Type II Aerobic Methane Oxidizing Bacteria (AMOB) Drive Methane Oxidation in Pulsed Wetlands as Indicated by 13C-Phospholipid Fatty Acid Composition

Methane (CH4) is a potent greenhouse gas and management strategies have been proposed to limit CH4 emissions from freshwater wetlands. The methanotrophic bacteria can intercept much of the CH4 produced by methanogenic archaea and thus management protocols for wetlands could conceivably include manipulations not only to limit the production of CH4 by methanogens, but also to enhance the consumption of CH4 by benthic or planktonic methanotrophs. The hydrological characteristic of a wetland is a major determinant of the CH4 emission rates. A major consideration for CH4 production is whether a wetland is static or flowing (wetlands connected to rivers and streams). Very little is known about the effects of hydrologic pulsing on wetland carbon dynamics and especially CH4 oxidation. Furthermore, although it has been established that methanotrophs are very active at the oxic sediment water interface of wetlands, little is known about the ecology of methanotrophs in the “pulsing fringe”. Stable isotope
probing (SIP) of biomarker Phospholipid Fatty Acids provide a means to connect CH4 oxidation to specific methanotrophs and track the shifts in community structure. Three landscape treatments were: 1) upland aerobic soil, 2) the intermediately flooded zone, and 3) the permanently flooded site with two landscape level replicates in a freshwater pulsing experimental wetlands at the Olentangy River Wetland (ORW) Research Park, The Ohio State University, Columbus. Two soil depths (organic horizon, 0-8 cm that includes the oxidized layer in flooded sites and 8-16 cm depth of surface mineral layer) were sampled at each site four times/year over a two-year period (early spring, mid summer, early fall and mid winter). Immediately after sampling the samples are stored at -20° C and transported under dry ice to the Soil Microbial Ecology Lab, SENR, the Ohio State University, Columbus for analysis. Samples were taken back to the lab to determine potential CH4 oxidation and 13C-PLFA analyses after extraction and analysis on GC-C-IRMS.The PF sites had significantly higher (p<0.05) Potential Methane Oxidation (PMO) than the IF sites. PMO rates at 0-8 cm depth of soil were significantly higher than those at depth of 8-16 cm (p<0.05). PMO in Winter was also significantly higher than in Summer (p< 0.01). PLFA profiling of methanotrophs showed that the Type type II methanotrophs and I methanotrophs were more pronounced in winter that was highly correlated by the seasonal dynamics of PMO. Concentrations of the Type II methanotroph PLFA biomarker (18:ω8c, 18:ω9c and 18:ω7c) were significantly higher (p<0.05) than the Type I PLFA biomarkers (16:ω5c).The highest potential to oxidize the substrate-available methane in the Permanently Flooded site is entirely attributed to the
methanotrophic population (as reflected by the relative abundance of the signature PLFAs). Even if with very low 13C incorporation, the PLFA profile in the Intermittently Flooded site is dominated by the Type II methanotrophs

The T1 state of p-nitroaniline and related molecules: a CNDO/S study

The nature of the lowest energy triplet state (T1) of p-nitroaniline (PNA), N,N-dimethyl-p-nitroaniline (DMPNA) and nitrobenzene (NB) is reexamd. using the semiempirical CNDO/S-CI method with selected parameter options. In the case of the unperturbed mols. the short-axis polarized p* A- singlet excitation. Computations suggest, however, that polar solvents strongly stabilize the PNA and DMPNA p* <- p charge-transfer triplet relative to other excitations, whereas specific solvent hydrogen-bonded interactions stabilize the p* <- n(s) triplet of NB below those of p* <- p character. These assignments allow a rationalization of phosphorescence lifetime data, Tn <- T1 absorption measurements and relative photochem. behavior

Partnership to Develop Agroecology and Extension Programs in Senegal

IMPACT. 1: Thirteen UGB faculty in the new Department of Agricultural Sciences, Aquaculture, and Food Technology are being mentored by CFAES OSU faculty in teaching, research and extension. The first group of 94 associate and BS students have been trained and will graduate in July 2013. Two Ph.D. students are being trained at OSU in agricultural engineering and weed science. The project has implemented a pilot UGB extension program with 144 farmers on newly irrigated land in northern Senegal. Eleven farmers are participating in an on-farm research program. Farmers are requesting that vegetable transplanters, which OSU introduced to Senegal, be imported to Senegal.OSU PARTNERS: School of Environment and Natural Resources; Office of International Programs in Agriculture; Department of Horticulture and Crop Science; Department of Food, Agriculture, and Biological Engineering; College of Public Health; Food Science and Technology; Department of Animal Sciences; Agricultural and Extension Education; OSU Extension; College of Food, Agricultural and Environmental SciencesCOMMUNITY PARTNERS: The University of Gaston Berger; Green SenegalPRIMARY CONTACT: Richard Dick ([email protected])The objective of the project is to implement state-of-the-art agricultural education and extension programs at the University of Gaston Berger (UGB), focused on enhancing sustainable agriculture in the fragile Sahelien agroecosystems of Africa. The project has established Associate and BS degree programs, and updated laboratories. Another main objective is to establish the land grant model at UGB, incorporating extension and research into the traditional teaching role of the university. This project is an innovative way to export the land grant model to Sub-Saharan Africa and to support sustainable agriculture

Measuring and Predicting Heterogeneous Recessions

This paper conducts an empirical analysis of the heterogeneity of recessions in monthly U.S. coincident and leading indicator variables. Univariate Markovswitching models indicate that it is appropriate to allow for two distinct recession regimes, corresponding with ‘mild’ and ‘severe’ recessions. All downturns start with a mild decline in the level of economic activity. Contractions that develop into severe recessions mostly correspond with periods of substantial credit squeezes as suggested by the ‘financial accelerator’ theory. Multivariate Markov-switching models that allow for phase shifts between the cyclical regimes of industrial production and the Conference Board Leading Economic Index confirm these findings.Business cycle, phase shifts, regime-switching models, Bayesian analysis

Characterization of a set of abdominal neuroendocrine cells that regulate stress physiology using colocalized diuretic peptides in Drosophila

Multiple neuropeptides are known to regulate water and ion balance in Drosophila melanogaster. Several of these peptides also have other functions in physiology and behavior. Examples are corticotropin-releasing factor-like diuretic hormone (diuretic hormone 44; DH44) and leucokinin (LK), both of which induce fluid secretion by Malpighian tubules (MTs), but also regulate stress responses, feeding, circadian activity and other behaviors. Here, we investigated the functional relations between the LK and DH44 signaling systems. DH44 and LK peptides are only colocalized in a set of abdominal neurosecretory cells (ABLKs). Targeted knockdown of each of these peptides in ABLKs leads to increased resistance to desiccation, starvation and ionic stress. Food ingestion is diminished by knockdown of DH44, but not LK, and water retention is increased by LK knockdown only. Thus, the two colocalized peptides display similar systemic actions, but differ with respect to regulation of feeding and body water retention. We also demonstrated that DH44 and LK have additive effects on fluid secretion by MTs. It is likely that the colocalized peptides are coreleased from ABLKs into the circulation and act on the tubules where they target different cell types and signaling systems to regulate diuresis and stress tolerance. Additional targets seem to be specific for each of the two peptides and subserve regulation of feeding and water retention. Our data suggest that the ABLKs and hormonal actions are sufficient for many of the known DH44 and LK functions, and that the remaining neurons in the CNS play other functional roles

PhD

dissertationClinically-oriented computer assisted instruction (CAI) has been receiving greater emphasis in the last few years. Similarly progress has been made in the development of (a) generative CAI techniques and (b) the refinement of a formalized medical decision-making criterion. These developments have led to the implementation of a nonauthored CAI system for training clinicians in medical decision-making using actual patient data. The nonauthored CAI system is composed of several subsystems. The principal components include (a) a statistical analysis system providing many options including the generation of histograms, (b) an automated medical decision-making system, and (c) a system for finding patients with desired characteristics and generating populations interactively. The functions and interrelationships of each component are described in detail. The nonauthored CAI system's primary advantages include: (a) it provides the capability of studying medical decision-making procedures in a formal setting; (b) it is a subject-independent system and therefore is relevant to a broad spectrum of clinicians (it is limited by the extent of the clinical data available); (c) because of its generative qualities no courseware authoring"" is required; and (d) because the system requires little training to use, investigations may be conducted in either a formalized group setting or in an independent study mode. Due to the system's relevance to clinical medicine, several persons affiliated with academic medicine have seen the system demonstrated. In addition to these observers, a demonstration of the system in a more structured setting v;as explored. A broad spectrum of clinicians repeatedly used the CAI system to investigate subjects of interest during these structured sessions. Details of their investigations and comments are included. Finally, a few future possibilities and enhancements for the system are explored."

Hydrolysis and availability to plants of polyphosphates added to soils

The hydrolysis by plant roots and in soils of seven linear oligomers (P(,2), P(,3), P(,5), P(,15), P(,25), P(,35), and P(,65)) and one cyclic polyphosphate, trimetaphosphate (TMP), was investigated. Nonsterile intact corn roots showed greater rates of hydrolysis than sterile corn roots, with hydrolysis rates in the order: P(,2) \u3e P(,3) \u3e P(,5) \u3e TMP \u3e P(,15) \u3e P(,25) \u3e P(,35) \u3e P(,65). An experiment with sterile intact corn roots suggested that pyrophosphatase was induced in corn roots in the presence of its substrate. The amount of polyphosphate-P hydrolyzed in four Iowa surface soils at 25(DEGREES)C with incubation times ranging from 1 to 14 days decreased with increasing polyphosphate chain length, with 37 to 74% hydrolysis in 14 days. The relationship between the nonhydrolyzed polyphosphate and time of incubation showed that polyphosphate hydrolysis in soils was controlled by two first-order reactions. The initial faster rate (k(,1)) changed to a slower rate (k(,2)) at incubation times ranging from 2 to 7 days, depending on the polyphosphate, soil type, and soil moisture status. The k(,1) and k(,2) values for soils incubated aerobically ranged from 1.7 x 10(\u27-4) to 3.3 x 10(\u27-5)/min and from 4.5 x 10(\u27-5) to 7.4 x 10(\u27-6)/min, respectively. The corresponding values for soils incubated under waterlogging conditions ranged from 2.4 x 10(\u27-4) to 2.6 x 10(\u27-5)/min and from 5.2 x 10(\u27-5) to 1.0 x 10(\u27-5)/min. Hydrolysis of polyphosphates in 29 Iowa soils incubated for one week at 25(DEGREES)C showed that from 27 to 47% of the orthophosphate produced was due to chemical hydrolysis; the rest was due to biochemical hydrolysis. Multiple regression analysis showed that polyphosphate hydrolysis was significantly correlated with pH, water-soluble Ca(\u272+), and nonbuffered pyrophosphatase activity, and negatively correlated with clay content, water-soluble Mg(\u272+) (except for P35 and P(,65)), and dithionite-extractable Al(\u273+) (except for P(,3) and TMP);The uptake of P from four Iowa surface soils amended with four linear oligomers (P(,2), P(,3), P(,15), P(,45)), one cyclic polyphosphate (TMP), and orthophosphate in a greenhouse study using ryegrass and corn as indicator plants showed that all of these sources of P are equally available to plants. Tests indicated that the residual P levels were similar among the P compounds after a short cropping period with corn (35 days) and a long cropping period with ryegrass (120 days)

The Viability of Imported Liquified Natural Gas as an Energy Resource

As the United States enters the 1980\u27s, the need for secure and efficient energy sources is rapidly moving to the forefront of our foreign and domestic policies. It is apparent that our existence, as well as that of our allies, is closely tied to the ability to secure energy resources. The importation of Liquified Natural Gas (LNG), by specially designed ships, from oil exporting nations to energy consuming nations has been a highly touted energy resource. United States importation of LNG is not a cost effective energy resource due to: (1) dependence on foreign sources, (2) transportation costs including hidden expenses involving shipping subsidies, (3) safety regulations, and (4) pricing schemes by exporting nations as well as those mandated by federal regulation

Continuous thickening of non-ideal suspensions

The purpose of this study was to investigate the steady state continuous thickening of non-ideal suspensions such as sludges from water and wastewater treatment plants. Suspensions of high grade calcium carbonate, activated sludges, water softening sludges, and suspensions of fine glass beads were used. The suspensions were thickened in a closed, continuous, pi lot, thickening system. The sol ids flux theory was used successfully for predicting performance of the steady state continuous thickener from batch settling velocities of the suspensions. For the optimal performance of the thickener, effective stirring of concentration layers near the underflow level was found to be an absolute necessity. This was to prevent dilute solids from reaching the thickener bottom. Homogeneous distribution of the feed over the area of the tank was also essential. The feed concentration generally did not affect the thickening function. However, the interaction between thickening and clarification functions of the tank was established through the magnitude of feed concentrations. As the feed concentration decreased with fixed solids loading, the overflow velocity increased, and the clarity of overflow generally deteriorated.U.S. Department of the InteriorU.S. Geological SurveyOpe