586 research outputs found
Modelação de organismos com crescimento logarítmico: aplicação às amonites *
This work refers to the development of modelling tools to create Ammonite shells in order to produce animated models for
scientific dissemination and didactic purposes.
In the approach here proposed we assume that the growth of those shells from an initial stage – the protoconch – can be interpreted as a succession of revolutions in turn of a central axis; thus the conch’s section will increase as a non-linear progression. So, we emphasise that the shape of many type of shells, e.g. gastropods and bivalves, is based on the equation of the logarithmic spiral deduced by R. Descartes.
Pixels 3d (Pixels Digital Inc., 2005) is a TCL – scriptable modelling and animation software that allows extendable interapplication communication. Hence a standalone prototype (Shellia) with shell assignable parameters was produced and some of their issues and results will be presented here
Os topónimos algarvios na Paleontologia portuguesa
Since the XIX century, Portuguese and foreign geologists have defined 47 new invertebrate taxa (foraminifera, ostracods,
coelenterates, brachiopods, gastropods, ammonoids, echinoids), 2 new fossil plant taxa (charophyte and pteridophyte) and 1
ichnofossil, using toponymy from the Algarve; these taxa refer to 1 genera, 47 species and 2 varieties.
Besides the Algarve toponym, the most used as specific name, twenty others have been used, mostly from western Algarve; these toponyms are associated to:
– Miocene units, particularly from Ribeira de Cacela and Ferragudo;
– Cretaceous units between Zavial and Marim;
– Upper Jurassic units from Sagres, Carrapateira and Loulé and Middle Jurassic units from Sagres and Guilhim;
– Triassic units from Vila do Bispo to Tavira;
– Carboniferous units, particularly from the Aljezur-Bordeira-Carrapateira region.
The earliest of these designations were attributed to seven gastropods from the Upper Miocene of Cacela (COSTA, 1866-1867).
The majority of the named species are typical of the Algarve, but some have been collected, as well, in the Lusitanian Basin.
Although extensively cited in the geological literature, some of these taxa either do not fulfill the ICZN rules, or fall into
synonymy with previously established taxa, or should be formally considered as non valid names (nomem nudum and nomen oblitum). Only widespread bibliographical review, associated with the palaeontological revision of some of these groups and the
correct interpretation of the ICZN articles, will allow confirming, or not, the doubts that have now arisen
The toponym Lisbon in Portuguese Palaeontology
RESUMO: Desde o século XIX foram definidos um novo género e dezanove
novas espécies de cinco vertebrados e quinze invertebrados utilizando o
topónimo Lisboa. Apesar de muito citados na bibliografia geológica, alguns
dos nomes destes taxa não cumprem as regras do International Code of
Zoological Nomenclature (ICZN) e do International Code of Botanical
Nomenclature (ICBN), caem em sinonímia com outros mais antigos ou
devem ser considerados, formalmente, nomes não válidos.ABSTRACT: Since the nineteenth century one new genus and nineteen
new species of five vertebrates and fifteen invertebrates were defined
using the toponym Lisbon. Although widely cited in the geological literature, some of the names of these taxa do not comply with the rules
of the International Code of Zoological Nomenclature (ICZN) and the
International Code of Botanical Nomenclature (ICBN); they either fall
into synonymity with older designations or should be formally considered as invalid names.info:eu-repo/semantics/publishedVersio
Pela construção de um repositório científico (temático) geológico
e-Terra - Revista Electrónica de Ciências da Terra ISSN 1645-0388, Volume 15 – nº 10 2010É apresentado o panorama actual, nacional e internacional, sobre o Acesso Livre ao
conhecimento científico através da Web. São apresentadas estatísticas que demonstram os benefícios e a utilidade desta nova forma de divulgação do conhecimento, não apenas pelo incremento das citações, mas
também pela formação dos jovens investigadores e, mesmo do ponto de vista ético. São também
apresentadas estatísticas sobre as publicações periódicas de Geologia em Portugal, sobre as quais se
conclui também pela necessidade da constituição de um repositório bibliográfico digital
The toponym Tagus in Portuguese Palaeontology
RESUMO: Desde o século XIX foram definidas sete novas espécies de três
invertebrados, dois microfósseis e de dois vegetais fósseis, utilizando o topónimo Tejo. Apesar de pouco citados na bibliografia geológica, eles cumprem, na generalidade, as regras do International Code of Zoological
Nomenclature (ICZN) e do International Code of Botanical Nomenclature
(ICBN), e são considerados, formalmente, como nomes válidos.ABSTRACT: Since the nineteenth century seven new species of three
invertebrates, two microfossils and two fossil plants were defined using the
toponym of the Tagus River. Although not much cited in the geological
literature, the names of these taxa comply, in general, with the rules of the
International Code of Zoological Nomenclature (ICZN) and the
International Code of Botanical Nomenclature (ICBN) and must be formally
considered as valid names.info:eu-repo/semantics/publishedVersio
Moths and butterflies (Insecta: Lepidoptera) of the Russian Arctic islands in the Barents Sea
Faunistic data are scarce for the Lepidoptera from the Arctic islands of European Russia. New sampling and revision of the earlier findings have revealed the occurrence of 60 species of moths and butterflies on Kolguev, Vaygach and Dolgij Islands and on the Novaya Zemlya archipelago. The faunas of Kolguev and Dolgij Islands (19 and 18 species, respectively) include typical moths of the northern taiga (Aethes deutschiana, Syricoris lacunana and Xanthorhoe designata), and the low numbers of species discovered on these islands have resulted primarily from low collecting efforts. By contrast, the fauna of Vaygach Island (22 species) is relatively well known and includes several high Arctic species, such as Xestia aequaeva, X. liquidaria and X. lyngei. Nevertheless, Vaygach Island is depauperated even relative to the fauna of Amderma (29 species), which is located on the continent next to the Vaygach Island. The fauna of Novaya Zemlya totals 30 species, but only eight of these were collected from the Northern Island, mostly near Matochkin Shar strait. Noteworthy is the record of Plutella polaris from Novaya Zemlya: this species was recently re-discovered in Svalbard, where the type series was collected in 1873. Udea itysalis, described from North America, is reported here for the first time from Europe. The fauna of the Russian Arctic islands in the Barents Sea is dominated by holarctic species, many of which are confined to tundra habitats. We estimate that some 40–60 moth species remain to be found in this region.</p
A sol-gel method for growing superconducting MgB2 films
In this paper we report a new sol-gel method for the fabrication of MgB2
films. Polycrystalline MgB2 films were prepared by spin-coating a precursor
solution of Mg(BH_4)_2 diethyl ether on (001)Al2O3 substrates followed with
annealing in Mg vapor. In comparison with the MgB2 films grown by other
techniques, our films show medium qualities including a superconducting
transition temperature of Tc ~ 37 K, a critical current density of Jc(5 K, 0 T)
~ 5 {\times} 10^6 A cm^{-2}, and a critical field of H_{c2}(0) ~ 19 T. Such a
sol-gel technique shows potential in the commercial fabrication of practically
used MgB2 films as well as MgB2 wires and tapes.Comment: 8 pages, 5 figure
TLR1/TLR2 Heterodimers Play an Important Role in the Recognition of Borrelia Spirochetes
After infection with Borrelia species, the risk for developing Lyme disease varies significantly between individuals. Recognition of Borrelia by the immune system is mediated by pattern recognition receptors (PRRs), such as TLRs. While TLR2 is the main recognition receptor for Borrelia spp., little is known about the role of TLR1 and TLR6, which both can form functionally active heterodimers with TLR2. Here we investigated the recognition of Borrelia by both murine and human TLR1 and TLR6. Peritoneal macrophages from TLR1- and TLR6- gene deficient mice were isolated and exposed to Borrelia. Human PBMCs were stimulated with Borrelia with or without specific TLR1 and TLR6 blocking using specific antibodies. Finally, the functional consequences of TLR polymorphisms on Borrelia-induced cytokine production were assessed. Splenocytes isolated from both TLR1−/− and TLR6−/− mice displayed a distorted Th1/Th2 cytokine balance after stimulation with B.burgdorferi, while no differences in pro-inflammatory cytokine production were observed. In contrast, blockade of TLR1 with specific neutralizing antibodies led to decreased cytokine production by human PBMCs after exposure to B.burgdorferi. Blockade of human TLR6 did not lead to suppression of cytokine production. When PBMCs from healthy individuals bearing polymorphisms in TLR1 were exposed to B.burgdorferi, a remarkably decreased in vitro cytokine production was observed in comparison to wild-type controls. TLR6 polymorphisms lead to a minor modified cytokine production. This study indicates a dominant role for TLR1/TLR2 heterodimers in the induction of the early inflammatory response by Borrelia spirochetes in humans
Revision and Update of the Consensus Definitions of Invasive Fungal Disease From the European Organization for Research and Treatment of Cancer and the Mycoses Study Group Education and Research Consortium.
BACKGROUND: Invasive fungal diseases (IFDs) remain important causes of morbidity and mortality. The consensus definitions of the Infectious Diseases Group of the European Organization for Research and Treatment of Cancer and the Mycoses Study Group have been of immense value to researchers who conduct clinical trials of antifungals, assess diagnostic tests, and undertake epidemiologic studies. However, their utility has not extended beyond patients with cancer or recipients of stem cell or solid organ transplants. With newer diagnostic techniques available, it was clear that an update of these definitions was essential. METHODS: To achieve this, 10 working groups looked closely at imaging, laboratory diagnosis, and special populations at risk of IFD. A final version of the manuscript was agreed upon after the groups' findings were presented at a scientific symposium and after a 3-month period for public comment. There were several rounds of discussion before a final version of the manuscript was approved. RESULTS: There is no change in the classifications of "proven," "probable," and "possible" IFD, although the definition of "probable" has been expanded and the scope of the category "possible" has been diminished. The category of proven IFD can apply to any patient, regardless of whether the patient is immunocompromised. The probable and possible categories are proposed for immunocompromised patients only, except for endemic mycoses. CONCLUSIONS: These updated definitions of IFDs should prove applicable in clinical, diagnostic, and epidemiologic research of a broader range of patients at high-risk
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