Climate change impact assessments using the Water Erosion Prediction Project model

This study was conducted to develop a simplified method of obtaining future climate data inputs for natural resource models and apply that method to three locations within the continental United States to assess the effect of climate change on soil erosion, runoff, and fire risk. A method was developed for quickly obtaining future climate data over a wide range of scenarios, General Circulation Models (GCMs), and timescales from the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (AR4) and Fifth Assessment Report (AR5) model families using the MarkSim® DSSAT Weather Generator and a Microsoft Excel VBA Macro, the final result being a properly formatted parameter file which can be used by CLIGEN (CLImate GENerator) within the Water Erosion Prediction Project (WEPP) model. By using software which already exists on most computers and not requiring climatological or modeling knowledge to operate, the method herein for creating WEPP climate input files is fast and simple, requiring as little as 15 minutes.^ At the first site, analysis of a small (6.7 acre, 2.71 ha) field site monitored as part of the USDA-ARS Conservation Effects Assessment Project in NE Indiana was conducted to determine the effect of climate change on agricultural resources. Precipitation, runoff, soil erosion, and crop growth were modeled using WEPP and the four Representative Concentration Pathway (RCP) scenarios used with the CMIP5 model family from the IPCC 5AR to determine the effectiveness of common agricultural Best Management Practices (BMPs) under predicted climate change. Although precipitation is predicted here to increase by 2100, sediment loss and runoff will decrease due to a reduction of concrete frost conditions during late winter. However, an increase in the amount of precipitation falling in spring and earlier soybean senescence was predicted to lead to increased soil loss in early spring and fall.^ At the second site, a small agricultural hillslope managed by the USDA-ARS in the Southern Coastal Plain of the United States was modeled using WEPP under current and future climates to assess the effect of predicted future climate change on soil erosion, runoff, and BMP effectiveness. Future climate data was similar to that used at the first site. Predicted climatic shift caused soil loss and runoff to be reduced in the first three months of the year, while late fall and early winter months had increases in predicted soil loss and runoff. Increased temperatures were predicted to cause winter cover crops to grow faster, unhindered by frost in winter. Soil loss increased when cotton senesced earlier under warmer temperatures. Early season water deficits and higher evapotranspiration also increased irrigation demands in the growing season. The combination of no-till, rye cover crop, and riparian buffer increased in effectiveness into the future, while all other management systems had either similar or slightly reduced effectiveness under predicted future climate. ^ At the third site, the Blackwood Creek watershed, a tributary of Lake Tahoe in California, was assessed for potential changes in climate and fire risk under 21st century climates projected by the IPCC AR5. While total precipitation varied by decade, the portion of precipitation falling as snow decreased by as much as 26%, and projected air temperatures increased by as much as 3.4°C by 2090. Total soil water (TSW) predictions by WEPP indicated that fire ignition in the Sierra Nevada region from 1984-2013 coincided with simulated minimum TSW. Risk categories based on simulated TSW changed under projected future climate, with an increase in the number of high risk days defined by TSWs less than 40 mm. Simulated TSW in the Blackwood Creek watershed at the time of historic fires in the region also indicated that the Keetch-Byram Drought Index (KBDI) was correlated to TSW (R2 = 0.59) when KBDI was less than 500

Climate change impact assessments using the Water Erosion Prediction Project model

This study was conducted to develop a simplified method of obtaining future climate data inputs for natural resource models and apply that method to three locations within the continental United States to assess the effect of climate change on soil erosion, runoff, and fire risk. A method was developed for quickly obtaining future climate data over a wide range of scenarios, General Circulation Models (GCMs), and timescales from the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (AR4) and Fifth Assessment Report (AR5) model families using the MarkSim® DSSAT Weather Generator and a Microsoft Excel VBA Macro, the final result being a properly formatted parameter file which can be used by CLIGEN (CLImate GENerator) within the Water Erosion Prediction Project (WEPP) model. By using software which already exists on most computers and not requiring climatological or modeling knowledge to operate, the method herein for creating WEPP climate input files is fast and simple, requiring as little as 15 minutes.^ At the first site, analysis of a small (6.7 acre, 2.71 ha) field site monitored as part of the USDA-ARS Conservation Effects Assessment Project in NE Indiana was conducted to determine the effect of climate change on agricultural resources. Precipitation, runoff, soil erosion, and crop growth were modeled using WEPP and the four Representative Concentration Pathway (RCP) scenarios used with the CMIP5 model family from the IPCC 5AR to determine the effectiveness of common agricultural Best Management Practices (BMPs) under predicted climate change. Although precipitation is predicted here to increase by 2100, sediment loss and runoff will decrease due to a reduction of concrete frost conditions during late winter. However, an increase in the amount of precipitation falling in spring and earlier soybean senescence was predicted to lead to increased soil loss in early spring and fall.^ At the second site, a small agricultural hillslope managed by the USDA-ARS in the Southern Coastal Plain of the United States was modeled using WEPP under current and future climates to assess the effect of predicted future climate change on soil erosion, runoff, and BMP effectiveness. Future climate data was similar to that used at the first site. Predicted climatic shift caused soil loss and runoff to be reduced in the first three months of the year, while late fall and early winter months had increases in predicted soil loss and runoff. Increased temperatures were predicted to cause winter cover crops to grow faster, unhindered by frost in winter. Soil loss increased when cotton senesced earlier under warmer temperatures. Early season water deficits and higher evapotranspiration also increased irrigation demands in the growing season. The combination of no-till, rye cover crop, and riparian buffer increased in effectiveness into the future, while all other management systems had either similar or slightly reduced effectiveness under predicted future climate. ^ At the third site, the Blackwood Creek watershed, a tributary of Lake Tahoe in California, was assessed for potential changes in climate and fire risk under 21st century climates projected by the IPCC AR5. While total precipitation varied by decade, the portion of precipitation falling as snow decreased by as much as 26%, and projected air temperatures increased by as much as 3.4°C by 2090. Total soil water (TSW) predictions by WEPP indicated that fire ignition in the Sierra Nevada region from 1984-2013 coincided with simulated minimum TSW. Risk categories based on simulated TSW changed under projected future climate, with an increase in the number of high risk days defined by TSWs less than 40 mm. Simulated TSW in the Blackwood Creek watershed at the time of historic fires in the region also indicated that the Keetch-Byram Drought Index (KBDI) was correlated to TSW (R2 = 0.59) when KBDI was less than 500

6S RNA regulation of relA alters ppGpp levels in early stationary phase

6S RNA is a small, non-coding RNA that interacts directly with σ70-RNA polymerase and regulates transcription at many σ70-dependent promoters. Here, we demonstrate that 6S RNA regulates transcription of relA, which encodes a ppGpp synthase. The 6S RNA-dependent regulation of relA expression results in increased ppGpp levels during early stationary phase in cells lacking 6S RNA. These changes in ppGpp levels, although modest, are sufficient to result in altered regulation of transcription from σ70-dependent promoters sensitive to ppGpp, including those promoting expression of genes involved in amino acid biosynthesis and rRNA. These data place 6S RNA as another player in maintaining appropriate gene expression as cells transition into stationary phase. Independent of this ppGpp-mediated 6S RNA-dependent regulation, we also demonstrate that in later stationary phase, 6S RNA continues to downregulate transcription in general, and specifically at a subset of the amino acid promoters, but through a mechanism that is independent of ppGpp and which we hypothesize is through direct regulation. In addition, 6S RNA-dependent regulation of σS activity is not mediated through observed changes in ppGpp levels. We suggest a role for 6S RNA in modulating transcription of several global regulators directly, including relA, to downregulate expression of key pathways in response to changing environmental conditions

Stainless steel made to rust: a robust water-splitting catalyst with benchmark characteristics

The oxygen evolution reaction (OER) is known as the efficiency-limiting step for the electrochemical cleavage of water mainly due to the large overpotentials commonly used materials on the anode side cause. Since Ni–Fe oxides reduce overpotentials occurring in the OER dramatically they are regarded as anode materials of choice for the electrocatalytically driven water-splitting reaction. We herewith show that a straightforward surface modification carried out with AISI 304, a general purpose austenitic stainless steel, very likely, based upon a dissolution mechanism, to result in the formation of an ultra-thin layer consisting of Ni, Fe oxide with a purity >99%. The Ni enriched thin layer firmly attached to the steel substrate is responsible for the unusual highly efficient anodic conversion of water into oxygen as demonstrated by the low overpotential of 212 mV at 12 mA cm−2 current density in 1 M KOH, 269.2 mV at 10 mA cm−2 current density in 0.1 M KOH respectively. The Ni, Fe-oxide layer formed on the steel creates a stable outer sphere, and the surface oxidized steel samples proved to be inert against longer operating times (>150 ks) in alkaline medium. In addition Faradaic efficiency measurements performed through chronopotentiometry revealed a charge to oxygen conversion close to 100%, thus underpinning the conclusion that no “inner oxidation” based on further oxidation of the metal matrix below the oxide layer occurs. These key figures achieved with an almost unrivalled-inexpensive and unrivalled-accessible material, are among the best ever presented activity characteristics for the anodic water-splitting reaction at pH 13

Non-biological methods for phosphorus and nitrogen removal from wastewater: A gap analysis of reinvented-toilet technologies with respect to ISO 30500 [version 1; peer review: 2 approved, 1 not approved]

The aims of the Reinvent the Toilet Challenge (RTTC) include creation of an off-the-grid sanitation system with operating costs of less than US$0.05 per user per day. Because of the small scale at which many reinvented toilets (RT) are intended to operate, non-biological treatment has been generally favored. The RTTC has already instigated notable technological advances in non-sewered sanitation systems (NSSS). However, increasingly stringent effluent standards for N and P could limit the deployment of current RT in real-world scenarios, despite the urgent need for these systems. The newly adopted ISO 30500 standards for water reuse in NSSS dictate minimal use of chemical/biological additives, while at the same time requiring a 70% and 80% reduction in total nitrogen and phosphorus, respectively. This document provides a brief overview of the mature and emerging technologies for N and P removal from wastewater. At present, the dearth of nutrient removal methods proven to be effective at small scales is a significant barrier to meeting ISO 30500 standards. Closing the gap between RTs and ISO 30500 will require significant investments in basic R&D of emerging technologies for non-biological N and P remediation and/or increased reliance on biological processes. Adaptation of existing nutrient-removal technologies to small-scale NSSS is a viable option that merits additional investigation

Analogs of the CLV3 Peptide: Synthesis and Structure–Activity Relationships Focused on Proline Residues

CLAVATA3 (CLV3) is a plant peptide hormone in which the proline residues are post-translationally hydroxylated and glycosylated. CLV3 plays a key role in controlling the stem cell mass in the shoot meristem of Arabidopsis thaliana. In a previous report, we identified a dodecapeptide (MCLV3) from CLV3-overexpressing Arabidopsis calli; MCLV3 was the smallest functional peptide derived from the CLV3 precursor. Here, we designed a series of MCLV3 analogs in which proline residues were substituted with proline derivatives or N-substituted glycines (peptoids). Peptoid substitution at Pro9 decreased bioactivity without affecting specific binding to the CLV1-related protein in cauliflower membrane. These findings suggest that peptoid-substituted peptides would be lead compounds for developing potential agonists and antagonists of CLV3

Northern blot detection of endogenous small RNAs (∼14 nt) in bacterial total RNA extracts

Here we describe a northern blot procedure that allows the detection of endogenous RNAs as small as ∼14 nt in total RNA extracts from bacteria. RNAs that small and as part of total bacterial RNA extracts usually escape detection by northern blotting. The approach combines LNA probes 5′-digoxigenin-endlabeled for non-radioactive probe detection with 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide-mediated chemical crosslinking of RNAs to nylon membranes, and necessitates the use of native PAGE either with the TBE or MOPS buffer system

The suboptimal structures find the optimal RNAs: homology search for bacterial non-coding RNAs using suboptimal RNA structures

Non-coding RNAs (ncRNAs) are regulatory molecules encoded in the intergenic or intragenic regions of the genome. In prokaryotes, biocomputational identification of homologs of known ncRNAs in other species often fails due to weakly evolutionarily conserved sequences, structures, synteny and genome localization, except in the case of evolutionarily closely related species. To eliminate results from weak conservation, we focused on RNA structure, which is the most conserved ncRNA property. Analysis of the structure of one of the few well-studied bacterial ncRNAs, 6S RNA, demonstrated that unlike optimal and consensus structures, suboptimal structures are capable of capturing RNA homology even in divergent bacterial species. A computational procedure for the identification of homologous ncRNAs using suboptimal structures was created. The suggested procedure was applied to strongly divergent bacterial species and was capable of identifying homologous ncRNAs

Multiphase Nanostructure of a Quinary Metal Oxide Electrocatalyst Reveals a New Direction for OER Electrocatalyst Design

Ce-rich mixed metal oxides comprise a recently discovered class of -electrocatalysts for the oxygen evolution reaction (OER). In particular, at current densities below 10 mA cm^(−2), Ni_(0.3)Fe_(0.07)Co_(0.2)Ce_(0.43)O_x exhibits ¬superior activity compared to the corresponding transition metal oxides, despite the relative inactivity of ceria. To elucidate the enhanced activity and underlying catalytic mechanism, detailed structural characterization of this quinary oxide electrocatalyst is reported. Transmission electron microscopy imaging of cross-section films as-prepared and after electrochemical testing reveals a stable two-phase nanostructure composed of 3–5 nm diameter crystallites of fluorite CeO_2 intimately mixed with 3–5 nm crystallites of transition metal oxides alloyed in the rock salt NiO structure. Dosing experiments demonstrate that an electron flux greater than ≈1000 e Å^(−2) s^(−1) causes the inherently crystalline material to become amorphous. A very low dose rate of 130 e Å^(−2) s^(−1) is employed for atomic resolution imaging using inline holography techniques to reveal a nanostructure in which the transition metal oxide nanocrystals form atomically sharp boundaries with the ceria nanocrystals, and these results are corroborated with extensive synchrotron X-ray absorption spectroscopy measurements. Ceria is a well-studied cocatalyst for other heterogeneous and electrochemical reactions, and our discovery introduces biphasic cocatalysis as a design concept for improved OER electrocatalysts