270 research outputs found
Flower fields and pesticide use interactively shape pollen beetle infestation and parasitism in oilseed rape fields
Pollen beetles (Brassicogethes spp.) are the main pests of oilseed rape (OSR, Brassica napus) in Europe and responsible for massive yield losses. Upcoming pesticide resistances highlight the need for other means of crop protection, such as natural pest control. Sown flower fields aim to counteract the decrease of insect biodiversity in agricultural landscapes by providing resources to ecosystem service providers. However, the optimal age and size of flower fields to increase natural pest control is still unclear. We conducted experiments on 31 OSR fields located along a gradient of landscape-scale semi-natural habitat (SNH). OSR fields were located adjacent to flower fields which differed in age, continuity and size, or adjacent to crop fields or calcareous grasslands. Pesticide-free areas were established to examine interactive effects of pesticide use and flower field characteristics. The abundance of pollen beetle adults and larvae, parasitism and superparasitism rates in OSR were recorded at increasing distances to the adjacent sites. Flower fields and calcareous grasslands increased pollen beetle parasitism when compared to OSR fields neighbouring crop fields. The threshold for effective natural pest control of 35% could be reached in the pesticide-free areas of OSR fields adjacent to calcareous grasslands and flower fields maintained continuously for at least 6 years. In pesticide-sprayed areas, pollen beetle parasitism and superparasitism declined with increasing distance to the adjacent field. Furthermore, flower fields larger than 1.5 ha were able to improve pollen beetle parasitism more than smaller fields. Synthesis and applications. To promote natural pest control in oilseed rape (OSR), large flower fields should be maintained for several years, to create stable habitats for natural enemies. The continuous maintenance of flower fields should be preferred, as ploughing and resowing after 5–6 years decreased the positive effects of the flower fields on natural pest control in adjacent OSR fields. However, pesticide use can abrogate positive effects of flower fields on pollen beetle parasitism. This study highlights that sown flower fields have the potential to increase natural pest control in OSR, but this potential is depending on its age, continuity and size and can be hindered by pesticide use. © 2021 The Authors. Journal of Applied Ecology published by John Wiley & Sons Ltd on behalf of British Ecological Societ
Proton Interaction Vertex Imaging With Silicon-Pixel CMOS Telescope For Carbon Therapy Quality control
International audienceMonitoring of the dose deposition during carbon ion therapy is a crucial issue for the quality control of such treatments. Recent studies have demonstrated that an ion-range control with millimeter resolution is feasible on a pencil-beam basis in homogeneous targets with prompt gamma detection for proton beams [1] and with Proton Interaction Vertex Imaging (PIVI) for carbon beams [2]. The present communication aims at describing our experimental and Monte Carlo simulation results. [1] J. Smeets et al., Phys. Med. Biol. 57 (2012) 3371-3405 [2] P. Henriquet et al., Phys. Med. Biol. 57 (2012) 4655-466
Bacterial porin disrupts mitochondrial membrane potential and sensitizes host cells to apoptosis
The bacterial PorB porin, an ATP-binding beta-barrel protein of pathogenic Neisseria gonorrhoeae, triggers host cell apoptosis by an unknown mechanism. PorB is targeted to and imported by host cell mitochondria, causing the breakdown of the mitochondrial membrane potential (delta psi m). Here, we show that PorB induces the condensation of the mitochondrial matrix and the loss of cristae structures, sensitizing cells to the induction of apoptosis via signaling pathways activated by BH3-only proteins. PorB is imported into mitochondria through the general translocase TOM but, unexpectedly, is not recognized by the SAM sorting machinery, usually required for the assembly of beta-barrel proteins in the mitochondrial outer membrane. PorB integrates into the mitochondrial inner membrane, leading to the breakdown of delta psi m. The PorB channel is regulated by nucleotides and an isogenic PorB mutant defective in ATP-binding failed to induce delta psi m loss and apoptosis, demonstrating that dissipation of delta psi m is a requirement for cell death caused by neisserial infection
The helicity amplitudes A and A for the D resonance obtained from the reaction}
The helicity dependence of the reaction
has been measured for the first time in the photon energy range from 550 to 790
MeV. The experiment, performed at the Mainz microtron MAMI, used a
4-detector system, a circularly polarized, tagged photon beam, and a
longitudinally polarized frozen-spin target. These data are predominantly
sensitive to the resonance and are used to determine its
parameters.Comment: 5 pages, 4 figure
Development of a concept and basis for the DEMO diagnostic and control system
An initial concept for the plasma diagnostic and control (D&C) system has been developed as part of European studies towards the development of a demonstration tokamak fusion reactor (DEMO). The main objective is to develop a feasible, integrated concept design of the DEMO D&C system that can provide reliable plasma control and high performance (electricity output) over extended periods of operation. While the fusion power is maximized when operating near to the operational limits of the tokamak, the reliability of operation typically improves when choosing parameters significantly distant from these limits. In addition to these conflicting requirements, the D&C development has to cope with strong adverse effects acting on all in vessel components on DEMO (harsh neutron environment, particle fluxes, temperatures, electromagnetic forces, etc.). Moreover, space allocation and plasma access are constrained by the needs for first wall integrity and optimization of tritium breeding. Taking into account these boundary conditions, the main DEMO plasma control issues have been formulated, and a list of diagnostic systems and channels needed for plasma control has been developed, which were selected for their robustness and the required coverage of control issues. For a validation and refinement of this concept, simulation tools are being refined and applied for equilibrium, kinetic and mode control studies
First measurement of the Gerasimov-Drell-Hearn integral for Hydrogen from 200 to 800 MeV
A direct measurement of the helicity dependence of the total photoabsorption
cross section on the proton was carried out at MAMI (Mainz) in the energy range
200 < E_gamma < 800 MeV. The experiment used a 4 detection system, a
circularly polarized tagged photon beam and a frozen spin target.
The contributions to the Gerasimov-Drell-Hearn sum rule and to the forward
spin polarizability determined from the data are 226 \pm 5 (stat)\pm
12(sys) \mu b and -187 \pm 8 (stat)\pm 10(sys)10^{-6} fm^4, respectively, for
200 < E_\gamma < 800 MeV.Comment: 6 pages, 3 figures, 3 table
Targeting a Versatile Actuator for EU-DEMO: Real Time Monitoring of Pellet Delivery to Facilitate Burn Control
Core particle fueling, an essential task in the European demonstration fusion power plant EU-DEMO, relies on adequate pellet injection. However, pellets are fragile objects, and their delivery efficiency can hardly be assumed to be unity. Exploring kinetic control of the EU-DEMO1 scenario indicates that such missed-out pellets do cause a considerable problem for keeping a burning plasma. Missed-out pellets can cause a severe drop of plasma density that in turn results in a potential drastic loss of burn power. Efforts are under way at the ASDEX Upgrade (AUG) tokamak aiming to provide real-time monitoring of pellet arrival and announcement of missed-out cases to the control systems. To further optimize the controllers, system identification experiments have been performed to identify the dynamic response of the system to the actuator
Wyniki leczenia topiramatem padaczki u osób w podeszłym wieku
Cele. Ocena skuteczności, tolerancji i jakości życia u starszych
pacjentów z padaczką, leczonych topiramatem. Metody. Otwarte,
trwające rok badanie kliniczne z elastycznym dawkowaniem. Wyniki.
Przebadano 107 pacjentów (średni wiek 69 lat; 53% mężczyzn) przez okres 273 ± 141 dni. Średnia dawka, którą osiąga-
no ostatecznie w monoterapii, wynosiła 98 mg/dobę - w porównaniu z 153 mg/dobę w ramach leczenia wspomagającego. Średnia skumulowana miesięczna częstość napadów padaczkowych
zmniejszyła się z 3,7 ± 15 do 1,6 ± 7,7 (n = 101; p < 0,0001).
U 78% pacjentów z napadami padaczkowymi w momencie rozpoczęcia badania (n = 102) osiągnięto przynajmniej 50-procentową
redukcję częstości napadów, 44% nie miało napadów w okresie
badania. Całkowita punktacja w skali jakości Ŝycia osób z padaczką (QOLIE-31) poprawiła się z 57 ± 17 na 68 ± 18 (n = 64;
p < 0,0001). Najczęściej zgłaszanymi zdarzeniami niepożądanymi były drgawki, zawroty głowy i zmęczenie. Wnioski. Pacjenci
w starszym wieku leczeni topiramatem osiągali wyraźne zmniejszenie liczby napadów padaczkowych i istotną poprawę w zakresie licznych aspektów jakości życia przy dobrej tolerancji leku
Using ecological and field survey data to establish a national list of the wild bee pollinators of crops
The importance of wild bees for crop pollination is well established, but less is known about which species contribute to service delivery to inform agricultural management, monitoring and conservation. Using sites in Great Britain as a case study, we use a novel qualitative approach combining ecological information and field survey data to establish a national list of crop pollinating bees for four economically important crops (apple, field bean, oilseed rape and strawberry). A traits data base was used to establish potential pollinators, and combined with field data to identify both dominant crop flower visiting bee species and other species that could be important crop pollinators, but which are not presently sampled in large numbers on crops flowers. Whilst we found evidence that a small number of common, generalist species make a disproportionate contribution to flower visits, many more species were identified as potential pollinators, including rare and specialist species. Furthermore, we found evidence of substantial variation in the bee communities of different crops. Establishing a national list of crop pollinators is important for practitioners and policy makers, allowing targeted management approaches for improved ecosystem services, conservation and species monitoring. Data can be used to make recommendations about how pollinator diversity could be promoted in agricultural landscapes. Our results suggest agri-environment schemes need to support a higher diversity of species than at present, notably of solitary bees. Management would also benefit from targeting specific species to enhance crop pollination services to particular crops. Whilst our study is focused upon Great Britain, our methodology can easily be applied to other countries, crops and groups of pollinating insects.LH was funded by NERC QMEE CDT. EJB was funded by a BBSRC Ph.D. studentship under grant BB/F016581/1. LB was was supported by the Scholarship Program of the German Federal Environmental Foundation (Deutsche Bundesstiftung Umwelt, DBU, AZ 20014/302). AJC was funded by the BBSRC and Syngenta UK as part of a case award Ph.D. (grant no. 1518739). AE was funded by the Swiss National Science Foundation (grant number 405940-115642). DG and A-MK were funded by grant PCIN2014-145-C02-02 (MinECo; EcoFruit project BiodivERsA-FACCE2014-74). MG was supported by Establishing a UK Pollinator Monitoring and Research Partnership (PMRP) a collaborative project funded by Defra, the Welsh and Scottish Governments, JNCC and project partners’. GAdG was funded via research projects BO-11-011.01-051 and BO-43-011.06-007, commissioned by the Dutch Ministry of Agriculture, Nature and Food Quality. DK was funded by the Dutch Ministry of Economic Affairs (BO-11-011.01-011). AK-H was funded by the NKFIH project (FK123813), the Bolyai János Fellowship of the MTA, the ÚNKP-19-4-SZIE-3 New National Excellence Program of the Ministry for Innovation and Technology, and together with RF by the Hungarian Scientific Research Fund OTKA 101940. MM was funded by Waitrose & Partners, Fruition PO, and the University of Worcester. MM was funded by grant INIA-RTA2013-00139-C03-01 (MinECo and FEDER). BBP and RFS were funded by the UK Natural Environment Research Council as part of Wessex BESS (ref. NE/J014680/1). NJV was funded by the Walloon Region (Belgium) Direction générale opérationnelle de l’Agriculture, des Ressources naturelles et de l’Environnement (DGO3) for the "Modèle permaculturel" project on biodiversity in micro-farms, FNRS/FWO joint programme EOS — Excellence Of Science CliPS: Climate change and its impact on Pollination Services (project 30947854)". CW was funded by the Deutsche Forschungsgemeinschaft (DFG) (Project number 405945293). BW was funded by the Natural Environment Research Council (NERC) under research programme NE/N018125/1 ASSIST – Achieving Sustainable Agricultural Systems www.assist.ceh.ac.uk. TB and TO are supported by BBSRC, NERC, ESRC and the Scottish Government under the Global Food Security Programme (Grant BB/R00580X/1)
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