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| Registros recuperados: 3.453 | |
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| Xin Wang; Shaolin Zheng. |
| Despite of angiosperms in the Yixian Formation (>125 Ma, early Cretaceous), there is no perfect flower typical of angiosperms to date. Here we report _Euanthus dilaensis_ gen. et sp. nov as the earliest perfect flower known to date. The flower includes tepals, androecium and gynoecium. The anthers are globose in form, with bristles atop and in situ round-triangular pollen grains. The gynoecium is composed of probably two carpels with plumose stigmas and a carpel-enclosing receptacle. The discovery of _Euanthus_ increases the diversity of early angiosperms, and indicates that perfect flowers occurred as early as 125 Ma ago.
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| Tipo: Manuscript |
Palavras-chave: Ecology; Evolutionary Biology. |
| Ano: 2007 |
URL: http://precedings.nature.com/documents/1320/version/1 |
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| Flávio Codeço Coelho; Claudia Codeco; Oswaldo Cruz. |
| The construction of complex statial simulation models such as those used in network epidemiology, is a daunting task due to the large amount of data involved in their parameterization. Such data, which frequently resides on large geo-referenced databases, has to be processed and assigned to the various components of the model. All this just to construct the model, then it still has to be simulated and analyzed under different epidemiological scenarios. This workflow can only be achieved efficiently by computational tools that can automate most if not all these time-consuming tasks. In this paper, we present a simulation software, Epigrass, aimed to help designing and simulating network-epidemic models with any kind of node behavior.
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| Tipo: Manuscript |
Palavras-chave: Bioinformatics. |
| Ano: 2007 |
URL: http://precedings.nature.com/documents/378/version/1 |
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| Tatiana From; Ute K. Petersen; Johannes Isselstein. |
| Grassland management experiment (GrassMan) was set up in 2008 on a permanent semi-natural grassland in the Solling uplands, Germany. The main research focus is on the ecosystem functioning of the phytodiverse grassland (e.g. productivity and forage quality, water and nutrient fluxes). The aim of our study was to analyse the effects of vegetation composition and functional diversity on productivity and forage quality of the semi-natural permanent grassland. Variation in sward composition was achieved by herbicide application and resulted in three sward types: control sward type (without herbicide application), monocot-reduced and dicot-reduced. Further management factors included different nutrient input levels (without fertilizer and 180-30-100 kg/ha of... |
| Tipo: Poster |
Palavras-chave: Ecology; Earth & Environment; Plant Biology. |
| Ano: 2011 |
URL: http://precedings.nature.com/documents/6622/version/1 |
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| Kevin Duffy. |
| Animal movements can influence their ecology and demographics. Animal movements are often characterized by path structures with directional persistence. The extent to which directional persistence improves forage success is investigated in this paper using theoretical simulations. It is shown that a movement strategy with directional persistence enables simulated animals to find more forage as compared to a random movement strategy. Situations where resources are chosen with certainty (optimally) are even more successful. Choosing resource with certainty cannot result in directional persistence. However, in cases where animals choose with certainty adjacent cells with resource but continue in their existing direction if none of these have resources then... |
| Tipo: Manuscript |
Palavras-chave: Ecology. |
| Ano: 2010 |
URL: http://precedings.nature.com/documents/5156/version/1 |
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| Michael E. Baker; Charlie Chandsawangbhuwana. |
| *Background.* The origins of steroid-dependent regulation of the vertebrate estrogen receptor (ER) are poorly understood. Genes with statistically significant sequence similarity to vertebrate ERs have been found in lamprey, a basal vertebrate, and amphioxus, a basal chordate. Motif analysis of these sequences provides an opportunity to investigate early events in the evolution of the ER.
*Results.* We used artificial intelligence-based software to construct twelve motifs specific to the estrogen-binding domain of ER[alpha] and ER[beta] in land vertebrates and teleosts. We mapped these ER-specific motifs onto the sequences of lamprey, amphioxus, invertebrate and selected vertebrate ERs and amphioxus, Ciona and human estrogen-related... |
| Tipo: Manuscript |
Palavras-chave: Cancer; Developmental Biology; Ecology; Evolutionary Biology. |
| Ano: 2008 |
URL: http://precedings.nature.com/documents/1542/version/2 |
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| Sakyasingha Dasgupta; J. Michael Herrmann. |
| Critical behavior in neural networks characterized by scale-free event distributions and brought about by self-regulatory mechanisms such as short-term synaptic dynamics or homeostatic plasticity, is believed to optimize sensitivity to input and information transfer in the system. Although theoretical predictions of the spike distributions have been confirmed by in-vitro experiments, in-vivo data yield a more complex picture which might be due to the in-homogeneity of the network structure, leakage in currents or massive driving inputs which has so far not been comprehensively covered by analytical or numerical studies.

We address these questions by the study of a neural model of memory that allows for storage and... |
| Tipo: Poster |
Palavras-chave: Neuroscience. |
| Ano: 2011 |
URL: http://precedings.nature.com/documents/5829/version/1 |
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| Adeilton Brandao. |
| With the thousands of scientific papers being produced every month, picking an authors name, associate it to a research field and right evaluate his or her performance is in most of times a cumbersome task. I am proposing here that science indexes as h-index, g-index, total citations and published papers could be added to biomedical bibliographic citation in order to create a unique identifier for a given researcher. |
| Tipo: Manuscript |
Palavras-chave: Bioinformatics. |
| Ano: 2007 |
URL: http://precedings.nature.com/documents/794/version/1 |
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| Stuart L. Moodie; Nicolas Le Novere; Emek Demir; Huaiyu Mi; Falk Schreiber. |
| Standard graphical representations have played a crucial role in science and engineering throughout the last century. Without electrical symbolism, it is very likely that our industrial society would not have evolved at the same pace. Similarly, specialized notations such as the Feynmann notation or the process flow diagrams did a lot for the adoption of concepts in their own fields. With the advent of Systems Biology, and more recently of Synthetic Biology, the need for precise and unambiguous descriptions of biochemical interactions has become more pressing. While some ideas have been advanced over the last decade, with a few detailed proposals, no actual community standard has emerged. The Systems Biology Graphical Notation (SBGN) is a graphical... |
| Tipo: Manuscript |
Palavras-chave: Biotechnology; Bioinformatics. |
| Ano: 2011 |
URL: http://precedings.nature.com/documents/3721/version/3 |
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| Gary Griffith; Ross Vennell. |
| The Southern Ocean is considered a zone of high nutrients and low chlorophyll (HNLC). Despite the year round availability of nutrients, phytoplankton biomass remains low. Key modes of control are now thought to be light, grazing, iron and supply of silicic acid^1^. Physiological photoprotective mechanisms used by phytoplankton to regulate photosynthesis versus rapid light fluctuations have not been considered important. In diatoms and haptophytes, which are the major component of phytoplankton biodiversity in the Southern Ocean, the one step de-epoxidation of diadinoxanthin (Dd) into diatoxanthin (Dt) of the Dd-cycle constitutes the main photoprotective mechanism^2,3^. Here we show that Southern Ocean diatoms and haptophytes have higher concentrations of... |
| Tipo: Manuscript |
Palavras-chave: Ecology; Earth & Environment. |
| Ano: 2010 |
URL: http://precedings.nature.com/documents/5377/version/1 |
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| Ulrich Bodenhofer; Andreas Kothmeier; Ingrid G. Abfalter; Carsten C. Mahrenholz; Sepp Hochreiter. |
| Classifying biological sequences is one of the most important tasks in computational biology. In the last decade, support vector machines (SVMs) in combination with sequence kernels have emerged as a de-facto standard. These methods are theoretically well-founded, reliable, and provide high-accuracy solutions at low computational cost. However, obtaining a highly accurate classifier is rarely the end of the story in many practical situations. Instead, one often aims to acquire biological knowledge about the principles underlying a given classification task. SVMs with traditional sequence kernels do not offer a straightforward way of accessing this knowledge.

In this contribution, we propose a new approach to analyzing... |
| Tipo: Poster |
Palavras-chave: Bioinformatics. |
| Ano: 2010 |
URL: http://precedings.nature.com/documents/4708/version/1 |
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| Edgard Bontempo e Silva; Toshihiko Hara; Akihiro Sumida; Kiyomi Ono. |
| Background/Question/Methods 
_Abies sachalinensis_ (Sakhalin Fir) and _Picea glehnii_ (Glehn’s Spruce) are major components of the sub-boreal forests of Hokkaido, Japan. Similar Spruce-Fir forests can be found in many other places in the northern hemisphere and will probably be impacted by global warming. Therefore, detailed knowledge of these species’ physiology and life-history strategies at different growth stages is important to understand present communities and to support reliable prediction of possible consequences of global climate change. 
Accordingly, the objective of this study was to establish relations between community dynamics, life-history strategies and photosynthetic adaptation of... |
| Tipo: Poster |
Palavras-chave: Ecology; Plant Biology. |
| Ano: 2010 |
URL: http://precedings.nature.com/documents/5298/version/1 |
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| Kai Wang; Shile Zhang; Jessica Weber; David Baxter; David J. Galas. |
| The discovery of microRNAs (miRNAs) as a new class of regulators of gene expression has triggered an explosion of research, but has left many unanswered questions about how this regulation works and how it is integrated with other regulatory mechanisms. A number of miRNAs have been found to be present in blood plasma and other body fluids of humans and mice in surprisingly high concentrations. This observation was unexpected in two respects: first, the fact that these molecules are present at all outside the cell at significant concentrations; and second, that these molecules appear to be stable outside of the cell. In light of this it has been suggested that the biological function of miRNAs may also extend outside of the cell and mediate cell-cell... |
| Tipo: Manuscript |
Palavras-chave: Molecular Cell Biology. |
| Ano: 2009 |
URL: http://precedings.nature.com/documents/3718/version/1 |
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| Sohail Ahmad. |
| Previously, the concept of a gestation period of sheep shorter than 121 days was unheard of in the field of sheep biology. Our findings during a farmers’ survey in the Lotkho area of Chitral, Pakistan, revealed that the sheep native to the region, locally called “Kari”, gestates for a period of only three months. This duration is 25-40% short of the usual gestation length and is shorter than ever recorded for the species. The mean and mode gestation length (GL) was 110 and 92 days respectively and was concentrated in three distinct clusters: day 87-95, 120-123 and 151-153, accounting for 52% of all observations. GL was influenced by location, season of conception and lambing and the interaction of location with season; had... |
| Tipo: Manuscript |
Palavras-chave: Ecology. |
| Ano: 2008 |
URL: http://precedings.nature.com/documents/1620/version/1 |
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| Vinita Yadav; Kapil Deo Singh Yadav. |
| Two fungal strains were isolated and tentatively identified as Penicillium VY and Aspergillus VY. All the isolated species show the maximum production on third day in a liquid culture media. The pH optimum was found to be 10.0 for Penicillium VY and 11.0 for Aspergillus VY. The temperature optima were 50ºC in both the cases. The enzyme produced by Penicillium VY was found to be stable in the pH range 3.0-7.0 and 3.0–6.0 in case of Aspergillus VY. The enzyme does not loose activity up to 40º C in case of Penicillium VY and 40ºC in case of Aspergillus VY if exposed for 1 h.
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| Tipo: Poster |
Palavras-chave: Biotechnology; Chemistry; Microbiology. |
| Ano: 2008 |
URL: http://precedings.nature.com/documents/2560/version/1 |
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| Gudmundur A. Thorisson; Mikael Linden; Anthony J. Brookes; Myles Byrne; Juha Muilu; Tommi Nyronen. |
| Motivation for the IRISC workshop came from the observation that identity and digital identification are increasingly important factors in modern scientific research, especially with the now near-ubiquitous use of the Internet as a global medium for dissemination and debate of scientific knowledge and data, and as a platform for scientific collaborations and large-scale e-science activities.

The 1 1/2 day IRISC2011 workshop sought to explore a series of interrelated topics under two main themes: i) unambiguously identifying authors/creators & attributing their scholarly works, and ii) individual identification and access management in the context of identity federations. Specific aims of the workshop... |
| Tipo: Manuscript |
Palavras-chave: Biotechnology; Data Standards. |
| Ano: 2011 |
URL: http://precedings.nature.com/documents/6609/version/1 |
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| Lucie Kalvodova; Yongmin Zhang. |
| In this short report, we demonstrate that liposomes bearing the Lewis X trisaccharide on the surface (“Awesosomes”) efficiently target human dendritic cells. We chose a glycolipid with Lewis X trisaccharide headgroup to facilitate the targeted liposome uptake via the DC-SIGN internalization pathway. While no uptake of Awesosomes was detected with wild-type human HEK293 cells, HEK293 cells transfected with human DC-SIGN internalized Awesosomes extensively. In samples of human blood-derived leukocytes, the extent of uptake of Awesosomes correlated with the expression of DC-SIGN, which is a dendritic cells marker. There was a marked difference in the uptake of Awesosomes and plain liposomes by DC-SIGN expressing dendritic cells. There... |
| Tipo: Manuscript |
Palavras-chave: Immunology; Pharmacology. |
| Ano: 2010 |
URL: http://precedings.nature.com/documents/4764/version/1 |
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| Hasmik S. Movsesyan; Arevik M. Sargsyan; Naira P. Ghazaryan. |
| Much attention in the complex of forest pest control methods nowadays is devoted to the application of biological preparations, especially to bacterial formulations produced on the base of Bacillus thuringiensis (BT) that in addition to their high biological effectiveness against injurious insects are safe for man, homoiоtherms, beneficial insects and fish. As is known only 20-40% of sprayed preparation influences directly on pests while its 60-80% by different ways eventually penetrates into the soil. Taking into account also the fact that usage norm of commercial bacterial preparations makes up to 1-3 kg ha^-1^ and that preparation powder contains 45-100 billion viable spores g^-1^ it becomes evident that as a result of spraying huge quantity... |
| Tipo: Poster |
Palavras-chave: Ecology; Earth & Environment. |
| Ano: 2011 |
URL: http://precedings.nature.com/documents/6426/version/1 |
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| Registros recuperados: 3.453 | |
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