300 research outputs found

    Biological control of the cherry fruit fly, Rhagoletis cerasi L. (Diptera, Tephriti-dae) by use of entomopathogenic nematodes: first experiences towards practi-cal implementation.

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    The use of entomopathogenic nematodes (EPN) is a promising approach to control the cherry fruit fly, Rhagoletis cerasi L.. We already demonstrated the high potential of EPN to infect larvae after leaving the cherry for pupation in the soil in laboratory and field experiments. For practice, an appli-cation technique is needed, that is both, grower- and EPN friendly. We tested a tractor mounted spray boom for treatment under the canopy area. The achieved rate of EPN in the soil met the ex-pectations. The activity of EPN in soil samples was high after application, but dropped to 60% of the initial activity within one week. Exact forecasting of larval drop from cherries is another major chal-lenge. To obtain basic data, we recorded the phenology of infestation and larval emergence on trees which were not harvested. Sequential infestation on the same cherry variety was observed and larvae dropped from individual trees for several weeks

    Basic results in biological control of the European Cherry Fruit Fly Rhagoletis cerasi L. (Diptera: Tephritidae) with entomopathogenic nematodes

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    In 2002 and 2003, within the ‚Bundesprogramm Ökologischer Landbau’, initial experiments to control the European cherry fruit fly Rhagoletis cerasi were carried out under laboratory, semi-field and field conditions with several entomopathogenic nematode species and strains. In the laboratory the efficacy of nematodes against R. cerasi larvae, pupae and adults was examined. To characterize the controlling potential, different nematode dosages, exposure temperatures and substrates were tested in cell wells, petri dishes and plastic boxes. In the semi-field experiments plastic fruit boxes, filled with soil, were used. In the field tests R. cerasi-larvae and nematodes were released in defined areas in a cherry orchard of the institute. For evaluation of the experiments, the infestation rates and efficiencies (ABBOTT) were determined. Steinernema carpocapsae and S. feltiae achieved the highest efficacies. In laboratory, infestation rates in cell wells up to 91 % and efficencies up to 96 %, in petri dishes up to 96 %, respectively 98 %, and in plastic boxes 88 %, respectively 89 %, were attained. The experimental substrates like quartz sand or soil type and the tested temperatures did not result in consistent significant differences in laboratoy tests. A dosage below 25 nematodes per cm2 resulted in insufficient infestation rates. In the semi-field experiments a maximum infestation rate of 86 % (efficiency 78 %) and in a first field test an efficiency of 88 % was obtained. R. cerasipupae were not infested. These results indicate a high controlling potential of entomopathogenic nematodes against R cerasi, especially of the steinernematid species S. carpocapsae and S. feltiae. Further experiments under realistic conditions in the field are forcibly necessary before putting this control method into practice

    Two-stage membrane cascades for post-combustion CO2 capture using facilitated transport membranes: Importance on sequence of membrane types

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    The use of membrane module performance data obtained in industrially-relevant environment as the basis in process simulation can lead to a more realistic prediction of a CO2 capture system. In this work, we report the use of two classes of industrially validated membranes, i.e., hybrid facilitated transport membranes (HFTMs), which are characterized by higher permeances and lower selectivity, and the fixed site carrier (FSC) polyvinylamine (PVAm) membrane, which is characterized by lower permeance and higher selectivity relative to each other, to study the potential of these membranes in two-stage configurations for post-combustion CO2 capture applications. Two-stage cascades with and without recycle streams were simulated for a target CO2 recovery of >80% and purity of 80–99.5%. Recycle systems were found to contribute in reaching high purity targets of CO2 >90% at the fixed recovery of 90%. The positioning of membranes with different properties in different stages was found to influence the performance of the system significantly. Processes employing HFTMs in the first stage coupled with a PVAm membrane in the second stage performed best with the lowest total energy/membrane area requirement and recycle ratio for a target of 90% recovery and >90% purity of CO2. The process employing HFTMs in both stages outperformed all other cases in terms of membrane area required. The case employing PVAm membranes in both stages performs at its optimum only at a lower purity requirement (<90%). This study reveals the importance of using an optimized combination of membranes with different separation capabilities at different stages.publishedVersio

    Considerations Perceived by Coaches as Specific to Coaching Elite Women’s Soccer Teams

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    This study investigated challenges perceived by coaches when working with elite women’s soccer teams. Six men and four women coaches with experience in the first Norwegian League or Norwegian national team participated. Semi-structured interviews were carried out, and the data was analyzed using thematic interpretational analysis. Participants identified professionalism, early-career termination, mental characteristics, intrateam communication, romantic relationships, access to the locker rooms (men only), and team selection (women only) as the specific challenges they face when coaching these teams. The findings are discussed in relation to ensuring that good performance and development are achieved when coaching elite women’s soccer teams and helping future coaches optimize their coaching techniques when working with elite women players

    Local Councillors and Citizens. An exploratory study of the interaction between councillors and citizens in 4 municipalities in the Meuse-Rhine Euregion

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    The aim of this study is to look into into role behaviour of local councillors and their relation with citizens in their municipality. As little is known about the actual interaction between councillors and citizens in local government the nature of the study is mainly explorative. The research focuses on councillors in 4 different municipalities in the 3 countries of the Meuse-Rhine Euregion: Valkenburg (Netherlands), Riemst (Belgium-Flanders), Visé (Belgium-Wallonia) and Übach-Palenberg (Germany). The study reveals that there are many similarities between the councillors in the different countries. All councillors receive input from citizens, always about specific and often even individual issues of citizens, and surprisingly they leave the initiative mostly to the citizens, instead of actively looking for input. We also found significant differences. We noticed different patterns of contacts between citizens and councillors in the municipalities and it seems that input by citizens is valued differently on the different sides of the border. Several questions for further research were identified.

    BOOST -- A Satellite Mission to Test Lorentz Invariance Using High-Performance Optical Frequency References

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    BOOST (BOOst Symmetry Test) is a proposed satellite mission to search for violations of Lorentz invariance by comparing two optical frequency references. One is based on a long-term stable optical resonator and the other on a hyperfine transition in molecular iodine. This mission will allow to determine several parameters of the standard model extension in the electron sector up to two orders of magnitude better than with the current best experiments. Here, we will give an overview of the mission, the science case and the payload.Comment: 11 pages, 2 figures, accepted for publication in Phys. Rev.

    Optimization of the IPP precursor supply for the production of lycopene, decaprenoxanthin and astaxanthin by Corynebacterium glutamicum

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    Heider S, Wolf N, Hofemeier A, Peters-Wendisch P, Wendisch VF. Optimization of the IPP precursor supply for the production of lycopene, decaprenoxanthin and astaxanthin by Corynebacterium glutamicum. Frontiers in Bioengineering and Biotechnology. 2014;2: 28.The biotechnologically relevant bacterium Corynebacterium glutamicum, currently used for the million ton-scale production of amino acids for the food and feed industries, is pigmented due to synthesis of the rare cyclic C50 carotenoid decaprenoxanthin and its glucosides. The precursors of carotenoid biosynthesis, isopenthenyl pyrophosphate (IPP) and its isomer dimethylallyl pyrophosphate, are synthesized in this organism via the methylerythritol phosphate (MEP) or non-mevalonate pathway. Terminal pathway engineering in recombinant C. glutamicum permitted the production of various non-native C50 and C40 carotenoids. Here, the role of engineering isoprenoid precursor supply for lycopene production by C. glutamicum was characterized. Overexpression of dxs encoding the enzyme that catalyzes the first committed step of the MEP-pathway by chromosomal promoter exchange in a prophage-cured, genome-reduced C. glutamicum strain improved lycopene formation. Similarly, an increased IPP supply was achieved by chromosomal integration of two artificial operons comprising MEP pathway genes under the control of a constitutive promoter. Combined overexpression of dxs and the other six MEP pathways genes in C. glutamicum strain LYC3-MEP was not synergistic with respect to improving lycopene accumulation. Based on C. glutamicum strain LYC3-MEP, astaxanthin could be produced in the milligrams per gram cell dry weight range when the endogenous genes crtE, crtB, and crtI for conversion of geranylgeranyl pyrophosphate to lycopene were coexpressed with the genes for lycopene cyclase and β-carotene hydroxylase from Pantoea ananatis and carotene C(4) oxygenase from Brevundimonas aurantiaca

    Local Online Motor Babbling: Learning Motor Abundance of a Musculoskeletal Robot Arm

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    Motor babbling and goal babbling has been used for sensorimotor learning of highly redundant systems in soft robotics. Recent works in goal babbling have demonstrated successful learning of inverse kinematics (IK) on such systems, and suggest that babbling in the goal space better resolves motor redundancy by learning as few yet efficient sensorimotor mappings as possible. However, for musculoskeletal robot systems, motor redundancy can provide useful information to explain muscle activation patterns, thus the term motor abundance. In this work, we introduce some simple heuristics to empirically define the unknown goal space, and learn the IK of a 10 DoF musculoskeletal robot arm using directed goal babbling. We then further propose local online motor babbling guided by Covariance Matrix Adaptation Evolution Strategy (CMA-ES), which bootstraps on the goal babbling samples for initialization, such that motor abundance can be queried online for any static goal. Our approach leverages the resolving of redundancies and the efficient guided exploration of motor abundance in two stages of learning, allowing both kinematic accuracy and motor variability at the queried goal. The result shows that local online motor babbling guided by CMA-ES can efficiently explore motor abundance at queried goal positions on a musculoskeletal robot system and gives useful insights in terms of muscle stiffness and synergy.IEEE/RSJ International Conference on Intelligent Robots and Systems (iROS2019), November 4 - 8, 2019, Macau, Chin
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