994 resultados para Opiinae, Braconidae, Parasitoids, taxonomy, identification, diagnostics.
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Tumor-initiating cells with stem cell properties are believed to sustain the growth of gliomas, but proposed markers such as CD133 cannot be used to identify these cells with sufficient specificity. We report an alternative isolation method purely based on phenotypic qualities of glioma-initiating cells (GICs), avoiding the use of molecular markers. We exploited intrinsic autofluorescence properties and a distinctive morphology to isolate a subpopulation of cells (FL1(+)) from human glioma or glioma cultures. FL1(+) cells are capable of self-renewal in vitro, tumorigenesis in vivo and preferentially express stem cell genes. The FL1(+) phenotype did not correlate with the expression of proposed GIC markers. Our data propose an alternative approach to investigate tumor-initiating potential in gliomas and to advance the development of new therapies and diagnostics.
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RESUME :Les fourmis du groupe Formica rufa, ou fourmis des bois, ainsi appelées en raison de leur préférence pour les écosystèmes forestiers, sont parmi les fourmis les plus fascinantes et les plus étudiées d'Europe. Ces fourmis jouent un rôle clé dans la plupart des forêts dans lesquelles elles vivent et sont considérées comme étant les meilleurs bioindicateurs de ces milieux. Pour ces raisons, les fourmis des bois sont protégées par la loi dans de nombreux pays européens, y compris en Suisse. Cependant, malgré leur protection, ces fourmis sont inscrites sur la liste rouge des espèces menacées dans plusieurs pays d'Europe et il est donc indispensable de bien les connaître afin de mieux les protéger.À l'heure actuelle, on considère que le groupe Formica rufa est composé de six espèces distinctes : F. rufa, F. polyctena, F. lugubris, F. paralugubris, F. aquilonia et F. pratensis. Toutefois, malgré la grande quantité d'études effectuées sur ces espèces, la systématique et l'identification des fourmis des bois sont toujours sujettes à discussion. Ceci est essentiellement dû au fait que ces espèces sont morphologiquement similaires et qu'elles sont parfois capables de s'hybrider ou de former des colonies mixtes.Une des conditions fondamentales pour toute étude en biologie de la conservation est l'identification correcte des espèces à protéger. Avec cette étude, nous désirons donc dénouer les problèmes liés à la systématique des fourmis des bois et analyser la diversité de ces espèces en adoptant une approche multidisciplinaire.Nous avons d'abord étudié la distribution des espèces jumelles F. lugubris et F. paralugubris dans les Álpes italiennes en re-analysant l'une des plus grandes collections de références sur ces espèces, déposée à l'Université de Pavie, Italie, et en récoltant de nouveaux échantillons sur le terrain. Nos analyses ont montré que F, paralugubris, décrite récemment et souvent «oubliée »par les chercheurs, est bien présente dans les Alpes et vit souvent en sympathie avec F. lugubris. Ensuite nous avons développé un outil moléculaire basé sur l'ADN mitochondrial pour une identification rapide et efficace de ces deux espèces. Au vu des bons résultats, nous avons étendu nos analyses génétiques (microsatellites) à toutes les espèces du groupe F. rufa, ce qui nous a permis de montrer que les outils moléculaires sont très efficaces pour identifier ces fourmis. En outre, nos analyses ont mis en évidence la présence d'une nouvelle espèce cryptique (appelée F. lugubris-X) au sein du Parc National Suisse. L'existence d'une nouvelle espèce peut avoir une grande influence sur les projets de conservation en faveur de ces espèces. Nous avons donc décidé de confirmer ce résultat avec des analyses comportementales et des analyses chimiques basées sur les phéromones sexuelles des différentes espèces, y compris F. lugubris-X. Les deux approches confirment nos données génétiques et indiquent que F. lugubris-X représente bel et bien une nouvelle espèce de fourmis des bois dans les Alpes Suisses.Les résultats de cette étude ont une grande importance du point de vue de la biodiversité. En plus, ils livrent aux futurs chercheurs des outils fiables pour l'identification des fourmis des bois et ouvrent de captivantes perspectives pour une meilleure protection de ces insectes et, par conséquent, de nos écosystèmes forestiers. .Abstract :Mound building red wood ants (species of the Formica rufa group) belong to one of the most studied groups of ants in Europe and have fundamental roles and positive effects in forested habitats of the northern hemisphere. In addition, they are considered among the most promising bioindicators of forest ecosystems. Because of their importance, these ants are protected by law in many European countries, including Switzerland. However, despite this protection, they are included on the red list of threatened species edited by the International Union for Conservation of Nature (IUCN) and on the red list of some particular countries like Switzerland. Because of their similar morphology and a high intraspecific variability, the morphological identification of these species can be quite complicated. In addition, they are sometimes able to hybridize or to form mixed colonies. Consequently, the taxonomy of this group of ants has been much debated during the past decades. Based on a phylogenetic study, today the group is considered to count six species in Europe: F. rufa, F. po/yctena, F. lugubris, F. paralugubris, F. aquilonia and F. pratensis. Nevertheless, the taxonomy of the group is often neglected mainly due to the lack of reliable and easy to use identification methods.Considering the importance of correct species assessment in conservation biology, in this study we want to disentangle the taxonomical difficulties within the Formica rufa group and to clarify the diversity of these protected ants, by using an integrative approach.We first analyzed the distribution of .the sibling species F. lugubris and F. paralugubris in the Italian Alps by collecting new samples on the field and by examining one of the major red wood ant collections, which is deposited at the University of Pavia, Italy. After that, we developed a molecular tool based on mitochondria) DNA, which provides a reliable and easy-to-use technique for the identification of F. lugubris and F. paralugubris. Afterwards, we extended the use of molecular markers for species identification to the whole F. rufa group and made a microsatellite analysis. Results confirm that molecular markers are consistent tools for species identification and that the six known species represent six different genetic pools. In addition, genetic data highlighted the existence of a new cryptic species in the Swiss Alps, called Formica lugubris-X.The presence of a new species can have a great influence on future conservation plans in favour of these protected ants and consequently for forested habitats. We therefore completed molecular data by behavioural (pupae recognition) and chemical analyses based on six pheromones of the entire F. rufa group. Both approaches are in accordance to genetic results and confirm that F. lugubris-X really represents a new cryptic species of red wood ant within the Swiss National Park (Eastern Swiss Alps).Results obtained in this study have a great importance in terms of biodiversity. Moreover, they provide important taxonomical information, reliable tools for species identifications and future perspectives for a consequent conservation of red wood ant species.
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The biodiversity of soil communities remains very poorly known and understood. Soil biological sciences are strongly affected by the taxonomic crisis, and most groups of animals in that biota suffer from a strong taxonomic impediment. The objective of this work was to investigate how DNA barcoding - a novel method using a microgenomic tag for species identification and discrimination - permits better evaluation of the taxonomy of soil biota. A total of 1,152 barcode sequences were analyzed for two major groups of animals, collembolans and earthworms, which presented broad taxonomic and geographic sampling. Besides strongly reflecting the taxonomic impediment for both groups, with a large number of species-level divergent lineages remaining unnamed so far, the results also highlight a high level (15%) of cryptic diversity within known species of both earthworms and collembolans. These results are supportive of recent local studies using a similar approach. Within an impeded taxonomic system for soil animals, DNA-assisted identification tools can facilitate and improve biodiversity exploration and description. DNA-barcoding campaigns are rapidly developing in soil animals and the community of soil biologists is urged to embrace these methods.
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The objective of this work was to determine how taxonomy benefited from the ecological quantitative and site-based sampling methods in enchytraeids studies. Enchytraeids (small relatives of earthworms) were sampled in different phases of rain forest regeneration in the southern Mata Atlântica in Paraná, Brazil. The research combined ecological and taxonomic work, because enchytraeids are poorly studied and difficult to identify, and many new species were expected. The provision of large numbers of specimens enabled the test of species diagnoses by investigating the ranges of character variations in a larger series of specimens. Simplified species diagnoses adapted to the local conditions that allowed the identification of all specimens, juveniles included, were developed. Key characters and character states are presented for the three genera: Achaeta, Hemienchytraeus and Guaranidrilus. Among several new species, a rare species, possibly a remnant of the autochthonous forest fauna, was found and described.
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Spodoptera frugiperda is a pest of great economic importance in the Americas. It is attacked by several species of parasitoids, which act as biological control agents. Parasitoids are morphologically identifiable as adults, but not as larvae. Laboratory rearing conditions are not always optimal to rear out parasitic wasps from S. frugiperda larvae collected from wild populations, and it frequently happens that parasitoids do not complete their life cycle and stop developing at the larval stage. Therefore, we explored ways to identify parasitoid larvae using molecular techniques. Sequencing is one possible technique, yet it is expensive. Here we present an alternate, cheaper way of identifying seven species of parasitoids (Cotesia marginiventris, Campoletis sonorensis, Pristomerus spinator, Chelonus insularis, Chelonus cautus, Eiphosoma vitticolle and Meteorus laphygmae) using PCR amplification of COI gene followed by a digestion with a combination of four restriction endonucleases. Each species was found to exhibit a specific pattern when the amplification product was run on an agarose gel. Identifying larvae revealed that conclusions on species composition of a population of parasitic wasps can be biased if only the emerging adults are taken into account.
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Summary Background Dermatophytes are the main cause of superficial mycoses in humans and animals. Molecular research has given useful insights into the phylogeny and taxonomy of the dermatophytes to overcome the difficulties with conventional diagnostics. Objectives The Trichophyton mentagrophytes complex consists of anthropophilic as well as zoophilic species. Although several molecular markers have been developed for the differentiation of strains belonging to T. mentagrophytes sensu lato, correct identification still remains problematic, especially concerning the delineation of anthropophilic and zoophilic strains of T. interdigitale. This differentiation is not academic but is essential for selection of the correct antimycotic therapy to treat infected patients. Methods One hundred and thirty isolates identified by morphological characteristics as T. mentagrophytes sensu lato were investigated using restriction fragment length polymorphism (RFLP) and sequence analysis of the polymerase chain reaction-amplified internal transcribed spacer (ITS) region of the rDNA. Results Species of this complex produced individual RFLP patterns obtained by the restriction enzyme MvaI. Subsequent sequence analysis of the ITS1, 5.8S and ITS2 region of all strains, but of T. interdigitale in particular, revealed single unique polymorphisms in anthropophilic and zoophilic strains. Conclusions Signature polymorphisms were observed to be useful for the differentiation of these strains and epidemiological data showed a host specificity among zoophilic strains of T. interdigitale/Arthroderma vanbreuseghemii compared with A. benhamiae as well as characteristic clinical pictures in humans when caused by zoophilic or anthropophilic strains. The delineation is relevant because it helps in determining the correct treatment and provides clues regarding the source of the infection.
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One of the targets of the climate and energy package of the European Union is to increase the energy efficiency in order to achieve a 20 percent reduction in primary energy use compared with the projected level by 2020. The energy efficiency can be improved for example by increasing the rotational speed of large electrical drives, because this enables the elimination of gearboxes leading to a compact design with lower losses. The rotational speeds of traditional bearings, such as roller bearings, are limited by mechanical friction. Active magnetic bearings (AMBs), on the other hand, allow very high rotational speeds. Consequently, their use in large medium- and high-speed machines has rapidly increased. An active magnetic bearing rotor system is an inherently unstable, nonlinear multiple-input, multiple-output system. Model-based controller design of AMBs requires an accurate system model. Finite element modeling (FEM) together with the experimental modal analysis provides a very accurate model for the rotor, and a linearized model of the magneticactuators has proven to work well in normal conditions. However, the overall system may suffer from unmodeled dynamics, such as dynamics of foundation or shrink fits. This dynamics can be modeled by system identification. System identification can also be used for on-line diagnostics. In this study, broadband excitation signals are adopted to the identification of an active magnetic bearing rotor system. The broadband excitation enables faster frequency response function measurements when compared with the widely used stepped sine and swept sine excitations. Different broadband excitations are reviewed, and the random phase multisine excitation is chosen for further study. The measurement times using the multisine excitation and the stepped sine excitation are compared. An excitation signal design with an analysis of the harmonics produced by the nonlinear system is presented. The suitability of different frequency response function estimators for an AMB rotor system are also compared. Additionally, analytical modeling of an AMB rotor system, obtaining a parametric model from the nonparametric frequency response functions, and model updating are discussed in brief, as they are key elements in the modeling for a control design. Theoretical methods are tested with a laboratory test rig. The results conclude that an appropriately designed random phase multisine excitation is suitable for the identification of AMB rotor systems.
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The Amazonian region, the biggest rain forest of our planet, is known for its extraordinary biodiversity. Most of this diversity is still unexplored and new species of different taxa are regularly found there. In this region, as in most areas of the world, insects are some of the most abundant organisms. Therefore, studying this group is important to promote the conservation of these highly biodiverse ecosystems of the planet. Among insects, parasitoid wasps are especially interesting because they have potential for use as biodiversity indicators and biological control agents in agriculture and forestry. The parasitoid wasp family Ichneumonidae is one of the most species rich groups among the kingdom Animalia. This group is still poorly known in many areas of the world; the Amazonian region is a clear example of this situation. Ichneumonids have been thought to be species poor in Amazonia and other tropical areas. However, recent studies are suggesting that parasitoid wasps may be quite abundant in Amazonia and possibly in most tropical areas of the world. The aim of my doctoral thesis is to study the species richness and taxonomy of two of the best known ichneumonid subfamilies in the Neotropical region, Pimplinae and Rhyssinae. To do this I conducted two extensive sampling programs in the Peruvian Amazonia. I examined also a large number of Neotropical ichneumonids deposited to different natural history museums. According to the results of my thesis, the species richness of these parasitoids in the Amazonian region is considerably higher than previously reported. In my research, I firstly further develop the taxonomy of these parasitoids by describing many new species and reporting several new faunistic records (I, II, III). In this first part I focus on two genera (Xanthopimpla and Epirhyssa) which were thought to be rather species poor. My thesis demonstrates that these groups are actually rather species rich in the Amazonian region. Secondly, I concentrate on the species richness of these parasitoids in a global comparison showing that the Neotropical region and especially the Peruvian Amazonia is one of the most species rich areas of Pimpliformes ichneumonids (V). Furthermore, I demonstrate that with the data available to date no clear latitudinal gradient in species richness is visible. Thirdly, increasing the macroecological knowledge of these parasitoids I show that some previously unreported ichneumonid subfamilies are present in the Amazonian region (IV). These new insights and the results of the global comparison of ichneumonid inventories suggest that the previous belief of low diversity in the tropics is most likely related to a lack of sampling effort in the region. Overall, my research increases the knowledge of Neotropical ichneumonids highlighting the importance of Peruvian Amazonia as one of the diversity hotspots of parasitoid wasps.
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This thesis embodies findings on a taxonomical investigation of a group of lower marine invertebrates belonging to the category coelomata. Bryozoans are well known both in fossil and recent taxonomical history. They comprise of about 5,000 living and 16000 fossil species. Bryozoans are well known for their taxonomic abundance and structural diversity,representing the various ecological niches ranging from the intertidal to the abyssal benthic. At a time when global marine biological diversity has become a concern of not only to the scientists but also to the policy makers,an understanding of species diversity and abundance are cardinal aspects of biological studies. Geological time scales which is known that by Pre-Cambrian, marine invertebrate diversity reach the maximum and this diversity has become more comprehensive as time advanced. Taxonomists a vanishing species of scientists have become more concerned in discerning patterns of species diversity. The basic tool for this is identification fo animals. with this idea in mind a detailed study of taxonomy of bryozoan was undertaken . The major part of this thesis is devoted to describe various species of bryozoans with detailed description and ecotypical variations.The pattern of distribution and abundance which are important aspects of animal groups have also been documented. Possible effects of heavy metal contamination on the tolerance and growth of bryozoans, a few species of which have been eliminated from the chronically polluted areas of Cochin backwaters have also been documented.
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Here, we analyze the complete coding sequences of all recognized tick-borne flavivirus species, including Gadgets Gully, Royal Farm and Karshi virus, seabird-associated flaviviruses, Kadam virus and previously uncharacterized isolates of Kyasanur Forest disease virus and Omsk hemorrhagic fever virus. Significant taxonomic improvements are proposed, e.g. the identification of three major groups (mammalian, seabird and Kadam tick-borne flavivirus groups), the creation of a new species (Karshi virus) and the assignment of Tick-borne encephalitis and Louping ill viruses to a unique species (Tick-borne encephalitis virus) including four viral types (i.e. Western Tick-borne encephalitis virus, Eastern Tick-borne encephalitis virus, Turkish sheep Tick-borne encephalitis virus and Louping ill Tick-borne encephalitis virus). The analyses also suggest a complex relationship between viruses infecting birds and those infecting mammals. Ticks that feed on both categories of vertebrates may constitute the evolutionary bridge between the three distinct identified lineages.
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Several species of the genus Rhipsalis (Cactaceae) are extremely important as ornamentals and are endangered in their natural habitat. However, only a few studies have addressed its taxonomy, morphology (including anatomy), phylogeny and evolutionary history. Consequently, the limited knowledge of the genus coupled with the problematic delimitation of species had led to problems in the identification of taxa. In the current work six species of Rhipsalis, R. cereoides, R. elliptica, R. grandiflora, R. paradoxa, R. pentaptera and R. teres were studied to evaluate the relevance of anatomical characters for the taxonomy of the genus. An anatomical characterization of the primary structure of the stem of Rhipsalis is provided highlighting the differences between species. Features of the stem epidermis are found to discriminate best between species and therefore provide clear and useful characters for the separation of species.
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A new genus and species of Normanellidae (Copepoda, Harpacticoida), Paranaiara inajae gen. et sp. nov., is described from the continental shelf off the northern coast of Sao Paulo State, Brazil. The new genus differs from the type genus Normanella Brady, 1880 and Sagamiella Lee & Huys, 1999 in its presence of lamelliform caudal rami, a maxillulary endopod represented by 2 setae, an unarmed maxillipedal syncoxa, and reduced setation on P2 enp-2 (without outer spine) and P3 enp-2 (with only 2 inner setae). All these apomorphic character states are shared with the genus Pseudocletodes Scott & Scott, 1893, formerly placed in the family Nannopodidae (ex Huntemanniidae) and here assigned to the Normanellidae. Pseudocletodes can be differentiated from Paranaiara by the loss of the P1 endopod and of the inner seta on P2-P4 enp-1, the presence of only 2 inner setae on P2 enp-2 (instead of 3) and only 1 inner seta on P4 exp-3 (instead of 2), the presence of a second inner seta on P4 enp-2 (instead of 1), the morphology of the fifth pair of legs which are not medially fused and have only 3 endopodal elements (instead of 4) in the male, and the well developed caudal ramus seta V (instead of rudimentary). It is postulated that prehensility of the P1 endopod was secondarily lost in the common ancestor of Paranaiara and Pseudocletodes. An updated family diagnosis of the Normanellidae and a dichotomous identification key to the 22 currently valid species are presented.
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Xenomorellia Malloch, a subgenus of Morellia Robineau-Desvoidy, is revised to include two new species, Morellia (Xenomorellia) inca Nihei and Carvalho sp. nov. from South America, and M. (X.) maia Carvalho and Nihei sp. nov. from Costa Rica and Mexico. Diagnoses for M. (X.) holti (Malloch) and M. (X.) montanhesa (Albuquerque) are provided, as well as an identification key to the four species of the subgenus. A cladistic analysis was performed to test the monophyly of Xenomorellia and to recover the phylogenetic relationships among its species. Tree searches resulted in one single most-parsimonious cladogram, wherein the monophyly of Xenomorellia is supported, as well as a sister-group relationship with the Neotropical subgenus Trichomorellia Stein. Xenomorellia was divided into two clades: one with Caribbean-Andean species (maia + inca), and another with species from southeastern South America (holti + montanhesa).
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Diaugia angusta Perty, 1833 is a Neotropical species of Tachinidae (Diptera) reported here as a parasitoid of Metamasius ensirostris (Germar, 1824) and M hemipterus (Linnaeus, 1758) (Coleoptera: Dryophthoridae) in Brazil. Several species of Dryophthoridae and Curculionidae cause damage to bromeliad and palm species, and most are regarded as pests. In the present study, the male and female of D. angusta are morphologically characterized and illustrated to provide a means for the identification of this parasitoid. Data obtained from preliminary field research show that natural parasitism of Metamasius pupae by D. angusta varies by year but can reach nearly 30%. A network of parasitoid-host interactions among tachinid parasitoids and coleopteran hosts reported as bromeliad and palm pests (Dryophthoridae and Curculionidae) in the Americas indicates that the species of the tribe Dexiini sensu lam (including D. angusta) might be promising as biological control agents of these pests.
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Flies of the tribe Muscini (Diptera, Muscidae) are worldwide in distribution and are represented by some 350 species in 18 genera. The present study provides an identification key and diagnoses for all the genera of world Muscini: Biopyrellia Townsend, Curranosia Paterson, Dasyphora Robineau-Desvoidy, Deltotus Seguy, Hennigmyia Peris, Mesembrina Meigen, Mitroplatia Enderlein, Morellia Robineau-Desvoidy, Musca Linnaeus, Myiophaea Enderlein, Neomyia Walker, Neorypellia Pont, Polietes Rondani, Polietina Schnabl & Dziedzicki, Pyrellia Robineau-Desvoidy, Pyrellina Malloch, Sarcopromusca Townsend, Ziminellia Nihei & de Carvalho. Most infrageneric taxa are also represented, namely, the sub-genera of Dasyphora and Morellia. Comments on phylogeny support (whenever pertinent) and the major references containing revisions and regional identification keys to species are provided for each genus and subgenus.