Soil erosion assessment in alpine grasslands using fallout radionuclides: critical points, solutions and applications

Soil erosion processes are one of the main threats to the Alps. They affect slope stability, water budgets, vegetation productivity and the overall biodiversity of the alpine ecosystem. In particular, recent land use and climate changes exacerbated the impact that sheet erosion, a dominant but scarcely visible process, has on alpine grasslands. Yet, the quantitative estimation of the effects of sheet erosion is constrained by the topographic and climatic conditions of the Alps, which hinder the application of conventional assessment techniques. Recently, the use of fallout radionuclides (FRN) as soil erosion tracers showed very promising results in deriving integrated estimates of soil degradation processes affecting alpine soils, over a range of different time scales. Nonetheless, for a correct application of the FRN method, special attention should be paid to three main critical points that are extensively discussed in this thesis, namely: (i) the selection of suitable reference sites; (ii) the selection of the approach (i.e. the traditional approach, the resampling approach, or the repeated sampling approach); and (iii) the selection of the appropriate conversion model. First, we investigated the suitability of undisturbed reference sites in an alpine valley (Urseren Valley, Canton Uri, Switzerland) for the application of 137Cs, the most commonly used FRN for soil erosion studies. In alpine regions, which are heavily affected by the heterogeneous Chernobyl 137Cs fallout and by high geomorphic and anthropogenic activity, the choice of reference sites is a great challenge. To avoid the uncertainties associated with a wrong selection of reference sites, we have developed and proposed the decision support tool CheSS, which allows Checking the Suitability of reference Sites using a repeated sampling strategy and a decision tree. Comparing the 137Cs inventories of reference sites, which have been sampled in two different periods, enables identifying the sites where no soil disturbance processes have occurred and that can be further used as a stable and reliable basis for the application of the method. Chess also directs particular attention to the analysis of the spatial variability of the 137Cs distribution at the sites. The results of the Chess application to our study area imply that no suitable reference sites could be found. As a further step, we have tested the application of a 137Cs repeated sampling approach in the Piora Valley (Canton Ticino, Switzerland), where previous studies have failed to identify undisturbed and homogeneous reference sites. The repeated sampling approach facilitates the derivation of short-term soil redistribution rates by comparing the FRN inventories measured at sampling sites in different times, thus without the need of reference sites. Twelve points located along four transects have been sampled in 2010 and in 2014, and their 137Cs inventory has been compared. The results indicate high soil degradation dynamics, which correspond to a range of yearly soil redistribution rates of 3-36 t ha-1. At both study areas, the high difficulties associated with the use of 137Cs as tracers (i.e. the extremely high small-scale variability of 137Cs distribution) led us to examine the applicability of 239+240Pu (also an artificial FRN), whose presence in the Alps is not connected to the Chernobyl fallout, but mainly to the atmospheric nuclear weapon tests. As a result, its distribution is much more homogeneous compared to 137Cs. 239+240Pu is also preferable to 137Cs, because it has a longer half-life and its measurements are more cost- and time-effective. However, the conversion of 239+240Pu inventories into soil redistribution rates has been impeded by the fact that the available models are not able to describe the specific behavior of Pu isotopes in the soil, as they are mainly designed for 137Cs. Consequently, our energy has been directed towards developing a new conversion model, called MODERN (Modelling Deposition and Erosion rates with fallout RadioNuclides). MODERN is an innovative model based on a single formula that derives both soil erosion and deposition rates. MODERN accurately depicts the soil profile shape of any selected FRN at reference sites and allows the adaptation of the depth profile to simulate the behavior of the FRN under different agro-environmental conditions. A first application of MODERN has been performed on a 239+240Pu dataset collected in the Urseren valley. Thanks to its characteristics and its adaptability, MODERN describes the specific depth distribution of Pu isotopes in the soil better than other models. The MODERN code has been developed in Matlab™ and is publically released on the website of our research group. In order to expand its accessibility, the new package modeRn has been recently developed using the free and open-source system R. modeRn also includes new features that enhance its potential and usability. This thesis offers a detailed overview of the difficulties associated with the application of FRN in alpine areas. It also presents new, effective, and useful tools that help reduce the sources of uncertainty of the FRN method (CheSS) and promote its application to derive soil redistribution rates at different land use conditions (MODERN). Future studies should focus on using precise and accurate FRN-based estimates to validate large-scale modelling techniques, in order to improve the monitoring and identification of soil erosion risk areas in alpine regions

The zone of "becoming": game, text and technicity in videogame narratives

Videogames have emerged as arguably the most prominent form of entertainment in recent years. Their versatility has made them key contributory factors in social, literary, cultural and philosophical discourse; however, critics also tend to see videogames as posing a threat to established cultural parameters. This thesis argues that videogames are firmly grounded in older media and they are important for the development of the notions of textuality, technicity and identity that literary and cultural theories have been debating in recent years. As its point of departure, the thesis takes the contested role of videogames as storytelling media. Challenging the opposition between games and narratives that is posited in earlier research, the framework of the Derridean concept of supplementarity has been adopted to illustrate how the ludic and the narrative inform each other's core, and yet retain their media-specific identities. It is also vital to consider how the technicity and narrative of games inform their perception as texts. Videogames provide a direct illustration of this but they develop on similar principles in earlier media instead of doing something entirely 'new'. The multitelic structure of videogames tends to be looked upon as symptomatic of novelty; in reality, however, they illustrate more clearly the inherent nature of telos in all narrative media

AI and OR in management of operations: history and trends

The last decade has seen a considerable growth in the use of Artificial Intelligence (AI) for operations management with the aim of finding solutions to problems that are increasing in complexity and scale. This paper begins by setting the context for the survey through a historical perspective of OR and AI. An extensive survey of applications of AI techniques for operations management, covering a total of over 1200 papers published from 1995 to 2004 is then presented. The survey utilizes Elsevier's ScienceDirect database as a source. Hence, the survey may not cover all the relevant journals but includes a sufficiently wide range of publications to make it representative of the research in the field. The papers are categorized into four areas of operations management: (a) design, (b) scheduling, (c) process planning and control and (d) quality, maintenance and fault diagnosis. Each of the four areas is categorized in terms of the AI techniques used: genetic algorithms, case-based reasoning, knowledge-based systems, fuzzy logic and hybrid techniques. The trends over the last decade are identified, discussed with respect to expected trends and directions for future work suggested

Why heuristics work

ABSTRACT—The adaptive toolbox is a Darwinian-inspired theory that conceives of the mind as a modular system that is composed of heuristics, their building blocks, and evolved capacities. The study of the adaptive toolbox is descriptive and analyzes the selection and structure of heuristics in social and physical environments. The study of ecological rationality is prescriptive and identifies the structure of environments in which specific heuristics either succeed or fail. Results have been used for designing heuristics and environments to improve professional decision making in the real world. Logic, probability, and heuristics are three central ideas in the intellectual history of the mind. For Aristotle, logic was a theory of ideal human reasoning and inference. Probability theory emerged only late in the mid-17th century, replacing logica

Towards the representation of groundwater in the Joint UK Land Environment Simulator

Groundwater is an important component of the hydrological cycle with significant interactions with soil hydrological processes. Recent studies have demonstrated that incorporating groundwater hydrology in land surface models (LSMs) considerably improves the prediction of the partitioning of water components (e.g., runoff and evapotranspiration) at the land surface. However, the Joint UK Land Environment Simulator (JULES), an LSM developed in the United Kingdom, does not yet have an explicit representation of groundwater. We propose an implementation of a simplified groundwater flow boundary parameterization (JULES‐GFB), which replaces the original free drainage assumption in the default model (JULES‐FD). We tested the two approaches under a controlled environment for various soil types using two synthetic experiments: (1) single‐column and (2) tilted‐V catchment, using a three‐dimensional (3‐D) hydrological model (ParFlow) as a benchmark for JULES’ performance. In addition, we applied our new JULES‐GFB model to a regional domain in the UK, where groundwater is the key element for runoff generation. In the single‐column infiltration experiment, JULES‐GFB showed improved soil moisture dynamics in comparison with JULES‐FD, for almost all soil types (except coarse soils) under a variety of initial water table depths. In the tilted‐V catchment experiment, JULES‐GFB successfully represented the dynamics and the magnitude of saturated and unsaturated storage against the benchmark. The lateral water flow produced by JULES‐GFB was about 50% of what was produced by the benchmark, while JULES‐FD completely ignores this process. In the regional domain application, the Kling‐Gupta efficiency (KGE) for the total runoff simulation showed an average improvement from 0.25 for JULES‐FD to 0.75 for JULES‐GFB. The mean bias of actual evapotranspiration relative to the Global Land Evaporation Amsterdam Model (GLEAM) product was improved from −0.22 to −0.01 mm day−1. Our new JULES‐GFB implementation provides an opportunity to better understand the interactions between the subsurface and land surface processes that are dominated by groundwater hydrology

Challenges in coupling atmospheric electricity with biological systems

The atmosphere is host to a complex electric environment, ranging from a global electric circuit generating fluctuating atmospheric electric fields to local lightning strikes and ions. While research on interactions of organisms with their electrical environment is deeply rooted in the aquatic environment, it has hitherto been confined to interactions with local electrical phenomena and organismal perception of electric fields. However, there is emerging evidence of coupling between large- and small-scale atmospheric electrical phenomena and various biological processes in terrestrial environments that even appear to be tied to continental waters. Here, we synthesize our current understanding of this connectivity, discussing how atmospheric electricity can affect various levels of biological organization across multiple ecosystems. We identify opportunities for research, highlighting its complexity and interdisciplinary nature and draw attention to both conceptual and technical challenges lying ahead of our future understanding of the relationship between atmospheric electricity and the organization and functioning of biological systems

Catching Treacherous Turn: A Model of the Multilevel AI Boxing

With the fast pace of AI development, the problem of preventing its global catastrophic risks arises. However, no satisfactory solution has been found. From several possibilities, the confinement of AI in a box is considered as a low-quality possible solution for AI safety. However, some treacherous AIs can be stopped by effective confinement if it is used as an additional measure. Here, we proposed an idealized model of the best possible confinement by aggregating all known ideas in the field of AI boxing. We model the confinement based on the principles used in the safety engineering of nuclear power plants. We show that AI confinement should be implemented in several levels of defense. These levels include 1) AI design in fail-safe manner 2) limiting its capabilities, preventing self-improving and circuit breakers on treacherous turn 3) isolation from the outside world and, lastly, as the final hope 4) outside measures oriented on stopping AI in the wild. We demonstrate that the substantial number (more than 50 ideas listed in the article) of mutually independent measures could provide a relatively high probability of the containment of a human-level AI but may be not sufficient to preserve runaway of superintelligent AI. Thus, these measures will work only if they are used to prevent superintelligent AI creation, but not for containing superintelligence. We suggest that there could be a safe operation threshold, on which AI is useful, but is not able to hack containment system from the inside, the same way as a safe level of chain reaction inside nuclear power plants is maintained. However, overall, a failure of the confinement is inevitable, so we need to use the full AGI limited number of times (AI-ticks)