931 resultados para plumifer species group
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In this study, the genetic variability among 130 accessions of the Portuguese germplasm collection of Cucurbita pepo L. maintained at the Banco Portugues de Germoplasma Vegetal was assessed using AFLP (amplified fragment length polymorphism) and RAPD (random amplified polymorphic DNA) techniques for the identification of a genetically diverse core group of accessions for field phenotypic analysis. The surprisingly completely different molecular patterns exhibited by multiple accessions was later confirmed in the distribution of the putative C. pepo plants into two clusters drastically separated at a very low level of genetic similarity (DICE coefficient = 0.37). Additional analyses with RAPD and ISSR (inter single sequence repeat) markers and the introduction of standard genotypes of C. maxima L. and C. moschata L. into the analyses allowed the identification of multiple accessions of the last species wrongly included in the C. pepo collection. This study is a good example of the usefulness of DNA markers in the establishment and management of plant germplasm collections.
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Dissertação de Mestrado Integrado em Medicina Veterinária
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Ten species of Copestylum (Diptera: Syrphidae) were reared from fruits and flowers in Costa Rica, Ecuador and Trinidad. Seven were new and in this paper, we describe them, their development sites and the third stage larva and/or the puparium of all ten species. One new synonym is proposed, Copestylum pinkusi (Curran) [= Copestylum cinctiventre (Curran)]. Similarities and differences between these new and other Copestylum species, suggest they separate into two groups, referred to as the Vagum and Cinctiventre species groups. Features characterising these groups for both adult and early stages are assessed. Each species was also distinguished using adult and early stage characters. Within the Vagum group, adults were more disparate morphologically than the larval stage; this was reversed in the Cinctiventre group. Adult colour patterns are probably cryptic in function and for disguise. Vagum species have disruptive marks, while the Cinctiventre species have reflective colours. Biologically, the groups are almost distinguished by larval development sites. Vagum species use predominantly fruits and have a larval stage that is relatively generalised in form and habit. Cinctiventre species are confined to developing in flowers and the larva is more specialised. A key to both adult and early stages of all ten species is provided.
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Purpose: To investigate the occurrence of Listeria spp., (particularly L. monocytogenes ), in different foods and to compare diagnostic tools for their identification at species level. Methods: Samples of high protein foods such as raw meats and meat products and including beef products, chicken, fish and camel milk were analysed for the presence of Listeria spp. The isolates were characterised by morphological and cultural analyses, and confirmed isolates were identified by protein profiling and verified using API Listeria system. Protein profiling by SDS-PAGE was also used to identify Listeria spp. Results: Out of 40 meat samples, 14 (35 %) samples were contaminated with Listeria spp., with the highest incidence (50 %) occurring in raw beef products and raw chicken. Protein profiling by SDSPAGE was used to identify Listeria spp. The results were verified with API Listeria system. Approximately 25 % of the identified isolates were Listeria seeligeri , Listeria welshimeri , and Listeria grayi (three positive samples), while 16.66 % of the isolates were Listeria monocytogenes (two positive samples); 16.6 % of the isolates were Listeria innocua (two positive samples), while 8.3 % of the isolates were Listeria ivanovii (one positive sample). Conclusion: High protein foods contain different types of Listeria species; whole-cell protein profiles and API Listeria system can help in the identification of Listeria at the species level.
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In this study, the genetic variability among 130 accessions of the Portuguese germplasm collection of Cucurbita pepo L. maintained at the Banco Portugues de Germoplasma Vegetal was assessed using AFLP (amplified fragment length polymorphism) and RAPD (random amplified polymorphic DNA) techniques for the identification of a genetically diverse core group of accessions for field phenotypic analysis. The surprisingly completely different molecular patterns exhibited by multiple accessions was later confirmed in the distribution of the putative C. pepo plants into two clusters drastically separated at a very low level of genetic similarity (DICE coefficient = 0.37). Additional analyses with RAPD and ISSR (inter single sequence repeat) markers and the introduction of standard genotypes of C. maxima L. and C. moschata L. into the analyses allowed the identification of multiple accessions of the last species wrongly included in the C. pepo collection. This study is a good example of the usefulness of DNA markers in the establishment and management of plant germplasm collections.
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Purpose: To characterise the phytochemical profile of whole plants of Centaurea balsamita, C. depressa and C. lycopifolia with LC-ESI-MS/MS, and as well as their antioxidant, anticholinesterase and antimicrobial activities. Methods: Organic and aqueous extracts of the three Centaurea species were evaluated for DPPH free radical, ABTS cation radical scavenging and cupric reducing antioxidant capacity (CUPRAC). Acetyland butyryl-cholinesterase enzyme inhibition abilities of the extracts using petroleum ether, acetone, methanol and water were studied to determine anticholinesterase activity, while antimicrobial activity was determined by disc diffusion method using appropriate antimicrobial standards and organisms. The phytochemical components of the methanol extracts were assessed by LC-MS/MS. Results: The methanol extract of C. balsamita exhibited much higher DPPH free and ABTS cation radicals scavenging activities (with IC50 of 62.65 ± 0.97 and 24.21 ± 0.70 mg/ml, respectively) than the other extracts. The petroleum ether extracts of the plant species exhibited moderate inhibitory activity against butyrylcholinesterase enzymes while the acetone extract of C. balsamita showed good antifungal activity against Candida albicans. Quinic acid (17513 ± 813 μg/g, 63874 ± 3066 μg/g and 108234 ± 5195 μg/g) was the major compound found in the methanol extracts of C. balsamita, C. depressa and C. Lycopifolia, respectively. Conclusion: These results indicate quinic acid is the major compound in the three plant species and that Centaurea balsamita has significant antioxidant, anticholinesterase and antimicrobial properties. Further studies to identify the compounds in the extracts responsible for the activities are required.
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Tricodinídeos são protozoários ciliados móveis com ampla distribuição mundial; são considerados um dos agentes parasitários que mais acometem peixes cultivados. No Brasil, a maioria dos tricodinídeos que parasitam importantes espécies de peixes cultivados são desconhecidos, o que requer mais estudos taxonômicos com esse grupo de parasitos. Este estudo caracteriza morfologicamente Trichodina colisae Asmat & Sultana, 2005 de pacu (Piaractus mesopotamicus) e do híbrido patinga (P. mesopotamicus × P. brachypomus) cultivados, respectivamente, no Centro-Oeste e Sudeste do Brasil. Foram feitas montagens a fresco do raspado de muco da pele, nadadeiras e brânquias, fixados com metanol e, posteriormente, impregnados com nitrato de prata e coradas com Giemsa para avaliação em microscopia óptica. O presente estudo relata não só a segunda ocorrência de T. colisae no mundo, mas também a primeira ocorrência na América do Sul.
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Many vertebrates are known to show behavioural lateralization, whereby they differentially use one side of their body or either of their bilateral organs or limbs. Behavioural lateralization often manifests in a turning bias in fishes, with some individuals showing a left bias and others a right bias. Such biases could be the source of considerable conflict in fish schools given that there may be considerable social pressure to conform to the group to maintain effective group evasion. Here, we show that predation pressure is a major determinant of the degree of lateralization, both in a relative and absolute sense, in yellow-and-blueback fusiliers (Caesio teres), a schooling fish common on coral reefs. Wild-caught fish showed a bias for right turning. When predation pressure was experimentally elevated or relaxed, the strength of lateralization changed. Higher predation pressure resulted in an increase in the strength of lateralization. Individuals that exhibited the same turning bias as the majority of individuals in their group had improved escape performance compared with individuals that were at odds with the group. Moreover, individuals that were right-biased had improved escape performance, compared with left-biased ones. Plasticity in lateralization might be an important evolutionary consequence of the way gregarious species respond to predators owing to the probable costs associated with this behaviour.
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The species and size selectivity of long-lines using small hooks were studied off the south coast of Portugal using ''Mustad'' brand round bent, flatted sea hooks (Quality 2316 DT) numbers 15, 13, and 11 baited with razor shell clam (Ei-isis siliqua). Hook numbers 13 and 11 are 49 and 109% larger respectively than number 15 hooks in terms of overall size (maximum width x maximum length). A total of 39 900 hooks were fished in 45 sets and 35 species of fish and cephalopods were caught. As a group, 13 species of sea breams (Sparidae) dominated the catch by numbers (58%) and weight (73%). Six species of sea breams, along with the greater weever fish (Trachinus draco) accounted for 81% of the total catch by weight, with the common or white sea bream (Diplodus sargus) bring the most important (29%). Catch size distributions by hook size were, in general, highly overlapped for all species and hook size had little apparent effect on minimum size at capture. All hooks caught a wide range of sizes per species, but the catch rate (number of fish per 100 hooks) was significantly lower for the largest hook. Except for the black sea bream (Spondyliosoma cantharus), capture of illegally sized or immature fish was minimal. Small increases in average size with hook size were evident for four species: Diplodus sargus, D. vulgaris, Lithognathus mormyrus and Serranus cabrilla. No differences in size selectivity were detected for Boops boops, D. annularis, Spondyliosoma cantharus and Trachinus draco. A skew-normal model adequately described differences in size selectivity in five of six species. (C) 1996 International Council for the Exploration of the Sea
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We identified and quantified the effect of season, depth, and inner and outer panel mesh size on the trammel net catch species composition and catch rates in four southern European areas (Northeast Atlantic: Basque Country, Spain; Algarve, Portugal; Gulf of Cadiz, Spain; Mediterranean: Cyclades, Greece), all of which are characterised by important trammel net fisheries. In each area, we conducted, in 1999-2000, seasonal, experimental fishing trials at various depths with trammel nets of six different inner/outer panel mesh combinations (i.e., two large outer panel meshes and three small inner panel meshes). Overall, our study covered some of the most commonly used inner panel mesh sizes, ranging from 40 to 140 mm (stretched). We analysed the species composition and catch rates of the different inner/outer panel combinations with regression, multivariate analysis (cluster analysis and multidimensional scaling) and other 'community' techniques (number of species, dominance curves). All our analyses indicated that the outer panel mesh sizes used in the present study did not significantly affect the catch characteristics in terms of number of species, catch rates and species composition. Multivariate analyses and seasonal dominance plots indicated that in Basque, Algarve and Cyclades waters, where sampling covered wide depth ranges, both season and depth strongly affected catch species compositions. For the Gulf of Cadiz, where sampling was restricted to depths 10-30 m, season was the only factor affecting catch species composition and thus group formation. In contrast, the inner panel mesh size did not generally affect multidimensional group formation in all areas but affected the dominance of the species caught in the Algarve and the Gulf of Cadiz. Multivariate analyses also revealed 11 different metiers (i.e., season-depth-species-inner panel mesh size combinations) in the four areas. This clearly indicated the existence of trammel net 'hot spots', which represent essential habitats (e.g., spawning, nursery or wintering grounds) of the life history of the targeted and associated species. The number of specimens caught declined significantly with inner panel mesh size in all areas. We attributed this to the exponential decline in abundance with size, both within- and between-species. In contrast, the number of species caught in each area was not related to the inner mesh size. This was unexpected and might be a consequence of the wide size-selective range of trammel nets. (c) 2006 Elsevier B.V All rights reserved.
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Global biodiversity patterns are often driven by diff erent environmental variables at diff erent scales. However, it is still controversial whether there are general trends, whether similar processes are responsible for similar patterns, and/or whether confounding eff ects such as sampling bias can produce misleading results. Our aim is twofold: 1) assessing the global correlates of diversity in a group of microscopic animals little analysed so far, and 2) inferring the infl uence of sampling intensity on biodiversity analyses. As a case study, we choose rotifers, because of their high potential for dispersal across the globe. We assembled and analysed a new worldwide dataset of records of monogonont rotifers, a group of microscopic aquatic animals, from 1960 to 1992. Using spatially explicit models, we assessed whether the diversity patterns conformed to those commonly obtained for larger organisms, and whether they still held true after controlling for sampling intensity, variations in area, and spatial structure in the data. Our results are in part analogous to those commonly obtained for macroorganisms (habitat heterogeneity and precipitation emerge as the main global correlates), but show some divergence (potential absence of a latitudinal gradient and of a large-scale correlation with human population). Moreover, the eff ect of sampling eff ort is remarkable, accounting for 50% of the variability; this strong eff ect may mask other patterns such as latitudinal gradients. Our study points out that sampling bias should be carefully considered when drawing conclusions from large-scale analyses, and calls for further faunistic work on microorganisms in all regions of the world to better understand the generality of the processes driving global patterns in biodiversity.
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Bitter taste has been extensively studied in mammalian species and is associated with sensitivity to toxins and with food choices that avoid dangerous substances in the diet. At the molecular level, bitter compounds are sensed by bitter taste receptor proteins (T2R) present at the surface of taste receptor cells in the gustatory papillae. Our work aims at exploring the phylogenetic relationships of T2R gene sequences within different ruminant species. To accomplish this goal, we gathered a collection of ruminant species with different feeding behaviors and for which no genome data is available: American bison, chamois, elk, European bison, fallow deer, goat, moose, mouflon, muskox, red deer, reindeer and white tailed deer. The herbivores chosen for this study belong to different taxonomic families and habitats, and hence, exhibit distinct foraging behaviors and diet preferences. We describe the first partial repertoires of T2R gene sequences for these species obtained by direct sequencing. We then consider the homology and evolutionary history of these receptors within this ruminant group, and whether it relates to feeding type classification, using MEGA software. Our results suggest that phylogenetic proximity of T2R genes corresponds more to the traditional taxonomic groups of the species rather than reflecting a categorization by feeding strategy.
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Os gradientes altitudinais são importantes modelos em ecologia pois permitem, numa escala reduzida, estudar a influência da variação de diversas variáveis ambientais nos padrões de biodiversidade existentes. Estes padrões são influenciados por diversos factores, desde variáveis climáticas às relacionadas com a perturbação humana. Nesta tese é estudada a variação na composição das comunidades de borboletas ao longo do gradiente altitudinal na Serra da Estrela e são testadas duas hipóteses sobre os padrões de riqueza específica ao longo do gradiente altitudinal: a regra de Rapoport e o “Mid Domain Effect” (MDE). Foram assinaladas 70 espécies de borboletas neste estudo e constatou-se que a variação na riqueza de espécies de borboletas apresenta um padrão “mid peak” apoiando o MDE. Verificou-se também que as comunidades de borboletas do mesmo nível altitudinal são mais semelhantes entre si independentemente da vertente em que se encontram e são também mais semelhantes com as comunidades dos níveis altitudinais adjacentes. Finalmente, a análise da distribuição de algumas espécies ameaçadas de borboletas torna evidente a necessidade de realização de mais estudos sobre a biologia da conservação deste grupo de animais em Portugal; Abstract: Altitudinal gradients are important ecological models because they allow us to study the influence of diverse environmental variables in the existing biodiversity patterns. These patterns are influenced by various factors, from climatic variables to variables related to human disturbance. In this thesis we studied the variations in the composition of the butterfly assemblages along the altitudinal gradient of Serra da Estrela and we tested two hypotheses regarding the species richness patterns along the altitudinal gradient: Rapoport’s rule and the Mid Domain Effect (MDE). In this study 70 butterfly species were marked recorded and it was observed that the butterfly species richness presents a mid-peak pattern supporting the MDE. It was also noted that the butterfly assemblages in the same altitudinal level show more similarity within themselves regardless of the slope they are found in, and are also more similar to the assemblages present in the adjacent altitudinal levels. Finally, the distribution of some threatened butterfly species was analyzed and it became evident the need to do more studies regarding the conservation biology of this animal group in Portugal.
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Knowledge of the geographical distribution of timber tree species in the Amazon is still scarce. This is especially true at the local level, thereby limiting natural resource management actions. Forest inventories are key sources of information on the occurrence of such species. However, areas with approved forest management plans are mostly located near access roads and the main industrial centers. The present study aimed to assess the spatial scale effects of forest inventories used as sources of occurrence data in the interpolation of potential species distribution models. The occurrence data of a group of six forest tree species were divided into four geographical areas during the modeling process. Several sampling schemes were then tested applying the maximum entropy algorithm, using the following predictor variables: elevation, slope, exposure, normalized difference vegetation index (NDVI) and height above the nearest drainage (HAND). The results revealed that using occurrence data from only one geographical area with unique environmental characteristics increased both model overfitting to input data and omission error rates. The use of a diagonal systematic sampling scheme and lower threshold values led to improved model performance. Forest inventories may be used to predict areas with a high probability of species occurrence, provided they are located in forest management plan regions representative of the environmental range of the model projection area.