Search

Herbivorous insects, such as phloem-sap feeders and chewers, induce resistance response in plants. There is a long-standing hypothesis that herbivores increase the emission of volatile organic compounds (VOCs) in the Arabidopsis plant model. However, most works were restricted to the study of the regulation of plant VOCs emissions and only in some cases to the effects of insects on such emissions. Often these investigations do not establish a link between quantitative and qualitative emission of plant VOCs with actual damages caused by insects. Moreover, information remain limited about the processes that occur at the protein level encoded of the host plant under stress conditions. Here, we briefly summarize the effects of specific chewing and phloem-sap feeding insects on the emission of VOCs by Arabidopsis thaliana Col-, and review some predictions about pathogenesis-related (PR-) proteins, based on current evolutionary hypotheses. Further investigation of the effects of herbivorous insects on VOC emissions and protein expression is expected to improve our knowledge about their patterns and functions in plant responses to stresses.

Kashin-Beck disease (KBD) is an endemic and chronic osteochondropathy. This disease principally occurs in the Tibet Autonomous Region and in several provinces of the People's Republic of China. The etiology of the disease remains obscure although environmental factors are assumed to be involved. Diet, in particular, differentiates the rural community, affected by KBD, from the other communities (nomads and city-dwellers), who remain unaffected. In anticipation of a nutrition survey, this study aimed to measure the mineral content (Ca, P, Mg, Fe, Zn, Mn, Cu, Ni, Se, Al, Sr, Mo, Cd, As, Pb, Hg, Cr, and Co) of eight Tibetan staple foods and to compare the results against two food composition tables (FCTs). Foods were sampled in twenty households selected from both an endemic and a non-endemic area of rural Tibet. Ten minerals involved in bone metabolism were measured using atomic and molecular spectrometric methods. Results revealed that a very limited number of food/constituent pairs showed a variation in mineral composition during a single year of testing for a given region. In addition, results showed significant differences in mineral content between the endemic and the non-endemic area, especially for wheat flour. Following our analysis of the mineral content of the Tibetan food samples, results were statistically compared with similar foods listed in two food composition tables: the USDA National Nutrient Database (USDA Food Search for Windows, Version 1.0, database version SR23), and the China Food Composition Table (book 1, 2nd edition). More than 50 to 60% of p-values < 0.05 were highlighted, suggesting the inappropriateness of using FCTs as a reference for nutrition surveys in rural Tibet, and emphasizing the need for analysis of traditional foods. Differences were found to be more or less marked depending on the element considered, and calcium content seemed to show the greatest difference. Although it is obviously too early for definite conclusions to be reached (insufficient number of samples by food and insufficient number of foods analyzed), it seems that the present pilot-study indicates significant discrepancies between measured and tabulated values of the mineral content of certain foods. A more complete survey would therefore seem mandatory.

Nutritional importance of cassava and perspectives as a staple food in Senegal. A review. Cassava is one of the main plants and starchy roots grown in the world. In 2008, the total yield of cassava in West Africa represented 29% of the world production. However, in many West African countries such as Senegal, cassava is not used as a staple food. In fact, the processing techniques used for cassava are poorly known. In addition, the chemical composition of local cassava varieties has not yet been determined, nor has their toxicity been assessed. In 2004, showing an aggressive agricultural policy and revived interest, the Senegalese government launched a major program for intensifying the production of cassava for food security purposes. Cassava is an important source of calories and can be an interesting option for imported rice and wheat. Although many food products made from cassava are well known in the region, their use in the Senegalese diet is rare. Nevertheless, these cassava products are found as delicacies in some restaurants, and are consumed by the Senegalese and many other Africans. The objective of the present study is to demonstrate the nutritional value and the dietary possibilities of using cassava as a staple food in Senegal.

Maize storage and pest control method as practiced in traditional clay granaries in the Kédougou region in eastern Senegal were evaluated under rural conditions during two successive years. Three storage modes, i.e. maize cobs, winnowed and non-winnowed maize grains, were tested in seven granaries where the insecticidal plants Hyptis spicigera or H. suaveolens were either incorporated in the store structure or deposited as layers intermittently with maize. At the beginning of the storage period, all granaries were artificially infested with 7 pairs Tribolium castaneum and Sitophilus zeamais. No damage, losses or live insects were observed during 7 months of storage when maize cobs were placed between layers of H. spicigera. Compared with the control, incorporation of insecticidal plants within the granary bottom had no significant effect on the damage and loss level irrespective of the storage mode. Non-winnowed maize always suffered less damage and losses than the winnowed variant. In all granaries depredation, insect abundance and moisture content were highest toward the end of storage period between June and July.

Typology of maize storage and conservation systems in the East and the South of Senegal. A survey was conducted in Senegal in the Eastern departments of Tambacounda, Bakel and Kedougou and in Casamance mainland in the departments of Kolda, Sedhiou and Velingara encompassing 330 maize users in 185 villages. Six major types and two modes of storage were found. Differences are presented in relation to ethnic groups who do not adopt the same methods of storage. The impact of types and storage methods are reviewed with regard to loss levels, perception of the producers on the main storage determinants, specificities inherent to ethnic groups, localities as well as pesticides and natural products used in post-harvest treatment.

This review focuses on carrion beetles (Coleoptera, Silphidae) of the Western Palearctic and their potential use in forensic entomology as bioindicators. Few studies have looked at Silphidae in forensic context and investigations. However, some Silphidae present the desirable characteristics of some Diptera used in postmortem estimates and thus may extend the minimum postmortem interval (PMImin). We review here the taxonomy and distribution of Western Palearctic Silphidae. The anatomical and morphological characteristics of both subfamilies are described for adults and larvae. The biology and ecology of silphids are also summarized for Silphinae and Nicrophorinae. A specific chapter gives an overview of the current uses of Silphidae in forensic entomology as postmortem indicator.

Monoterpenes: sources and implications in the indoor air quality. Terpenes are recurrent in indoor environments. Their sources, biogenic or anthropological origin, are very varied: plants, wooden building materials, household products and furnishings, paints, air fresheners, perfumed candles. However, in spite of their natural character, these compounds can have significant effects on occupant's health. Indeed, some monoterpenes are recognized as irritating or allergenic. Furthermore, they react with the other molecules to form potentially more harmful secondary products such as formaldehyde. Numerous studies demonstrated that reactions between monoterpenes and ozone produced airborne particulate matter as well as secondary pollutants among which formaldehyde, acetaldehyde and acetone. However, few studies were realized in the indoor to demonstrate the terpenes and secondary pollutants evolution. The most frequently used technique for the monoterpenes analysis is the TD-GC-MS. The sampling mode depends on the sample introduction system, either the sampling on sorbent tube, or the sampling in a tank. The attraction for the wooden constructions and ecological materials leads to higher indoor monoterpenes concentrations. Has this occurrence to arouse our interest? The present article has the objective to review the knowledge relative to terpenes, and more exactly on the monoterpenes sources in indoor and their implication in its quality.

The development of integrated pest management (IPM) strategies is increasing since many problems appeared with the use of synthetic pesticides. Semiochemicals – informative molecules used in insect-insect or plant-insect interaction – are more and more considered within IPM strategies as alternative or complementary approach to insecticide treatments. Indeed, these species-specific compounds do not present any related adversely affectation of beneficial organisms and do not generate any risk of pest insect resistance as observed with insecticides. Because of their complex biological activity, their dispersion in the environment to be protected or monitored needs the elaboration of slow-release devices ensuring a controlled release of the biologically active volatile compounds. These sensitive molecules also need to be protected from degradation by UV light and oxygen. Many studies were conducted on estimation of release-rate from commercialized or experimental slow-release devices. The influence of climatic parameters and dispenser type were estimated by previous authors in order to provide indications about the on-field longevity of lures. The present review outlines a list of slow-release studies conducted by many authors followed by a critical analysis of these studies.

Controlling pests of cereals and legumes in Senegal and West Africa: a review. Post-harvest losses of cereals and legumes are a major problem in Senegal and West Africa. The solutions to eliminate insects, major pests of stored products were mainly chemical. However, due to pollution associated with pesticides use, selection of resistant strains, environmental pollution, poisoning, the search for alternatives is needed. It is reported on different methods of protecting stocks performed alternatively or in combination with pesticides. The major pest species encountered, particularly Prostephanus truncatus (Horn), insect emerging in Senegal, could be controlled by alternative methods including specially the use of insecticide plants. Different aspects related to this alternative way to chemical pesticides are reviewed herein.

Cola pierlotii R.Germ.: study of the chemical composition of the seed. This note reports the first analysis of the chemical composition of Cola pierlotii seed. It compares the recorded values with various literature data on Cola nitida and Cola acuminata that are the two most used species or as agent flavor or as a precursor drugs. Cola pierlotii is characterized in particular by a high caffeine content up to 1.27%.