859 research outputs found
SALMON RECOVERY IN THE COLUMBIA RIVER BASIN: ANALYSIS OF MEASURES AFFECTING AGRICULTURE
The effects of salmon recovery measures on the Northwest agricultural sector are evaluated. Relevant recovery measures, such as: modified timing for dam releases, reservoir drawdown, and flow augmentation in the Columbia River basin, on the regional agricultural sector are evaluated. Combined, these measures would increase power rates, grain transportation costs, and irrigation water costs and reduce the supply of water to irrigators. We quantify these input cost and quantity changes and combine them into seven recovery scenarios for analysis. Results suggest that drawdown and/or minor reductions in irrigation water diversions would reduce producers' profits by less than 1% of baseline levels. However, the most extreme scenario-a long drawdown period combined with a large reduction in irrigation diversions-would reduce producers' profits by 35 million decline in annual profits, more than $27 million occur in southern Idaho and eastern Oregon. The federal government would bear these costs if it acquires water via voluntary transactions.Agricultural and Food Policy, Resource /Energy Economics and Policy,
On the tear resistance of skin.
Tear resistance is of vital importance in the various functions of skin, especially protection from predatorial attack. Here, we mechanistically quantify the extreme tear resistance of skin and identify the underlying structural features, which lead to its sophisticated failure mechanisms. We explain why it is virtually impossible to propagate a tear in rabbit skin, chosen as a model material for the dermis of vertebrates. We express the deformation in terms of four mechanisms of collagen fibril activity in skin under tensile loading that virtually eliminate the possibility of tearing in pre-notched samples: fibril straightening, fibril reorientation towards the tensile direction, elastic stretching and interfibrillar sliding, all of which contribute to the redistribution of the stresses at the notch tip
POLICY DIRECTIONS TO MITIGATE WATER-SUPPLY RISK IN IRRIGATED AGRICULTURE: A FEDERAL PERSPECTIVE
Water reallocation to meet mandated flow requirements and trust responsibilities, established in Federal law and water authority, can result in large uncompensated losses to irrigated agriculture. This paper discusses the nature and potential cost of water-supply interruptions due to Federal actions, and provides a comparative assessment of alternative risk-mitigation measures.Resource /Energy Economics and Policy,
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Author Correction: Enhanced tenacity of mycobacterial aerosols from necrotic neutrophils
The original version of this Article contained errors within the affiliations section. Affiliation 4 was incorrectly given as ‘Leibniz Research Alliance INFECTIONS’21, Leipzig, Germany’. The correct affiliation is listed below: Leibniz Research Alliance INFECTIONS’21, Borstel, 23845, Germany Also, Affiliation 5 was incorrectly given as ‘German Center for Infection Research, TTU-TB, Borstel, 23845, Germany’. The correct affiliation is listed below: German Center for Infection Research (DZIF), Partner Site Hamburg-Lübeck-Borstel, Germany. Finally, the original HTML version of this Article omitted an affiliation for G. Gabriel. The correct affiliations for G. Gabriel are listed below: Heinrich Pette Institute, Leibniz Institute for Experimental Virology, Hamburg, 20251, Germany. Leibniz Research Alliance INFECTIONS’21, Borstel, 23845, Germany. German Center for Infection Research (DZIF), Partner Site Hamburg-Lübeck-Borstel, Germany. These errors have now been corrected in the PDF and HTML versions of the Article
Performance of chemically modified reduced graphene oxide (CMrGO) in electrodynamic dust shield (EDS) applications
Electrodynamic Dust Shield (EDS) technology is a dust mitigation strategy
that is commonly studied for applications such as photovoltaics or thermal
radiators where soiling of the surfaces can reduce performance. The goal of the
current work was to test the performance of a patterned nanocomposite EDS
system produced through spray-coating and melt infiltration of chemically
modified reduced graphene oxide (CMrGO) traces with thermoplastic high-density
polyethylene (HDPE). The EDS performance was tested for a dusting of lunar
regolith simulant under high vacuum conditions (~10-6 Torr) using both 2-phase
and 3-phase configurations. Uncapped (bare) devices showed efficient dust
removal at moderate voltages (1000 V) for both 2-phase and 3-phase designs, but
the performance of the devices degraded after several sequential tests due to
erosion of the traces caused by electric discharges. Further tests carried out
while illuminating the dust surface with a UV excimer lamp showed that the EDS
voltage needed to reach the maximum cleanliness was reduced by almost 50% for
the 2-phase devices (500 V minimum for rough and 1000 V for smooth), while the
3-phase devices were unaffected by the application of UV. Capping the CMrGO
traces with low-density polyethylene (LDPE) eliminated breakdown of the
materials and device degradation, but larger voltages (3000 V) coupled with UV
illumination were required to remove the grains from the capped devices.Comment: 22 pages, 7 figure
Mutations in the SLC2A9 Gene Cause Hyperuricosuria and Hyperuricemia in the Dog
Allantoin is the end product of purine catabolism in all mammals except humans, great apes, and one breed of dog, the Dalmatian. Humans and Dalmatian dogs produce uric acid during purine degradation, which leads to elevated levels of uric acid in blood and urine and can result in significant diseases in both species. The defect in Dalmatians results from inefficient transport of uric acid in both the liver and renal proximal tubules. Hyperuricosuria and hyperuricemia (huu) is a simple autosomal recessive trait for which all Dalmatian dogs are homozygous. Therefore, in order to map the locus, an interbreed backcross was used. Linkage mapping localized the huu trait to CFA03, which excluded the obvious urate transporter 1 gene, SLC22A12. Positional cloning placed the locus in a minimal interval of 2.5 Mb with a LOD score of 17.45. A critical interval of 333 kb containing only four genes was homozygous in all Dalmatians. Sequence and expression analyses of the SLC2A9 gene indicated three possible mutations, a missense mutation (G616T;C188F) and two promoter mutations that together appear to reduce the expression levels of one of the isoforms. The missense mutation is associated with hyperuricosuria in the Dalmatian, while the promoter SNPs occur in other unaffected breeds of dog. Verification of the causative nature of these changes was obtained when hyperuricosuric dogs from several other breeds were found to possess the same combination of mutations as found in the Dalmatian. The Dalmatian dog model of hyperuricosuria and hyperuricemia underscores the importance of SLC2A9 for uric acid transport in mammals
Improved mini-Tn 7 Delivery Plasmids for Fluorescent Labeling of
Fluorescently labeled bacterial cells have become indispensable for many aspects of microbiological research, including studies on biofilm formation as an important virulence factor of various opportunistic bacteria of environmental origin such as . Using a Tn 7 -based genomic integration system, we report the construction of improved mini-Tn 7 delivery plasmids for labeling of with sfGFP, mCherry, tdTomato and mKate2 by expressing their codon-optimized genes from a strong, constitutive promoter and an optimized ribosomal binding site. Transposition of the mini-Tn 7 transposons into single neutral sites located on average 25 nucleotides downstream of the 3'-end of the conserved glmS gene of different wild-type strains did not have any adverse effects on the fitness of their fluorescently labeled derivatives. This was demonstrated by comparative analyses of growth, resistance profiles against 18 antibiotics of different classes, the ability to form biofilms on abiotic and biotic surfaces, also independent of the fluorescent protein expressed, and virulence in . It is also shown that the mini-Tn 7 elements remained stably integrated in the genome of over a prolonged period of time in the absence of antibiotic selection pressure. Overall, we provide evidence that the new improved mini-Tn 7 delivery plasmids are valuable tools for generating fluorescently labeled strains that are indistinguishable in their properties from their parental wild-type strains. IMPORTANCE The bacterium is an important opportunistic nosocomial pathogen that can cause bacteremia and pneumonia in immunocompromised patients with a high rate of mortality. It is now considered as a clinically relevant and notorious pathogen in cystic fibrosis patients but has also been isolated from lung specimen of healthy donors. The high intrinsic resistance to a wide range of antibiotics complicates treatment and most likely contributes to the increasing incidence of infections worldwide. One important virulence-related trait of is the ability to form biofilms on any surface, which may result in the development of increased transient phenotypic resistance to antimicrobials. The significance of our work is to provide a mini-Tn 7 -based labeling system for to study the mechanisms of biofilm formation or host-pathogen interactions with live bacteria under non-destructive conditions
Mycobacterium tuberculosis Responds to Chloride and pH as Synergistic Cues to the Immune Status of its Host Cell
PubMed ID: 23592993This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
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Characterizing the Nano and Micro Structure of Concrete toImprove its Durability
New and advanced methodologies have been developed to characterize the nano and microstructure of cement paste and concrete exposed to aggressive environments. High resolution full-field soft X-ray imaging in the water window is providing new insight on the nano scale of the cement hydration process, which leads to a nano-optimization of cement-based systems. Hard X-ray microtomography images of ice inside cement paste and cracking caused by the alkali?silica reaction (ASR) enables three-dimensional structural identification. The potential of neutron diffraction to determine reactive aggregates by measuring their residual strains and preferred orientation is studied. Results of experiments using these tools are shown on this paper
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