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| Registros recuperados: 900 | |
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| Petanidou, T.; Van Laere, A.; Ellis, W.; Smets, E.. |
| We studied the amino acid (AA) composition of the floral nectars of 73 plant species occurring in a phryganic (East Mediterranean garrigue) community and investigated whether AA and sugar composition is shaped by evolutionary (plant phylogeny), ecological (flowering time as a direct effect of summer drought) and coevolutionary (pollinator partnership) constraints. Our study utilised an extensive plantpollinator matrix compiled in the same area where the plants had been sampled. Using HPLC we detected 22 AA compounds/groups of compounds, out of which 15 were commonly present in almost all nectars. Among all AAs, phenylalanine was the most abundant, especially in keystone (ââcornucopianââ) plant species visited by many insect species, such as the... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Floral nectar; Composition; Mediterranean; Evolution; Ecology; Coeveloution. |
| Ano: 2006 |
URL: http://www.repository.naturalis.nl/record/407342 |
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| Marques, João Carlos; Bellan-Santini, Denise. |
| Amphipods from the Portuguese south and south-western continental shelf were studied with regard to the species inventory, distribution, and ecology. This study allowed the identification of 113 species, belonging to 52 genera; of these species 28 are recorded for the first time along the Portuguese coast. Two species, Ampelisca heterodactyla Schellenberg, 1925, and A. latifrons Schellenberg, 1925, are redescribed. The latter is different from the Ampelisca named latifrons by Ledoyer in 1972 and 1982. The absolute frequencies and abundances of the species, and their distribution in terms of bathymetry and type of substrate are also analysed. The most frequent and abundant species also presented wide ranges of vertical distribution. In addition, these... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Gammaridea; Caprellidea; Taxonomy; Distribution; Ecology; Portugal. |
| Ano: 1991 |
URL: http://www.repository.naturalis.nl/record/504578 |
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| Breure, A.S.H.. |
| In this publication a revision is given of the genera of the subfamily Bulimulinae (Gastropoda, Pulmonata, Bulimulidae). The morphological variation of the shell, radula, pallial organs and genitalia is analized and 21 character transition series are recognized. In the systematical part the following data are presented for each genus : description of shell and anatomy, distribution, ecology, bibliography and a list of taxa. The number of (sub) genera is reduced from 80 to 43 ( + two nomina inquirenda). A new synonymy is : Paracochlea Hylton Scott, 1967 = Eudioptus Albers, 1860. The following new species names are introduced : Bostryx sophieae, Drymaeus (Drymaeus) marcapatensis, Drymaeus (Drymaeus) sophieae, Drymaeus (Mesembrinus) pseudobesus. Berendtia... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Gastropoda; Pulmonata; Bulimulidae; Revision; Description; Distribution; Ecology; 42.73. |
| Ano: 1979 |
URL: http://www.repository.naturalis.nl/record/323943 |
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| Spoel, S. van der. |
| Biodiversity can be considered to be a human appreciation of the biological entity diversity. Diversity can be expressed numerically on the basis of taxa found, but it can also be expressed as the contribution of a specimen to the diversity, for which a formula is proposed. Diversity is the sum of the taxonomic or numerical diversity, and the ecological, genetical, historical, and phylogenetic diversity. Moreover, each group, or larger taxon, has its own characteristic diversity. These types of diversity are considered separately. One formula is tentatively proposed to calculate the overall diversity. Diversity in nature is variable, which is demonstrated in a diagram for comparison with societyinduced diversity changes. Diversity in the pelagic fluctuates... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Biodiversity; Diversity calculation; Ecology; Pelagic; Phylogeny. |
| Ano: 1994 |
URL: http://www.repository.naturalis.nl/record/504018 |
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| Willemse, F.; Helversen, O. von; Odé, B.. |
| This paper presents a summary of the current knowledge on the systematics of the Greek taxa of Chorthippus, morphologically characterised by angled lateral pronotal keels (usually grouped as Glyptobothrus). Prior to this paper, based on traditional morphology, ten taxa of Chorthippus with angled lateral pronotal keels were recognized from Greece. Based on morphology as well as (and more importantly so) bioacoustics thirteen Greek taxa are now recognised. With addition of a few additional related taxa that occur only outside Greece, all are treated in this paper: Chorthippus apricarius apricarius (Linnaeus, 1758), C. vagans vagans (Eversmann, 1848) (not in Greece), C. v. cypriotus (Uvarov, 1936) stat. nov. [Cyprus], C. v. africanus Nadig, 1981 [N. Africa],... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Chorthippus; Glyptobothrus; Greece; Acrididae; Orthoptera; Morphology; Bioacoustics; Taxonomy; Variability; Transitional or hybrid populations; Phylogeny; Evolution; Palaeobiogeography; Key; Distribution; Ecology; 42.75. |
| Ano: 2009 |
URL: http://www.repository.naturalis.nl/record/314191 |
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| Calder, D.R.; Maÿal, E.M.. |
| Hydroid distribution patterns along a horizontal ecocline in the Rio Formoso/Rio Ariquindá/Rio Porto Alegre system, a small and seasonally poikilohaline estuary on the tropical northeast coast of Brazil, were investigated. Collecting was undertaken during the dry season, in November 1993, by diving (with and without SCUBA). Nine stations were sampled on a transect extending from a reef outside the river mouth to a mangrove system at the upper end of the estuary. Four major regions were distinguished along the ecocline based on numerical analyses of hydroid species/station location data: (1) nearshore reef — a sandstone ledge outside the entrance of the estuary; (2) river mouth — a sandy and shelly flood-tidal delta area inside the entrance of the Rio... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Cnidaria; Hydrozoa; Hydroids; Estuary; Zonation; Distribution; Ecology; Brazil.; 42.72. |
| Ano: 1998 |
URL: http://www.repository.naturalis.nl/record/317616 |
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| Baoping Ren; Dayong Li; Zhijin Liu; Hua Wu; Ming Li. |
| If it is true that extant primates evolved from an insectivorous ancestor, then primate entomophagy would be a primitive trait. Many taxa, however, have undergone a dietary shift from entomophagy to phytophagy, evolving a specialised gut and dentition and becoming exclusive herbivores. The exclusively herbivorous taxa are the Malagasy families Indriidae and Lepilemuridae, and the Old World Monkey subfamily Colobinae, and among these meat-eating has not been observed except as an anomaly, with the sole exception of the Hanuman langur (_Semnopithecus entellus_), which feeds on insects seasonally, and a single observation of a nestling bird predated by wild Sichuan snub-nosed monkeys (_Rhinopithecus roxellana_). Here, we describe the regular capture of... |
| Tipo: Manuscript |
Palavras-chave: Ecology. |
| Ano: 2009 |
URL: http://precedings.nature.com/documents/3021/version/1 |
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| Quddus Khan; Munawer Khan. |
| Acclimation of the waterflea Daphnia magna Straus (Crustacea: Cladocera) at 2 o to 12 o C above their habitat temperature (16 o C) for 6 months increased the rate of their metabolic activity (respiration and heartbeat rates). Temperature-enhanced activity appeared to be supported by cellular ATP synthesis (increased cytochrome c oxidase and succinic dehydrogenase activities) and hydrolysis (increased ATPases activities), indicating high rate of intermediary metabolism, the substrates for which may come from the stored glycogen and fat in addition to ingested food. Temperature-enhanced activity was associated with loss of body mass and decrease in body size, both of which may result from hyperactivity (causing lack of replenishment of consumed stored... |
| Tipo: Manuscript |
Palavras-chave: Ecology; Earth & Environment. |
| Ano: 2008 |
URL: http://precedings.nature.com/documents/1909/version/1 |
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| Wei Sheng Zeng; Shou Zheng Tang. |
| To implement monitoring and assessment of national forest biomass, it is becoming the trend to develop generalized single-tree biomass models suitable for large scale forest biomass estimation. Considering that the theoretical biomass allometric model developed by West et al. [1,2] was statistically different from the empirical one, the two parameters in the most commonly used biomass equation M=aDb were analyzed in this paper. Firstly, based on the knowledge of geometry, the theoretical value of parameter b was deduced, i.e., b=7/3(~2.33), and the comparison with many empirical studies conducted throughout the globe indicated that the theoretical parameter could describe soundly the average allometric relationship between aboveground biomass M and D... |
| Tipo: Manuscript |
Palavras-chave: Ecology. |
| Ano: 2011 |
URL: http://precedings.nature.com/documents/6704/version/2 |
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| Roderic Page. |
| The fact that all living organisms are related by common descent is one of the central principles of modern biology. Since the early 1990's the amount of data available to evolutionary biologists has exploded, and Elsevier’s journal _Molecular Phylogenetics and Evolution_, has become the largest single publisher of evolutionary trees (phylogenies). These trees and their supporting data potentially form a tremendous resource for biologists, with applications in genomics, evolutionary biology, biodiversity, and public health. However, most published trees are not available in any public database, but instead languish as images, "locked up" in the pages of journals. A long term solution to this problem is to invert the... |
| Tipo: Manuscript |
Palavras-chave: Ecology; Bioinformatics. |
| Ano: 2008 |
URL: http://precedings.nature.com/documents/2217/version/1 |
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| Romulus Breban; Virginie Supervie; Justin Okano; Raffaele Vardavas; Sally Blower. |
| The Centers for Disease Control (CDC) is currently attempting to eliminate syphilis in the United States (US); to ensure that their control strategies will be effective it is important to understand the transmission dynamics of syphilis. Epidemics of certain infectious diseases (e.g., influenza) can rise and fall with a well-defined periodicity; this cycling behavior is important because it can have significant implications for the design and effectiveness of control strategies. Here we discuss the methodology that has been used to identify epidemic cycles in longitudinal data sets, and the endogenous and exogenous mechanisms that generate cycling. We then examine the recently proposed hypothesis that syphilis epidemics cycle. This hypothesis was proposed... |
| Tipo: Manuscript |
Palavras-chave: Ecology. |
| Ano: 2007 |
URL: http://precedings.nature.com/documents/1373/version/1 |
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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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| 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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| Registros recuperados: 900 | |
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