Realizing topological edge states with Rydberg-atom synthetic dimensions.

A discrete degree of freedom can be engineered to match the Hamiltonian of particles moving in a real-space lattice potential. Such synthetic dimensions are powerful tools for quantum simulation because of the control they offer and the ability to create configurations difficult to access in real space. Here, in an ultracold 84Sr atom, we demonstrate a synthetic-dimension based on Rydberg levels coupled with millimeter waves. Tunneling amplitudes between synthetic lattice sites and on-site potentials are set by the millimeter-wave amplitudes and detunings respectively. Alternating weak and strong tunneling in a one-dimensional configuration realizes the single-particle Su-Schrieffer-Heeger (SSH) Hamiltonian, a paradigmatic model of topological matter. Band structure is probed through optical excitation from the ground state to Rydberg levels, revealing symmetry-protected topological edge states at zero energy. Edge-state energies are robust to perturbations of tunneling-rates that preserve chiral symmetry, but can be shifted by the introduction of on-site potentials.

Comparative efficacy, safety, and cost-effectiveness of abobotulinumtoxinA and onabotulinumtoxinA in children with upper limb spasticity: a systematic literature review, indirect treatment comparison, and economic evaluation.

OBJECTIVE: The objective of this study was to compare clinical- and cost-effectiveness of type A botulinum toxin (BoNT-A) therapies for management of pediatric upper limb spasticity, including AbobotulinumtoxinA (aboBoNT-A) and Onabotulinumtoxin A (onaBoNT-A). METHODS: Systematic literature review and indirect treatment comparisons were conducted of randomized controlled trials reporting efficacy and safety outcomes. Efficacy was characterized by Modified Ashworth Scale (MAS) and Ashworth Scale (AS) up to 16-weeks post-injection. Results were used to inform a cost-effectiveness model with a 1-year time horizon, linking response rates with health-related quality-of-life (HRQoL) outcomes and costs from a UK perspective. Other data sources included in the cost-effectiveness model were drug unit costs, health care resource utilization based on UK physician survey, and HRQoL impacts of adverse events associated with oral anti-spasticity therapies. Results were characterized as cost per quality-adjusted life year and cost per responder. RESULTS: Six studies were included in evidence syntheses. There was a trend towards greater response rate for aboBoNT-A which resulted in improved HRQoL and lower annual costs compared with onaBoNT-A. Safety outcomes were similar across BoNT-A therapies. In cost-effectiveness analysis, aboBoNT-A was an economically dominant therapy with respect to cost per quality-adjusted life year. The cost per responder at 1 year was estimated to be £39,056 for aboBoNT-A vs. £54,831 for onaBoNT-A. LIMITATIONS AND CONCLUSIONS: Based on observed safety and efficacy data, aboBoNT-A is estimated to result in higher treatment response and consequently increased quality-of-life and reduced costs, vs. onaBoNT-A in children with upper limb spasticity. Limitations to the study include study heterogeneity limited details available for onaBoNT-A studies (e.g. use of physical therapy), and limited availability of responder data. Where assumptions were required, they were made to be conservative towards aboBoN-A.

Sweet Corn Sentinel Monitoring for Lepidopteran Field-Evolved Resistance to Bt Toxins.

As part of an insect resistance management plan to preserve Bt transgenic technology, annual monitoring of target pests is mandated to detect susceptibility changes to Bt toxins. Currently Helicoverpa zea (Boddie) monitoring involves investigating unexpected injury in Bt crop fields and collecting larvae from non-Bt host plants for laboratory diet bioassays to determine mortality responses to diagnostic concentrations of Bt toxins. To date, this monitoring approach has not detected any significant change from the known range of baseline susceptibility to Bt toxins, yet practical field-evolved resistance in H. zea populations and numerous occurrences of unexpected injury occur in Bt crops. In this study, we implemented a network of 73 sentinel sweet corn trials, spanning 16 U.S. states and 4 Canadian provinces, for monitoring changes in H. zea susceptibility to Cry and Vip3A toxins by measuring differences in ear damage and larval infestations between isogenic pairs of non-Bt and Bt hybrids over three years. This approach can monitor susceptibility changes and regional differences in other ear-feeding lepidopteran pests. Temporal changes in the field efficacy of each toxin were evidenced by comparing our current results with earlier published studies, including baseline data for each Bt trait when first commercialized. Changes in amount of ear damage showed significant increases in H. zea resistance to Cry toxins and possibly lower susceptibility to Vip3a. Our findings demonstrate that the sentinel plot approach as an in-field screen can effectively monitor phenotypic resistance and document field-evolved resistance in target pest populations, improving resistance monitoring for Bt crops.

Correction to: Cost-effectiveness analysis of umeclidinium bromide/vilanterol 62.5/25 mcg versus tiotropium/olodaterol 5/5 mcg in symptomatic patients with chronic obstructive pulmonary disease: a Spanish National Healthcare System perspective.

Following publication of the original article [1], we have been notified of the below corrections to the 5th paragraph in the Discussion section.

Cost-effectiveness analysis of umeclidinium bromide/vilanterol 62.5/25 mcg versus tiotropium/olodaterol 5/5 mcg in symptomatic patients with chronic obstructive pulmonary disease: a Spanish National Healthcare System perspective.

BACKGROUND: A head-to-head study demonstrated the superiority of once-daily umeclidinium bromide/vilanterol (UMEC/VI) 62.5/25 mcg on trough forced expiratory volume in 1 s (FEV1) versus once-daily tiotropium/olodaterol (TIO/OLO) 5/5 mcg in symptomatic patients with chronic obstructive pulmonary disease (COPD). This analysis evaluated the cost effectiveness of UMEC/VI versus TIO/OLO from a Spanish National Healthcare System perspective, using data from this study and Spanish literature. METHODS: This analysis was conducted from the perspective of the Spanish National Healthcare System with a 3-year horizon as base case. A disease progression model using a linked risk equation approach was used to estimate disease progression and associated healthcare costs, and quality-adjusted life years (QALYs). The Evaluation of COPD Longitudinally to Identify Predictive Surrogate Endpoints (ECLIPSE) study was used to develop the statistical risk equations for clinical endpoints, and costs were calculated using a health state approach (by dyspnea severity). Utilities for QALY calculation were estimated using patient baseline characteristics within a regression fit to Spanish observational data. Treatment effect, expressed as change from baseline in FEV1 was obtained from the head-to-head study and used in the model (UMEC/VI minus TIO/OLO difference: + 52 mL [95% confidence interval: 28, 77]). Baseline patient characteristics were sourced from Spanish literature or the head-to-head study if unavailable. A scenario analysis using only the intent-to-treat (ITT) population from the head-to-head study, and sensitivity analyses (including probabilistic sensitivity analyses), were conducted. Direct healthcare costs (2017 Euro) were obtained from Spanish sources and costs and benefits were discounted at 3% per annum. RESULTS: UMEC/VI was associated with small improvements in QALYs (+ 0.029) over a 3-year time horizon, compared with TIO/OLO, alongside cost savings of €393/patient. The ITT scenario analysis and sensitivity analyses had similar results. All probabilistic simulations resulted in UMEC/VI being less costly and more effective than TIO/OLO. CONCLUSION: UMEC/VI dominated TIO/OLO (more effective and less expensive). These results may aid payers and decision-makers in Spain when making judgements on which long-acting muscarinic antagonist/long-acting ß2-agonist (LAMA/LABA) treatments can be considered cost effective in Spain.

A deep look into thin melanomas: What's new for the clinician and the impact on the patient.

Melanoma incidence and mortality are on the rise and although most new cases of melanoma are thin, a significant percentage of these patients still experience disease progression. The American Joint Committee on Cancer publishes staging criteria for melanoma, which were recently updated to the 8th edition. The most significant revision from the 7th edition affects the T1b classification, which now includes melanomas with a Breslow depth of 0.8 mm to 1.0 mm. The second major revision eliminates mitoses as a criterion to upstage a thin melanoma to T1b. Although mitotic figures have been established as an independent prognostic factor, they do not have a significant correlation with sentinel lymph node (SLN) biopsy positivity. SLN status remains the most important independent prognostic factor in thin melanomas. Nonetheless, the identification of patients who are at the highest risk for having a positive SLN test result remains difficult. Importantly, a positive SLN test result has high positive predictive value, but a negative one has very low negative predictive value. Since there is no proven survival benefit in performing an SLN biopsy in T1 disease, dermatologists need to have a personalized discussion with patients with thin melanomas to review expected risks and benefits before undertaking this procedure.

Creation of Rydberg Polarons in a Bose Gas.

We report spectroscopic observation of Rydberg polarons in an atomic Bose gas. Polarons are created by excitation of Rydberg atoms as impurities in a strontium Bose-Einstein condensate. They are distinguished from previously studied polarons by macroscopic occupation of bound molecular states that arise from scattering of the weakly bound Rydberg electron from ground-state atoms. The absence of a p-wave resonance in the low-energy electron-atom scattering in Sr introduces a universal behavior in the Rydberg spectral line shape and in scaling of the spectral width (narrowing) with the Rydberg principal quantum number, n. Spectral features are described with a functional determinant approach (FDA) that solves an extended Fröhlich Hamiltonian for a mobile impurity in a Bose gas. Excited states of polyatomic Rydberg molecules (trimers, tetrameters, and pentamers) are experimentally resolved and accurately reproduced with a FDA.

Seasonal Abundance and Phenology of Halyomorpha halys (Hemiptera: Pentatomidae) on Different Pepper Cultivars in the Mid-Atlantic (United States).

The brown marmorated stink bug, Halyomorpha halys (Stål), is an invasive stink bug (Hemiptera: Pentatomidae) introduced into the United States in the mid-1990s. Since its initial establishment, it has spread throughout the east coast as far south as Georgia, and as far north as New Hampshire. While information is available regarding H. halys behavior and life history in some crops, relatively little information is available for vegetables such as peppers. Key questions include understanding when H. halys enters pepper fields to feed and how best to predict infestations, what population levels create economic damage, and if peppers that vary in capsaicin levels also vary in susceptibility to attack. To answer these questions, replicated plots were set up across four mid-Atlantic states using three types of peppers: sweet bell, sweet banana, and hot chili. We found that there was no difference in the overall abundance of all life stages of H. halys on all pepper varieties tested. However, there were differences in bug density by site, but these differences did not translate to differences in the proportion of damaged fruit. The presence of adult H. halys is a better predictor of damage in banana peppers, whereas nymphs are a better predictor in bell pepper. In addition, across all sites, the presence of egg masses was low in pepper crops and densities of both adults and immatures tend to peak on pepper plants in early August. Altogether, this information can be used to help develop a pest management program in peppers that will reduce crop losses to this new devastating pest, while reducing the reliance on insecticides to manage this pest at the same time.

Comparison of Two Sampling Methods for Assessing Halyomorpha halys (Hemiptera: Pentatomidae) Numbers in Soybean Fields.

Sampling soybean fields for the brown marmorated stink bug, Halyomorpha halys Stål (Hemiptera: Pentatomidae), can be challenging. Both adults and nymphs have a "startle response" and drop to the ground with even the slightest disturbance. This behavior could reduce the effectiveness of the traditional sweep net and ground cloth sampling methods. In 2013 and 2014, in Virginia, Delaware, and Maryland, we evaluated a visual plant inspection method that consisted of counting the number of brown marmorated stink bug nymphs and adults seen on soybean plants in a 2-min inspection period while walking carefully between two rows. After a 30-min interval, which allowed the stink bugs to reposition in the canopy, the area was resampled using 15 sweeps with a 38-cm-diameter sweep net. In total, 76 soybean fields and 2,042 paired comparisons were used to determine a strong linear relationship between sampling methods (y = 0.984x + 0.4359, R2 = 0.6934, where y = brown marmorated stink bugs/2-min visual count and x = brown marmorated stink bugs/15 sweeps). An average visual count of 5.4 brown marmorated stink bugs in 2 min was estimated as being equivalent to the current economic threshold of 5 stink bugs per 15 sweeps. Visual inspection appears to be an effective method for assessing brown marmorated stink bug populations in soybeans.

Improved electrode material for deep brain stimulation.

Deep brain stimulation (DBS) devices have been implanted for treatment of basic tremor, Parkinson's disease and dystonia. These devices use electrodes in contact with tissue to deliver electrical pulses to targeted cells, to elicit specific therapeutic responses. In general, the neuromodulation industry has been evolving towards smaller, less invasive electrodes. However, current electrode materials do not support small sizes without severely restricting the stimulus output. Hence, an improved electrode material will benefit present and future DBS systems. In this study, five DBS leads were modified using a cost-effective and materials-efficient process for applying an ultra-low impedance platinum-iridium alloy coating. One DBS lead was used for insertion test and four DBS leads were chronically pulsed for 12 weeks. The platinum-iridium alloy significantly improved the electrical properties of the DBS electrodes and was robust to insertion into brain and to 12 weeks of chronic pulsing.

Influence of charge and coordination number on bond dissociation energies, distances, and vibrational frequencies for the phosphorus-phosphorus bond.

We report a comprehensive and systematic experimental and computational assessment of the P-P bond in prototypical molecules that represent a rare series of known compounds. The data presented complement the existing solid-state structural data and previous computational studies to provide a thorough thermodynamic and electronic understanding of the P-P bond. Comparison of homolytic and heterolytic bond dissociation for tricoordinate-tricoordinate, tricoordinate-tetracoordinate, and tetracoordinate-tetracoordinate P-P bonds in frameworks 1-6 provides fundamental insights into covalent bonding. For all types of P-P bond discussed, homolytic dissociation is favored over heterolytic dissociation, although the distinction is small for 2(1+) and 6(1+). The presence of a single cationic charge in a molecule substantially strengthens the P-P bond (relative to analogous neutral frameworks) such that it is comparable with the C-C bond in alkanes. Nevertheless, P-P distances are remarkably independent of molecular charge or coordination number, and trends in values of d(PC) and νsymm(PC) imply that a molecular cationic charge is distributed over the alkyl substituents. In the gas phase, the diphosphonium dication 3(2+) has similar energy to two [PMe3](+) radical cations, so that it is the lattice enthalpy of 3[OTf]2 in the solid-state that enables isolation, highlighting that values from gas-phase calculations are poor guides for synthetic planning for ionic compounds. There are no relationships or correlations between bond lengths, strengths, and vibrational frequencies.

The effect of specimen temperature on the polymerization of a resin-composite.

OBJECTIVE: To use rapid scan FT-IR and Knoop microhardness to determine the effect of specimen temperature on the rate and extent of polymerization of a dental resin. METHODS: Two-millimeter thick specimens of shade A2 Tetric EvoCeram were light cured for 20s at 22, 26, 30, and 35°C. The IR spectrum was obtained at the bottom of the specimens at a rate of 3 measurements per second for the first 5 min, and then again 2h later. The Knoop microhardness was measured at the bottom of the samples in the region where the IR spectrum was recorded at 5 min and 2h after light curing. Data were statistically analyzed using mixed model ANOVA (with Fisher's PLSD) to examine the effect of temperature, time and their interaction. The rate of conversion was determined using first differences and smoothed using a cubic spline procedure. RESULTS: The bottom surfaces of the samples light cured at 22, 26, 30 and 35°C were all significantly different from each other (p<0.05). The higher temperature resulted in higher degree of conversion and Knoop microhardness values, and faster maximum rate of polymerization, which also occurred sooner. One second after the light was turned on, the rate of conversion was 106% faster at 35°C than at 22°C (p=0.003). Regression analysis showed a positive linear correlation between the degree of conversion and Knoop microhardness (r²=0.93). SIGNIFICANCE: A relatively small difference in temperature can have a large and significant effect on the rate and extent of polymerization of dental resin. Consequently laboratory studies comparing the performance of resins should be conducted at clinically relevant temperatures.

Effect of distance on irradiance and beam homogeneity from 4 light-emitting diode curing units.

PURPOSE: To quantify the effect of distance on the irradiance and beam homogeneity from 4 curing lights. METHODS: Four light-emitting diode curing lights were evaluated: Fusion, Bluephase 16i, Demi and FlashLite Magna. The irradiance at the centre of the light beam (ICB) was measured at 1.0 to 9.0 mm from the emitting tip using a 3.9-mm diameter probe connected to a spectrometer. The uniformity of the beam from each curing light was characterized by means of the "top hat factor" at 2.0, 4.0, 6.0 and 8.0 mm from the emitting tip. The useful beam diameter, within which irradiance values were greater than 400 mW/cm2, was calculated. The ICB, top hat factor and useful beam diameter were compared by analysis of variance and Fisher's protected least significant difference test at α = 0.01. RESULTS: At all distances, the ICB was lowest for the FlashLite Magna and highest for the Fusion. Only the Fusion maintained an ICB above 1000 mW/cm2 at the 8.0 mm distance. For distances between 2.0 and 8.0 mm, the top hat factors were similar for the Fusion and the Demi, lower for the Bluephase 16i and lowest for the FlashLite Magna. CONCLUSIONS: Beam homogeneity, top hat factors and ICB varied significantly among the curing lights. These results indicate that deep restorations may not be adequately cured if the curing time is based on data obtained when the curing light is positioned close to the radiometer or resin. In addition, a single irradiance value cannot be used to describe the light output from a curing light.

Co[V2]o4: a spinel approaching the itinerant electron limit.

Studies of the structure, magnetization, and resistivity under pressure on stoichiometric normal spinel Co[V(2)]O(4) single crystals show (i) absence of a structural distortion, (ii) abnormal magnetic critical exponents, and (iii) metallic conductivity induced by pressures at low temperatures. All these results prove that Co[V(2)]O(4) sits on the edge of the itinerant-electron limit. Compared with similar measurements on Fe[V(2)]O(4) and other A[V(2)]O(4) studies, it is shown that a critical V-V separation for a localized-itinerant electronic phase transition exists.

Factors affecting the energy delivered to simulated class I and class v preparations.

PURPOSE: To determine the effect of operator, curing light and preparation location, as well as any correlations among these variables, on the amount of light energy delivered to simulated cavity preparations. MATERIALS AND METHODS: Each of 10 dentists and 10 fourth-year dental students light-cured a Class I preparation in tooth 26 and a Class V preparation in tooth 37 in a dental mannequin head. The operators exposed each preparation for 10 seconds with each of 3 LED-based curing lights (Bluephase G2 on high power, Demi and VALO on standard power). Each operator also used the VALO unit in the plasma mode for 2 sequential 3-second curing cycles. For each combination of operator, curing light and preparation, the irradiance (mW/cm(2)) received at the base of the preparation was measured with a laboratory-grade spectroradiometer, and software was used to calculate the energy density delivered in real time. The statistical analysis included 3-way analysis of variance (ANOVA) and the Fisher protected least significant difference (PLSD) test for post hoc pairwise comparisons. RESULTS: There was a large qualitative and quantitative variation in the irradiance delivered to the preparations by each operator. Three-way ANOVA showed no statistically significant differences between dentists and dental students in terms of the amount of energy delivered (p = 0.90). However, there were statistically significant differences in energy delivered by the various curing lights (p < 0.001) and between the 2 preparation locations (p < 0.001). According to the Fisher PLSD test for post hoc pairwise comparison of means, the VALO unit used in the plasma mode for two 3-second curing cycles delivered the most energy (16.4 +/- 3.1 J/cm(2)) to the Class I preparation, and the same light used for 10 seconds in the standard mode delivered the least amount of energy (9.9 +/- 2.4 J/cm(2)) (p < 0.001). For the Class V preparation, the VALO unit used in the plasma mode for two 3-second curing cycles delivered the most energy (12.5 +/- 4.0 J/cm(2)), and the Demi unit, used for 10 seconds, delivered the least energy (7.4 +/- 2.5 J/cm(2)). CONCLUSIONS: The energy delivered by a curing light to a preparation in a simulated clinical environment was affected by the operator's light-delivery technique, the choice of curing light and the location of the preparation.

Syntheses of [F5TeNH3][AsF6], [F5TeN(H)Xe][AsF6], and F5TeNF2 and characterization by multi-NMR and Raman spectroscopy and by electronic structure calculations: the X-ray crystal structures of alpha- and beta-F5TeNH2, [F5TeNH3][AsF6], and [F5TeN(H)Xe][AsF6].

The salt, [F5TeN(H)Xe][AsF6], has been synthesized in the natural abundance and 99.5% 15N-enriched forms. The F5TeN(H)Xe+ cation has been obtained as the product of the reactions of [F5TeNH3][AsF6] with XeF2 (HF and BrF5 solvents) and F5TeNH2 with [XeF][AsF6] (HF solvent) and characterized in solution by 129Xe, 19F, 125Te, 1H, and 15N NMR spectroscopy at -60 to -30 degrees C. The orange [F5TeN(H)Xe][AsF6] and colorless [F5TeNH3][AsF6] salts were crystallized as a mixture from HF solvent at -35 degrees C and were characterized by Raman spectroscopy at -165 degrees C and by X-ray crystallography. The crystal structure of the low-temperature phase, alpha-F5TeNH2, was obtained by crystallization from liquid SO2 between -50 and -70 degrees C and is fully ordered. The high-temperature phase, beta-F5TeNH2, was obtained by sublimation at room temperature and exhibits a 6-fold disorder. Decomposition of [F5TeN(H)Xe][AsF6] in the solid state was rapid above -30 degrees C. The decomposition of F5TeN(H)Xe+ in HF and BrF5 solution at -33 degrees C proceeded by fluorination at nitrogen to give F5TeNF2 and Xe gas. Electronic structure calculations at the Hartree-Fock and local density-functional theory levels were used to calculate the gas-phase geometries, charges, Mayer bond orders, and Mayer valencies of F5TeNH2, F5TeNH3+, F5TeN(H)Xe+, [F5TeN(H)Xe][AsF6], F5TeNF2, and F5TeN2- and to assign their experimental vibrational frequencies. The F5TeN(H)Xe+ and the ion pair, [F5TeN(H)Xe][AsF6], systems were also calculated at the MP2 and gradient-corrected (B3LYP) levels.

[Osteoblastic differentiation of human adult mesenchymal stem cells after through gene transfer of BMP-2 in the absence of dexamethasone]. / Osteoblastäre Differenzierung von humanen adulten mesenchymalen Stammzellen durch transgenes BMP-2 in Abwesenheit von Dexamethason.

AIM: Mesenchymal stem cells (MSC) of various species appear to require different cues to differentiate towards the osteoblastic lineage. For MSC of human origin, recombinant hBMP-2 is reported to be not sufficient but dexamethasone seems to be essential. The aim of this study was to analyse changes in genotype and phenotype of hMSC after adenoviral transfer of the BMP-2 gene in the absence of dexamethasone. METHODS: We employed hMSC and analysed changes in expression of the Runx2, Osterix and type I collagen gene by quantitative PCR after adenoviral transfer of the human BMP-2 gene in the absence of dexamethasone. As a phenotypic marker alkaline phosphatase activity was assessed. ANOVA and post hoc statistical analyses were used to determine differences among data (p < 0.05). RESULTS: Transfer of the hBMP-2 gene and consecutive production of transgenic BMP-2 up-regulated bone marker gene expression and increased alkaline phosphatase activity and thus promoted an enhanced lineage progression to the osteoblast phenotype without the addition of dexamethasone. CONCLUSION: These findings are noteworthy in the light of a possible superiority of endogenous transgenic proteins compared to exogenous recombinant proteins.

[Refined adenoviral transduction for controlled gene transfer into human adult mesenchymal stem cells]. / Kontrollierter Gentransfer in humane adulte mesenchymale Stammzellen mittels adenoviraler Vektoren.

AIM: Adenoviral gene transfer remains a powerful tool for basic research purposes. We hypothesize that adenoviral transduction of human mesenchymal stem cells (hMSC) in vitro can be improved by refined use of experimental parameters. METHODS: hMSCs were transduced by adenoviral vectors encoding Luciferase or BMP-2 at a selection of multiplicities of infection (MOI) and exposure times. Transgene production and total protein content were measured. To determine practical relevance, expression of the bone marker genes Runx2 and Type I collagen was analyzed by quantitative PCR. As a phenotypic marker alkaline phosphatase was assessed. ANOVA and post hoc statistical analyses were used to determine differences among data (p < 0.05). RESULTS: Prolonged exposure led to a decrease in transgene production and total protein content. Increasing MOI at exposure of up to 4 hours resulted in a higher production of the transgene. Transfer of the hBMP-2 gene promoted an enhanced lineage progression to the osteoblast phenotype indicating biological activity. CONCLUSION: Time of exposure is of major importance for toxicity in vitro and should not exceed 4 hours for hMSC. While increase in exposure time leads to cell death, surviving cells, up to a certain limit, seem to compensate by increasing production of the transgene indicating that transduction efficiency cannot be positively measured in a binary yes-or-no scheme.

Rates of Seed Treatment Insecticides and Control of Stewart's Wilt in Sweet Corn.

Neonicotinoid insecticides applied as seed treatments reduce the incidence of Stewart's wilt. The objectives of this study were to examine the efficacy of different rates of seed treatment insecticides to control Stewart's wilt on susceptible sweet corn hybrids and to compare the economic value of Stewart's wilt control in sweet corn grown for processing and fresh market. Clothianidin (Poncho), imidacloprid (Gaucho), and thiamethoxam (Cruiser) applied to seed at rates ranging from 0.125 to 1.25 mg a.i. per kernel were evaluated in 11 field trials in Illinois and Delaware from 2000 to 2003. Incidence of Stewart's wilt was significantly lower when seed was treated with insecticides than when plants were grown from nontreated seed in all but one trial. The level of control usually was between 50 and 90%. Small but statistically significant differences in incidence of systemically infected plants occurred among rates of insecticides in all trials except those in 2001. Usually, incidence of systemic Stewart's wilt was lower when higher rates of insecticides were applied; however, increasing the rate of insecticides from 0.125 mg a.i. to 1.25 mg a.i. per kernel had a relatively small effect on the level of Stewart's wilt control compared with the difference between treated and nontreated sweet corn seed. Based on a regression analysis, the lowest rates of the insecticides provided 64 to 72% control. The level of control increased about 1.85% with each additional 0.1 mg a.i. of insecticide per kernel from 0.125 mg a.i. to 1.25 mg a.i. Clothianidin provided an 8 or 9% higher level of control than thiamethoxam or imidacloprid at the same rate. Recommendations for application of seed treatment insecticides to processing and fresh market sweet corn differed somewhat due to substantial differences in the value of the crops. Based on estimated costs of $6 to $12 per 0.4 ha for the seed treatments, the economic break even point (i.e., cost of control = value from control) occurred in the range of 3 to 6% Stewart's wilt incidence for processing sweet corn valued at $325 per 0.4 ha and at about 1% Stewart's wilt incidence for fresh market sweet corn valued at $1,625 per 0.4 ha. Relatively small differences in levels of control conferred by commercially available rates of clothianidin (0.25 mg a.i. per kernel) and thiamethoxam (0.125 mg a.i. per kernel) were of little consequence in processing sweet corn but had considerable economic value in fresh market sweet corn.