762 research outputs found
Effects of nitrogen fertilization on fungal community structure in a temperate hardwood forest: Implicit links between structure, function and resilience
This study documents soil fungal communities at the Harvard Forest Chronic Nitrogen Addition experiment, which was established in 1989 to test the effects of long-term nitrogen fertilization on ecosystem processes. Researchers at this site have observed an accumulation of soil carbon in the nitrogen fertilized plots and a decrease in fungal biomass, ligninolytic enzyme activity, and rates of litter decay. We hypothesized that decreased decomposition rates in nitrogen-fertilized plots were due to changes in the structure of the fungal community, especially Basidiomycetes, the primary decomposers of lignin in this ecosystem. We performed a marker gene study of fungal communities in the organic soil horizon using 454 high-throughput sequencing of three separate loci. The dominant OTU increased significantly in relative abundance in the highest N treatment. Additionally, Basidiomycete community composition was altered by N additions. These results suggest that changes in fungal community structure may contribute to decreased decomposition rates
Electromagnetic Forces in a Hybrid Magnetic-Bearing Switched-Reluctance Motor
Analysis and experimental measurement of the electromagnetic force loads on the hybrid rotor in a novel hybrid magnetic-bearing switched-reluctance motor (MBSRM) have been performed. A MBSRM has the combined characteristics of a switched-reluctance motor and a magnetic bearing. The MBSRM discussed in this report has an eight-pole stator and a six-pole hybrid rotor, which is composed of circular and scalloped lamination segments. The hybrid rotor is levitated using only one set of four stator poles, while a second set of four stator poles imparts torque to the scalloped portion of the rotor, which is driven in a traditional switched reluctance manner by a processor. Static torque and radial force analysis were done for rotor poles that were oriented to achieve maximum and minimum radial force loads on the rotor. The objective is to assess whether simple one-dimensional magnetic circuit analysis is sufficient for preliminary evaluation of this machine, which may exhibit strong three-dimensional electromagnetic field behavior. Two magnetic circuit geometries, approximating the complex topology of the magnetic fields in and around the hybrid rotor, were employed in formulating the electromagnetic radial force equations. Reasonable agreement between the experimental and the theoretical radial force loads predictions was obtained with typical magnetic bearing derating factors applied to the predictions
Rescue of Lipid-Induced Autophagy Inhibition by Torin1 Treatment
Autophagy is an essential cellular process that degrades proteins and organelles and autophagy dysfunction is a hallmark of Parkinson’s disease and Alzheimer’s disease. Therefore, understanding how autophagy is regulated by lipid signaling factors can potentially reveal therapeutic targets for these diseases. Our lab has identified 3 lipids (5-oxo-ete, stearic acid and hydroxystearic acid) that repress autophagy using a lipidomic mass spectrometry screen of serum. RNA sequencing data suggests that mTOR might be affected by these lipids. We have therefore hypothesized that the 3 lipids inhibit autophagy by activating mTOR. To determine if these 3 lipids utilize mTOR for autophagy repression, we will treat differentiated human SH-SY5Y cells (neuron-like cells) with each lipid in the presence or absence of the mTOR inhibitor, Torin 1. Autophagy will then be assessed through examination of LC3-II protein levels by western blot. Our results will add to our understanding of the molecular mechanism of action for these 3 autophagy-repressing lipids which could ultimately aid in the development of treatments for neurodegenerative disease
A high-quality draft genome sequence of Neonectria faginata, causative agent of beech bark disease of Fagus grandifolia
DATA AVAILABILITY : This Whole Genome Shotgun project has been deposited at DDBJ/ENA/GenBank
under the accession JAULBG000000000. The version described in this paper is version
JAULBG010000000. Raw sequence data are available at NCBI SRA under project number
PRJNA994555. Sequences of TEF1- and RPB2 are deposited in GenBank under accession
numbers OR338330 and OR338331.The draft genome of Neonectria faginata was sequenced with Oxford Nanopore and Illumina 250 bp paired-end sequencing technologies. The assembled genome was 42.9 Mb distributed over 24 contigs, with N50 of 4.4 Mb and 98.6% BUSCO completeness. This genome sequence will aid in understanding N. faginata population structure and ecology.Partial funding was provided by the New Hampshire Agricultural Experiment Station. Supported by the USDA National Institute of Food and Agriculture McIntire-Stennis, the state of New Hampshire and a USDA National Institute of Food and Agriculture postdoctoral fellowship.https://journals.asm.org/journal/mrahj2024BiochemistryForestry and Agricultural Biotechnology Institute (FABI)GeneticsMicrobiology and Plant PathologyNon
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Estimating the economic impacts of climate change on 16 major US fisheries
Observational evidence shows marine species are shifting their geographic distribution in response to warming ocean temperatures. These shifts have implications for the US fisheries and seafood consumers. The analysis presented here employs a two-stage inverse demand model to estimate the consumer welfare impacts of projected increases or decreases in commercial landings for 16 US fisheries from 2021 to 2100, based on the predicted changes in thermally available habitat. The fisheries analyzed together account for 56% of the current US commercial fishing revenues. The analysis compares welfare impacts under two climate scenarios: a high emissions case that assumes limited efforts to reduce atmospheric greenhouse gas and a low emissions case that assumes more stringent mitigation. The present value of consumer surplus impacts when discounted at 3% is a net loss of ) in the low emissions case and 278–901 million by 2100
Estimating the impact of city-wide Aedes aegypti population control: An observational study in Iquitos, Peru.
During the last 50 years, the geographic range of the mosquito Aedes aegypti has increased dramatically, in parallel with a sharp increase in the disease burden from the viruses it transmits, including Zika, chikungunya, and dengue. There is a growing consensus that vector control is essential to prevent Aedes-borne diseases, even as effective vaccines become available. What remains unclear is how effective vector control is across broad operational scales because the data and the analytical tools necessary to isolate the effect of vector-oriented interventions have not been available. We developed a statistical framework to model Ae. aegypti abundance over space and time and applied it to explore the impact of citywide vector control conducted by the Ministry of Health (MoH) in Iquitos, Peru, over a 12-year period. Citywide interventions involved multiple rounds of intradomicile insecticide space spray over large portions of urban Iquitos (up to 40% of all residences) in response to dengue outbreaks. Our model captured significant levels of spatial, temporal, and spatio-temporal variation in Ae. aegypti abundance within and between years and across the city. We estimated the shape of the relationship between the coverage of neighborhood-level vector control and reductions in female Ae. aegypti abundance; i.e., the dose-response curve. The dose-response curve, with its associated uncertainties, can be used to gauge the necessary spraying effort required to achieve a desired effect and is a critical tool currently absent from vector control programs. We found that with complete neighborhood coverage MoH intra-domicile space spray would decrease Ae. aegypti abundance on average by 67% in the treated neighborhood. Our framework can be directly translated to other interventions in other locations with geolocated mosquito abundance data. Results from our analysis can be used to inform future vector-control applications in Ae. aegypti endemic areas globally
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