GALL INDUCTION BY PEGOMYA CURTICORNIS (STEIN) (DIPTERA: ANTHOMYIIDAE) WITHIN THE ROOTS OF SPURGES EUPHORBIA VIRGATA WALDST. AND KIT. AND E. ESULA L. (EUPHORBIACEAE)

The anthomyiid fly Pegomya curticornis (Stein), introduced into Alberta from Europe for the biocontrol of leafy spurge (Euphorbia esula L.), normally induces simple galls on subterranean stems. Here we describe the anatomy of galls collected in Europe that had been induced by P. curticornis on horizontal roots of spurges. Four mature galls were found on the roots of E. virgata Waldst. and Kit. and 10 on the roots of E. esula. Tissues of the root galls were composed of gall parenchyma that had proliferated from feeding sites near the outside edge of secondary xylem. It is assumed that some larvae inadvertently tunnel beyond the base of stems into the roots and that similar galls will form on Alberta spurge

STRUCTURAL DAMAGE AND GALL INDUCTION BY PEGOMYA CURTICORNIS AND PEGOMYA EUPHORBIAE (DIPTERA: ANTHOMYIIDAE) WITHIN THE STEMS OF LEAFY SPURGE (EUPHORBIA × PSEUDOVIRGATA) (EUPHORBIACEAE)

Leafy spurge (Euphorbia × pseudovirgata [Schur]) is an herbaceous perennial and serious weed of European origin that has been accidently introduced into North America. The European anthomyiid flies Pegomya curticornis (Stein) and Pegomya euphorbiae (Kieffer) are found on several spurge species in Europe and also attack leafy spurge. The two flies induce identical galls on the subterranean stems of their host plants, and the shoots wilt and die. Eggs are laid on the shoot tip, and the larvae bore into the stem by eating pith which is later replaced by callus. This is a rare example of an insect with both boring and gall-inducing feeding strategies. Galls are induced when larvae feed on the ring of vascular tissue. There is no proliferation of nutritive cells but instead thick layers of gall parenchyma are produced. The vascular connections are broken at the gall level and concentric vascular bundles appear in the cortical and gall parenchyma. After pupation an inner periderm differentiates around the chamber surfac

Description of European Chamaesphecia spp. (Lepidoptera: Sesiidae) feeding on Euphorbia (Euphorbiaceae), and their potential for biological control of leafy spurge (Euphorbia esula) in North America

The description of the ten Chamaesphecia species associated with Euphorbia in eastern and south-eastern Europe is based on external adult morphology, male and female genitalia, and the structure of the egg chorion. These species can be divided into two groups according to the shape of the setae of the dorso-basal part of the valvae in the male genitalia. Most Chamaesphecia species are associated with one species of host-plant and all are closely tied to one habitat type. The host-plant and the structure of the egg chorion are fundamental characteristics for the determination of a few species, and very helpful for the others. All species bore into the main root of their host-plant and overwinter as larvae. With the exception of two species which have an annual or biennial life cycle, all species are univoltine. The larvae of three of the eight Chamaesphecia spp. investigated feed and develop in the roots of North American leafy spurge, Euphorbia esula sensu lato. Of these, the best candidate for the biological control of leafy spurge is C. crassicornis, because the larvae have a similar survival rate on the target weed and the European host-plant, E. virgat

AGAPETA ZOEGANA (L.) (LEPIDOPTERA: COCHYLIDAE), A SUITABLE PROSPECT FOR BIOLOGICAL CONTROL OF SPOTTED AND DIFFUSE KNAPWEED, CENTAUREA MACULOSA MONNET DE LA MARCK AND CENTAUREA DIFFUSA MONNET DE LA MARCK (COMPOSITAE) IN NORTH AMERICA

The taxonomy, distribution, life history, and host plant relationships of the cochylid moth Agapeta zoegana (L.), an oligophagous, facultatively multivoltine root feeder, are discussed. The results of oviposition and larval feeding tests with 56 plant species in five families are presented and show that A. zoegana is restricted to a few closely related species of Centaurea. In Europe the moth is widely distributed and abundant in the majority of the root-feeding guilds of Centaurea maculosa Monnet de la Marck studied, with densities of 23.6 larvae per 100 roots in eastern Austria/northwestern Hungary and less than 8 larvae per 100 roots in central Hungary and the Alsace. The acceptance of target North American species (the tetraploid form of C. maculosa and the diploid Centaurea diffusa Monnet de la Marck), the damage caused, and the active searching ability rate A. zoegana as a potentially effective natural enemy of spotted and diffuse knapweed in North America. Agapeta zoegana will be especially promising as it predominantly attacks the rosette, which is, according to a recently developed population model for diffuse knapweed in Canada, the most sensitive stage determining equilibrium knapweed density. Agapeta zoegana is compatible with Pelochrista medullana Staudinger (Lepidoptera: Cochylidae), another knapweed root feeder recently introduced into North America, and will complement the seed-feeding species already established. The moth was approved for release in Canada and the USA and has been established in British Columbia since 1984 on C. diffus

Quantum Dissipative Dynamics of the Magnetic Resonance Force Microscope in the Single-Spin Detection Limit

We study a model of a magnetic resonance force microscope (MRFM) based on the cyclic adiabatic inversion technique as a high-resolution tool to detect single electron spins. We investigate the quantum dynamics of spin and cantilever in the presence of coupling to an environment. To obtain the reduced dynamics of the combined system of spin and cantilever, we use the Feynman-Vernon influence functional and get results valid at any temperature as well as at arbitrary system-bath coupling strength. We propose that the MRFM can be used as a quantum measurement device, i.e., not only to detect the modulus of the spin but also its direction

A method for determining gas-hydrate or free-gas saturation of porous media from seismic measurements

The occurrence of gas hydrate or free gas in a porous medium changes the medium’s elastic properties. Explicit formulas for gas-hydrate or free-gas saturation of pore space on the basis of the Frenkel-Gassmann equations describe the elastic moduli and seismic velocities of a porous medium for low frequencies. A key assumption of the model is that either gas hydrate or free gas is present in the pore space in addition to water. Under this assumption, the method uses measured P- and S-wave velocities and bulk density along with estimates of the moduli and densities of the solid and fluid phases present to determine whether gas or hydrate is present. The method then determines the saturation level of either the gas or the hydrate. I apply the method to published velocity and density data from seismic studies at the antarctic Shetland margin and at the Storegga slide, offshore Norway, and to borehole log and core data from Ocean Drilling Program (ODP) Leg 164 at Blake Ridge, offshore South Carolina. A sensitivity analysis reveals that the standard deviations of the gas-hydrate and free-gas saturations reach 30%–70% of the saturations if the standard deviations of the P- and S-wave velocities and of the bulk density are 50m∕s ..

Non-Markoffian effects of a simple nonlinear bath

We analyze a model of a nonlinear bath consisting of a single two-level system coupled to a linear bath (a classical noise force in the limit considered here). This allows us to study the effects of a nonlinear, non-Markoffian bath in a particularly simple situation. We analyze the effects of this bath onto the dynamics of a spin by calculating the decay of the equilibrium correlator of the spin's z-component. The exact results are compared with those obtained using three commonly used approximations: a Markoffian master equation for the spin dynamics, a weak-coupling approximation, and the substitution of a linear bath for the original nonlinear bath.Comment: 7 pages, 6 figure

Post-acute delivery of erythropoietin induces stroke recovery by promoting perilesional tissue remodelling and contralesional pyramidal tract plasticity

The promotion of post-ischaemic motor recovery remains a major challenge in clinical neurology. Recently, plasticity-promoting effects have been described for the growth factor erythropoietin in animal models of neurodegenerative diseases. To elucidate erythropoietin's effects in the post-acute ischaemic brain, we examined how this growth factor influences functional neurological recovery, perilesional tissue remodelling and axonal sprouting of the corticorubral and corticobulbar tracts, when administered intra-cerebroventricularly starting 3 days after 30 min of middle cerebral artery occlusion. Erythropoietin administered at 10 IU/day (but not at 1 IU/day), increased grip strength of the contralesional paretic forelimb and improved motor coordination without influencing spontaneous locomotor activity and exploration behaviour. Neurological recovery by erythropoietin was associated with structural remodelling of ischaemic brain tissue, reflected by enhanced neuronal survival, increased angiogenesis and decreased reactive astrogliosis that resulted in reduced scar formation. Enhanced axonal sprouting from the ipsilesional pyramidal tract into the brainstem was observed in vehicle-treated ischaemic compared with non-ischaemic animals, as shown by injection of dextran amines into both motor cortices. Despite successful remodelling of the perilesional tissue, erythropoietin enhanced axonal sprouting of the contralesional, but not ipsilesional pyramidal tract at the level of the red and facial nuclei. Moreover, molecular biological and histochemical studies revealed broad anti-inflammatory effects of erythropoietin in both hemispheres together with expression changes of plasticity-related molecules that facilitated contralesional axonal growth. Our study establishes a plasticity-promoting effect of erythropoietin after stroke, indicating that erythropoietin acts via recruitment of contralesional rather than of ipsilesional pyramidal tract projection

Spectroscopic evidence of anthropogenic compounds extraction from polymers by fluorescent dissolved organic matter in natural water

FDOM is one of the most important carriers of anthropogenic compounds in natural waters. It can combine with environmental contaminants and polymers to form diverse chemical structures. To this end, here a microfluidic chip was designed for the analysis of these changes in fluorescent dissolved organic matter (FDOM) fingerprints due to thermal treatment and varying time intervals of exposure. Excitation Emission Matrix Spectroscopy (EEMS) approach was utilized to detect and identify the inherent compounds in sampled FDOM. Strong direct correlations were founded, Spearman rank correlation values (ρ = 0.85 at α = 0.1, n = 4) and linear correlation R² = 0.8359 were noted between thermal treatment pattern 2 and fluorescence intensity of samples. Materials, acrylic based glue and cyclic olefin copolymer (COC) polymer, used to design the microfluidic sensor were determined to possess unique spectral features in the ultraviolet to green spectrum using EEMS. The study therefore provides an insight on methods to identify contaminants in natural waters. This underlines the potential of optical sensors providing measurements at fast intervals, enabling environmental monitoring

CRISPR/Cas9-Based Gene Editing Using Egg Cell-Specific Promoters in Arabidopsis and Soybean

CRISPR/Cas9-based systems are efficient genome editing tools in a variety of plant species including soybean. Most of the gene edits in soybean plants are somatic and non-transmissible when Cas9 is expressed under control of constitutive promoters. Tremendous effort, therefore, must be spent to identify the inheritable edits occurring at lower frequencies in plants of successive generations. Here, we report the development and validation of genome editing systems in soybean and Arabidopsis based on Cas9 driven under four different egg-cell specific promoters. A soybean ubiquitin gene promoter driving expression of green fluorescent protein (GFP) is incorporated in the CRISPR/Cas9 constructs for visually selecting transgenic plants and transgene-evicted edited lines. In Arabidopsis, the four systems all produced a collection of mutations in the T2 generation at frequencies ranging from 8.3 to 42.9%, with egg cell-specific promoter AtEC1.2e1.1p being the highest. In soybean, function of the gRNAs and Cas9 expressed under control of the CaMV double 35S promoter (2x35S) in soybean hairy roots was tested prior to making stable transgenic plants. The 2x35S:Cas9 constructs yielded a high somatic mutation frequency in soybean hairy roots. In stable transgenic soybean T1 plants, AtEC1.2e1.1p:Cas9 yielded a mutation rate of 26.8%, while Cas9 expression driven by the other three egg cell-specific promoters did not produce any detected mutations. Furthermore, the mutations were inheritable in the T2 generation. Our study provides CRISPR gene-editing platforms to generate inheritable mutants of Arabidopsis and soybean without the complication of somatic mutagenesis, which can be used to characterize genes of interest in Arabidopsis and soybean