202 research outputs found
Le pattern de la bourse caudale chez les Heligmonellidae (Nematoda: Trichostrongylina): Caractérisation et hypothÚse sur son évolution
The different patterns of the caudal bursa of the Heligmonellidae (Nematoda) are redefined, taking into account the grouping of rays 2-6 and the sequence of origin of these rays from their common trunk. The type of symmetry of the caudal bursa is also redefined. The following patterns were observed and characterized: the basic patterns: types 2-3, 2-2-1, 1-3-1 and 1-4 and the intermediary patterns: type 2-3 tending to type 2-2-1, type 2-2-1 tending to type 1-3-1, type 1-3-1 tending to type 1-4 and type 2-2-1 tending to type 1-4. An evolutionary interpretation of the patterns is attempted and seems to follow the direction: 2-3 to 2-2-1 to 1-3-1 to 1-4. Seven atypical patterns are described. The caudal bursae were classified based on their symmetry: subsymmetrical, dissymmetrical and asymmetrical. Independently of the type of symmetry, the two latero-ventral lobes may have the same or different patterns. The type of symmetry, the ratio between the two latero-ventral lobes and a characteristic pattern were utilized to characterize the caudal bursae at the level of the genus and the subfamily. The combination of the right/left ratio and the type of symmetry gives heterogeneous results, with no real association between these characters. The most conspicuous asymmetries and dissymmetries were found among the Nippostrongylinae. The most frequent pattern in the Heligmonellidae is the basic type 2-2-1; types 1-3-1 and 1-4 are less frequent but are characteristic of several genera; type 1-4 is absent from the Heligmonellinae. Whatever the pattern, in the Heligmonellidae rays 4 and 5 are the last to diverge from the common trunk of rays 2-6.Les diffĂ©rents patterns de la bourse caudale chez les Heligmonellidae (Nematoda) sont redĂ©finis en tenant compte du groupement des cĂŽtes 2-6 et de la sĂ©quence dâapparition de ces cĂŽtes sur leur tronc commun. Le type de symĂ©trie est Ă©galement redĂ©fini. Les patterns suivants sont observĂ©s et caractĂ©risĂ©s : les patterns de base : type 2-3, 2-2-1, 1-3-1 et 1-4 et les patterns intermĂ©diaires : type 2-3 Ă tendance 2-2-1, 2-2-1 Ă tendance 1-3-1, 1-3-1 Ă tendance 1-4 et 2-2-1 Ă tendance 1-4. Une interprĂ©tation Ă©volutive des patterns est proposĂ©e et semble suivre la direction : 2-3 vers 2-2-1 vers 1-3-1 vers 1-4. Sept patterns atypiques sont dĂ©crits. Les bourses caudales sont classifiĂ©es selon leur symĂ©trie en : subsymĂ©trique, dissymĂ©trique et asymĂ©trique. IndĂ©pendamment du type de symĂ©trie, les deux lobes latĂ©ro-ventraux peuvent avoir un pattern identique ou diffĂ©rent. Le type de symĂ©trie, le rapport Ă©volutif entre les deux lobes latĂ©ro-ventraux et un type de pattern caractĂ©ristique ont Ă©tĂ© utilisĂ©s pour caractĂ©riser les bourses caudales au niveau du genre et de la sous-famille. La combinaison du rapport droite/gauche et le type de symĂ©trie donnent des rĂ©sultats hĂ©tĂ©rogĂšnes sans vĂ©ritable lien entre ces caractĂšres. Les asymĂ©tries et les dissymĂ©tries les plus manifestes sont trouvĂ©es parmi les Nippostrongylinae. Le pattern le plus frĂ©quemment rencontrĂ© chez les Heligmonellidae est le type de base 2-2-1 ; les types 1-3-1 et 1-4 sont moins frĂ©quents mais caractĂ©ristiques de plusieurs genres ; le type 1-4 est absent chez les Heligmonellinae. Chez les Heligmonellidae, quel que soit le pattern, les cĂŽtes 4 et 5 sont les derniĂšres Ă diverger du tronc commun aux cĂŽtes 2-6.Facultad de Ciencias Naturales y Muse
Nouvelles données métriques et morphologiques sur_ quelques Heligmonellidae (Nematoda : Trichostrongylina) parasites de Rongeurs néotropicaux (Cricetidae)
Some additional morphological and metrical data are provided, particularly on the synlophe of the following species: Hassalstrongylus dessetae Pinto, 1978, Stilestrongylus eta (Travassos, 1937), Stilestrongylus manni DenkĂ© & MurĂșa, 1977 and Stilestrongylus valdivianus Durette-Desset & MurĂșa, 1979, based on type and voucher material deposited in Brazilian and French collections. Heligmonoides crassidorsualis Franco, 1967 is considered as a Nippostrongylinae incertae sedis: its synlophe not being known it is impossible to report the species to a given genus. However, it is unlikely that the species belong to the genus Heligmonoides Baylis, 1928, present only in commensal Murinae from the Old World. Heligmonoides mirzai Smales, 2009, is also regarded, temporarily, as a Nippostrongylinae incertae sedis.Nous apportons quelques nouvelles donnĂ©es mĂ©triques et morphologiques, en particulier sur le synlophe des espĂšces suivantes: Hassalstrongylus dessetae Pinto, 1978, Stilestrongylus eta (Travassos, 1937), Stilestrongylus manni DenkĂ© & MurĂșa, 1977 et Stilestrongylus valdivianus Durette-Desset & MurĂșa, 1979, sur la base de matĂ©riel type et de matĂ©riel complĂ©mentaire dĂ©posĂ©s dans des collections brĂ©siliennes et françaises. Heligmonoides crassidorsualis Franco, 1967 est considĂ©rĂ© comme un Nippostrongylinae incertae sedis: son synlophe Ă©tant inconnu, il est impossible dâattribuer lâespĂšce Ă un genre donnĂ©. Il est pourtant improbable que lâespĂšce concerne le genre Heligmonoides Baylis, 1928, prĂ©sent seulement chez des Murinae commensaux de lâAncien Monde. Heligmonoides mirzai Smales, 2009, est aussi considĂ©rĂ©e, temporairement, comme un Nippostrongylinae incertae sedis.Fil: Durette Desset, M. C.. MusĂ©um National d'Histoire Naturelle; FranciaFil: Digiani, Maria Celina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. DivisiĂłn ZoologĂa Invertebrados; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - La Plata; Argentin
Le pattern de la bourse caudale chez les Heligmonellidae (Nematoda: Trichostrongylina): Caractérisation et hypothÚse sur son évolution
The different patterns of the caudal bursa of the Heligmonellidae (Nematoda) are redefined, taking into account the grouping of rays 2-6 and the sequence of origin of these rays from their common trunk. The type of symmetry of the caudal bursa is also redefined. The following patterns were observed and characterized: the basic patterns: types 2-3, 2-2-1, 1-3-1 and 1-4 and the intermediary patterns: type 2-3 tending to type 2-2-1, type 2-2-1 tending to type 1-3-1, type 1-3-1 tending to type 1-4 and type 2-2-1 tending to type 1-4. An evolutionary interpretation of the patterns is attempted and seems to follow the direction: 2-3 to 2-2-1 to 1-3-1 to 1-4. Seven atypical patterns are described. The caudal bursae were classified based on their symmetry: subsymmetrical, dissymmetrical and asymmetrical. Independently of the type of symmetry, the two latero-ventral lobes may have the same or different patterns. The type of symmetry, the ratio between the two latero-ventral lobes and a characteristic pattern were utilized to characterize the caudal bursae at the level of the genus and the subfamily. The combination of the right/left ratio and the type of symmetry gives heterogeneous results, with no real association between these characters. The most conspicuous asymmetries and dissymmetries were found among the Nippostrongylinae. The most frequent pattern in the Heligmonellidae is the basic type 2-2-1; types 1-3-1 and 1-4 are less frequent but are characteristic of several genera; type 1-4 is absent from the Heligmonellinae. Whatever the pattern, in the Heligmonellidae rays 4 and 5 are the last to diverge from the common trunk of rays 2-6.Les diffĂ©rents patterns de la bourse caudale chez les Heligmonellidae (Nematoda) sont redĂ©finis en tenant compte du groupement des cĂŽtes 2-6 et de la sĂ©quence dâapparition de ces cĂŽtes sur leur tronc commun. Le type de symĂ©trie est Ă©galement redĂ©fini. Les patterns suivants sont observĂ©s et caractĂ©risĂ©s : les patterns de base : type 2-3, 2-2-1, 1-3-1 et 1-4 et les patterns intermĂ©diaires : type 2-3 Ă tendance 2-2-1, 2-2-1 Ă tendance 1-3-1, 1-3-1 Ă tendance 1-4 et 2-2-1 Ă tendance 1-4. Une interprĂ©tation Ă©volutive des patterns est proposĂ©e et semble suivre la direction : 2-3 vers 2-2-1 vers 1-3-1 vers 1-4. Sept patterns atypiques sont dĂ©crits. Les bourses caudales sont classifiĂ©es selon leur symĂ©trie en : subsymĂ©trique, dissymĂ©trique et asymĂ©trique. IndĂ©pendamment du type de symĂ©trie, les deux lobes latĂ©ro-ventraux peuvent avoir un pattern identique ou diffĂ©rent. Le type de symĂ©trie, le rapport Ă©volutif entre les deux lobes latĂ©ro-ventraux et un type de pattern caractĂ©ristique ont Ă©tĂ© utilisĂ©s pour caractĂ©riser les bourses caudales au niveau du genre et de la sous-famille. La combinaison du rapport droite/gauche et le type de symĂ©trie donnent des rĂ©sultats hĂ©tĂ©rogĂšnes sans vĂ©ritable lien entre ces caractĂšres. Les asymĂ©tries et les dissymĂ©tries les plus manifestes sont trouvĂ©es parmi les Nippostrongylinae. Le pattern le plus frĂ©quemment rencontrĂ© chez les Heligmonellidae est le type de base 2-2-1 ; les types 1-3-1 et 1-4 sont moins frĂ©quents mais caractĂ©ristiques de plusieurs genres ; le type 1-4 est absent chez les Heligmonellinae. Chez les Heligmonellidae, quel que soit le pattern, les cĂŽtes 4 et 5 sont les derniĂšres Ă diverger du tronc commun aux cĂŽtes 2-6.Facultad de Ciencias Naturales y Muse
Polycomb Group-Dependent, Heterochromatin Protein 1-Independent, Chromatin Structures Silence Retrotransposons in Somatic Tissues Outside Ovaries
Somatic cells are equipped with different silencing mechanisms that protect the genome against retrotransposons. In Drosophila melanogaster, a silencing pathway implicating the argonaute protein PIWI represses retrotransposons in cells surrounding the oocyte, whereas a PIWI-independent pathway is involved in other somatic tissues. Here, we show that these two silencing mechanisms result in distinct chromatin structures. Using sensor transgenes, we found that, in somatic tissues outside of the ovaries, these transgenes adopt a heterochromatic configuration implicating hypermethylation of H3K9 and K27. We identified the Polycomb repressive complexes (PRC1 and 2), but not heterochromatin protein 1 to be necessary factors for silencing. Once established, the compact structure is stably maintained through cell divisions. By contrast, in cells where the silencing is PIWI-dependent, the transgenes display an open and labile chromatin structure. Our data suggest that a post-transcriptional gene silencing (PTGS) mechanism is responsible for the repression in the ovarian somatic cells, whereas a mechanism that couples PTGS to transcriptional gene silencing operates to silence retrotransposons in the other somatic tissues
Flexible Power Modeling of LTE Base Stations
With the explosion of wireless communications in number of users and data rates, the reduction of network power consumption becomes more and more critical. This is especially true for base stations which represent a dominant share of the total power in cellular networks. In order to study power reduction techniques, a convenient power model is required, providing estimates of the power consumption in different scenarios. This paper proposes such a model, accurate but simple to use. It evaluates the base station power consumption for different types of cells supporting the 3GPP LTE standard. It is flexible enough to enable comparisons between state-of-the-art and advanced configurations, and an easy adaptation to various scenarios. The model is based on a combination of base station components and sub-components as well as power scaling rules as functions of the main system parameters
Molineus cati n. sp. (Nematoda, Trichostrongylina, Molineoidea), a parasite of feral cats, Felis catus Linnaeus, 1758 in South Africa
A new species of the genus Molineus Cameron, 1923 was recovered from feral cats, Felis catus
Linnaeus, 1758, in Mpumalanga Province, South Africa. Because of a caudal bursa with rays of the
2-1-2 type, but with the extremities of rays 4 nearer those of rays 3 than those of rays 5, the new species
is closely related to seven Neotropical Molineus spp., four parasitic in Primates, two parasitic in
Mustelidae and one a parasite of Procyonidae. Amongst these species, only Molineus barbaris
Cameron, 1936, a parasite of Tayra barbara (Mustelidae) from Trinidad and Molineus vexillarius (Dunn,
1961), a parasite of Tamarinus nigricollis (Primates) from Peru have rays 4 longer than two-thirds the
length of rays 3, like the new species. However, the new species is differentiated from the other two
in that rays 9 arise at the level of the bifurcation of the dorsal ray and not after the division as is the
case with M. barbaris and M. vexillarius.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi.
Adobe Acrobat v.9 was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.mn201
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