Search results for "Systematics"
showing 10 items of 6702 documents
<p class="HeadingRunIn"><strong>A review of the genus <em>Discomyza </em>(Diptera: Ephydridae) from Afrotropical, Australasia…
2015
Tropical Old World species of the genus Discomyza are redescribed, including male terminalia, photographs of heads and wings. One new species Discomyza fagomoga sp. nov. is described from D. R. Congo, Ethiopia, Kenya and Uganda. Two new synonyms are proposed: Discomyza obscuricornis Canzoneri and Rampini, 1996 = D. dolichocerus Cresson, 1944 and D. intermedia Canzoneri and Meneghini, 1969 = D. eritrea Cresson, 1939. A key to all species is provided. Relationships among species of Discomyza are suggested.
Molecular evidence for phylogenetic relationships among buntings and American sparrows (Emberizidae)
2001
To help clarify controversial phylogenetic relationships within the family Emberizidae, we sequenced 1238 bp of mitochondrial DNA from the cytochrome b gene and a flanking portion of ND5. Although the longspurs (Calcarius) and the snow buntings (Plectrophenax) have been grouped with the Old World buntings (Emberiza) in traditional classifications, our molecular phylogenies constructed with maximum likelihood and maximum parsimony place these general basal to a clade in which the Old World buntings and North American sparrows are sister groups. Contrary to the hypothesis that the radiation within Emberiza is recent following a westward expansion of emberizid stock into Eurasia from North Ame…
<p><strong>A revision of the Old World species of <em>Leptopsilopa</em> Cresson (Insecta: Diptera: Ephydridae)</strong>…
2016
Diagnoses and illustrations of three Leptopsilopa species known in the Old World: L. africana Cresson, L. mutabilis Cresson and L. pollinosa (Kertesz) are provided. Three new synonyms are proposed: L. aurata (Canzoneri and Meneghini) and L. tibialis (Canzoneri and Meneghini) = L. africana; Psilopa confeteae Canzoneri and Munari = L. pollinosa . Three other species are removed from Leptopsilopa and combined with Athyroglossa , as A. leonensis (Canzoneri and Rampini), new combination, A. mianii (Canzoneri) new combination and A. rossii (Canzoneri and Raffone), new combination.
A taxonomic revision of the Capparis spinosa group (Capparaceae) from eastern Africa to Oceania
2015
The variability, autecology and distribution of the Capparis spinosa group have been studied in eastern Africa, Madagascar, southern Asia, Australia and Oceania. In these areas the taxonomic treatment of the group, also represented in holoarctic Regions of the Old World, is still critical. The forms widespread in the study area are here referred to four subspecies of C. spinosa . The recognized subspecies mostly show geographical vicariance, except in some contact areas of the Middle East and western Himalaya. Two nomenclatural novelties, i. e. C. spinosa subsp. cordifolia comb. et stat. nov. and C. spinosa subsp. himalayensis stat. nov., are proposed. Among the recognized taxa, C. spinosa …
Physiological responses and central nervous projections of antennal olfactory receptor neurons in the adult desert locust, Schistocerca gregaria (Ort…
1996
Olfactory receptor neurons present in two morphological sensillum types on the male Schistocerca gregaria antenna were for the first time investigated physiologically when stimulated with behaviourally relevant odours. Neurons present in trichoid/basiconic sensilla showed clear excitatory responses to compounds present in the male-produced aggregation pheromone and also to a plant produced compound. Sensilla could be categorised physiologically according to the responses of their receptor neurons to the tested stimuli. Also receptor neurons present in sensilla coeloconica responded to aggregation pheromone components, but always in an inhibitory fashion. These neurons could, however, be exc…
Ontogenesis of the Extra-Bulbar Olfactory Pathway inXenopus laevis
2013
Although the development, anatomy, and physiology of the vertebrate olfactory system are fairly well understood, there is still no clear definition of the terminal nerve complex acknowledged by all. Among the most debated matters is whether or not the extrabulbar projections found in anamniotes should or should not be considered part of the terminal nerve complex. In this context, we investigated the early development of the extrabulbar pathway in Xenopus larvae from placodal differentiation to postmetamorphic stages. We showed that the extrabulbar fibers become visible around Stage 42 and are conserved throughout metamorphosis. We confirmed previous reports concerning their central project…
Exotic Models May Offer Unique Opportunities to Decipher Specific Scientific Question: The Case ofXenopusOlfactory System
2013
The fact that olfactory systems are highly conserved in all animal species from insects to mammals allow the generalization of findings from one species to another. Most of our knowledge about the anatomy and physiology of the olfactory system comes from data obtained in a very limited number of biological models such as rodents, Zebrafish, Drosophila, and a worm, Caenorhabditis elegans. These models have proved useful to answer most questions in the field of olfaction, and thus concentrating on these few models appear to be a pragmatic strategy. However, the diversity of the organization and physiology of the olfactory system amongst phyla appear to be greater than generally assumed and th…
On the ecology of littoral Oligochaeta of an oligotrophic Finnish lake
1982
In material sampled from 0.5–6 m on two sampling dates and three subareas the dominant Oligochaeta were Limnodrilus hoffmeisteri Claparede and Peloscolex ferox (Eisen), both composing more than 30% of the abundances of oligochaetes present. The numbers of Oligochaeta were mostly higher in August than in May. Regional differences could be found although the lake seems to be very homogenous. Temporal and vertical variations were detectable in separate subareas. The oligochaete biomass was maximal at 2 m depth. In soft bottom sediments the oligochaetes composed 15.9% of macrobenthos biomass and 12.2% of numbers, but on the stony bottom only 1.9% of numbers. The ratio of Oligochaeta/Chironomida…
Metabolic differences between a wild and a wine strain of Saccharomyces cerevisiae during fermentation unveiled by multi‐omic analysis
2021
Saccharomyces cerevisiae, a widespread yeast present both in the wild and in fermentative processes, like winemaking. During the colonization of these human‐associated fermentative environments, certain strains of S. cerevisiae acquired differential adaptive traits that enhanced their physiological properties to cope with the challenges imposed by these new ecological niches. The advent of omics technologies allowed unveiling some details of the molecular bases responsible for the peculiar traits of S. cerevisiae wine strains. However, the metabolic diversity within yeasts remained poorly explored, in particular that existing between wine and wild strains of S. cerevisiae. For this purpose,…
Study of axillary lymph node asymmetry in a female population
2001
We analysed a large series of axillary lymph nodes, with and without metastases following radical mastectomy for breast cancer. We found left/right asymmetry in numbers of lymph nodes, and also asymmetry of lymph node dimensions, which could have been the caused by tumoral antigenic stimulation. The distribution of hyperplastic node patterns differed significantly.