1,113 research outputs found
Influencing European Corn Borer (Lepidoptera: Crambidae) Aggregation Sites in Small Grain Crops
Reliable methods to attract European corn borer, Ostrinia nubilalis (Hübner), adults to small grain crops could be used to aggregate moths into small well-defined areas for control purposes or could be used in a resistance management program for delaying potential O. nubilalis resistance to transgenic corn. The objective of this research was to determine whether small-grain crops could be managed to influence O. nubilalis aggregation behavior. In farmer-managed oat, Atena sativa (L.), fields, more O. nubilalis adults were attracted to high-density patches of oat compared with standard patches of oat; no difference was found between patches of high-density oat and brome, Bromus spp. Numbers of O. nubilalis moths found in 6 barley, Hordeum vulgare (L.), and legume treatments (1995), and 4 oat/legume treatments (1996) were significantly different. The highest number of O. nubilalis adults were observed in barley planted with alfalfa, Medicago sativa (L.), followed by barley planted with crimson clover, Trifolium incarnatum(L.), barley planted with berseem, Trifolium alexandrinum (L.), barley planted with black medic, Medicago lupulina (L.), barley alone, and barley planted with lespedeza, Lespedeza stipulacea (Maximowicz). Double-planted oat attracted the highest number of O. nubilalis adults followed by oat planted with crimson clover, oat planted with alfalfa, and single-planted oat. Each study suggests that there is a positive correlation between moth aggregation and canopy area. Suggestions are made that timing canopy closure of a small-grain crop with peak O. nubilalis flight should maximize O. nubilalis aggregation and should thereby increase the efficacy of any control measures
Reduced Fusarium Ear Rot and Symptomless Infection in Kernels of Maize Genetically Engineered for European Corn Borer Resistance
ABSTRACT Field experiments were conducted in 1994, 1995, and 1996 to evaluate the incidence and severity of Fusarium ear rot and the incidence of symp-tomless Fusarium infection in kernels of maize hybrids genetically engineered with Bacillus thuringiensis genes encoding for the delta-endotoxin CryIA(b). Treatments included manual infestation with European corn borer (ECB) larvae and insecticide applications to limit ECB activity to specific maize growth stages or mimic standard ECB control practices. Fusarium symptoms and infection were affected by the specific cryIA(b) transformation used in each hybrid that determines tissue-specific expression of CryIA(b). In hybrids expressing CryIA(b) in kernels, incidence and severity of Fusarium ear rot and incidence of symptomless kernel infection were reduced compared with near-isogenic hybrids lacking cryIA(b) genes. In plants that were manually infested with ECB, ear rot incidence was reduced by 87, 58, and 68%; severity was reduced by 96, 54, and 64%; and incidence of kernel infection by Fusarium species was reduced by 17, 38, and 38% in 1994, 1995, and 1996, respectively. Results were similar in treatments that were not manually infested, but differences between transgenic and nontransgenic hybrids were smaller. Most kernel infection was due to F. moniliforme, F. proliferatum, and F. subglutinans (section Liseola) collectively, and it was within this group that transgenic hybrids exhibited reduced infection. Expression of CryIA(b) in plant tissues other than kernels did not consistently affect Fusarium symptoms or infection. Disease incidence was positively correlated with ECB damage to kernels. Insecticide applications also reduced Fusarium symptoms and infection when applied to nontransgenic plants
Analysing I/O bottlenecks in LHC data analysis on grid storage resources
We describe recent I/O testing frameworks that we have developed and applied within the UK GridPP Collaboration, the ATLAS experiment and the DPM team, for a variety of distinct purposes. These include benchmarking vendor supplied storage products, discovering scaling limits of SRM solutions, tuning of storage systems for experiment data analysis, evaluating file access protocols, and exploring I/O read patterns of experiment software and their underlying event data models. With multiple grid sites now dealing with petabytes of data, such studies are becoming essential. We describe how the tests build, and improve, on previous work and contrast how the use-cases differ. We also detail the results obtained and the implications for storage hardware, middleware and experiment software
Frequency of Resistance to Bacillus thuringiensis Toxin Cry1Ab in an Iowa Population of European Corn Borer (Lepidoptera: Crambidae)
The refuge plus high-dose strategy for resistance management assumes that the frequency of resistance alleles is low. We used an F2 screen to estimate the frequency of resistance to transgenic corn that produces Bacillus thuringiensis Berliner Cry1Ab toxin (Bt corn) in an Iowa population of European corn borer, Ostrinia nubilalis (Hu¨ bner). We also proposed a modiÞcation to the statistical analysis of the F2 screen that extends its application for nonuniform prior distributions and for repeated sampling of a single population. Based on a sample of 188 isofemale lines derived from females caught at light traps during the 2nd ßight of 1997, we show with 95% conÞdence that the frequency of resistance to Bt corn was ,3.9 3 1023 in this Iowa population. These results provide weak evidence that the refuge plus high-dose strategy may be effective for managing resistance in O. nubilalis to Bt corn. Partial resistance to Cry1Ab toxin was found commonly. The 95% CI for the frequency of partial resistance were [8.231024, 9.431023] for the Iowa population. Variable costs of the method were $14.90 per isofemale line, which was a reduction of 25% compared with our initial estimate
Effects of Bt Transformation on Diseases of Corn
The availability of genetically engineered com hybrids that are resistant to insect pests is an exciting development for com producers and the entire com industry. These hybrids are likely to become very popular as they continue to demonstrate dependable insect protection and yield performance. But these hybrids have other advantages as well. Because of the relationship between com insects, particularly the European com borer, and certain diseases, Bt hybrids have shown reduced levels of these diseases in side-by-side comparisons
Genetics, sleep and memory:a recall-by-genotype study of ZNF804A variants and sleep neurophysiology
© 2015 Hellmich et al.Background: Schizophrenia is a complex, polygenic disorder for which over 100 genetic variants have been identified that correlate with diagnosis. However, the biological mechanisms underpinning the different symptom clusters remain undefined. The rs1344706 single nucleotide polymorphism within ZNF804A was among the first genetic variants found to be associated with schizophrenia. Previously, neuroimaging and cognitive studies have revealed several associations between rs1344706 and brain structure and function. The aim of this study is to use a recall-by-genotype (RBG) design to investigate the biological basis for the association of ZNF804A variants with schizophrenia. A RBG study, implemented in a population cohort, will be used to evaluate the impact of genetic variation at rs1344706 on sleep neurophysiology and procedural memory consolidation in healthy participants. Methods/Design: Participants will be recruited from the Avon Longitudinal Study of Parents and Children (ALSPAC) on the basis of genotype at rs1344706 (n = 24). Each participant will be asked to take part in two nights of in-depth sleep monitoring (polysomnography) allowing collection of neurophysiological sleep data in a manner not amenable to large-scale study. Sleep questionnaires will be used to assess general sleep quality and subjective sleep experience after each in-house recording. A motor sequencing task (MST) will be performed before and after the second night of polysomnography. In order to gather additional data about habitual sleep behaviour participants will be asked to wear a wrist worn activity monitor (actiwatch) and complete a sleep diary for two weeks. Discussion: This study will explore the biological function of ZNF804A genotype (rs1344706) in healthy volunteers by examining detailed features of sleep architecture and physiology in relation to motor learning. Using a RBG approach will enable us to collect precise and detailed phenotypic data whilst achieving an informative biological gradient. It would not be feasible to collect such data in the large sample sizes that would be required under a random sampling scheme. By dissecting the role of individual variants associated with schizophrenia in this way, we can begin to unravel the complex genetic mechanisms of psychiatric disorders and pave the way for future development of novel therapeutic approaches
Convex Shape and Rotation Model of Lucy Target (11351) Leucus from Lightcurves and Occultations
We report new photometric lightcurve observations of the Lucy Mission target (11351) Leucus acquired during the 2017, 2018, and 2019 apparitions. We use these data in combination with stellar occultations captured during five epochs to determine the sidereal rotation period, the spin axis orientation, a convex shape model, the absolute scale of the object, its geometric albedo, and a model of the photometric properties of the target. We find that Leucus is a prograde rotator with a spin axis located within a sky-projected radius of 3° (1σ) from J2000 Ecliptic coordinates (λ = 208°, β = +77°) or J2000 Equatorial Coordinates (R.A. = 248°, decl. = +58°). The sidereal period is refined to P_(sid) = 445.683 ± 0.007 h. The convex shape model is irregular, with maximum dimensions of 60.8, 39.1, and 27.8 km. The convex model accounts for global features of the occultation silhouettes, although minor deviations suggest that local and global concavities are present. We determine a geometric albedo of p_V = 0.043 ± 0.002. The derived phase curve supports a D-type classification for Leucus
Convex Shape and Rotation Model of Lucy Target (11351) Leucus from Lightcurves and Occultations
We report new photometric lightcurve observations of the Lucy Mission target
(11351) Leucus acquired during the 2017, 2018 and 2019 apparitions. We use
these data in combination with stellar occultations captured during five epochs
(Buie et al. 2020) to determine the sidereal rotation period, the spin axis
orientation, a convex shape model, the absolute scale of the object, its
geometric albedo, and a model of the photometric properties of the target. We
find that Leucus is a prograde rotator with a spin axis located within a
sky-projected radius of 3{\deg} (1) from J2000 Ecliptic coordinates
(, ) or J2000 Equatorial Coordinates
(RA=248, Dec=+58). The sidereal period is refined to
h. The convex shape model is irregular, with maximum
dimensions of (60.8, 39.1, 27.8) km. The convex model accounts for global
features of the occultation silhouettes, although minor deviations suggest that
local and global concavities are present. We determine a geometric albedo
. The derived phase curve supports a D-type classification
for Leucus
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