82 research outputs found
Essays in macroeconomics on short-term dynamics of inflation and financial markets
Cette thĂšse comprend trois chapitres relatifs aux dynamiques Ă court terme de l'inflation et Ă l'impact des marchĂ©s financiers sur l'Ă©conomie rĂ©elle. Le premier chapitre propose un modĂšle d'Ă©quilibre gĂ©nĂ©ral dynamique et stochastique (DSGE) qui incorpore une structure en boucle de production Ă cĂŽtĂ© du trend d'inflation positif, afin d'analyser les sources des dynamiques Ă court terme de l'inflation. Il s'agit principalement de dĂ©velopper pour la premiĂšre fois dans la littĂ©rature et en prĂ©sence de ces deux ingrĂ©dients, une formulation gĂ©nĂ©rale de la courbe de Phillips nĂ©o-keynĂ©sienne oĂč, l'inflation est exprimĂ©e comme une fonction des coĂ»ts marginaux rĂ©els et de l'inflation future anticipĂ©e. En se concentrant sur l'analyse de la pente de la courbe de Phillips, nous montrons que le trend d'inflation positif et la structure en boucle de production sont nĂ©cessaires pour expliquer la persistance de l'inflation observĂ©e dans les donnĂ©es. Cependant, sous des valeurs raisonnables du trend d'inflation, les inputs intermĂ©diaires jouent un rĂŽle beaucoup plus important que le trend d'inflation en ce qui concerne la persistance inflationniste. Dans le deuxiĂšme chapitre, nous visons Ă approfondir notre comprĂ©hension des dynamiques Ă court terme de l'inflation. Pour ce faire, nous simulons un modĂšle DSGE qui intĂšgre non seulement la structure en boucle de production et le trend d'inflation positif, mais aussi des frictions rĂ©elles comme la formation d'habitude de consommation, les coĂ»ts d'ajustement du capital et l'utilisation variable du capital. Les autocorrĂ©lations thĂ©oriques de l'inflation obtenues du modĂšle simulĂ© sont ensuite confrontĂ©es Ă celles observĂ©es dans les donnĂ©es de l'Ă©conomie amĂ©ricaine. Les conclusions de la dĂ©marche analytique du premier chapitre sont confirmĂ©es ici. En effet, nous trouvons d'une part que le trend d'inflation positif a un effet nĂ©gligeable sur la persistance de l'inflation en prĂ©sence des inputs intermĂ©diaires. D'autre part, la structure en boucle de production fournit une meilleure explication de l'Ă©vidence empirique sur la persistance de l'inflation. Le troisiĂšme chapitre Ă©tudie les interconnections entre les marchĂ©s financiers et l'Ă©conomie rĂ©elle. Le cadre d'analyse est un modĂšle DSGE qui rend compte des interventions des mĂ©nages sur les marchĂ©s financiers, Ă travers le modĂšle d'Ă©valuation des actifs financiers de Fama et French (2004). Par ailleurs, nous proposons une modĂ©lisation explicite des dynamiques des marchĂ©s financiers sur la base du mouvement brownien gĂ©omĂ©trique. Comme rĂ©sultats, nous montrons que la consommation, l'output et l'investissement rĂ©agissent moins alors que l'inflation et le travail rĂ©agissent plus fortement au choc technologique ici, que dans le cas d'une Ă©conomie oĂč le secteur financier est ignorĂ©. En outre, les effets nĂ©gatifs d'un choc de politique monĂ©taire restrictive sur l'output, la consommation, l'inflation, l'investissement et le travail sont beaucoup plus importants. Par ailleurs, nous trouvons qu'un choc positif aux marchĂ©s financiers exerce une pression Ă la baisse sur le taux d'intĂ©rĂȘt nominal lorsque le coefficient beta du portefeuille d'actifs du mĂ©nage est positif. Enfin, le modĂšle DSGE avec le secteur financier reproduit mieux la plupart des caractĂ©ristiques de l'Ă©conome U.S., en particulier, les volatilitĂ©s et autocorrĂ©lations des principales variables macroĂ©conomiques ainsi que leurs corrĂ©lations avec l'output.\ud
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MOTS-CLĂS DE LâAUTEUR : Dynamiques de l'inflation, persistance de l'inflation, prix rigides, biens intermĂ©diaires, trend d'inflation positif, production en boucle, CAPM, marchĂ©s boursiers, politique monĂ©taire, choix de portefeuille, mouvement brownien gĂ©omĂ©trique
Etudes ethnomycologiques et identification des champignons sauvages comestibles les plus consommes dans la region des Monts-Kouffe au Benin (Afrique de lâouest)
Les connaissances endogĂšnes sur les champignons comestibles sont peu documentĂ©es en Afrique de lâOuest. La prĂ©sente Ă©tude vise Ă identifier les champignons sauvages les plus consommĂ©s dans la rĂ©gion des Monts-KouffĂš au BĂ©nin. Cette Ă©tude rĂ©alisĂ©e de juillet Ă aoĂ»t 2014, a dâabord consistĂ© en une enquĂȘte ethnomycologique sur une centaine dâindividus alĂ©atoirement choisis au sein de quatre groupes ethniques (Nagot, BĂštamaribĂš, Peuhl et Lokpa) appartenant Ă deux villages forestiers (Manigri-OkĂ© et Manigri-Ikani) de la commune de Bassila dans le centre du BĂ©nin. Cette enquĂȘte a Ă©tĂ© suivie dâun inventaire mycologique dans des Ă©cosystĂšmes naturels reprĂ©sentatifs de la zone dâĂ©tude, permettant sur base des enquĂȘtes dâidentifier les champignons sauvages comestibles les plus consommĂ©s en fonction du groupe sociolinguistique. Pour identifier les champignons comestibles prioritaires de la rĂ©gion, la technique de simple ranking et de Matrix ranking ainsi quâune Analyse Factorielle de Correspondance tenant compte de 5 critĂšres (qualitĂ© organoleptique, frĂ©quence de consommation, facilitĂ© de consommation et de digestion, durĂ©e de conservation et disponibilitĂ© temporelle) et des scores numĂ©riques attribuĂ©s Ă chaque critĂšre par enquĂȘtĂ©s ont Ă©tĂ© effectuĂ©es. Dix-neuf (19) espĂšces comestibles, dominĂ©es par celles du genre Termitomyces, sont majoritairement exploitĂ©es par les populations locales Ă des fins alimentaires. Parmi celles-ci, une dizaine dâespĂšces a Ă©tĂ© identifiĂ©e comme prioritaire pour lâalimentation des groupes sociolinguistiques des Monts-KouffĂš. Les rĂ©sultats ont montrĂ© que les Nagots utilisent plus de ressources fongiques (18 espĂšces comestibles) que les Peuhls (14), les BĂštamaribĂš (12) et les Lokpa (9). Vu le grand usage que font les populations de la rĂ©gion des Monts-KouffĂš des champignons sauvages il est nĂ©cessaire aujourdâhui de trouver un compromis pour une exploitation durable de ces ressources Ă travers une gestion durable de leurs habitats et la promotion dâune filiĂšre de champignons sauvages comestibles en Afrique de lâOuest.Mots clĂ©s: Ethnomycologie, Champignons comestibles, EspĂšces de prioritĂ© alimentaire, RĂ©gion des Monts-KouffĂš, BĂ©ninEnglish Title: Ethnomycological studies and identification of the most popular wild edible mushrooms of the Monts-KouffĂš region in Benin (west Africa)English AbstractEndogenous knowledge on edible fungi are not well known in West Africa. This study aims at identifying the most popular wild edible mushrooms in the « Monts KouffĂš » area in Benin. This study was carried out from July to August 2014, firstly consisted of an ethnomycological survey on 100 individuals randomly selected within four ethnic groups (Nagot, BetamaribĂ©, Peuhl and Lokpa) within two forest villages (Manigri-Oke and Manigri-Ikani) of the township of Bassila in the center of Benin. This survey was followed by a mycological inventory in representative natural ecosystems of the study area, enabling on the base of investigations to identify wild edible mushrooms the most consumed according to sociolinguistic group. The technique of simple and Matrix ranking and a Factorial Analysis of Correspondence were performed for the identification of mushrooms. Nineteen (19) edible species, dominated by Termitomyces species, are mainly exploited for food purposes. Ten of these species has been identified as priority for feeding of sociolinguistic groups of «Monts KouffÚ». The results showed that the Nagot people use more fungal resources (18 edible species) than the Peuhl (14), the BetamaribĂ© (12) and the Lokpa (9). As a result of the great use of mushrooms by local people of « Monts KouffĂš » area, it is necessary today to find a compromise for sustainable exploitation of these resources through a sustainable management of their habitat and the promotion of wild edible mushroom sector in West Africa.Keywords: Ethnomycology, edible fungi, food priority species, Monts- KouffĂš area, Beni
Inocybaceae and affiliated taxa from West Africa
Inocybaceae and affiliated taxa reported in West Africa were examined through a survey of available publications coupled with field data collections. Twenty-eight Inocyboid taxa have been reported in the region, including six species validly described in the genera Inocybe, Inosperma and Mallocybe. All taxonomic names have been confirmed in Index Fungorum (http://www.indexfungorum.org/names/names.asp). Among them, four taxa were synonyms of other species of Inocybaceae, Crepidotaceae or Chromocyphellaceae. Consequently, only six taxa, Inocybe ghanaensis, Mallocybe africana, Inosperma africanum, I. bulbomarginatum, I. flavobrunneum and Pseudosperma squamatum make the diversity of Inocybaceae from West Africa. Here the distribution of known taxa has been reported along with checklist. In addition, results of BLAST searches including any potential environmental matches (>97%) similarity is reported.
Key words: Checklist, Ectomycorrhizal fungi, Inocybe, Distribution, Pseudosperma, West Afric
Phylogenetic and microscopic studies in the genus Lactifluus (Basidiomycota, Russulales) in West Africa, including the description of four new species
Despite the crucial ecological role of lactarioid taxa (Lactifluus, Lactarius) as common ectomycorrhiza formers in tropical African seasonal forests, their current diversity is not yet adequately assessed. During the last few years, numerous lactarioid specimens have been sampled in various ecosystems from Togo (West Africa). We generated 48 ITS sequences and aligned them against lactarioid taxa from other tropical African ecozones (Guineo-Congolean evergreen forests, Zambezian miombo). A Maximum Likelihood phylogenetic tree was inferred from a dataset of 109 sequences. The phylogenetic placement of the specimens, combined with morpho-anatomical data, supported the description of four new species from Togo within the monophyletic genus Lactifluus: within subgen. Lactifluus (L. flavellus), subgen. Russulopsis (L. longibasidius and L. pectinatus), and subgen. Edules (L. melleus). This demonstrates that the current species richness of the genus is considerably higher than hitherto estimated for African species and, in addition, a need to redefine the subgenera and sections within it
Les Champignons sauvages comestibles du Parc National Fazao-Malfakassa (PNFM) au Togo (Afrique de lâOuest) : DiversitĂ© et connaissances ethnomycologiques
Les champignons sauvages comestibles jouent un rĂŽle important pour les populations dâAfrique tropicale. Ils servent de nourriture, de mĂ©dicaments et de source de revenus. Pour Ă©valuer leur pertinence socioĂ©conomique au Togo et promouvoir leur exploitation durable, un inventaire a Ă©tĂ© rĂ©alisĂ© Ă travers un Ă©chantillonnage alĂ©atoire suivant des transects virtuels de 250 x 20 m Ă©tablis au sein de quatre types de formations vĂ©gĂ©tales, dont les forĂȘts claires, les forĂȘts sĂšches, des galeries forestiĂšres et savanes du Parc National de Fazao-Malfakassa situĂ© dans la partie centre ouest du togo (Afrique de lâOuest). Les enquĂȘtes ethnomycologiques semi-structurĂ©es ont Ă©tĂ© menĂ©es auprĂšs de 676 personnes choisies au hasard dans le village de Fazao, village riverain du Parc, en groupe et parfois des entretiens individuels sur 1 300, lâensemble des Kotokoli, le groupe ethnique majoritaire. Cent soixante Ă©chantillons classĂ©s en 14 familles ont Ă©tĂ© enregistrĂ©s. Dix-sept espĂšces ont Ă©tĂ© identifiĂ©es. AprĂšs les enquĂȘtes ethnomycologiques, 23 taxa sont reconnus couramment utilisĂ©s par les populations pour des fins alimentaires, deux taxa sont utilisĂ©s pour des fins mĂ©dicinales et alimentaires tandis que un taxon est utilisĂ© exclusivement Ă des fins mĂ©dicinales. Les champignons comestibles sont dominĂ©s par les familles des Lyophilaceae et des Amanitaceae reprĂ©sentant respectivement 33 et 29 %. Les populations locales reconnaissent parfaitement les champignons comestibles. Les femmes ĂągĂ©es sont plus familiĂšres.Mots-clĂ©s : Parc National de Fazao - Malfakassa, champignons, gestion durable, connaissances ethnomycologiques, importance socio- Ă©conomique.English AbstractWild edible fungi of the Fazao-malfakassa national park (FMNP) in Togo (West Africa): diversity and ethnomycological knowledgeWild edible fungi play an important role for tropical African people as food, source of drugs and source of cash income. To assess the socio-economic relevance of these mushrooms in central Togo and promote their sustainable and durable exploitation, a mycological survey was undertaken in the Fazao Malfakassa National Park located in central western part of Togo (West Africa). Mushrooms were inventoried using random sampling method along virtual transects of 250 x 20 m within 4 vegetation types including woodlands, dry forests, galleries forests and savannas. Ethnomycological surveys were conducted using semi-structural sampling on 676 persons via focus group and/or individual interviews from 1 300 peoples sampled from the kotokolis, the autochthon majority ethnic group surrounding the National Park. One hundred and sixty specimens sorted into 14 families have been recorded. On the whole, 17 species were fully identified. Twenty tree taxa are used as edible mushrooms, two taxa are used as medicinal and edible mushrooms; and only one species explicitly exploited for therapeutic purpose. The families as Lyophylaceae and Amanitaceae are the mostly dominant edible taxa accounting for about 33 and 29 % respectively. Local people recognize perfectly edible mushrooms. Elderly women are more familiar with edible mushrooms than young and children.Keywords : National Park of Fazao - Malfakassa, Wild edible Mushrooms, sustainable uses, know-how, socio-economic role
The genus Lactarius s. str. (Basidiomycota, Russulales) in Togo (West Africa) : phylogeny and a new species described
Lactarius s. str. represents a monophyletic group of about 40 species in tropical Africa, although the delimitation of the genus from Lactifluus is still in progress. Recent molecular phylogenetic and taxonomic revisions have led to numerous changes in names of tropical species formerly referred to Lactarius. To better circumscribe the genus Lactarius in Togo, we combined morphological data with sequence analyses and phylogeny inference of rDNA ITS sequences. Morphological and molecular data were generated from specimens sampled in various native woodlands and riverside forests; Lactarioid- and Russula sequences from public GenBank NCBI, and UNITE are included for phylogenetic analysis. The Maximum likelihood phylogeny tree inferred from aligned sequences supports the phylogenetic position of the studied samples from Togo within the subgenera Piperites, and Plinthogali. Lactarius s. str. includes about 13 species described from West Africa, of which eight were not previously known from Togo, including one new species: Lactarius subbaliophaeus identifiable by the presence of winged basidiospores, a pallisadic pileipellis with a uprapellis composed of cylindrical cells, inconspicuous pleurocystidia, and fusiform or tortuous, often tapering apex marginal cells. It can also be recognised by a transparent white latex that turns pinkish and then blackish, and a bluish reaction of the flesh context with FeSO4. These features mentioned do not match any of the morpho-anatomically most similar species, notably L. baliophaeus and L. griseogalus
ARBUSCULAR MYCORRHIZAS IN THE ROOTS OF AFZELIA AFRICANA, ENTADA AFRICANA, AND PTEROCARPUS ERINACEUS
Afzelia africana, Entada africana, and Pterocarpus erinaceus are economically important tropical tree species in Africa. In this study, we performed morphological and molecular analyses to examine the mycorrhizal status of these species in their natural habitat in Benin, West Africa. Fine roots were examined using trypan blue staining. Putative arbuscular mycorrhizal fungi (AMF) were identified by extracting root DNA and sequencing the large subunit region of ribosomal DNA. Operational taxonomic units (OTUs) were positioned on a consensus phylogenetic tree produced using maximum likelihood and neighbor-joining models. Morphological analyses revealed vesicles, arbuscules, and inter- and intracellular hyphae in roots of all three tree species. Molecular analyses revealed 39 AMF OTUs, among which 18 were from roots of E. africana, 15 from P. erinaceus, and 9 from A. africana. These OTUs belonged to Glomus, Nanoglomus, Rhizoglomus, Sclerocystis, Septoglomus, and Scutellospora; two unidentified species belonged to the family Glomeraceae. This is the first study to report AMF in roots of A. africana, E. africana, and P. erinaceus in Benin, and opens new avenues for future studies.Peer reviewe
Ectomycorrhizae of Tomentella badia: description and molecular identification
Species within the genera Tomentella are among the most important ECM in forests. However, our knowledge about their functional characteristics is still rather limited. The ectomycorrhizae of Tomentella badia on Picea abies are described here in detail and compared to the non-identified ECM Piceirhiza obscura. A pseudoparenchymatous mantle formed by epidermoid cells is covered by heaps of epidermoid cells. This mantle type is regarded as a new one and designated as mantle type R. Many cells filled with dark blue contents and/or blue granules, together with clampless hyphae, are distinct characters of these ectomycorrhizae. Molecular-phylogenetic analysis of the ITS region was used for identification
Les champignons ectomycorrhiziens consommés par les Bassar et les KabyÚ, peuples riverains du Parc National Fazao-Malfakassa (PNFM) au Togo (Afrique de l'Ouest)
The wild edible mushrooms are often used by people who live around the PNFM of Togo. To know better the ecto-mycorrhizal taxa used and to document the endogenous knowledge, surveys on ethno-mycological knowledge were conducted in the city of Bassar from the ethnic group of Bassar and in the village of HezoudĂš from KabyĂš ethnic group. During this study, based on semi-structural ethno-mycological survey, 432 people aged 10 to 80 years from the KabyĂš and Bassar areas are interviewed via focus group and/or individual interviews. After ethno-mycological investigations, 23 taxa are known as edible. The ethno-mycological indices such as Use Value (UV), Index of Fisher (p) and Index of Importance Value (IVI) are calculated to test the knowledge on the different use of mushrooms by the two ethnic groups. The study revealed that there is no significant difference regarding the number of consumed taxa for each ethnic group and the levels of their traditional knowledge. The study also showed that the traditional ethno-mycological knowledge of the population varies according to age, the ethnical group and sex. The elders are proven to be the holders of the best mycological knowledge. The most ecto-mycorrhizal mushrooms consumed are Amanita loosii, Russula oleifera and Cantharellus congolensis. These preliminary data indicate that the ecto-mycorrhizal mushrooms and their uses are well known by the people who live around the PNFM.
Keywords: Edible ecto-mycorrhizal mushrooms, exploitation, ethnic groups, National Park Fazao-Malfakassa, Togo.Les champignons sauvages sont trĂšs prisĂ©s par les populations riveraines du PNFM du Togo. Pour mieux connaĂźtre les taxa ecto-mycorrhiziens consommĂ©s et documenter les connaissances endogĂšnes, une Ă©tude rĂ©alisĂ©e sur les connaissances ethno-mycologiques traditionnelles dans la ville de Bassar auprĂšs des peuples Bassar et dans le village de HezoudĂš auprĂšs des peuples KabyĂš a Ă©tĂ© couplĂ©e Ă des observations de terrain. Les enquĂȘtes ethno-mycologiques semi-structurĂ©es ont Ă©tĂ© rĂ©alisĂ©es sur 432 personnes dâĂąge compris entre 10 ans et 80 ans. Vingt trois (23) taxa sont connus comme Ă©tant comestibles. Les indices ethno-mycologiques tels que la valeur dâusage (VU), lâindice de diversitĂ© de Fisher (p), lâindice de valeur dâimportance (IVI) ont Ă©tĂ© calculĂ©s pour tester les connaissances sur les diffĂ©rents usages des champignons. LâĂ©tude a rĂ©vĂ©lĂ© quâil nâexiste pas de diffĂ©rence significative en ce qui concerne les niveaux de connaissances traditionnelles par chaque groupe ethnique et le nombre de taxa consommĂ©s. LâĂ©tude a montrĂ© que les connaissances mycologiques traditionnelles de ces populations varient en fonction de lâĂąge, de lâethnie et du sexe. Les champignons ecto-mycorrhiziens les plus consommĂ©s sont Amanita loosii, Russula oleifera et Cantharellus congolensis. Ces donnĂ©es prĂ©liminaires ont montrĂ© que les champignons ecto-mycorrhiziens sont bien connus des populations riveraines du PNFM.
Mots clés: Champignons ecto-mycorrhiziens comestibles, exploitation, groupes ethniques, Parc National Fazao-Malfakassa, Togo
The Numbers Behind Mushroom Biodiversity
Fungi are among the most diverse groups of organisms on Earth. with a global diversity estimated at 0.8 million to 5.1 million species. They play fundamental ecological roles as decomposers, mutualists, and pathogens, growing in almost all habitats and being important as sources of food and health benefits, income, and to maintain forest health. Global assessment of wild edible fungi indicate the existence of 2327 useful wild species; 2166 edible and 1069 used as food; 470 medicinal species. Several million tonnes are collected, consumed, and sold each year in over 80 countries. The major mushroom-producing countries in 2012 were China, Italy, USA, and The Netherlands, with 80% of the world production, 64% of which came from China. The European Union produces 24% of the world production. Italy is the largest European producer, Poland is the largest exporter, UK the largest importer.Fungi are difficult to preserve and fossilize and due to the poor preservation of most
fungal structures, it has been difficult to interpret the fossil record of fungi. Hyphae,
the vegetative bodies of fungi, bear few distinctive morphological characteristicss,
and organisms as diverse as cyanobacteria, eukaryotic algal groups, and oomycetes
can easily
be mistaken for them (Taylor & Taylor 1993). Fossils provide minimum
ages for divergences and genetic lineages can be much older than even the oldest
fossil representative found. According to Berbee and Taylor (2010), molecular clocks
(conversion of molecular changes into geological time) calibrated by fossils are the
only available tools to estimate timing of evolutionary events in fossilâpoor groups,
such as fungi.
The arbuscular mycorrhizal symbiotic fungi from the division Glomeromycota, generally
accepted as the phylogenetic sister clade to the Ascomycota and Basidiomycota,
have left the most ancient fossils in the Rhynie Chert of Aberdeenshire in the north of
Scotland (400 million years old). The Glomeromycota and several other fungi have been
found associated with the preserved tissues of early vascular plants (Taylor et al. 2004a).
Fossil spores from these shallow marine sediments from the Ordovician that closely
resemble Glomeromycota spores and finely branched hyphae arbuscules within plant
cells were clearly preserved in cells of stems of a 400 Ma primitive land plant,
Aglaophyton, from Rhynie chert 455â460 Ma in age (Redecker et al. 2000; Remy et al.
1994) and from roots from the Triassic (250â199 Ma) (Berbee & Taylor 2010; Stubblefield
et al. 1987).info:eu-repo/semantics/publishedVersio
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