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Abstract
Heterodera schachtii population densities were monitored in a H. schachtii -suppressive soil cropped in screenhouse experiments for two consecutive seasons with wheat, susceptible or resistant cultivars of either sugar beet or oilseed radish, or left fallow. Heterodera schachtii population densities under wheat and the resistant cultivars of sugar beet and oilseed radish did not differ significantly from the fallow treatment. Populations declined under all crops, with a reproductive factor between 0.08 and 0.57. In glasshouse experiments, introduced H. schachtii populations increased greatly on susceptible Swiss chard grown in previously wheat-monocultured soils, suggesting that significant loss of H. schachtii suppressiveness occurred during the monoculture. Following fallow, two H. schachtii-resistant or two H. schachtii-susceptible cultivars, introduced sugar beet cyst nematode populations remained small, suggesting that suppressiveness had been maintained. In a field trial with H. schachtii suppressive soil, cyst nematode population densities remained lower under wheat, resistant sugar beet, resistant radish and susceptible radish than under susceptible sugar beet.
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Nematology
Mosquitoes (Culicidae) are at the centre of worldwide entomological research and control efforts primarily because of their medical importance as vectors of diseases, like malaria, dengue, Zika, Chikungunya, West Nile or Yellow fever. They are responsible for more than half a million deaths per year. Despite their role as vectors, culicids can also cause considerable nuisance like floodwater mosquitoes frequently create as they can reproduce in a short time in enormous numbers. The consequence is that outdoor activities in parks or recreation areas are not possible and this has a detrimentrous effect on touristic activities. The most successful approach for managing nuisance or vector mosquitoes is when an integrated vector mosquito management (IVM) is implemented in which all appropriate technologies and control techniques are used, to bring about a decline of target species populations in a cost effective and environmentally safe manner. The IVM strategy can include environmental management, physical, chemical, biological or genetical components. Environmental management means physical reduction of breeding resources, water management to create conditions unfavourable for mosquito breeding. Physical control includes the use of nets and surface layers to avoid vector contact or breathing by mosquito developing stages. Chemical control by using organochlorines, organophosphates, carbamates or pyrethroids is still the most frequently practised approach to combat mosquitoes but usually these chemicals are broad-spectrum products which can have also unwanted side effects on non-target organisms and on the biodiversity when they are used in ecological sensitive areas. Therefore, biological control aiming at the reduction of target populations by the use of predators, pathogens or toxins from microorganisms are nowadays more and more in focus of control operators. Especially the use of protein toxins such as from Bacillus thuringiensis israelensis or Lysinibacillus sphaericus provide efficient control of target organisms on the one hand and environmental safety on the other hand. The increased application of biological and microbiological methods or Insect growth regulators as well as genetic methods as the Sterile Insect technique (SIT) contribute to an environmentally friendly solution of the mosquito problems. New and improved techniques like the CRISPR (clustered regularly interspaced short palindromic repeats) as a mean of editing mosquito genomes to drive desirable gene constructs into mosquito population can help in future to avoid the transmission of human pathogens. The Geographic Information System (GIS) integrated with digital mobile collection systems supported by a Global Positioning System (GPS) and modern information-technology, can significantly contribute to improving the planning, realisation and documentation of mosquito control/management operations and allow a more effective effort to reducing mosquito-borne diseases. It is out of question that all strategies should involve the public to raise the awareness of people, e.g. for the control of invasive mosquitoes by community participation.
Der traditionell behauptete Gattungsunterschied von wahrheitsorientierter philosophischer Prosa und fi ktionaler Literatur stellt sich nicht zuletzt dann als problematisch heraus, wenn Formen des Denkens und Erkennens aus der Betrachtung herausfallen, die sich keinem der beiden Modelle zuordnen lassen.
Das Konzept der »Literarischen Denkformen« soll dazu dienen, philosophische und literarische Modi des Erkennens gleichermaßen einzufangen. Die Leitfragen der vorliegenden Analysen sind somit, ob und auf welche Weise philosophische Texte auf »dichterische« Mittel angewiesen sind und inwiefern Literatur in Philosophie umschlägt, wenn man sich denkend in sie versenkt.
Das Konzept der »Literarischen Denkformen« soll dazu dienen, philosophische und literarische Modi des Erkennens gleichermaßen einzufangen. Die Leitfragen der vorliegenden Analysen sind somit, ob und auf welche Weise philosophische Texte auf »dichterische« Mittel angewiesen sind und inwiefern Literatur in Philosophie umschlägt, wenn man sich denkend in sie versenkt.
Der traditionell behauptete Gattungsunterschied von wahrheitsorientierter philosophischer Prosa und fi ktionaler Literatur stellt sich nicht zuletzt dann als problematisch heraus, wenn Formen des Denkens und Erkennens aus der Betrachtung herausfallen, die sich keinem der beiden Modelle zuordnen lassen.
Das Konzept der »Literarischen Denkformen« soll dazu dienen, philosophische und literarische Modi des Erkennens gleichermaßen einzufangen. Die Leitfragen der vorliegenden Analysen sind somit, ob und auf welche Weise philosophische Texte auf »dichterische« Mittel angewiesen sind und inwiefern Literatur in Philosophie umschlägt, wenn man sich denkend in sie versenkt.
Das Konzept der »Literarischen Denkformen« soll dazu dienen, philosophische und literarische Modi des Erkennens gleichermaßen einzufangen. Die Leitfragen der vorliegenden Analysen sind somit, ob und auf welche Weise philosophische Texte auf »dichterische« Mittel angewiesen sind und inwiefern Literatur in Philosophie umschlägt, wenn man sich denkend in sie versenkt.