3,483 research outputs found
Diversité des ravageurs des denrées et méthodes alternatives de lutte en milieu tropical
Diversity of Stored Grain Pests and Alternative Methods for their Control in Tropics. The major cause of important post-harvest losses in northern Cameroon is due to the attacks of insects pests. These beetles (Insecta: Coleoptera) during their development depreciate food in storage, they are able to destroy a whole stock in a very short period of time. To protect stored products against these insects, synthetic insecticides and many other biological or physical methods are used, very important amount of work had been carried out on this subject. This review summarises the importance and the diversification of stored grain pests in Cameroon and presents current methods. Hence, the review highlights the use of the essential oils from spices as an important user and consumer friendly method to protect grain in storage
Potential use of essential oils from local Cameroonian plants for the control of red flour weevil Tribolium castaneum (Herbst.) (Coleoptera : Tenebrionidae)
Animal feed is food constituted for breeding stock animals because it possesses vital nutrients for animal growth. Animal feed or their ingredients as constituted by cereal flour and are stored after formulation for ulterior breeds. These provender or cereal grains used are commonly attacked by storage insects principally of the genus Tribolium. Firstly, contact and ingestion test by two essential oils of aromatics plants Ocimum gratissimum L (Lamiaceae) and Xylopia aethiopica Dunal A. Rich (Annonaceae) were done firstly on adults and aged larvae of Tribolium castaneun. Secondly, the contact and inhalation test by three essential oils of the aromatic plants Annona senegalensis L. (Annonaceae), Lippia rugosa L. (Lamiaceae) and Hyptis spicigera Lam. (Verbenaceae) were done for the control larvae, young and aged adults of the red flour weevil Tribolium castaneum Herbst (Coleoptera : Tenebrionidae) very resistant pest to chemical pesticides. Essential oils of Ocimum gratissimum and Xylopia aethiopica have no contact and ingestion effect on adults of Tribolium castaneum; their insecticidal activity is characterized mostly by their inhibition of the nymphosis of aged larvae of the same species. On the other hand contact and inhalation tests with crude essential oils of Lippia rugosa and Hyptis spicigera are the most promising because of their efficacy on the other life stages. They are more efficient, with 100% mortality, on larvae at early stages and young adults. On resistant aged larvae and adults, the insecticidal efficacy decreases but remains significant. Since this insect, Tribolium castaneum is the major pest of stored flours and provender, the incorporation of these promising essential oils in flours or in storage formulations of these foods for animals could contribute to their better cereal food conservation. The important and indispensable element of cereals for storage, growth and reproduction animal feed could be preserved from insects attack by use of natural product and may contribute to diminish toxicity of feeder, environmental pollution and the resistance phenomenon of insects.Key words: Essential oils, Tribolium castaneum, Pesticides
Properties of Invariant Set Theory
In a recent paper (arXiv:2107.04761), Sen critiques a superdeterministic
model of quantum physics, Invariant Set Theory, proposed by one of the authors.
He concludes that superdeterminism is `unlikely to solve the puzzle posed by
the Bell correlations'. He also claims that the model is neither local nor
-epistemic. We here detail multiple inaccuracies with Sen's arguments -
notably that the hidden-variable model of quantum physics he uses to critique
Invariant Set Theory bares no relation to Invariant Set Theory - and use this
opportunity to lay out the properties of Invariant Set Theory as clearly as
possible.Comment: 6 pages, no figures. Substantial edits to address published version
of Sen's pape
Compte-rendu et apport de la conférence-débat : "Nature, conditionnalité et verdissement de la PAC : un tournant wallon ?", 9 novembre 2011, Espace Senghor, Gembloux, Belgique
Proceedings of the conference: "Nature, conditionnalité et verdissement de la PAC : un tournant wallon ?". 9th November 2011. Espace Senghor, Gembloux, Belgium. Recently, the European Union (EU) proposed a reform project for the Common Agricultural Policy (CAP). One of the proposed reforms consists of imposing a set aside proportion of 7% of arable land for biodiversity support purposes. A conference on this proposal was held in Gembloux, Belgium, on 9th November 2011. Such a set aside system already exists in neighboring countries. The French and Swiss systems were presented at the conference in order to highlight their advantages and limitations. Scientific arguments underlying such policies were also presented. It was shown that the creation of semi-natural elements within the agricultural matrix is an efficient way to promote biodiversity. Both the quantity and the quality of these elements need to be considered. In addition, biodiversity is likely to provide services to agriculture, notably crop pollination and pest control. Currently, uncertainties remain regarding areas that are eligible to be designated as reaching the 7% threshold. However, based on the most probable scenarios, the current likely eligible areas cover only 4.3% of arable land in Wallonia. Less than 20% of Walloon farms already reach the 7% threshold proposed by the EU. If the European project is approved, it will therefore be of great importance to have some form of societal recognition afforded to farmers for their efforts. In order to optimize the positive effects of the policy on biodiversity, it is also imperative to ensure that a high level of biological quality is reached in the areas dedicated to biodiversity and to monitor this quality using clearly defined objectives. Economical, societal and environmental issues all need to be considered when applying this policy in order to improve agricultural sustainability and to stop the decline in biodiversity in agricultural landscapes
Exchange-free computation on an unknown qubit at a distance
We present a way of directly manipulating an arbitrary qubit, without the exchange of any particles. This includes as an application the exchange-free preparation of an arbitrary quantum state at Alice by a remote classical Bob. As a result, we are able to propose a protocol that allows one party to directly enact, by means of a suitable program, any computation exchange-free on a remote second party\u27s unknown qubit. Further, we show how to use this for the exchange-free control of a universal two-qubit gate, thus opening the possibility of directly enacting any desired algorithm remotely on a programmable quantum circuit
Human-Induced Expanded Distribution of Anopheles plumbeus, Experimental Vector of West Nile Virus and a Potential Vector of Human Malaria in Belgium
For the majority of native species, human-created habitats provide a hostile environment that prevents their colonization. However, if the conditions encountered in this novel environment are part of the fundamental niche of a particular species, these low competitive environments may allow strong population expansion of even rare and stenotopic species. If these species are potentially harmful to humans, such anthropogenic habitat alterations may impose strong risks for human health. Here, we report on a recent and severe outbreak of the viciously biting and day-active mosquito Anopheles plumbeus Stephens, 1828, that is caused by a habitat shift toward human-created habitats. Although historic data indicate that the species was previously reported to be rare in Belgium and confined to natural forest habitats, more recent data indicate a strong population expansion all over Belgium and severe nuisance at a local scale. We show that these outbreaks can be explained by a recent larval habitat shift of this species from tree-holes in forests to large manure collecting pits of abandoned and uncleaned pig stables. Further surveys of the colonization and detection of other potential larval breeding places of this mosquito in this artificial environment are of particular importance for human health because the species is known as a experimental vector of West Nile virus and a potential vector of human malari
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