112 research outputs found
Ponderosa pine ecosystems restoration and conservation: Steps toward stewardship
This volume is divided into three sections: (1) Ecological, Biological, and Physical Science; (2) Social and Cultural; and (3) Economics and Utilization. Effective ecological restoration requires a combination of science and management. The authors of the first section exemplified this integration in the course of addressing a broad range of topics, from detailed microsite and small-scale changes in fungal, plant, and animal communities, up through landscape, regional, and subcontinental scales. Although the themes were diverse, papers were linked by underscoring the relationship between restorative management actions and ecological effects. Social sciences play a key role in ecosystem restoration because collaboration, development of common goals, and political and economic feasibility are essential for success. The authors of the second section focused on public attitudes, partnerships, and the relationship between social and ecological factors. In the third section, the economics and utilization of products from forest restoration were compared in several Western locations. Both the markets for these products and the range of utilization opportunitiesfrom small-diameter logs to energy creationwill surely evolve rapidly as society moves to address the fire hazards and other problems caused by stressed and weakened ecosystems. The turn of the century is an appropriate point to capture dramatic changes in perspective: consider how attitudes toward Western forests have evolved between 1900 and 2000. The papers in this volume chronicle adaptive research that continues to deepen our understanding of restoration in ecosystems and social systems
Nutrient (C, N and P) enrichment induces significant changes in the soil metabolite profile and microbial carbon partitioning
The cycling of soil organic matter (SOM) and carbon (C) within the soil is governed by the presence of key macronutrients, particularly nitrogen (N) and phosphorus (P). The relative ratio of these nutrients has a direct effect on the potential rates of microbial growth and nutrient processing in soil and thus is fundamental to ecosystem functioning. However, the effect of changing soil nutrient stoichiometry on the small organic molecule (i.e., metabolite) composition and cycling by the microbial community remains poorly understood. Here, we aimed to disentangle the effect of stoichiometrically balanced nutrient addition on the soil metabolomic profile and apparent microbial carbon use efficiency (CUE) by adding a labile C source (glucose) in combination with N and/or P. After incorporation of the added glucose into the microbial biomass (48 h), metabolite profiling was undertaken by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). 494 metabolites were identified across all treatments mainly consisting of lipids (n = 199), amino acids (n = 118) and carbohydrates (n = 43), >97% of which showed significant changes in concentration between at least one treatment. Overall, glucose-C addition generally increased the synthesis of other carbohydrates in soil, while addition of C and N together increased peptide synthesis, indicative of protein formation and turnover. The combination of C and P significantly increased the number of fatty acids synthesised. There was no significant change in the PLFA-derived microbial community structure or microbial biomass following C, N and P addition. Further, N addition led to an increase in glucose-C partitioning into anabolic processes (i.e., increased CUE), suggesting the microbial community was N, but not P limited. Based on the metabolomic profiles observed here, we conclude that inorganic nutrient enrichment causes substantial shifts in both primary and secondary metabolism within the microbial community, leading to changes in resource flow and thus soil functioning, however, the microbial community illustrated significant metabolic flexibility
Rapid Recurrence of Eosinophilic Esophagitis Activity After Successful Treatment in the Observation Phase of a Randomized, Double-Blind, Double-Dummy Trial
Background & Aims: Eosinophilic esophagitis (EoE) is chronic and recurs if treatment is discontinued. We aimed to determine rates of recurrence, and whether initial treatment with oral viscous budesonide (OVB) resulted in less recurrence than fluticasone from a multidose inhaler (MDI). Methods: This was the observation phase of a randomized, double-blind, double-dummy trial comparing OVB with MDI for initial EoE treatment. Subjects with a histologic response (<15 eosinophils/high-power field) in the trial entered an observation phase in which treatment was discontinued and symptoms were monitored. Patients underwent an endoscopy or a biopsy when symptoms recurred or at 1 year. We analyzed time to symptom recurrence and assessed endoscopic severity and histologic relapse (â„15 eosinophils/high-power field) at follow-up endoscopy. Results: Thirty-three of the 58 subjects (57%) had symptom recurrence before 1 year. The overall median time to symptom recurrence was 244 days. There was no difference in the rate of symptom recurrence for subjects treated with OVB vs MDI (hazard ratio, 1.04; 95% CI, 0.52â2.08). At symptom recurrence, 78% of patients had histologic relapse. The patients had significant increases in mean Dysphagia Symptom Questionnaire score (3.8 vs 8.7; P < .001), and the EoE Endoscopic Reference Score (1.3 vs 4.6; P < .001) compared with end of treatment. Conclusions: EoE disease activity recurred rapidly after initial histologic response to topical steroids (either OVB or MDI). Because most subjects had recurrent endoscopic and histologic signs not reliably detected by symptoms, maintenance therapy should be recommended in EoE patients achieving histologic response to topical steroids. Clinicaltrials.gov no: NCT02019758
Efficacy of Budesonide vs Fluticasone for Initial Treatment of Eosinophilic Esophagitis in a Randomized Controlled Trial
Background and Aims: Topical steroid treatments for eosinophilic esophagitis (EoE) include swallowed fluticasone from a multi-dose inhaler (MDI) or oral viscous budesonide (OVB) slurry, but the 2 have never been compared. We assessed whether OVB was more effective than MDI for initial treatment of patients with EoE. Methods: In a double-blind, double-dummy trial, patients with a new diagnosis of EoE were randomly assigned to groups given 8 weeks of either OVB (1 mg/4 mL) twice daily plus a placebo inhaler (n = 56) or fluticasone MDI (880 ÎŒg) twice daily plus a placebo slurry (n = 55). Primary outcomes were post-treatment maximum eosinophil counts per high-power field (eos/hpf) and a validated dysphagia score (dysphagia symptom questionnaire [DSQ]) at week 8. Secondary outcomes included endoscopic severity (validated EoE endoscopic reference score), histologic response (<15 eos/hpf), and safety. Results: In a modified intention-to-treat analysis, the subjects had baseline peak eosinophil counts of 73 and 77 eos/hpf in the OVB and MDI groups, respectively, and DSQ scores of 11 and 8. Post-treatment eosinophil counts were 15 and 21 in the OVB and MDI groups, respectively (P =.31), with 71% and 64% achieving histologic response (P =.38). DSQ scores were 5 and 4 in the OVB and MDI groups (P =.70). Similar trends were noted for post-treatment total EoE endoscopic reference scores (2 vs 3; P =.06). Esophageal candidiasis developed in 12% of patients receiving OVB and 16% receiving MDI; oral thrush was observed in 3% and 2%, respectively. Conclusions: In a randomized clinical trial, initial treatment of EoE with either OVB or fluticasone MDI produced a significant decrease in esophageal eosinophil counts and improved dysphagia and endoscopic features. However, OVB was not superior to MDI, so either is an acceptable treatment for EoE. ClinicalTrials.gov ID NCT02019758
Theory of charge transport in diffusive normal metal / unconventional singlet superconductor contacts
We analyze the transport properties of contacts between unconventional
superconductor and normal diffusive metal in the framework of the extended
circuit theory. We obtain a general boundary condition for the Keldysh-Nambu
Green's functions at the interface that is valid for arbitrary transparencies
of the interface. This allows us to investigate the voltage-dependent
conductance (conductance spectrum) of a diffusive normal metal (DN)/
unconventional singlet superconductor junction in both ballistic and diffusive
cases. For d-wave superconductor, we calculate conductance spectra numerically
for different orientations of the junctions, resistances, Thouless energies in
DN, and transparencies of the interface. We demonstrate that conductance
spectra exhibit a variety of features including a -shaped gap-like
structure, zero bias conductance peak (ZBCP) and zero bias conductance dip
(ZBCD). We show that two distinct mechanisms: (i) coherent Andreev reflection
(CAR) in DN and (ii) formation of midgap Andreev bound state (MABS) at the
interface of d-wave superconductors, are responsible for ZBCP, their relative
importance being dependent on the angle between the interface normal
and the crystal axis of d-wave superconductors. For , the ZBCP is due
to CAR in the junctions of low transparency with small Thouless energies, this
is similar to the case of diffusive normal metal / insulator /s-wave
superconductor junctions. With increase of from zero to , the
MABS contribution to ZBCP becomes more prominent and the effect of CAR is
gradually suppressed. Such complex spectral features shall be observable in
conductance spectra of realistic high- junctions at very low temperature
An Integrated TCGA Pan-Cancer Clinical Data Resource to Drive High-Quality Survival Outcome Analytics
For a decade, The Cancer Genome Atlas (TCGA) program collected clinicopathologic annotation data along with multi-platform molecular profiles of more than 11,000 human tumors across 33 different cancer types. TCGA clinical data contain key features representing the democratized nature of the data collection process. To ensure proper use of this large clinical dataset associated with genomic features, we developed a standardized dataset named the TCGA Pan-Cancer Clinical Data Resource (TCGA-CDR), which includes four major clinical outcome endpoints. In addition to detailing major challenges and statistical limitations encountered during the effort of integrating the acquired clinical data, we present a summary that includes endpoint usage recommendations for each cancer type. These TCGA-CDR findings appear to be consistent with cancer genomics studies independent of the TCGA effort and provide opportunities for investigating cancer biology using clinical correlates at an unprecedented scale. Analysis of clinicopathologic annotations for over 11,000 cancer patients in the TCGA program leads to the generation of TCGA Clinical Data Resource, which provides recommendations of clinical outcome endpoint usage for 33 cancer types
Theory of charge transport in diffusive normal metal / conventional superconductor point contacts
Tunneling conductance in diffusive normal metal / insulator / s-wave
superconductor (DN/I/S) junctions is calculated for various situations by
changing the magnitudes of the resistance and Thouless energy in DN and the
transparency of the insulating barrier. The generalized boundary condition
introduced by Yu. Nazarov [Superlattices and Microstructures 25 1221 (1999)] is
applied, where the ballistic theory by Blonder Tinkham and Klapwijk (BTK) and
the diffusive theory by Volkov Zaitsev and Klapwijk based on the boundary
condition of Kupriyanov and Lukichev (KL) are naturally reproduced. It is shown
that the proximity effect can enhance (reduce) the tunneling conductance for
junctions with a low (high) transparency. A wide variety of dependencies of
tunneling conductance on voltage bias is demonstrated including a -shaped
gap like structure, a zero bias conductance peak (ZBCP) and a zero bias
conductance dip (ZBCD)
The chemical compound 'Heatin' stimulates hypocotyl elongation and interferes with the Arabidopsis NIT1-subfamily of nitrilases
Temperature passively affects biological processes involved in plant growth. Therefore, it is challenging to study the dedicated temperature signalling pathways that orchestrate thermomorphogenesis, a suite of elongation growth-based adaptations that enhance leaf-cooling capacity. We screened a chemical library for compounds that restored hypocotyl elongation in the pif4-2-deficient mutant background at warm temperature conditions in Arabidopsis thaliana to identify modulators of thermomorphogenesis. The small aromatic compound 'Heatin', containing 1-iminomethyl-2-naphthol as a pharmacophore, was selected as an enhancer of elongation growth. We show that ARABIDOPSIS ALDEHYDE OXIDASES redundantly contribute to Heatin-mediated hypocotyl elongation. Following a chemical proteomics approach, the members of the NITRILASE1-subfamily of auxin biosynthesis enzymes were identified among the molecular targets of Heatin. Our data reveal that nitrilases are involved in promotion of hypocotyl elongation in response to high temperature and Heatin-mediated hypocotyl elongation requires the NITRILASE1-subfamily members, NIT1 and NIT2. Heatin inhibits NIT1-subfamily enzymatic activity in vitro and the application of Heatin accordingly results in the accumulation of NIT1-subfamily substrate indole-3-acetonitrile in vivo. However, levels of the NIT1-subfamily product, bioactive auxin (indole-3-acetic acid), were also significantly increased. It is likely that the stimulation of hypocotyl elongation by Heatin might be independent of its observed interaction with NITRILASE1-subfamily members. However, nitrilases may contribute to the Heatin response by stimulating indole-3-acetic acid biosynthesis in an indirect way. Heatin and its functional analogues present novel chemical entities for studying auxin biology
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