123 research outputs found
Impact of stochastic hydrological forcing on root distribution and functioning
No full textThe objective of this thesis is to study and model the influence of climate and soil on the dynamics of root water uptake and root development. The assessment of the vertical root distribution and functioning by means of simple parameters linked to hydrologic, pedologic and vegetation characteristics can be useful for several purposes, both practical and theoretical. The more important novelty brought by this work is the analysis of the effect of the stochasticity of the hydrological forcing on these root dynamics. The stochastic ecohydrological models that we have developed show how different profiles of mean soil moisture influence the shape of the root system and favour different strategies of water uptak
Effect of water table fluctuations on phreatophytic root distribution
No full textThe verticalrootdistributionofriparianvegetationplaysarelevantroleinsoilwaterbalance,inthe
partition ofwater fluxesintoevaporationandtranspiration,inthebiogeochemistryofhyporheic
corridors, inrivermorphodynamicsevolution,andinbioengineeringapplications.Theaimofthiswork
is toassesstheeffectofthestochasticvariabilityoftheriverlevelontherootdistributionof
phreatophyticplants.Afunctiondescribingtheverticalrootprofile hasbeenanalyticallyobtainedby
coupling awhiteshotnoiserepresentationoftheriverlevelvariabilitytoadescriptionofthedynamics
of rootgrowthanddecay.Therootprofile dependsoneasilydeterminedparameters,linkedtostream
dynamics, vegetationandsoilcharacteristics.Theriparianvegetationofarivercharacterizedbyahigh
variabilityturnsouttohavearootingsystemspreadoverlargerdepths,butwithshallowermeanroot
depths. Incontrast,alowerrivervariabilitydeterminesrootprofiles withhighermeanrootdepths
Media Review: Tron
No full textThis review analyzes the film Tron from the perspective of the gamer. In it, the author explores how the both video games and the film are important forms of technology that have influenced society. It argues, Tron is the ultimate video game movie; it contains all the essential elements that comprise an engaging video game, even though it was released before the development of video games as we know them today
Mean root depth estimation at landslide slopes
No full texttPlant rooting systems affect slope stability through the soil reinforcement given by the root network.The vertical root distribution in particular is crucial for the assessment of the critical slip surface in slopestability analyses. We propose here an expeditious way to assess the major characteristics of the rootsystem at landslide slopes.More in detail, we extend and validate an ecohydrological model proposed for flat terrain and water-dependent ecosystems by Laio et al. (2006). This model has the merit to use readily available climaticand pedologic descriptors to predict the mean root depth, but its extension to hillslopes in semi-humidenvironments requires validation. The model has been improved and then tested on a case study innorthern Tuscany (Italy) which considers 17 landslide sites where the tree rooting systems have beenmeasured.The results show a quite good match between observed and modeled mean root depths. The accuracyof the results largely depends on the improvements brought to the model in the parameters estimationphase, in particular through the application of the Curve Number method and through the refinement ofthe definition of the growing season. The results show that in 14 cases out of 17 the error is lower than30%. Furthermore, the error becomes lower than 30% at all sites if we take into account differences amongsoils in the estimation of the portion of precipitation which infiltrates into the soil. These results provethe potential of the proposed method: using few and quite readily available parameters, it allows one todetermine the mean root depths of vegetation with good accuracy: an important parameter for stabilityassessment of vegetated slopes on a large scal
Monte Carlo Tree Search for Simultaneous Move Games: A Case Study in the Game of Tron
No full textMCTS has been successfully applied to many sequential games. This paper investigates Monte Carlo Tree Search (MCTS) for the simultaneous move game Tron. In this paper we describe two different ways to model the simultaneous move game, as a standard sequential game and as a stacked matrix game. Several variants are presented to adapt MCTS to simultaneous move games, such as Sequential UCT, Decoupled UCT, Exp3, and a novel stochastic method based on Regret Matching. Through the experiments in the game of Tron on four different boards, it is shown that Decoupled UCB1-Tuned perform best, winning 62.3% of games overall. We also show that Regret Matching wins 53.1% of games overall and search techniques that model the game sequentially win 51.4-54.3% of games overall
Can diversity in root architecture explain plant water use efficiency? A modeling study
No full texttDrought stress is a dominant constraint to crop production. Breeding crops with adapted root systemsfor effective uptake of water represents a novel strategy to increase crop drought resistance. Due tocomplex interaction between root traits and high diversity of hydrological conditions, modeling providesimportant information for trait based selection. In this work we use a root architecture model combinedwith a soil-hydrological model to analyze whether there is a root system ideotype of general adaptationto drought or water uptake efficiency of root systems is a function of specific hydrological conditions. Thiswas done by modeling transpiration of 48 root architectures in 16 drought scenarios with distinct soiltextures, rainfall distributions, and initial soil moisture availability. We find that the efficiency in wateruptake of root architecture is strictly dependent on the hydrological scenario. Even dense and deep rootsystems are not superior in water uptake under all hydrological scenarios. Our results demonstrate thatmere architectural description is insufficient to find root systems of optimum functionality. We findthat in environments with sufficient rainfall before the growing season, root depth represents the keytrait for the exploration of stored water, especially in fine soils. Root density, instead, especially nearthe soil surface, becomes the most relevant trait for exploiting soil moisture when plant water supplyis mainly provided by rainfall events during the root system development. We therefore concluded thattrait based root breeding has to consider root systems with specific adaptation to the hydrology of thetarget environmen
Pejzaż elekTRONiczny - o znaczeniu multimedialnych paratekstów na przykładzie filmu "TRON: Dziedzictwo"
No full textIn this article the author tries to deal with the common hypothesis about the growing role of multimedia
paratexts in the modern film industry. By analyzing Disney’s highly paratextualized production
TRON: Legacy this article attempts to reveal the very complex multimedia universe that surrounds
the initial text (a movie) and immerses viewers in the fictional world. The main object of
research is a specially designed website which is dedicated to the TRON: Legacy feature and represents
all possible ways of extending cinematic entertainment to social practices, thus creating completely
new ways of “using” a film production. Nonetheless, the question arises: are we dealing (in
such a multiplatform entertainment system) with a new kind of cyberculture which incorporates
our physical world into the imaginative dimension of popular culture? By referring to Derrick de
Kerckhove’s well-known statement about the evolution of the electronic layer that covers our culture
as we know it, the author intends to show TRON: Legacy not only as an entertaining space for
paratextual play, but also as a paratext of the non-elecTRONic space of our existence
ElecTRONic Landscape - the Role of Multimedia Paratexts Based on the Example of TRON: Legacy
No full textIn this article the author tries to deal with the common hypothesis about the growing role of multi-media paratexts in the modern film industry. By analyzing Disney’s highly paratextualized produc-tion TRON: Legacy this article attempts to reveal the very complex multimedia universe that sur-rounds the initial text (a movie) and immerses viewers in the fictional world. The main object of research is a specially designed website which is dedicated to the TRON: Legacy feature and repre-sents all possible ways of extending cinematic entertainment to social practices, thus creating com-pletely new ways of “using” a film production. Nonetheless, the question arises: are we dealing (in such a multiplatform entertainment system) with a new kind of cyberculture which incorporates our physical world into the imaginative dimension of popular culture? By referring to Derrick de Kerckhove’s well-known statement about the evolution of the electronic layer that covers our cul-ture as we know it, the author intends to show TRON: Legacy not only as an entertaining space for paratextual play, but also as a paratext of the non-elecTRONic space of our existence.Piotr Siud
The Attack of the ‘half-formed persons’:the 1811–2 Tron Riot in Edinburgh Revisited
No full textThe existing historiography of crowds and mob behaviour tends to emphasise systemic conflict, or class struggle. As a result, historians have entrenched the ‘protesting crowd’ as the dominant image of past encounters between authority and people. However, what if the riot lay outside the existing nomenclature of social relations? What if, at least on the surface, there was no community to defend, no established grievance, and no negotiation with the authorities to resolve the grievances behind the protests? This article addresses these issues through a forensic examination of the seemingly anarchic Tron riot of 1811–12, using the precognitions of victims and perpetrators – a source untapped by previous historians. Far from being historically unintelligible, the author argues that the actions of the rioters when placed within the context of deteriorating class relations and increased tensions in Edinburgh society in the early nineteenth century are comprehensible. The Tron Riot marked a symbolic turning point in the traditional relationship between the mob and the authorities: negotiation became less dependent on the psychological balance of power but more on open displays of overwhelming coercive power
The signature of randomness in riparian plant root distributions
No full textKnown as "the hidden half", plant roots are fundamental contributors to the riparian ecosystem functioning. Roots show an extraordinary architectural complexity that recalls their remarkable ability to adapt to environmental heterogeneity, resources availability, and climate. In fluvial environments, phreatophytes and hydrophytes cope with flow and sediment processes, and hydrotropism and aerotropism are the main drivers for root growth. In this work, we show how the vertical root density distribution in riparian plants is the result of how plants respond to the random fluctuations of river flows. A root data set from field and controlled outdoor experiments is used in combination with a physically based analytical model to demonstrate that the root vertical density distribution can be ascribed to the interplay of randomness and determinism in a simple mathematical form. The shape of the distribution reflects the profitability of plant roots to grow in different soil layers depending on the soil moisture availability. For the first time, this model helps understanding in an analytical manner the adaptation strategy of plant roots to different scenarios, paving the way for the comprehension of the effects of future changes in climate and environmental condition
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