Effect of strobilurin fungicides on control of early blight (Alternaria solani) and yield of potatoes grown under two N fertility regimes

Early blight, caused by Alternaria solani, is a ubiquitous disease that can reduce potato yield. Adequate crop fertility and appropriate fungicide applications usually suppress the development of this disease. Field trials were established in Prince Edward Island to determine whether strobilurin analogs, namely azoxystrobin and pyraclostrobin, could suppress early blight of potatoes (cvs. Shepody and Russet Burbank) grown under two nitrogen (N) fertility regimes (high or low N). Azoxystrobin and pyraclostrobin were linked to significantly higher total tuber yield for Russet Burbank in 2003 and Shepody in 2004 when compared to plots receiving no strobilurin fungicides. No significant differences in total tuber yield based on N fertility were observed, although the high N rate decreased disease in Russet Burbank control plots in 2004. Due to an absence of early blight in 2003, the increase in Russet Burbank yield may be attributed to the physiological and developmental alterations brought about by strobilurin products in treated plants. In 2004, early blight was severe in inoculated control plots, but it was significantly suppressed in plots having received azoxystrobin or pyraclostrobin, regardless of the cultivar type or fertility regime. Therefore, to prevent unnecessary N inputs, growers need to supply only the necessary N amount to optimize tuber yields and manage early blight with fungicides.L’alternariose, causée par Alternaria solani, est une maladie omniprésente qui peut réduire le rendement de la pomme de terre. Une fertilisation adéquate de la culture et l’application de fongicides appropriés suppriment généralement le développement de cette maladie. Des essais en champs ont été effectués à l’Île-du-Prince-Édouard pour déterminer si des analogues de la strobilurine, notamment l’azoxystrobine et la pyraclostrobine, pouvaient supprimer l’alternariose de la pomme de terre (cv. Shepody et Russet Burbank) cultivée sous deux régimes de fertilité azotée (forte et faible doses de N). L’azoxystrobine et la pyraclostrobine ont été associées au rendement total en tubercules significativement supérieur pour Russet Burbank en 2003 et pour Shepody en 2004, comparativement à des parcelles n’ayant reçu aucun fongicide apparenté à la strobilurine. La fertilité azotée n’a entraîné aucune différence significative du rendement, bien que la dose élevée d’azote ait significativement réduit la maladie dans les parcelles témoins de Russet Burbank en 2004. En raison de l’absence de l’alternariose en 2003, l’augmentation du rendement du cv. Russet Burbank peut être attribuée aux modifications causées par les produits de la strobilurine dans la physiologie et le développement des plantes traitées. En 2004, l’alternariose a été importante dans les parcelles témoins inoculées, mais la suppression a été significative dans les parcelles ayant reçu de l’azoxystrobine ou de la pyraclostrobine, quels que soient le cultivar ou le régime de fertilité. Ainsi, les producteurs devraient appliquer uniquement les quantités d’azote nécessaires pour optimiser les rendements en tubercules et contrôler l’alternariose avec des fongicides

Lack of Detectable HIV-1 Molecular Evolution during Suppressive Antiretroviral Therapy

A better understanding of changes in HIV-1 population genetics with combination antiretroviral therapy (cART) is critical for designing eradication strategies. We therefore analyzed HIV-1 genetic variation and divergence in patients' plasma before cART, during suppression on cART, and after viral rebound. Single-genome sequences of plasma HIV-1 RNA were obtained from HIV-1 infected patients prior to cART (N = 14), during suppression on cART (N = 14) and/or after viral rebound following interruption of cART (N = 5). Intra-patient population diversity was measured by average pairwise difference (APD). Population structure was assessed by phylogenetic analyses and a test for panmixia. Measurements of intra-population diversity revealed no significant loss of overall genetic variation in patients treated for up to 15 years with cART. A test for panmixia, however, showed significant changes in population structure in 2/10 patients after short-term cART (<1 year) and in 7/10 patients after long-term cART (1-15 years). The changes consisted of diverse sets of viral variants prior to cART shifting to populations containing one or more genetically uniform subpopulations during cART. Despite these significant changes in population structure, rebound virus after long-term cART had little divergence from pretherapy virus, implicating long-lived cells infected before cART as the source for rebound virus. The appearance of genetically uniform virus populations and the lack of divergence after prolonged cART and cART interruption provide strong evidence that HIV-1 persists in long-lived cells infected before cART was initiated, that some of these infected cells may be capable of proliferation, and that on-going cycles of viral replication are not evident

A single-label phenylpyrrolocytidine provides a molecular beacon-like response reporting HIV-1 RT RNase H activity

6-Phenylpyrrolocytidine (PhpC), a structurally conservative and highly fluorescent cytidine analog, was incorporated into oligoribonucleotides. The PhpC-containing RNA formed native-like duplex structures with complementary DNA or RNA. The PhpC-modification was found to act as a sensitive reporter group being non-disruptive to structure and the enzymatic activity of RNase H. A RNA/DNA hybrid possessing a single PhpC insert was an excellent substrate for HIV-1 RT Ribonuclease H and rapidly reported cleavage of the RNA strand with a 14-fold increase in fluorescence intensity. The PhpC-based assay for RNase H was superior to the traditional molecular beacon approach in terms of responsiveness, rapidity and ease (single label versus dual). Furthermore, the PhpC-based assay is amenable to high-throughput microplate assay format and may form the basis for a new screen for inhibitors of HIV-RT RNase H

Results from a Fermilab neutrino beam dump experiment

The flux of prompt neutrinos from a beam dump has been measured in an experiment at the Fermi National Accelerator Laboratory (E613). Assuming that the charm production has a linear dependence on atomic number and varies as (1−‖×‖)5 e−2mT, a model dependent cross section of 27±5μb/nucleon can be derived. For neutrino energies greater than 20 GeV, the flux of electron neutrinos with respect to muon neutrinos is 0.78±0.19. For neutrinos with energy greater than 30 GeV and p⟂ greater than 0.2, the flux of ν̄u compared to νμ is 0.96±0.22.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87363/2/100_1.pd

Ortervirales: A new viral order unifying five families of reverse-transcribing viruses

Reverse-transcribing viruses, which synthesize a copy of genomic DNA from an RNA template, are widespread in animals, plants, algae and fungi (1, 2).

Prompt Neutrino Results from Fermi Lab

Results from a Fermi lab experiment to study prompt neutrino production are presented. Assuming the prompt neutrinos come from the decay of charmed mesons we find a total DD production cross section of approx. 20 μb/nucleon, in good agreement with previous CERN results. We find a ν/ν ratio and a νe/νμ of approx. 1.0. The energy and pT spectra of the prompt neutrinos are consistent with those expected from DD production. Limits on the production of supersymmetric particles have also been obtained.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87356/2/262_1.pd

FLRT3 is expressed in sensory neurons after peripheral nerve injury and regulates neurite outgrowth

We used a molecular screen to identify genes upregulated in regenerating adult rat dorsal root ganglion cells. FLRT3 mRNA and protein characterized by a fibronectin type III domain and a leucine-rich repeat motif was upregulated in damaged sensory neurons. The protein was then transported into their peripheral and central processes where the FLRT3 protein was localized to presynaptic axon terminals. In vitro, the FLRT3 protein was expressed at the cell surface, regulated neurite outgrowth in sensory neurons, but did not exhibit homophilic binding. FLRT3 was widely expressed in the developing embryo, particularly in the central nervous system and somites. However, in the adult, we found no evidence for accumulation or reexpression of the FLRT3 protein in damaged axons of the central nervous system. We conclude that FLRT3 codes for a putative cell surface receptor implicated in both the development of the nervous system and in the regeneration of the peripheral nervous system (PNS).This work was supported by the MRC and MNDA.Peer reviewe

Measurements of ϕ\phi meson production in relativistic heavy-ion collisions at RHIC

We present results for the measurement of $\phi$ meson production via its charged kaon decay channel $\phi \to K^+K^-$ in Au+Au collisions at $\sqrt{s_{_{NN}}}=62.4$, 130, and 200 GeV, and in $p+p$ and $d$+Au collisions at $\sqrt{s_{_{NN}}}=200$ GeV from the STAR experiment at the BNL Relativistic Heavy Ion Collider (RHIC). The midrapidity ($|y|<0.5$) $\phi$ meson transverse momentum ($p_{T}$) spectra in central Au+Au collisions are found to be well described by a single exponential distribution. On the other hand, the $p_{T}$ spectra from $p+p$, $d$+Au and peripheral Au+Au collisions show power-law tails at intermediate and high $p_{T}$ and are described better by Levy distributions. The constant $\phi/K^-$ yield ratio vs beam species, collision centrality and colliding energy is in contradiction with expectations from models having kaon coalescence as the dominant mechanism for $\phi$ production at RHIC. The $\Omega/\phi$ yield ratio as a function of $p_{T}$ is consistent with a model based on the recombination of thermal $s$ quarks up to $p_{T}\sim 4$ GeV/$c$, but disagrees at higher transverse momenta. The measured nuclear modification factor, $R_{dAu}$, for the $\phi$ meson increases above unity at intermediate $p_{T}$, similar to that for pions and protons, while $R_{AA}$ is suppressed due to the energy loss effect in central Au+Au collisions. Number of constituent quark scaling of both $R_{cp}$ and $v_{2}$ for the $\phi$ meson with respect to other hadrons in Au+Au collisions at $\sqrt{s_{_{NN}}}$=200 GeV at intermediate $p_{T}$ is observed. These observations support quark coalescence as being the dominant mechanism of hadronization in the intermediate $p_{T}$ region at RHIC.Comment: 22 pages, 21 figures, 4 table

Enhanced strange baryon production in Au+Au collisions compared to p+p at sqrts = 200 GeV

We report on the observed differences in production rates of strange and multi-strange baryons in Au+Au collisions at sqrts = 200 GeV compared to pp interactions at the same energy. The strange baryon yields in Au+Au collisions, then scaled down by the number of participating nucleons, are enhanced relative to those measured in pp reactions. The enhancement observed increases with the strangeness content of the baryon, and increases for all strange baryons with collision centrality. The enhancement is qualitatively similar to that observed at lower collision energy sqrts =17.3 GeV. The previous observations are for the bulk production, while at intermediate pT, 1 < pT< 4 GeV/c, the strange baryons even exceed binary scaling from pp yields.Comment: 7 pages, 4 figures. Printed in PR