1,071 research outputs found
Geological heritage and high-school students: sedimentary aspects from SW Portugal
The present work intends to expose the interesting sedimentary features which may be observed at the Sudoeste Alentejano e Costa Vicentina Natural Park, envisaging its use for one-day field-trips dedicated to high-school students, as well as for the general public
Ações de transferência de tecnologia de sistemas de integração lavoura-pecuária-floresta 2007-2011.
bitstream/item/55832/1/Revista-iLPF.pd
Os tubarões hybodontiformes (Chondrichthyes: Euselachii) do Jurássico Superior de Torres Vedras, Portugal
ABSTRACT: In this work, the description and classification of a set of fossil shark tooth specimens, from the upper Kimmeridgian-lower Tithonian (Upper Jurassic) of Torres Vedras, was developed. The material, currently
housed in the paleontological collection of Sociedade de História Natural, was collected on the surface of the marine deposits at the top of the Praia Azul Member, Lourinhã Formation, Lusitanian Basin. The attribution of
the specimens to Hybodus cf. reticulatus, was based on the presence of the following most striking characteristics: a reticulated, spongy root, perpendicular to the crown; a completely to almost completely straight main cusp; several straight, well-defined, and parallel ridges that run from the base of the crown to about half of the height of the main cusp; and flat, well-defined cutting edges.RESUMO: No presente trabalho, fez-se a descrição e a classificação de um conjunto de espécimes de dentes fósseis de tubarão, do Kimmeridgiano superior-Tithoniano inferior (Jurássico Superior) de Torres Vedras. O
material, atualmente sediado na coleção paleontológica da Sociedade de História Natural, foi colhido à superfície nos depósitos marinhos do topo do Membro da Praia Azul, Formação da Lourinhã, Bacia Lusitaniana. A atribuição dos espécimes a Hybodus cf. reticulatus, baseou-se na presença das seguintes características mais marcantes: raiz reticulada, esponjosa e perpendicular à coroa; cúspide principal totalmente ou quase totalmente estreita; várias pregas estreitas, bem definidas e paralelas entre si, que
surgem desde a base da coroa até aproximadamente metade da altura da cúspide principal; e bordo cortante liso e bem definido.info:eu-repo/semantics/publishedVersio
New data on the carbonate microfacies from the upper Cenomanian of the Baixo Mondego region (Beira Litoral, Portugal)..
Th e Baixo Mondego region in western Portugal is reknown to expose a large record of middle to upper Cenomanian and lower
Turonian platform carbonates with rich fossil assemblages. Th ere is a huge variety of microfacies that suggests a rather complex palaeo-environmental setting. Several workers initiated their study since the 1960s, but the available information now require being complemented with new relevant bio-stratigraphic and palaeo-ecological data. Within this scope, the upper Cenomanian carbonate levels “C” to “J” of the
Costa d’Arnes Formation were sampled from stratigraphic sections located between the localities of Salmanha, Vila Verde and Lares. A representative collection of 85 thin sections was then prepared for a
micropalaeontological study completed in both the Earth Sciences
Department of the New University of Lisbon and the University of Vigo.
Subsequently, the following planktonic foraminifers were identifi ed in
bioclast-rich, wackstone-packstone, carbonate microfacies: Hedbergella
delrioensis, Heterohelix sp., Guembelitria cretacea, Helvetoglobotruncana
praehelvetica, Rotalipora cushmani, Whiteinella spp., Dicarinella sp.,
and Praeglobotruncana delrioensis. Th ey occur together with the
benthonic foraminifers: Th omasinella punica, Placopsilina cenomana,
Hemicyclammina sigali, Gavelinella sp., Marssonella oxycona, Dorothia
sp., and Ammobaculites spp., and forms attributed to Lenticulina,
Quinqueloculina and Nautiloculina. Other bioclasts include abundant
dasycladacean algae and small fragments of invertebrates, including
sponges, bryozoans, bivalves, gastropods, serpulid worms, echinoids,
and crinoids. Th ese Tethysian-infl uenced assemblages indicate the
presence of a rather distal, mid- to outer-shelf environment with open
marine conditions
Technological evolution and production arrangements of crop-livestock-forestry integration systems in Brazil.
Tubulin and Actin Interplay at the T Cell and Antigen-Presenting Cell Interface
T cells reorganize their actin and tubulin-based cytoskeletons to provide a physical basis to the immune synapse. However, growing evidence shows that their roles on T cell activation are more dynamic than merely serving as tracks or scaffold for different molecules. The crosstalk between both skeletons may be important for the formation and movement of the lamella at the immunological synapse by increasing the adhesion of the T cell to the antigen-presenting cells (APC), thus favoring the transport of components toward the plasma membrane and in turn regulating the T-APC intercellular communication. Microtubules and F-actin appear to be essential for the transport of the different signaling microclusters along the membrane, therefore facilitating the propagation of the signal. Finally, they can also be important for regulating the endocytosis, recycling, and degradation of the T cell receptor signaling machinery, thus helping both to sustain the activated state and to switch it off
Genetic structuring and fixed polymorphisms in the gene period among natural populations of Lutzomyia longipalpis in Brazil
Citation: Costa, C. R. L., Freitas, M. T. D., Figueiredo, C. A. S., Aragao, N. C., da Silva, L. G., Marcondes, C. B., . . . Balbino, V. D. (2015). Genetic structuring and fixed polymorphisms in the gene period among natural populations of Lutzomyia longipalpis in Brazil. Parasites & Vectors, 8, 9. doi:10.1186/s13071-015-0785-6Background: Even one hundred years after being originally identified, aspects of the taxonomy of the sand fly Lutzomyia longipalpis, the principal vector of Leishmania infantum in the Americas, remain unresolved for Brazilian populations of this vector. The diversity of morphological, behavioral, biochemical, and ethological characters, as well as the genetic variability detected by molecular markers are indicative of the presence of a complex of species. Methods: In this study, a 525 bp fragment of the period gene was used to evaluate sympatric populations of L. longipalpis. A combination of probabilistic methods such as maximum likelihood and genetic assignment approach to investigate sympatric species of L. longipalpis were applied in three populations of Northeast Brazil. Results: Fixed polymorphisms in geographically isolated populations of L. longipalpis from two localities in the state of Ceara and one in the state of Pernambuco, Brazil, was identified in a 525 bp fragment of the gene period (per). Our results suggest a direct relationship between the number of spots found in males' tergites and the genetic variation in cryptic species of L. longipalpis. The fragment used in this study revealed the nature of the ancestral morphotype 1S. Conclusion: New polymorphisms were identified in the gene per which can be used as a genetic barcode to sympatric taxonomy of L. longipalpis. The per gene fragment confirmed the presence of two siblings species of L. longipalpis in Sobral and showed that these same species are present in two other localities, representing an expansion within the L. longipalpis species complex with regards to the states of Ceara and Pernambuco
Calcite Scale Inhibition: The Case of Mahanagdong Wells
ABSTRACT The formation of a calcite scale blockage inside the wellbore of a production well has been one of the problems encountered in Mahanagdong. The presence of a calcite blockage was confirmed in at least six (6) wells, which is mainly attributed to high calcite saturation indices in their fluids. These blockages constrict the flow of geothermal fluids in these wells thus significantly reducing their output. Based on production historical data, decline in field steam availability in Mahanagdong-A sector is mainly attributed to this problem. To meet the steam requirement of the MG-A power plant, output of the wells with calcite blockage should be recovered. Thus, mechanical clearing using a drilling rig was conducted in each of the affected wells to remove the blockage. However, due to cost and risk involved in conducting periodic mechanical clearing, the use of a chemical inhibitor in preventing recurrence of calcite blockage deposition inside the wellbore was considered. To date, a calcite inhibition system was already installed in two (2) of the affected wells in Mahanagdong. The calcite inhibition system basically consists of surface injection facility for the preparation and injection of chemical solution and a downhole injection facility to allow injection of chemical solution inside the wellbore of a producing well below the flash point depth. Based on initial results, decline rate in both wells with installed calcite inhibition system has been reduced significantly from an average of 4.0 kg/s-month to less than 0.5 kg/s-month in terms of total massflow
Identificação molecular de cochonilhas-farinhentas (Pseudococcidae) associadas à videira no Submédio São Francisco.
Este trabalho teve como objetivo a identificação de cochonilhas-farinhentas por meio de análise molecular
Production of pions, kaons, and protons as a function of the relative transverse activity classifier in pp collisions at = 13 TeV
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