953 resultados para Didactic sequences


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Parasites are not typically considered to be important components of polar marine ecosystems. It was therefore surprising when 18S rDNA surveys of protists in the West Antarctic Peninsula in winter revealed high abundances of parasite sequences. Parasite sequences made up, on average, over half (52%) of sequence reads in samples from deep water in winter. Winter surface water and sediment samples contained relatively fewer, but still strikingly high, parasite sequence reads (13 and 9%, respectively), while surface water samples in summer contained fewer parasite sequences (1.8%). A total of 1028 distinct parasite Operational Taxonomic Units were observed in winter, with the largest abundances and diversities within Syndiniales groups I and II, including Amoebophrya. Less abundant parasite sequence groups included Apicomplexa, Blastodinium, Chytriodinium, Cryptocaryon, Paradinium, Perkinsidae, Pirsonia and Ichthyophonae. Parasite sequence distributions suggested interactions with known hosts, such as diatom parasites which were mainly in the sediments, where resting spores of Chaetoceros spp. diatoms were abundant. Syndiniales sequences were correlated with radiolarian sequences, suggesting parasite–host interactions. The abundant proportions of parasite sequences indicate a potentially important role for parasites in the Antarctic marine ecosystem, with implications for plankton population dynamics, the role of the microbial loop, carbon flows and ecosystem responses to ongoing anthropogenic climate change.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

[EN] Sea turtles bury their eggs in the sand of the beach, where they incuba te. After a period of approximately two months, hatchlings break the eggshell and remain inside the chamber for three to seven days (Hays & Speakman, 1993). Then they leave the nest and emerge to the surface of the beach, going quickly towards the surf, to begin their pelagic and developmental stage (e.g., López-Jurado & Andreu, 1998). Hatchlings usually do not emerge from the nest as a single group. They emerge in groups at different moments, resulting in more than one emergence per nest during sorne days (Whitherington et al.,4 1990; Hays et al., 1992; Peters et al., 1994).

Relevância:

20.00% 20.00%

Publicador:

Resumo:

AIRES, Kelson R. T. ; ARAÚJO, Hélder J. ; MEDEIROS, Adelardo A. D. . Plane Detection from Monocular Image Sequences. In: VISUALIZATION, IMAGING AND IMAGE PROCESSING, 2008, Palma de Mallorca, Spain. Proceedings..., Palma de Mallorca: VIIP, 2008

Relevância:

20.00% 20.00%

Publicador:

Resumo:

[EN] Gallotia simonyi (Steindachner, 1889) is a member of an endemic Canary Island genus and is among the largest of the approximately 250 recent species of lacertid lizards. Although Steindachner gave the locality of the types as the Roques de Salmor, off El Hierro island, previous workers (Urusaustegui, 1983; Manrique & Saavedra, 1873; Viera & Clavijo, 1983) and subsequent ones (Machado, 1985) regard the more western of the two rocks in the group, the Roque Chico de Salmor, as the actual source of material. The Roque Chico is 37 m high with a surface area of less than 10,000 m2 and lies 830 m from the northern coast of El Hierro (Machado, 1985).

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Hebb proposed that synapses between neurons that fire synchronously are strengthened, forming cell assemblies and phase sequences. The former, on a shorter scale, are ensembles of synchronized cells that function transiently as a closed processing system; the latter, on a larger scale, correspond to the sequential activation of cell assemblies able to represent percepts and behaviors. Nowadays, the recording of large neuronal populations allows for the detection of multiple cell assemblies. Within Hebb's theory, the next logical step is the analysis of phase sequences. Here we detected phase sequences as consecutive assembly activation patterns, and then analyzed their graph attributes in relation to behavior. We investigated action potentials recorded from the adult rat hippocampus and neocortex before, during and after novel object exploration (experimental periods). Within assembly graphs, each assembly corresponded to a node, and each edge corresponded to the temporal sequence of consecutive node activations. The sum of all assembly activations was proportional to firing rates, but the activity of individual assemblies was not. Assembly repertoire was stable across experimental periods, suggesting that novel experience does not create new assemblies in the adult rat. Assembly graph attributes, on the other hand, varied significantly across behavioral states and experimental periods, and were separable enough to correctly classify experimental periods (Naïve Bayes classifier; maximum AUROCs ranging from 0.55 to 0.99) and behavioral states (waking, slow wave sleep, and rapid eye movement sleep; maximum AUROCs ranging from 0.64 to 0.98). Our findings agree with Hebb's view that assemblies correspond to primitive building blocks of representation, nearly unchanged in the adult, while phase sequences are labile across behavioral states and change after novel experience. The results are compatible with a role for phase sequences in behavior and cognition.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In dem Aufsatz werden ausgewählte Ergebnisse aus einem Projekt der qualitativ-empirischen Unterrichtsforschung berichtet, in dem Unterricht zu Themen des Lernbereichs Globale Entwicklung untersucht wurde. Der Fokus des Beitrags liegt auf der Frage, wie Schülerinnen und Schüler mit Handlungsaufforderungen umgehen, die in Lehr-Lernarrangements des Globalen Lernens kommuniziert werden. Beispielhaft werden die Interpretationen von Sequenzen aus dem Unterricht vorgestellt, in denen unterschiedliche Formen des Umgangs mit Handlungsaufforderungen rekonstruiert wurden: die Reflexion über das Nicht-Handeln und die Reflexion über Handlungsaufforderungen als politisches Thema. Dabei kann gezeigt werden, wie Wissen und Kompetenzen von Schülerinnen und Schülern in didaktisch unterschiedlich strukturierten Lehr-Lernarrangements angeeignet werden. (DIPF/Orig.)

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Nucleic acids play key roles in the storage and processing of genetic information, as well as in the regulation of cellular processes. Consequently, they represent attractive targets for drugs against gene-related diseases. On the other hand, synthetic oligonucleotide analogues have found application as chemotherapeutic agents targeting cellular DNA and RNA. The development of effective nucleic acid-based chemotherapeutic strategies requires adequate analytical techniques capable of providing detailed information about the nucleotide sequences, the presence of structural modifications, the formation of higher-order structures, as well as the interaction of nucleic acids with other cellular components and chemotherapeutic agents. Due to the impressive technical and methodological developments of the past years, tandem mass spectrometry has evolved to one of the most powerful tools supporting research related to nucleic acids. This review covers the literature of the past decade devoted to the tandem mass spectrometric investigation of nucleic acids, with the main focus on the fundamental mechanistic aspects governing the gas-phase dissociation of DNA, RNA, modified oligonucleotide analogues, and their adducts with metal ions. Additionally, recent findings on the elucidation of nucleic acid higher-order structures by tandem mass spectrometry are reviewed.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

AIRES, Kelson R. T. ; ARAÚJO, Hélder J. ; MEDEIROS, Adelardo A. D. . Plane Detection from Monocular Image Sequences. In: VISUALIZATION, IMAGING AND IMAGE PROCESSING, 2008, Palma de Mallorca, Spain. Proceedings..., Palma de Mallorca: VIIP, 2008

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This paper includes some fundamental ideas about the theory of didactic transposition of Yve Chevallard (1980), from which it is made an analysis of the knowledge transformation suffers from the mathematical level to the scholastic level. To demonstrate this transformation, it is analyzed the theme of integers, which is included in the seventh- grade curriculum of the educational system of Costa Rica.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Acompanha: Unidade didática: elementos de astronomia e energia

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Acompanha: Da crueldade à duplicidade da alma humana: sequência expandida a partir de clássicos do terror

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Phosphorylation is amongst the most crucial and well-studied post-translational modifications. It is involved in multiple cellular processes which makes phosphorylation prediction vital for understanding protein functions. However, wet-lab techniques are labour and time intensive. Thus, computational tools are required for efficiency. This project aims to provide a novel way to predict phosphorylation sites from protein sequences by adding flexibility and Sezerman Grouping amino acid similarity measure to previous methods, as discovering new protein sequences happens at a greater rate than determining protein structures. The predictor – NOPAY - relies on Support Vector Machines (SVMs) for classification. The features include amino acid encoding, amino acid grouping, predicted secondary structure, predicted protein disorder, predicted protein flexibility, solvent accessibility, hydrophobicity and volume. As a result, we have managed to improve phosphorylation prediction accuracy for Homo sapiens by 3% and 6.1% for Mus musculus. Sensitivity at 99% specificity was also increased by 6% for Homo sapiens and for Mus musculus by 5% on independent test sets. In this study, we have managed to increase phosphorylation prediction accuracy for Homo sapiens and Mus musculus. When there is enough data, future versions of the software may also be able to predict other organisms.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Betanodavirus infections have a significant impact through direct losses and trade restrictions for aquaculture sectors in Australia. The giant grouper, Epinephelus lanceolatus, is a high-value, fast-growing species with significant aquaculture potential. With subacute to chronic mortalities reported from a commercial aquaculture facility in northern Queensland, the viral nervous necrosis in the affected fish was confirmed using a RT-qPCR followed by virus isolation using the SSN-1 cell line. The RNA1 and RNA2 segments were sequenced and nucleotide sequences were compared with betanodavirus sequences from GenBank. Phylogenetic analysis revealed that both these sequences clustered with sequences representing red spotted grouper nervous necrosis virus genotype and showed high sequence identity to virus sequences affecting other grouper species. This is the first report confirming infection by betanodavirus in E. lanceolatus from Australia with successful isolation of the virus in a cell culture system, and analysis of nearly full length RNA1 and RNA2 sequences.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The aim of the present study was to examine the effect of the systematic use of comics as a literary-didactic method to reduce gender differences in reading literacy and reading motivation at the primary level of education. It was assumed that the use of comics would have a positive effect on pupils’ reading literacy and reading motivation, while also reducing the aforementioned differences between boys and girls. The dimensions of reading literacy and reading motivation were examined in experimental and control groups, before and after the intervention, by means of questionnaires and tests for pupils. The sample consisted of 143 pupils from second to fifth grade from two Slovenian primary schools in a rural environment, of which 73 pupils participated in the experimental group and 70 pupils represented the control group. Effects of the use of comics as a literary-didactic method were not found: using comics as a literary-didactic method did not have a statistically significant effect on pupils’ reading literacy and reading motivation. However, when the four-way structure of the research (taking into account the age and gender of the pupils) was considered, some subgroups showed a statistically significant increase in reading interest and attitude towards reading. No reduction of gender differences in reading literacy and reading motivation was found. Based on the results, guidelines for further research are established and suggestions are offered for teachers’ work. (DIPF/Orig.)