation Function To 1/h Mpc
(abridged) We present measurements of galaxy-galaxy lensing from early
commissioning imaging data from the Sloan Digital Sky Survey (SDSS). We measure
a mean tangential shear around a stacked sample of foreground galaxies in three
bandpasses out to angular radii of 600'', detecting the shear signal at very
high statistical significance. The shear profile is well described by a
power-law. A variety of rigorous tests demonstrate the reality of the
gravitational lensing signal and confirm the uncertainty estimates. We
interpret our results by modeling the mass distributions of the foreground
galaxies as approximately isothermal spheres characterized by a velocity
dispersion and a truncation radius. The velocity dispersion is constrained to
be 150-190 km/s at 95% confidence (145-195 km/s including systematic
uncertainties), consistent with previous determinations but with smaller error
bars. Our detection of shear at large angular radii sets a 95% confidence lower
limit , corresponding to a physical radius of
kpc, implying that galaxy halos extend to very large radii. However, it is
likely that this is being biased high by diffuse matter in the halos of groups
and clusters. We also present a preliminary determination of the galaxy-mass
correlation function finding a correlation length similar to the galaxy
autocorrelation function and consistency with a low matter density universe
with modest bias. The full SDSS will cover an area 44 times larger and provide
spectroscopic redshifts for the foreground galaxies, making it possible to
greatly improve the precision of these constraints, measure additional
parameters such as halo shape, and measure the properties of dark matter halos
separately for many different classes of galaxies.Comment: 28 pages, 11 figures, submitted to A
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