Search results for "NCT"
showing 10 items of 16712 documents
Thompson Sampling Based Active Learning in Probabilistic Programs with Application to Travel Time Estimation
2019
The pertinent problem of Traveling Time Estimation (TTE) is to estimate the travel time, given a start location and a destination, solely based on the coordinates of the points under consideration. This is typically solved by fitting a function based on a sequence of observations. However, it can be expensive or slow to obtain labeled data or measurements to calibrate the estimation function. Active Learning tries to alleviate this problem by actively selecting samples that minimize the total number of samples needed to do accurate inference. Probabilistic Programming Languages (PPL) give us the opportunities to apply powerful Bayesian inference to model problems that involve uncertainties.…
Biogeography of Triassic ammonoids
2015
After the end-Permian mass extinction, ammonoids experienced an explosive recovery followed by episodes of radiation and extinction. These events were associated with sudden biogeographic changes often closely related to major climatic and oceanographic changes. Previous biogeographic studies of Triassic ammonoids have rarely focused on a specific time-interval and were rarely based on quantitative methods. Thus, we will first review biogeographical methods and the biogeographical signals known from Triassic ammonoids. Secondly, we will focus on quantitative approaches that improve our knowledge of ammonoid biogeographical structuring and dynamics during the Triassic, and we will discuss co…
Species loss leads to community closure
2008
Global extinction of a species is sadly irreversible. At a local scale, however, extinctions may be followed by re-invasion. We here show that this is not necessarily the case and that an ecological community may close its doors for re-invasion of species lost from it. Previous studies of how communities are assembled have shown that there may be rules for that process and that limitations are set to the order by which species are introduced and put together. Instead of focusing on the assembly process we randomly generated simple competitive model communities that were stable and allowed for two to 10 coexisting species. When a randomly selected single species was removed from the communit…
Ecological Determinants of Distribution Decline and Risk of Extinction in Moths
2006
For successful conservation of species it is important to identify traits that predispose species to the risk of extinction. By identifying such traits conservation efforts can be directed toward species that are most at risk of becoming threatened. We used data derived from the literature to determine ecological traits that affect distribution, distribution change, and the risk of extinction in Finnish noctuid moths (Lepidoptera, Noctuidae). The ecological traits we examined included body size, larval specificity, length of the flight period, and overwintering stage. In addition, in monophagous species we examined the effects of resource distribution. Larval specificity, length of the flig…
Natural Forest Management in Neotropical Mountain Rain Forests — An Ecological Experiment
2008
In tropical forests, the first step in the destruction cycle is usually the over-exploitation of high value timber, leading not only to extinction of the extracted species (Silva Matos and Bovi 2002) but also to the conversion of the forests into pastures in many cases (Wunder 1996b). In many highlands of Ecuador the productivity of the pastures is depleted due to the invasion of bracken fern (see Chapter 28 in this volume), which finally leads again to the conversion of primary forests by local farmers (Paulsch et al. 2001; Hartig and Beck 2003). This process usually is accompanied by loss of biodiversity (Brooks et al. 200 I), increased erosion, changes of hydrology (Bruijnzel 2004), and …
Evidence of a highly complex phylogeographic structure on a specialist river bird species, the dipper (Cinclus cinclus)
2008
This study details the phylogeographic pattern of the white-throated dipper (Cinclus cinclus), a Palearctic, temperate, passerine bird that is exclusively associated with flowing water. Our results reveal a complex phylogeographic structure with at least five distinct lineages for the Western Palearctic region. As for many species of the Western Palearctic fauna and flora, this genetic structure is probably linked to the isolation of populations in different southern refuges during glacial periods. Furthermore, the isolation of populations in Scandinavia and/or Eastern regions, but also in Morocco and probably in Corsica, was accentuated by ecological and biogeographic barriers during Quate…
An Appraisal of Calcium Cyanamide as Alternative N Source for Spring-Summer and Fall Season Curly Endive Crops: Effects on Crop Performance, NUE and …
2020
A two-year study was conducted in both spring-summer and fall seasons to evaluate calcium cyanamide (CaCN2) as an alternative nitrogen (N) source for curly endive (Cichorium endivia L. var. crispum) grown in a Mediterranean environment. Four types of N applications were administered: (i) pre-transplanting base application of 100 kg N ha&minus
Carnivore stable carbon isotope niches reflect predator-prey size relationships in African savannas.
2017
Predator-prey size relationships are among the most important patterns underlying the structure and function of ecological communities. Indeed, these relationships have already been shown to be important for understanding patterns of macroevolution and differential extinction in the terrestrial vertebrate fossil record. Stable isotope analysis (SIA) is a powerful remote approach to examining animal diets and paleodiets. The approach is based on the principle that isotope compositions of consumer tissues reflect those of their prey. In systems where resource isotope compositions are distributed along a body size gradient, SIA could be used to reconstruct predator-prey size relationships. We …
Bridging Ecology and Evolution
2017
Already by the early dawn of evolutionary biology, it was appreciated that ecological differences among species’ habitats, resources, and environments were key drivers of evolution and speciation. Thus, research on interactions between ecology and evolution is not a novel endeavor. It has, however, become increasingly popular to provide these interactions with ‘a new wrapping’, that is, the study of eco-evolutionary dynamics [1]. Consequently, eco-evolutionary dynamics is not a newly developed theory but rather a novel framework within which to study the interplay of ecology and evolution.
Celery (Apium graveolens L.) performances as subjected to different sources of protein hydrolysates
2020
The vegetable production sector is currently fronting several issues mainly connected to the increasing demand of high quality food produced in accordance with sustainable horticultural technologies. The application of biostimulants, particularly protein hydrolysates (PHs), might be favorable to optimize water and mineral uptake and plant utilization and to increase both production performance and quality feature of vegetable crops. The present study was carried out on celery plants grown in a tunnel to appraise the influence of two PHs, a plant-derived PH (P-PH), obtained from soy extract and an animal PH (A-PH), derived from hydrolyzed animal epithelium (waste from bovine tanneries) on yi…