Rust (Puccinia emaculata) Management and Impact on Biomass Yield in Switchgrass.

Rust, putatively caused by Puccinia emaculata, is a widespread and potentially damaging disease of switchgrass, a crop produced as feedstock for livestock and bioenergy. Azoxystrobin, chlorothalonil, and myclobutanil were applied at 1-, 2-, 3-, or 4-week intervals for 12 to 14 weeks to the vegetatively propagated switchgrass cultivar Cloud Nine to assess fungicide selection and application interval for the control of rust as well as the impact of this disease on switchgrass biomass yield. Although rust severity significantly differed among study years, azoxystrobin and myclobutanil were often equally and more effective than chlorothalonil at controlling rust, with superior disease control coming at shorter application intervals compared with extended application intervals. Year, product, application interval, and product × interval significantly impacted dry biomass yield, which was greatest in 2016 and lowest in 2014. Dry biomass yield protection was significantly better with azoxystrobin and myclobutanil applications than with chlorothalonil or no fungicide. Linear regression models with the final disease rating, as well as with the area under disease progress curve in each year, were significant, but coefficients of determination were low to moderate (0.21 < R2 < 0.60), indicating that rust response and subsequent disease impact on dry biomass yield were impacted by other factors. From our models, an estimated 3 to 5% biomass decline was calculated for each 10% increment in rust-related leaf necrosis observed at the final September rating date. With rust-related leaf necrosis ≥80% by 1 September in each of 4 study years, biomass yield may be reduced by 24 to 40% if rust problems are not managed in switchgrass crops.

Developing a Greenhouse Protocol for Evaluating Resistance to Corynespora cassiicola in Cotton (Gossypium hirsutum).

Target spot, caused by Corynespora cassiicola, has reemerged as a disease of economic importance in cotton (Gossypium hirsutum L.) in the southeastern United States. Although this pathogen affects other economically important crops, relatively little is known about C. cassiicola on cotton, especially with regard to conditions conducive for disease development and sources of genetic resistance. Therefore, to more efficiently screen cotton genotypes for resistance, a greenhouse protocol is needed. Optimum temperature and conducive leaf wetness duration were determined in growth chamber trials. Temperature range for disease onset and greatest lesion counts occurred between 20 and 28°C. Generally, with ≥24 h of leaf wetness at these temperatures, disease onset was noted as rapidly as 1 day after inoculation on a cultivar that was previously determined to be susceptible to target spot. A mist irrigation system was used to maintain prolonged periods of leaf wetness in the greenhouse. In greenhouse trials, inoculation of cotyledons with 4 × 104 conidia/ml allowed differentiation of five selected genotypes with disease reactions that reflected their field rankings. The current protocol will be useful for evaluating cotton breeding lines for resistance to target spot.

Adaptive behavior in autism: Minimal clinically important differences on the Vineland-II.

Autism Spectrum Disorder (ASD) is associated with persistent impairments in adaptive abilities across multiple domains. These social, personal, and communicative impairments become increasingly pronounced with development, and are present regardless of IQ. The Vineland Adaptive Behavior Scales, Second Edition (Vineland-II) is the most commonly used instrument for quantifying these impairments, but minimal clinically important differences (MCIDs) on Vineland-II scores have not been rigorously established in ASD. We pooled data from several consortia/registries (EU-AIMS LEAP study, ABIDE-I, ABIDE-II, INFOR, Simons Simplex Collection and Autism Treatment Network [ATN]) and clinical investigations and trials (Stanford, Yale, Roche) resulting in a data set of over 9,000 individuals with ASD. Two approaches were used to estimate MCIDs: distribution-based methods and anchor-based methods. Distribution-based MCID [d-MCID] estimates included the standard error of the measurement, as well as one-fifth and one-half of the covariate-adjusted standard deviation (both cross-sectionally and longitudinally). Anchor-based MCID [a-MCID] estimates include the slope of linear regression of clinician ratings of severity on the Vineland-II score, the slope of linear regression of clinician ratings of longitudinal improvement category on Vineland-II change, the Vineland-II change score maximally differentiating clinical impressions of minimal versus no improvement, and equipercentile equating. Across strata, the Vineland-II Adaptive Behavior Composite standardized score MCID estimates range from 2.01 to 3.2 for distribution-based methods, and from 2.42 to 3.75 for sample-size-weighted anchor-based methods. Lower Vineland-II standardized score MCID estimates were observed for younger and more cognitively impaired populations. These MCID estimates enable users of Vineland-II to assess both the statistical and clinical significance of any observed change. Autism Res 2018, 11: 270-283. © 2017 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: The Vineland Adaptive Behavior Scales (2nd edition; Vineland-II) is the most widely used scale for assessing day-to-day "adaptive" skills. Yet, it is unknown how much Vineland-II scores must change for those changes to be regarded as clinically significant. We pooled data from over 9,000 individuals with ASD to show that changes of 2-3.75 points on the Vineland-II Composite score represent the "minimal clinically-important difference." These estimates will help evaluate the benefits of potential new treatments for ASD.

Insect Damage, Aflatoxin Content, and Yield of Bt Corn in Alabama.

Isoline pairs of hybrid corn, similar except for presence or absence of a Bt trait, were planted at eight sites across Alabama over three years. This study evaluated insect damage, yield, and aflatoxin levels as affected by the Bt traits, YieldGard Corn Borer (expressing Cry1Ab), Herculex I (expressing Cry1F), Genuity VT Triple PRO (expressing Cry1A.105 and Cry2Ab2), Agrisure Viptera 3111 (expressing Vip3Aa20 and Cry1Ab), and Genuity SmartStax (expressing Cry1A.105, Cry2Ab2, and Cry1F). When examined over all sites and years, hybrids with any of the included Bt traits had lower insect damage and higher yields. However, insect damage was not consistently correlated to yield. Bt traits expressing multiple proteins provided greater protection from corn earworm feeding than did traits for single proteins. Yields and aflatoxin levels were highly variable among sites although irrigated sites had higher yields than nonirrigated sites. Aflatoxins commonly accumulate in corn in the southeastern United States because of prevailing high temperatures and frequent dry conditions. Aflatoxin levels were not consistently associated with any factors that were evaluated, including Bt traits.

Comparison of soil fungal community structure in different peanut rotation sequences using ribosomal intergenic spacer analysis in relation to aflatoxin-producing fungi.

The present study focuses on determining soil fungal community structure in different peanut-cropping sequences by using a high-resolution DNA fingerprinting technique: ribosomal intergenic spacer analysis (RISA). This study was initiated to determine fungal community profiles in four peanut-cropping sequences (continuous peanut, 4 years of continuous bahiagrass followed by peanut, peanut-corn-cotton, and peanut-cotton rotations), with a special focus to evaluate whether the profiles under investigation may have also indicated microbial differences that could affect Aspergillus flavus populations. Results indicated 75% similarities among fungal communities from the same cropping sequences as well as with similar times of sampling. Polymerase chain reaction (PCR)-based detection of A. flavus directly from these soils was carried out using A. flavus-specific primers (FLA1 and FLA2) and also through quantitative estimation on A. flavus and A. parasiticus agar medium. Population levels of A. flavus in soil samples ranged from zero to 1.2 × 10(3) CFU g(-1) of soil (based on culturable methods); however, the fungus was not detected with A. flavus-specific primers. The minimum threshold limit at which these aflatoxin-producing fungi could be detected from the total soil genomic DNA was determined through artificial inoculation of samples with 10-fold increases in concentrations. The results indicated that a minimum population density of 2.6 × 10(6) CFU g(-1) of soil is required for PCR detection in our conditions. These results are useful in further determining the relative population levels of these fungi in peanut soils with other soil fungi. This is a new approach to understanding soil fungal communities and how they might change over time and under different rotation systems.

Effect of environmental characteristics on Pythium and Mesocriconema spp. in golf course greens in Alabama.

The role the environment has on populations of Pythium and Mesocriconema spp. was investigated at 5 golf course locations in east central Alabama. Every 4 to 5 weeks soil samples were collected from 3 golf greens on each of the 5 golf courses. Environmental data, including air and soil temperature, pH and relative humidity, were also collected. Dilution plating and a combined sieving and sugar flotation procedure were conducted to determine the populations of Pythium and Mesocriconema spp. for each month. Isolates of Pythium from 4 months were also identified. Pythium spp. populations increased as soil temperature and ambient air temperature prior to sampling decreased (P < 0.05). Pythium spp. populations were highest in the winter and lowest in the spring. At some locations, populations of Mesocriconema spp. increased as soil acidity and populations of Pythium spp. decreased (P < 0.05) and as ambient air temperature prior to sampling increased (P < 0.05). Eight species of Pythium were isolated from 4 months, with Pythium rostratum being the most commonly isolated. Results suggest that Pythium and Mesocriconema spp. prefer different soil environments.

Effects of switchgrass (Panicum virgatum) rotations with peanut (Arachis hypogaea L.) on nematode populations and soil microflora.

A 3-year field rotation study was conducted to assess the potential of switchgrass (Panicum virgatum) to suppress root-knot nematodes (Meloidogyne arenaria), southern blight (Sclerotium rolfsii), and aflatoxigenic fungi (Aspergillus sp.) in peanut (Arachis hypogaea L.) and to assess shifts in microbial populations following crop rotation. Switchgrass did not support populations of root-knot nematodes but supported high populations of nonparasitic nematodes. Peanut with no nematicide applied and following 2 years of switchgrass had the same nematode populations as continuous peanut plus nematicide. Neither previous crop nor nematicide significantly reduced the incidence of pods infected with Aspergillus. However, pod invasion by A. flavus was highest in plots previously planted with peanut and not treated with nematicide. Peanut with nematicide applied at planting following 2 years of switchgrass had significantly less incidence of southern blight than either continuous peanut without nematicide application or peanut without nematicide following 2 years of cotton. Peanut yield did not differ among rotations in either sample year. Effects of crop rotation on the microbial community structure associated with peanut were examined using indices for diversity, richness, and similarity derived from culture-based analyses. Continuous peanut supported a distinctly different rhizosphere bacterial microflora compared to peanut following 1 year of switchgrass, or continuous switchgrass. Richness and diversity indices for continuous peanut rhizosphere and geocarposphere were not consistently different from peanut following switchgrass, but always differed in the specific genera present. These shifts in community structure were associated with changes in parasitic nematode populations.

Management of Black Spot of Rose with Winter Fungicide Treatment.

Fungicides were evaluated for their efficacy against black spot of rose, caused by Diplocarpon rosae, when applied during winter months to hybrid tea rose plants in two studies. One study, conducted at two Auburn University campus sites, consisted of applications of horticultural oil, chlorothalonil plus an antitranspirant, and cyproconazole, along with nontreated plants; one site included triforine applications. Rose canes were treated two and three times between late October and February in 1996-97 and 1997-98, respectively; then plants were examined every 2 to 4 days beginning in mid-February for onset of symptoms of black spot. In both years, winter applications of fungicides (chlorothalonil, cyproconazole, and triforine) delayed disease onset compared with treatments without fungicides (nontreated and oil applications). Decreased plant defoliation, as well as improved plant vigor, were observed through the 1998 growing season following fungicidal winter treatments at campus sites; winter treatments with oil did not suppress disease compared with no treatment. In a second study started in November 1997, at a site near Shorter, AL, three systemic fungicides (myclobutanil, cyproconazole, and triforine) were applied to rose canes during the winter; nontreated plants were included. Decreased disease symptoms and defoliation of rose plants were observed early in the 1998 and 1999 seasons following winter applications of cyproconazole and triforine compared with myclobutanil or nontreated plants. Winter treatments with these fungicides did not consistently provide season-long reduction of black spot. However, season-long plant vigor and flower production on plants were improved at the Shorter site following winter applications of any of the above systemic fungicides compared with nontreated plants.

Validation of highly polymorphic fluorescent multiplex short tandem repeat systems using two generations of DNA sequencers.

Validation studies are a crucial requirement before implementation of new genetic typing systems for clinical diagnostics or forensic identity. Two different fluorescence-based multiplex DNA profiling systems composed of amelogenin, HumD21S11 and HumFGA (referred to as multiplex 1A), and HumD3S1358, HumD21S11 and HumFGA (multiplex 1B) have been evaluated for use in forensic identification using the Applied Biosystems Model 373A and Prism 377 DNA Sequencers, respectively. Experiments were aimed at defining the limit of target DNA required for reliable profiling, the level of degradation that would still permit amplification of the short tandem repeat (STR) loci examined, and the robustness of each locus in the multiplexes after samples were exposed to environmental insults. In addition, the specificity of the multiplexes was demonstrated using nonhuman DNAs. Forensically relevant samples such as cigarette butts, chewing gum, fingernails and envelope flaps were processed using both an organic extraction procedure and a QIAamp protocol. DNAs and resultant multiplex STR profiles were compared. The validation of the triplex STR systems was extended to include over 140 nonprobative casework specimens and was followed with a close monitoring of initial casework (over 300 exhibits). Our results document the robustness of these multiplex STR profiling systems which, when combined with other multiplex systems, could provide a power of discrimination of approximately 0.9999.

Number of Tebuconazole Applications for Maximizing Disease Control and Yield of Peanut in Growers' Fields in Alabama.

Disease and yields of peanut were monitored in growers' fields treated with zero, one, two, three, and four applications of tebuconazole. Yields ranged from 1,918 to 6,891 kg/ha and averaged 4,319 kg/ha over eight locations in 3 study years. Defoliation caused by peanut leaf spots (Cercospora arachidicola and Cercosporidium acutatum) and incidence of southern stem rot (Sclerotium rolfsii) were inversely related to number of tebuconazole applications, while yield was directly related to number of tebuconazole applications. Average yields with zero, one, two, and four tebuconazole applications (each application at 0.25 kg a.i./ha) were 3,609, 4,088, 4,526, and 4,868 kg/ha, respectively. Data from each location were best modeled by quadratic equations allowing determination of numbers of tebuconazole applications for minimal disease and maximal yields. Calculated spray numbers indicate that between three and four applications of tebuconazole is best for disease control and yield maximization.

Monitoring of clinical trials and interim analyses from a drug sponsor's point of view.

This paper illustrates aspects of data monitoring of clinical trials in the pharmaceutical industry. Formal interim analyses are performed at least in part to address the question of whether the trial should proceed or whether there should be an early termination of the trial. For formal interim analyses, frequently independent data and safety monitoring committees are utilized for monitoring clinical trials, and adjustments to nominal significance levels for test statistics are required. Various statistical methods developed during the last fifteen years are utilized. Administrative interim analyses are those analyses that are performed without any intention to stop the trial as a consequence of those analyses. For administrative interim analyses, adjustments to significance levels may not be required, but results must still be carefully interpreted. Regardless of the interim analyses performed, it is critical that the plans for interim analyses be identified in the study protocol, and the dissemination of interim results be carefully restricted. The following clinical trials sponsored by Merck Sharp and Dohme Research Laboratories (MSDRL) will illustrate these points: CONSENSUS; CONSENSUS II; 4S; Haemophilus influenza type b efficacy trial; famotidine in upper gastrointestinal haemorrhage, and a phase II analgesic study. It is anticipated that data monitoring and interim analysis activities will increase for future clinical trials due to the availability of appropriate statistical methods and improved data management systems.

Famotidine relieves symptoms of gastroesophageal reflux disease and heals erosions and ulcerations. Results of a multicenter, placebo-controlled, dose-ranging study. USA Merck Gastroesophageal Reflux Disease Study Group.

We conducted a double-blind, placebo-controlled, multicenter trial comparing the efficacy of famotidine 40 mg administered at bedtime (HS), 20 mg given twice daily (BID), and placebo to relieve heartburn and to heal endoscopically documented esophageal erosions or ulcerations. A total of 338 patients were randomized: 135 to receive famotidine 40 mg HS, 137 to receive famotidine 20 mg BID, and 66 to receive placebo. In the group given famotidine 20 mg BID, there was a significantly greater proportion of patients with complete relief of daytime heartburn, and both famotidine groups demonstrated statistically significant advantages over placebo in global scores or by successful outcome. Antacid consumption was significantly reduced in the group given famotidine 20 mg BID as compared with placebo. Both famotidine regimens resulted in a significantly greater proportion of patients with complete endoscopic healing than placebo, with the BID dosing being numerically superior to the 40-mg HS dose.