Progress in the development of a biopesticide for the structural treatment of grain stores

Chemical insecticides are used to protect stored grain from infestation by stored product insects and mites. In the UK only a limited number of products are available for application and there are concerns about safety, pest resistance and environmental impact of these conventional pesticides. Biological control offers an alternative to the use of chemical insecticides. The potential for biological control of storage pests in the UK using an insect-specific fungus, Beauveria bassiana, to treat the structure of the stores, has previously been established. However, this study also highlighted areas where improvements were needed; specifically to improve the uptake of the fungal conidia by the pests and to improve their germination and penetration into the pests. In addition it was necessary to ensure that potential formulations had a good shelf-life and to develop a mass production method to consistently produce high quality fungal conidia. A four year project has recently been completed examining these  areas in detail. The work has concentrated on two different fungal isolates of B. bassiana, both of which were found from insects in UK grain stores. Optimisation of production methods, formulation and delivery systems has resulted in prototype formulations that exhibit good viability over periods up to one year and that have good efficacy against a range of storage insect pests under conditions that are likely to be found in UK grain stores. Pilot scale trials using three species of stored product beetle have shown that significant levels of control can be achieved. An overview of the key findings is presented. The study has made a significant contribution to the development of a biopesticide as a structural treatment for grain storage areas in the UK.Keywords: Biological control; Beauveria bassiana; Oryzaephilus surinamensis; Structural treatment; Biopesticid

First experimental results of very high accuracy centroiding measurements for the neat astrometric mission

NEAT is an astrometric mission proposed to ESA with the objectives of detecting Earth-like exoplanets in the habitable zone of nearby solar-type stars. NEAT requires the capability to measure stellar centroids at the precision of 5e-6 pixel. Current state-of-the-art methods for centroid estimation have reached a precision of about 2e-5 pixel at two times Nyquist sampling, this was shown at the JPL by the VESTA experiment. A metrology system was used to calibrate intra and inter pixel quantum efficiency variations in order to correct pixelation errors. The European part of the NEAT consortium is building a testbed in vacuum in order to achieve 5e-6 pixel precision for the centroid estimation. The goal is to provide a proof of concept for the precision requirement of the NEAT spacecraft. In this paper we present the metrology and the pseudo stellar sources sub-systems, we present a performance model and an error budget of the experiment and we report the present status of the demonstration. Finally we also present our first results: the experiment had its first light in July 2013 and a first set of data was taken in air. The analysis of this first set of data showed that we can already measure the pixel positions with an accuracy of about 1e-4 pixel.Comment: SPIE conference proceeding

A detector interferometric calibration experiment for high precision astrometry

Context: Exoplanet science has made staggering progress in the last two decades, due to the relentless exploration of new detection methods and refinement of existing ones. Yet astrometry offers a unique and untapped potential of discovery of habitable-zone low-mass planets around all the solar-like stars of the solar neighborhood. To fulfill this goal, astrometry must be paired with high precision calibration of the detector. Aims: We present a way to calibrate a detector for high accuracy astrometry. An experimental testbed combining an astrometric simulator and an interferometric calibration system is used to validate both the hardware needed for the calibration and the signal processing methods. The objective is an accuracy of 5e-6 pixel on the location of a Nyquist sampled polychromatic point spread function. Methods: The interferometric calibration system produced modulated Young fringes on the detector. The Young fringes were parametrized as products of time and space dependent functions, based on various pixel parameters. The minimization of func- tion parameters was done iteratively, until convergence was obtained, revealing the pixel information needed for the calibration of astrometric measurements. Results: The calibration system yielded the pixel positions to an accuracy estimated at 4e-4 pixel. After including the pixel position information, an astrometric accuracy of 6e-5 pixel was obtained, for a PSF motion over more than five pixels. In the static mode (small jitter motion of less than 1e-3 pixel), a photon noise limited precision of 3e-5 pixel was reached

Isomeric pair 95m,gNb{^{95\rm m,g}\rm{Nb}} in photonuclear reactions on nat^{\rm nat}Mo at end-point bremsstrahlung energy of 35-95 MeV

The ${^{\rm nat}\rm{Mo}}(\gamma,x\rm np)^{95\rm m,g}$Nb photonuclear reaction was studied using the electron beam from the NSC KIPT linear accelerator LUE-40. Experiment was performed using the activation and off-line $\gamma$-ray spectrometric technique. The experimental isomeric yield ratio $d(E_{\rm{\gamma max}}) = Y_{\rm m}(E_{\rm{\gamma max}}) / Y_{\rm g}(E_{\rm{\gamma max}})$ was determined for the reaction products $^{95\rm m,g}\rm{Nb}$ at the end-point bremsstrahlung energy $E_{\rm{\gamma max}}$ range of 35-95 MeV. The obtained values of $d(E_{\rm{\gamma max}})$ are in satisfactory agreement with the results of other authors and extend the range of previously known data. The theoretical values of the yields $Y_{\rm m,g}(E_{\rm{\gamma max}})$ and the isomeric yield ratio $d(E_{\rm{\gamma max}})$ for the isomeric pair $^{95\rm m,g}\rm{Nb}$ from the ${^{\rm nat}\rm{Mo}}(\gamma,x\rm np)$ reaction were calculated using the partial cross-sections $\sigma(E)$ from the TALYS1.95 code for six different level density models $LD$. The comparison showed a noticeable excess (more than 3.85 times) of the experimental isomeric yield ratio over all theoretical estimates. At the investigated range of $E_{\rm{\gamma max}}$ the theoretical dependence of $d(E_{\rm{\gamma max}})$ on energy was confirmed - the isomeric yield ratio smoothly decreases with increasing energy.Comment: 9 pages, 9 figures, 1 tabl

Production of 180m{^{180\rm{m}}}Hf in photoproton reaction 181{^{181}}Ta(γ,p)(\gamma,p) at energy EγmaxE_{\rm{\gamma max}} = 35-95 MeV

The production of the $^{180\rm{m}}\rm{Hf}$ nuclei in the photoproton reaction ${^{181}\rm{Ta}}(\gamma,p)$ was studied at end-point bremsstrahlung energies $E_{\rm{\gamma max}}$ = 35-95 MeV. The experiment was performed at the electron linear accelerator LUE-40 NSC KIPT with the use of the $\gamma$ activation and off-line $\gamma$-ray spectroscopy. The experimental values of the bremsstrahlung flux-averaged cross-sections $\langle{\sigma(E_{\rm{\gamma max}})}\rangle_{\rm{m}}$ for the ${^{181}\rm{Ta}}(\gamma,p)^{180\rm{m}}\rm{Hf}$ reaction were determined, and at $E_{\rm{\gamma max}} > 55$ MeV obtained for the first time. The measured values, also as the literature data, are significantly exceed the theoretical flux-averaged cross-sections $\langle{\sigma(E_{\rm{\gamma max}})}\rangle_{\rm{th}}$. The $\langle{\sigma(E_{\rm{\gamma max}})}\rangle_{\rm{th}}$ values were calculated using the cross-section $\sigma(E)$ computed with the TALYS1.95 code for six different level density models. A comparative analysis of the calculated total cross-sections for the reactions ${^{181}\rm{Ta}}(\gamma,p)^{180}\rm{Hf}$ and ${^{181}\rm{Ta}}(\gamma,n)^{180}\rm{Ta}$ was performed. It was shown that the photoproton $(\gamma,p)$ to photoneutron $(\gamma,n)$ strength ratio is consistent with the estimates based on the isospin selection rules and the value from the $(e,e'p)$ experiment.Comment: 9 pages, 4 figures, 2 table

Photonuclear reactions cross-sections at energies up to 100 MeV for different experimental setups

In experiments on the electron linac LUE-40 of RDC "Accelerator" NSC KIPT, the flux-averaged cross-sections $\langle{\sigma(E_{\rm{\gamma max}})}\rangle_{\rm{exp}}$ of photonuclear reactions ${^{100}\rm{Mo}}(\gamma,n)^{99}\rm{Mo}$, ${^{27}\rm{Al}}(\gamma,x)^{24}\rm{Na}$, ${^{93}\rm{Nb}}(\gamma,n)^{92m}\rm{Nb}$, ${^{93}\rm{Nb}}(\gamma,3n)^{90}\rm{Nb}$, and ${^{181}\rm{Ta}}(\gamma,n)^{180g}\rm{Ta}$ were measured using the $\gamma$-activation technique. The theoretical flux-average cross-sections $\langle{\sigma(E_{\rm{\gamma max}})}\rangle_{\rm{th}}$ were computed using the partial cross-section $\sigma(E)$ values from the TALYS1.9-1.95 codes and bremsstrahlung $\gamma$-flux calculated using GEANT4.9.2. Two different experimental setups were used in the experiments: an aluminum electron absorber and a deflecting magnet to clean the bremsstrahlung $\gamma$-flux from electrons. A comparison of the flux-average cross-sections measured for two experimental setups was performed. The possibility of using the reactions ${^{100}\rm{Mo}}(\gamma,n)^{99}\rm{Mo}$, ${^{27}\rm{Al}}(\gamma,x)^{24}\rm{Na}$, ${^{93}\rm{Nb}}(\gamma,n)^{92m}\rm{Nb}$, ${^{93}\rm{Nb}}(\gamma,3n)^{90}\rm{Nb}$, and ${^{181}\rm{Ta}}(\gamma,n)^{180g}\rm{Ta}$ as monitors of the bremsstrahlung $\gamma$-flux for the energy range 30-100 MeV was investigated.Comment: 8 pages, 6 figures, 1 tabl

Report of the expert meeting on food safety for seaweed – Current status and future perspectives

The world production of marine macroalgae, or seaweed, has more than tripled since the turn of the millennium, increasing from 10.6 million tonnes in 2000 to 32.4 million tonnes in 2018. Increased cultivation and utilization of seaweed are expected to be important pillars of sustainable food security and a robust aquatic economy in the coming years. It is important, therefore, to consider the food safety implications of (increased) seaweed use for food. Many factors can affect the presence of hazards in seaweed, including: the type of seaweed, its physiology, the season in which it is produced, production waters, harvesting methods and processing. Several hazards such as heavy metals and marine biotoxins have been reported to be (potentially) associated with seaweed. However, legislation and guidance documents on the production and utilization of seaweed are generally still lacking. FAO and the World Health Organization (WHO) have therefore developed this report to identify food safety hazards (microbiological, chemical and physical) linked to the consumption of seaweed and aquatic plants. The present analysis could therefore provide a basis for undertaking further work in this area. Moreover, both FAO and WHO believe that there would be a value in developing relevant Codex guidance on this subject.publishedVersio

Report of the expert meeting on food safety for seaweed – Current status and future perspectives

The world production of marine macroalgae, or seaweed, has more than tripled since the turn of the millennium, increasing from 10.6 million tonnes in 2000 to 32.4 million tonnes in 2018. Increased cultivation and utilization of seaweed are expected to be important pillars of sustainable food security and a robust aquatic economy in the coming years. It is important, therefore, to consider the food safety implications of (increased) seaweed use for food. Many factors can affect the presence of hazards in seaweed, including: the type of seaweed, its physiology, the season in which it is produced, production waters, harvesting methods and processing. Several hazards such as heavy metals and marine biotoxins have been reported to be (potentially) associated with seaweed. However, legislation and guidance documents on the production and utilization of seaweed are generally still lacking. FAO and the World Health Organization (WHO) have therefore developed this report to identify food safety hazards (microbiological, chemical and physical) linked to the consumption of seaweed and aquatic plants. The present analysis could therefore provide a basis for undertaking further work in this area. Moreover, both FAO and WHO believe that there would be a value in developing relevant Codex guidance on this subject

Structure and chemical bonds in reactively sputtered black Ti–C–N–O thin films

The evolution of the nanoscale structure and the chemical bonds formed in Ti–C–N–O films grown by reactive sputtering were studied as a function of the composition of the reactive atmosphere by increasing the partial pressure of an O2+N2 gas mixture from 0 up to 0.4 Pa, while that of acetylene (carbon source) was constant. The amorphisation of the films observed by transmission electron microscopy was confirmed by micro- Raman spectroscopy, but it was not the only effect associated to the increase of the O2+N2 partial pressure. The chemical environment of titanium and carbon, analysed by X-ray photoemission spectroscopy, also changes due to the higher affinity of Ti towards oxygen and nitrogen than to carbon. This gives rise to the appearance of amorphous carbon coexisting with poorly crystallized titanium oxynitride. The evolution of the films colour is explained on the basis of these structural changes.Fundação para a Ciência e a Tecnologia (FCT) - PTDC/CTM/69362/2006, SFRH/BPD/27114/2006CRUP (Acção Integrada Luso-francesa N° F-2307) and the GRICES/CNRS collaboration (Proc. 4.1.1 França