Stochastic Analysis for Water Quality

This report demonstrates the feasibility of applying stochastic techniques to linear water quality models. The Monte Carlo, First Order, and Generation of Moment Equation techniques are applied to a long term phosphorus model of Lake Washington. The effect of uncertainty of the phosphours loading term on simulated phosphous levels is analyzed. All three stochastic techniques produced the same results. The simulated concentrations of phosphorus in the water column are very responsive to uncertainty in annual phosphorus loading, the sediment concentrations relatively insensitive. The Monte Carlo technique is shown to require the most computation time of the three stochastic techniques applied. The First Order and Generation of Moment Equation techniques are shown to be precise and efficent methods of stochastic analysis. In this application they required less than one thousandth the computation time of the Monte Carlo technique. The Generation of Moment Equations technique is also applied to a steady state salinity model of the Colorado River system. Two sources of uncertainty are considered: 1) the estimation of steady state values of salinity loading from a limited historic data base and 2) the estimation of salinity loading from irrigated land by a semi-empirical approach. Six stochastic simulations of the Colorado River system are presented. Coefficients of variations of simulated salinities at Imperial Dam are shown to vary from 5.7 to 10.3 percent. The major source of uncertainty in all simulations is the estimation of the steady state salinity loading with the agricultural loading term becoming important in some simulated management alternatives

Arkansas Agriculture Situation and Outlook 2001

Many farmers in Arkansas and other parts of the United States are experiencing financial stress. The purpose of this special report is to highlight the situation of Arkansas farmers and to offer an outlook for 2001. The report emphasizes the production, price, income, financial, farmland value, and interest rate outlook for Arkansas farmers and considers the impact of the macro economy on agriculture. In addition, price risk management and pre-harvest marketing strategies for farmers are presented

Arkansas Agriculture Situation and Outlook 2002

Many farmers in Arkansas and other parts of the United States are experiencing financial stress. The purpose of this special report is to highlight the situation of Arkansas farmers and to offer an outlook for 2002. The report emphasizes the production, price, income, policy, financial, farmland value, and interest rate outlook for Arkansas farmers and considers the impact of the macro economy on agriculture. In addition, a summary of commercial rowcrop farm characteristics and production practices is presented

Arkansas Agriculture Situation and Outlook 2003

The purpose of this research series is to highlight the situation of Arkansas farmers and to offer an outlook for 2003. The research emphasizes the production, price, income, policy, financial, farmland value, and interest rate outlook for Arkansas farmers and considers the impact of the macro economy on agriculture. In addition, the advantages and disadvantages of biodiesel as an alternative to petroleum diesel are discussed

Controlled Thiol-ene Polymer Microsphere Production Using a Low-Frequency Acoustic Excitation Coaxial Flow Method

A novel technique for the production of thiol-ene microspheres using acoustic resonance and coaxial flow is reported. The method utilizes low-frequency acoustically driven mechanical perturbations to disrupt the flow of a thiol-ene liquid jet, resulting in small thiol-ene droplets that are photochemically polymerized to yield thiol-ene microspheres. Tuning of the frequency, amplitude, and monomer solution viscosity are critical parameters impacting the diameter of the microspheres produced. Characterization by optical microscopy, scanning electron microscopy, and dynamic light scattering reveal microspheres of diameters \u3c10 mu m, with narrow particle distributions. (C) 2016 Elsevier Ltd. All rights reserved

rbcL and matK Earn Two Thumbs Up as the Core DNA Barcode for Ferns

BACKGROUND: DNA barcoding will revolutionize our understanding of fern ecology, most especially because the accurate identification of the independent but cryptic gametophyte phase of the fern's life history--an endeavor previously impossible--will finally be feasible. In this study, we assess the discriminatory power of the core plant DNA barcode (rbcL and matK), as well as alternatively proposed fern barcodes (trnH-psbA and trnL-F), across all major fern lineages. We also present plastid barcode data for two genera in the hyperdiverse polypod clade--Deparia (Woodsiaceae) and the Cheilanthes marginata group (currently being segregated as a new genus of Pteridaceae)--to further evaluate the resolving power of these loci. PRINCIPAL FINDINGS: Our results clearly demonstrate the value of matK data, previously unavailable in ferns because of difficulties in amplification due to a major rearrangement of the plastid genome. With its high sequence variation, matK complements rbcL to provide a two-locus barcode with strong resolving power. With sequence variation comparable to matK, trnL-F appears to be a suitable alternative barcode region in ferns, and perhaps should be added to the core barcode region if universal primer development for matK fails. In contrast, trnH-psbA shows dramatically reduced sequence variation for the majority of ferns. This is likely due to the translocation of this segment of the plastid genome into the inverted repeat regions, which are known to have a highly constrained substitution rate. CONCLUSIONS: Our study provides the first endorsement of the two-locus barcode (rbcL+matK) in ferns, and favors trnL-F over trnH-psbA as a potential back-up locus. Future work should focus on gathering more fern matK sequence data to facilitate universal primer development

Molecular Identification of Synanthedonini Members (Lepidoptera: Sesiidae) Using Cytochrome Oxidase I

Many North American sesiid moths within Synanthodonini have been studied extensively because their feeding activity can cause detrimental economic and esthetic impacts to many commercially important ornamental and native plant species. Recent discoveries of nonnative clearwing moth pest introductions [e.g., Synanthedon myopaeformis (Borkh.)], reinforce the need for reliable and accurate molecular diagnostic tools that can be used by nontaxonomic experts, particularly when juvenile life stages are recovered from infested host-plant tissues. Cytochrome oxidase I (cox I) previously has been used to successfully identify species and resolve species complexes. In this study, the cox I phylogeny inferred from sequences generated from 21 species of sesiid moths classified within Synanthedonini confirms the close evolutionary relationship between sesiid species. As other authors have suggested in previous works, we observed that Synanthedon rileyana H. Edwards appears atypical for the genus, as it paired with Carmenta bassiformis (Walker) one node removed from, but not sister to, a large well-supported Synanthedon-rich clade. Sannina uroceriformis Walker and Podosesia MXöschler were observed nested deeply within the aforementioned well-supported clade (posterior probability [PP] of clade = 100) comprised of all Synanthedon species sampled, except S. rileyana. Placement of these two taxa conflicts with results from previous morphological studies. These placements were immune from repeated attempts to delete perceived nearby long branches within the data set. Despite these few conflicts and overall low statistical support for most interspecific and higher relationships, our data suggest that all species examined possess unique genetic signatures that lend themselves to accurate identification of all life history stages of these clearwing pests

The Relationship between Heart Rate Variability and Adiposity Differs for Central and Overall Adiposity

While frank obesity is associated with reduced HRV, indicative of poorer autonomic nervous system (ANS) function, the association between body mass index (BMI) and HRV is less clear. We hypothesized that effects of adiposity on ANS are mostly mediated by visceral fat and less by subcutaneous fat; therefore, centrally distributed adipose tissue, that is, waist circumference (WC), should be more strongly associated with HRV than overall adiposity (BMI). To examine this hypothesis, we used data collected in a subset of the Baltimore Longitudinal Study of Aging to compare strength of association between HRV and WC to that of HRV and BMI. Time domain HRV variables SDNN (standard deviation of successive differences in normal-to-normal (N-N) intervals) and RMSSD (root mean square of successive differences in N-N intervals) were calculated from 24-hour Holter recordings in 159 participants (29–96 years). Increasing WC was associated with decreasing SDNN and RMSSD in younger but not older participants (P value for WC-by-age interaction = 0.003). BMI was not associated with either SDNN or RMSSD at any age. In conclusion, central adiposity may contribute to sympathetic and parasympathetic ANS declines early in life

A Basic ddRADseq Two‐Enzyme Protocol Performs Well with Herbarium and Silica‐Dried Tissues across Four Genera

PREMISE: The ability to sequence genome-scale data from herbarium specimens would allow for the economical development of data sets with broad taxonomic and geographic sampling that would otherwise not be possible. Here, we evaluate the utility of a basic double-digest restriction site–associated DNA sequencing (ddRADseq) protocol using DNAs from four genera extracted from both silica-dried and herbarium tissue. METHODS: DNAs from Draba, Boechera, Solidago, and Ilex were processed with a ddRADseq protocol. The effects of DNA degradation, taxon, and specimen age were assessed. RESULTS: Although taxon, preservation method, and specimen age affected data recovery, large phylogenetically informative data sets were obtained from the majority of samples. DISCUSSION: These results suggest that herbarium samples can be incorporated into ddRADseq project designs, and that specimen age can be used as a rapid on-site guide for sample choice. The detailed protocol we provide will allow users to pursue herbariumbased ddRADseq projects that minimize the expenses associated with fieldwork and sample evaluation

A Basic ddRADseq Two‐Enzyme Protocol Performs Well with Herbarium and Silica‐Dried Tissues across Four Genera

PREMISE: The ability to sequence genome-scale data from herbarium specimens would allow for the economical development of data sets with broad taxonomic and geographic sampling that would otherwise not be possible. Here, we evaluate the utility of a basic double-digest restriction site–associated DNA sequencing (ddRADseq) protocol using DNAs from four genera extracted from both silica-dried and herbarium tissue. METHODS: DNAs from Draba, Boechera, Solidago, and Ilex were processed with a ddRADseq protocol. The effects of DNA degradation, taxon, and specimen age were assessed. RESULTS: Although taxon, preservation method, and specimen age affected data recovery, large phylogenetically informative data sets were obtained from the majority of samples. DISCUSSION: These results suggest that herbarium samples can be incorporated into ddRADseq project designs, and that specimen age can be used as a rapid on-site guide for sample choice. The detailed protocol we provide will allow users to pursue herbariumbased ddRADseq projects that minimize the expenses associated with fieldwork and sample evaluation