Effect of time of harvest on the incidence of Fusarium spp. in kernels of silage corn

The effect of time of harvest (at 75, 50 and 25% of milkline) on the incidence of kernel-borne Fusarium spp. was examined in four silage corn (Zea mays) hybrids (MAIZEX Leafy 4, NK BRAND Enerfeast 1, PIONEER 37M81 and MYCOGEN TMF94) in Ottawa, Ontario, in 2001 and 2002. Eleven Fusarium species were isolated over the 2 yr. Fusarium subglutinans was the dominant species recovered from 28.8% of the kernels. Other frequently isolated species included F. oxysporum (2.6%), F. graminearum (2.5%), F. proliferatum (0.3%) and F. sporotrichioides (0.2%). Trace amounts (< 0.1%) of the remaining six species, F. avenaceum, F. crookwellense, F. culmorum, F. equiseti and F. solani, were recovered from the kernels. When the kernels were harvested at 75, 50 and 25% of milkline, the incidence of F. subglutinans increased from 20.9 to 26.7 and to 38.7%, respectively; that of F. graminearum increased from 1.7 to 2.9 and to 3.1%; and for the total of the five main Fusarium species it increased from 28.7 to 32.2 and to 42.3%. Incidence of the other species was not affected by harvesting date. Of the four silage corn hybrids, NK BRAND Enerfeast1 had a significantly lower incidence of Fusarium species in kernels than the other hybrids, indicating a genotypic variation in resistance to kernel-borne infection by Fusarium species.L’effet de trois temps de récolte, correspondant à 75, 50 et 25 % de l’état laiteux, sur l’incidence des espèces de Fusarium a été étudié chez les grains de quatre hybrides de maïs (Zea mays) ensilage (MAIZEX Leafy 4, NK BRAND Enerfeast 1, PIONEER 37M81 et MYCOGEN TMF94) en 2001 et 2002 à Ottawa, en Ontario. Onze espèces de Fusarium ont été isolées pendant ces deux années. Le F. subglutinans a été l’espèce dominante, trouvée sur 28,8 % des grains. Les autres espèces détectées ont été les F. oxysporum (2,6 %), F. graminearum (2,5 %), F. proliferatum (0,3 %) et F. sporotrichioides (0,2 %). Des traces (< 0,1 %) des six autres espèces, les F. avenaceum, F. crookwellense, F. culmorum, F. equiseti et F. solani, ont aussi été détectées sur les grains. L’incidence du F. subglutinans a augmenté respectivement de 20,9 à 26,7 puis à 38,7 % en fonction du temps de récolte (75, 50 et 25 % de l’état laiteux), tandis qu’elle a augmenté de 1,7 à 2,8 puis à 3,1 % pour le F. graminearum et de 28,7 à 32,2 puis à 42,3 % pour les cinq espèces principales confondues. L’incidence des autres espèces n’a pas été affectée par les dates de récolte. Parmi les quatre hybrides à l’essai, l’hybride commercial NK BRAND Enerfeast1 a eu la plus basse incidence d’espèces de Fusarium dans le grain, ce qui indique qu’il existe une variation génotypique de la résistance des grains aux infections causées par les espèces de Fusarium

Bystander Program Effectiveness to Reduce Violence Acceptance: RCT in High Schools

Bystander-based violence prevention interventions have shown efficacy to reduce dating violence and sexual violence acceptance at the individual level yet no large randomized controlled trial (RCT) has evaluated this effect at the high-school level and over time. This rigorous cluster-randomized controlled trial addresses this gap by evaluating intervention effectiveness at both school and individual levels. Kentucky high schools were randomized to intervention or control conditions. In intervention schools educators provided school-wide ‘Green Dot’ presentations and bystander training with student popular opinion leaders. Each spring from 2010 to 2014; 73,044 students completed anonymous surveys with no missing data on relevant outcomes. Dating violence and sexual violence acceptance were the primary outcomes for this analysis. At the school level, slopes from linear mixed models using averaged school-level dating violence acceptance (condition–time, p \u3c 0.001) and sexual violence acceptance (condition–time interaction, p \u3c 0.001) differed indicating a significant reduction in the violence acceptance in the intervention relative to control schools over time and specifically in years 3 and 4 when ‘Green Dot’ was fully implemented. Analyses based on student’s self-reported receipt of ‘Green Dot’ training by condition confirmed the school level finding of significant reductions in both dating violence and sexual violence acceptance in years 3 and 4 for both males and females. In this RCT we find evidence that the bystander-based violence prevention intervention ‘Green Dot’ works, as hypothesized and as implemented, to reduce acceptance of dating violence and sexual violence at the school and individual levels

Theory of high-energy emission from the pulsar/Be-star system PSR 1259−-63 I: radiation mechanisms and interaction geometry

We study the physical processes of the PSR B1259-63 system containing a 47 ms pulsar orbiting around a Be star in a highly eccentric orbit. Motivated by the results of a multiwavelength campaign during the January 1994 periastron passage of PSR B1259-63, we discuss several issues regarding the mechanism of high-energy emission. Unpulsed power law emission from the this system was detected near periastron in the energy range 1-200 keV. We find that the observed high energy emission from the PSR B1259-63 system is not compatible with accretion or propeller-powered emission. Shock-powered high-energy emission produced by the pulsar/outflow interaction is consistent with all high energy observations. By studying the evolution of the pulsar cavity we constrain the magnitude and geometry of the mass outflow outflow of the Be star. The pulsar/outflow interaction is most likely mediated by a collisionless shock at the internal boundary of the pulsar cavity. The system shows all the characteristics of a {\it binary plerion} being {\it diffuse} and {\it compact} near apastron and periastron, respectively. The PSR B1259-63 cavity is subject to different radiative regimes depending on whether synchrotron or inverse Compton (IC) cooling dominates the radiation of electron/positron pairs advected away from the inner boundary of the pulsar cavity. The highly non-thermal nature of the observed X-ray/gamma-ray emission near periastron establishes the existence of an efficient particle acceleration mechanism within a timescale shown to be less than $\sim 10^2-10^3$ s. A synchrotron/IC model of emission of e\pm-pairs accelerated at the inner shock front of the pulsar cavity and adiabatically expanding in the MHD flow provides an excellent explanation of the observed time variableX-ray flux and spectrum from the PSRComment: 68 pages, accepted for publication in the Astrophys. J. on Aug. 26, 199

EGRET Gamma-Ray Observations of the Crab P2/P1 Ratio

Recent observations of the Crab pulsar by the Energetic Gamma-Ray Experiment Telescope (EGRET) on the Compton Gamma Ray Observatory show that the high-energy gamma-ray light curve has changed little over the lifetime of the instrument. Previous data collected by SAS-2 and COS-B in the years 1972-82, along with earlier EGRET data, suggested a 14 year sinusoidal variation in the flux ratio between the first and second peaks. The new data from EGRET indicate that the flux ratio is constant.Comment: 6 pages, 3 figures. To be published in Ap

Late Glacial and Holocene records of tree-killing conifer bark beetles in Europe and North America: Implications for forest disturbance dynamics

Outbreaks of conifer bark beetles in Europe and North America have increased in scale and severity in recent decades. In this study, we identify existing fossil records containing bark beetle remains from the end of the Last Glacial Maximum (~14,000 cal. yr BP) to present day using the online databases Neotoma and BugsCEP and literature searches, and compare these data with modern distribution data of selected tree-killing species. Modern-day observational data from the Global Biodiversity Information Facility (GBIF) database was used to map recorded distributions from AD 1750 to present day. A total of 53 fossil sites containing bark beetle remains, from both geological and archeological sites, were found during our searches. Fossil sites were fewer in Europe (n = 21) than North America (n = 32). In Europe, 29% of the samples in which remains were found were younger than 1000 cal. yr BP, while in North America, remains were mainly identified from late Glacial (~14,000–11,500 cal. yr BP) sites. In total, the fossil records contained only 8 of 20 species we consider important tree-killing bark beetles in Europe and North America based on their impacts during the last 100 years. In Europe, Ips sexdentatus was absent from the fossil record. In North America, Dendroctonus adjunctus, Dendroctonus frontalis, Dendroctonus jeffreyi, Dendroctonus pseudotsugae, Dryocoetes confusus, Ips calligraphus, Ips confusus, Ips grandicollis, Ips lecontei, Ips paraconfusus, and Scolytus ventralis were absent. Overall, preserved remains of tree-killing bark beetles are rare in the fossil record. However, by retrieving bulk material from new and existing sites and combining data from identified bark beetle remains with pollen, charcoal, tree rings, and geochemistry, the occurrence and dominance of bark beetles, their outbreaks, and other disturbance events can be reconstructed

Newtonian Gravity and the Bargmann Algebra

We show how the Newton-Cartan formulation of Newtonian gravity can be obtained from gauging the Bargmann algebra, i.e., the centrally extended Galilean algebra. In this gauging procedure several curvature constraints are imposed. These convert the spatial (time) translational symmetries of the algebra into spatial (time) general coordinate transformations, and make the spin connection gauge fields dependent. In addition we require two independent Vielbein postulates for the temporal and spatial directions. In the final step we impose an additional curvature constraint to establish the connection with (on-shell) Newton-Cartan theory. We discuss a few extensions of our work that are relevant in the context of the AdS-CFT correspondence.Comment: Latex, 20 pages, typos corrected, published versio

New constraints on Planck-scale Lorentz Violation in QED from the Crab Nebula

We set constraints on O(E/M) Lorentz Violation in QED in an effective field theory framework. A major consequence of such assumptions is the modification of the dispersion relations for electrons/positrons and photons, which in turn can affect the electromagnetic output of astrophysical objects. We compare the information provided by multiwavelength observations with a full and self-consistent computation of the broad-band spectrum of the Crab Nebula. We cast constraints of order 10^{-5} at 95% confidence level on the lepton Lorentz Violation parameters.Comment: 23 pages, 9 figures. v2: added comments and references, matches version accepted by JCA

RCT Testing Bystander Effectiveness to Reduce Violence

Introduction: Bystander-based programs have shown promise to reduce interpersonal violence at colleges, yet limited rigorous evaluations have addressed bystander intervention effectiveness in high schools. This study evaluated the Green Dot bystander intervention to reduce sexual violence and related forms of interpersonal violence in 26 high schools over 5 years. Design: A cluster RCT was conducted. Setting/participants: Kentucky high schools were randomized to intervention or control (wait list) conditions. Intervention: Green Dot−trained educators conducted schoolwide presentations and recruited student popular opinion leaders to receive bystander training in intervention schools beginning in Year 1. Main outcome measures: The primary outcome was sexual violence perpetration, and related forms of interpersonal violence victimization and perpetration were also measured using anonymous student surveys collected at baseline and annually from 2010 to 2014. Because the school was the unit of analysis, violence measures were aggregated by school and year and school-level counts were provided. Results: A total of 89,707 students completed surveys. The primary, as randomized, analyses conducted in 2014–2016 included linear mixed models and generalized estimating equations to examine the condition−time interaction on violence outcomes. Slopes of school-level totals of sexual violence perpetration (condition−time, p \u3c 0.001) and victimization (condition−time, p \u3c 0.001) were different over time. During Years 3–4, when Green Dot was fully implemented, the mean number of sexual violent events prevented by the intervention was 120 in Intervention Year 3 and 88 in Year 4. For Year 3, prevalence rate ratios for sexual violence perpetration in the intervention relative to control schools were 0.83 (95% CI=0.70, 0.99) in Year 3 and 0.79 (95% CI=0.67, 0.94) in Year 4. Similar patterns were observed for sexual violence victimization, sexual harassment, stalking, and dating violence perpetration and victimization. Conclusions: Implementation of Green Dot in Kentucky high schools significantly decreased not only sexual violence perpetration but also other forms of interpersonal violence perpetration and victimization