Detecting independence of random vectors: generalized distance covariance and Gaussian covariance

Distance covariance is a quantity to measure the dependence of two random vectors. We show that the original concept introduced and developed by Sz\'{e}kely, Rizzo and Bakirov can be embedded into a more general framework based on symmetric L\'{e}vy measures and the corresponding real-valued continuous negative definite functions. The L\'{e}vy measures replace the weight functions used in the original definition of distance covariance. All essential properties of distance covariance are preserved in this new framework. From a practical point of view this allows less restrictive moment conditions on the underlying random variables and one can use other distance functions than Euclidean distance, e.g. Minkowski distance. Most importantly, it serves as the basic building block for distance multivariance, a quantity to measure and estimate dependence of multiple random vectors, which is introduced in a follow-up paper [Distance Multivariance: New dependence measures for random vectors (submitted). Revised version of arXiv: 1711.07775v1] to the present article.Comment: Published at https://doi.org/10.15559/18-VMSTA116 in the Modern Stochastics: Theory and Applications (https://www.i-journals.org/vtxpp/VMSTA) by VTeX (http://www.vtex.lt/

Environmental benefits of a circular economy : connecting waste type and geographic proximity

Introduction: The aim of a circular economy is to transform waste into resources. There is a plethora of waste and by-products that remain unused in the traditional linear industrial system. However, transformation from a linear to a circular system is challenging, limited by several constraints such as the availability of information on the specific composition of the waste, the availability in time and space, the quantity of waste, as well as limited knowledge of the usability of such waste products. These challenges are exacerbated by the initial effort needed for implementation before an economy benefits from economic, ecological or societal improvements. Nevertheless, a circular economy generates less waste and consumes fewer resources, which in return makes it more profitable due to cost savings enabled by efficient resource use. The goal of the SHAREBOX project is the development of a platform for the facilitation of synergies within the industry to enable a more circular flow of resources within the European process industries. The project consortium has 15 partners including research organisations, SMEs and industrial partners as well as market actors and is part of the EU framework program Horizon 2020. Materials and Methods: The SHAREBOX platform is a database of available waste and resources required by companies, enabling the transformation of waste to resources by matching of two demands. The platform also serves as the first point of contact between different partners in a circular system. Furthermore, the platform enables the identification of new synergies overarching the different subsectors of the industries as well as optimal matching from the perspective of a circular economy. The key objectives are the facilitation of circular synergies through information and communications technology, the provision of information required to realise circular synergies within European industries and the identification of new circular synergies. Results and Discussion: The results of circular industry systems facilitated by the National Industrial Symbiosis Program (NISP) in the United Kingdom show a substantial reduction in the consumption of resources and generation of emissions compared to linear systems. Nevertheless, if there is a plethora of different types of waste, there is also a plethora of different synergies. This leads to different results for each type of waste that is transformed to a resource. Furthermore, the life cycle stage of transformation also has to be included. A transformation such as the reuse of polyethylene terephthalate (PET) can lead to emissions or require additional auxiliary materials as well as transportation. Therefore, the potential benefit will never be equal to the total impact of the primary input because of the transformation stage and the associated environmental impacts of collection and beneficiation. We analysed the implications of the transformation of different waste types to resources when industries are located in different geographic locations under consideration of the life cycle stage of transformation. Figure 2 shows the most significant results of the net benefit within the set of analysed waste types: the transformation of PET and concrete waste. Waste PET can be transported up to 10 000 km by lorry and still provide a net benefit regarding greenhouse gas emissions due to circular use. However, in case of concrete, the results are very different. A net benefit only occurs if the additional transport distance compared to primary concrete is less than 5 km. As a reference, the median of the transported distance of completed transformations within the NISP in the United Kingdom according to Jensen et al. is indicated with a black cross. About half of the 979 transformations within NISP were realised within a radius of 33 km and only one quarter of the synergies involved distances greater than 64 km. Conclusions: Transformation from linear to circular systems can substantially reduce total resource consumption as well as emissions of the whole value chain and therefore contribute to a greener economy. However, matching industries for transformations leading to the substitution of primary materials is still a major challenge. In addition, the environmental benefits of the reuse of resources is limited by the life cycle stage of the transformation as well as by additional transportation that may be required. The analysed set of types of waste shows a broad range of potential benefits. For some types of waste, the net benefits are still considerable after the subtraction of the additional impacts due to the life cycle stage of transformation as well as additional transport requirements. However, for selected types of waste, the net benefit tends to be negligible. The completeness of the scope will be crucial for the assessment and generalisations overarching different types of waste remain challenging

Yield losses in vegetable and arable crops caused by yellow nutsedge (Cyperus esculentus) in farmers fields in Switzerland

Cyperus esculentus ist zu einem Problemunkraut in der Schweiz geworden. Trotz Sensibilisierungsanstrengungen werden die drohenden Ertragsverluste von noch nicht betroffenen Landwirten oft unterschätzt. Dementsprechend wird den Auswirkungen eines Erdmandelgrasbefalls zu wenig Beachtung geschenkt und Eindämmungs- und Bekämpfungsmaßnahmen werden oft nur zögerlich ergriffen.Ertragsverlustzahlen aus dem Ausland sind breit verfügbar. Diese Zahlen erwiesen sich aber nur als bedingt hilfreich, um Schweizer Landwirte zu sensibilisieren. Die Übertragbarkeit auf Schweizer Anbausysteme wurde bezweifelt. Um diese Datenlücke zu schließen, wurden entsprechende Ertragsdaten für verschiedene Kulturen auf Schweizer Praxisflächen erhoben (2013-2016). Erträge mit und ohne Besatz von C. esculentus wurden erhoben und dessen Deckungsgrad geschätzt. Auf den Flächen war eine praxisübliche, chemische Unkrautbekämpfung erfolgt. Für Zuckerrüben und Kartoffeln betrugen die Ertragsverluste durchschnittlich 67 % und 34 %, bei einer Cyperus-Bedeckung von 68 % respektive 44 %. Bei einem hohen Besatz (80-100 % Deckungsgrad) betrugen die Ertragsverluste in Lauch, Zwiebeln und Rosenkohl 86 %, 90 % and 93 %. In Karotten führte ein starker Befall zu einer Ertragsreduktion von 61 %. Bei so hohen Dichten war auch die Qualität des Ernteguts beeinträchtigt.Die Ergebnisse sollen dazu dienen, Schweizer Landwirte weiter zu sensibilisieren. Die Ergebnisse werden zudem Forschungsinstituten bzw. landwirtschaftlichen Beratungsinstitutionen in anderen Ländern zur Verfügung gestellt, die mit der gleichen Problematik konfrontiert sind.Cyperus esculentus has become a serious weed in Switzerland. Despite intensive awareness training unaffected farmers tend to underestimate the consequences of C. esculentus infestation, especially the potential yield losses. Hence, countermeasures are often taken hesitantly.Yield loss data from abroad is widely available. However, this data was of limited value to raise awareness in Switzerland, because its transferability to our production systems was questioned. To close this gap yield losses caused by C. esculentus were determined for different crops in farmers’ fields in Switzerland (2013-2016). Yield was assessed with and without C. esculentus infestation and its coverage was estimated. Standard herbicides had been applied in the fields. For sugar beet and potatoes average, actual yield losses of 67% and 34% were detected at C. esculentus coverages of 68% and 44%, respectively. High infestation (80-100%) in leek, onions and Brussels sprouts caused losses of 86%, 90%, 93%, accordingly. In carrots: A high infestation led to 61% yield loss. At these infestation levels yield quality was also negatively affected.In Switzerland, these figures are employed to further train farmers. The findings are presented here to make this more recent yield loss data available to colleagues facing the same problem in their countries

Efficacy of herbicides against yellow nutsedge (Cyperus esculentus) plants originating from seeds

Erdmandelgras (Cyperus esculentus) ist ein gefürchtetes Unkraut. Es vermehrt und breitet sich hauptsächlich über Knöllchen aus. Es werden aber auch keimfähige Samen gebildet. Die Samen sind klein und verfügen dementsprechend über wenig Speicherstoffe. Erdmandelgrassämlinge sind zart gebaut und ähneln Süßgräsern (Poaceae). Daher vermuteten wir, dass Erdmandelgrassämlingspflanzen sensibler auf Herbizide reagieren als aus Knöllchen gekeimte Pflanzen. Im Gewächshaus wurden Erdmandelgraspflanzen aus Samen angezogen und mit Glyphosat, Bentazon, Bromoxynil, Pelargonsäure und Clethodim behandelt. Die Herbizidwirksamkeit wurde geschätzt und die Anzahl gebildeter Knöllchen bestimmt. Kein Verfahren zeigte eine volle Wirkung. 4 Wochen nach Behandlung konnte eine Wuchsreduktion um 84 % und 34 % in den Verfahren Glyphosat resp. Bentazon im Vergleich zur unbehandelten Kontrolle beobachtet werden. Bei den anderen Verfahren lag die Wuchsreduktion unter 15 %. In den Verfahren Glyphosat und Bentazon wurden deutlich weniger Knöllchen gebildet als in der unbehandelten Kontrolle. Zusammenfassend konnten wir unsere Hypothese nicht bestätigen. Bereits 6 Wochen nach Keimung waren die Sämlinge robust, vergleichsweise tolerant gegenüber den applizierten Herbiziden mit Ausnahme von Glyphosat und Bentazon und bildeten Knöllchen. Das bedeutet, dass bereits nach sehr kurzer Zeit aus Samen entstandene Erdmandelgrasnester die gleichen Probleme verursachen wie aus Knöllchen entstandene.Yellow nutsedge (Cyperus esculentus) is a troublesome weed. It reproduces and spreads mainly via tubers, but also viable seeds are produced. The seeds are very small and have little resources stored. The seedlings are very fragile and look like grasses (poaceae). We hypothesized that C. esculentus plants originating from seeds are more susceptible to herbicides than plants originating from tubers. Cyperus esculentus plants grown from seeds in the greenhouse were treated with glyphosate, bentazone, bromoxynil, pelargonic acid and clethodim. Herbicide efficacy was rated and produced tubers were counted. None of the treatments achieved full control. Four weeks after application a growth reduction of 84% was observed in the glyphosate treatment, whereas bentazone reduced growth by 34% compared to the control. In the other treatments, growth reduction was < 15%. In the glyphosate and bentazone treatment, considerably fewer tubers were produced than in the control. Concluding, we could not confirm our hypothesis. Already 6 weeks after germination seedlings were well developed, tolerant to the sprayed herbicides, except for glyphosate and bentazone, and produced tubers. This implies, that already after a short time Cyperus esculentus stands originating from seeds pose the same problems as the ones originating from tubers

Filling the Gap of Overfishing in LCIA: Eco-factors for Global Fish Resources

Introduction: Life cycle assessment has been widely used to measure the environmental impact of food production and value chains. However, there is a lack of LCIA methods to assess the contribution of fish consumption to the global problem of overfishing, despite that fact that more than two thirds of commercially used fish resources are overexploited. Due to this methodological gap, fish is often determined to have a lower environmental footprint than other sources of animal protein in LCA studies. The aim of this publication is to present the development of eco-factors for fish resources and by-catch as an addition to the Swiss Ecological Scarcity Method 2013 and to compare the eco-factors of different fish resources and the impacts of fishing as well as the impacts of dietary alternatives like chicken, pork, lamb, beef and veal. Materials and Methods: The sustainable use of fish resources ensures that the fish stock for each fish species exceeds the minimum stock needed for a maximum sustainable yield. Therefore, the method developed uses a distance to target approach based on the fish stock for maximum sustainable yield (FSMSY) and the current fish stock (FS) for the characterisation of the use of fish resources. Langlois et al. and Emanuelsson et al. also suggest approaches for the characterisation of overexploitation of fish resources based on the FSMSY. The eco-factors were calculated for each fish species and fishing area. Thereafter, they were aggregated for each fish species using the weighted average of the total catch per fishing area. The target value for FSMSY depends on the fish species and the fishing area. The amount of by-catch was approximated with the dead discard of the walleye pollock (gadus chalcogrammus), which has the highest by-catch rate worldwide. In order to be able to compare the eco-factors for fish resources with the eco-factors of meat production, the factors were corrected from live weight to product weight assuming that the product weight corresponds to 45 % of live weight and that 98 % of the economic value is associated with the final product weight. Results and Discussion: The inclusion of eco-factors for the overexploitation of fish resources and by-catch shows a relevant contribution to the total environmental impact of fish compared to other impacts resulting from fishing and fish processing. Depending on the fish species, fish can have significantly higher overall impacts compared with different types of meat. The contribution of the eco-factors for by-catch is minor compared to fish resources but still relevant for the comparison with dietary alternatives. The total contribution of the eco-factors for fish resources exceeds the impacts of the fishery and fish processing. Conclusions: Distance to target based eco-factors using regionalised data for FS and FSMSY not only follow a comparable underlying approach as suggested in literature but also enable aggregation into a single-score with other environmental impacts. The overexploitation of fish resources is highly variable for different fish species and fishing areas as well as for by-catch, which also requires the consideration of by-catch species and fishing method. When comparing fish to equivalent dietary alternatives like chicken, pork, lamb, beef or veal, consideration of the overexploitation of fish resources results in some fish species exceeding the environmental impact of dietary alternatives. Therefore, overexploitation of fish resources is relevant in the Life Cycle Assessment of fish products in different diets. The suggested approach can be integrated in a full single-score LCIA of meals and is able to reflect the regionalised impacts caused by the overexploitation of fish resources for different species and fishing areas as well as the impacts associated with by-catch and fishing method

Projekt Digitale Suffizienz : Ökobilanzbericht zur Nutzung digitaler Geräte durch Jugendliche in der Schweiz

Ziel der Studie: Diese Studie quantifiziert die Umweltbelastung durch die individuelle Nutzung digitaler Medien durch Schweizer Jugendliche mit der Methode der Ökobilanz (engl.: Life Cycle Assessment). Dabei wird analysiert, welcher Aspekt der Nutzung einen besonders hohen Einfluss auf die Umweltbelastung hat. Ziel der Ökobilanz ist, aus diesen Erkenntnissen Empfehlungen abzuleiten und angeben zu können, welche Handlungsänderungen der Jugendlichen diese Umweltauswirkungen reduzieren können. Bei der Analyse wird nicht nur der Durchschnittsjugendliche betrachtet, sondern auch verschiedene Nutzungstypen (siehe Kapitel 2.2), sodass die Empfehlungen individuell formuliert werden können. Ein weiteres Ziel der Studie ist die Abschätzung, ob durch die Digitalisierung auch Umweltvorteile entstehen, da Materialien wie Papier für Bücher und Zeitungen oder Fotopapier für Fotografien durch digitale Medien ersetzt werden. Dabei werden zwei Aspekte separat betrachtet: Ist es aus Umweltsicht besser, Geräte in meinem Besitz zu nutzen, um Medien digital zu nutzen anstatt die nicht digitale Alternative zu verwenden? Der andere Aspekt ist, ob es von Vorteil für die Umwelt ist, ein Gerät zu kaufen, um Tätigkeiten digital zu erledigen und so beispielsweise Papier zu sparen. Eine wichtige Überlegung dabei ist, ab wie vielen ersetzten nicht-digitalen Produkten sich der Gerätekauf lohnt. Beide Aspekte werden im Rahmen dieser Studie betrachtet