Partial Weyl Law for Billiards

For two-dimensional quantum billiards we derive the partial Weyl law, i.e. the average density of states, for a subset of eigenstates concentrating on an invariant region $\Gamma$ of phase space. The leading term is proportional to the area of the billiard times the phase-space fraction of $\Gamma$. The boundary term is proportional to the fraction of the boundary where parallel trajectories belong to $\Gamma$. Our result is numerically confirmed for the mushroom billiard and the generic cosine billiard, where we count the number of chaotic and regular states, and for the elliptical billiard, where we consider rotating and oscillating states.Comment: 5 pages, 3 figures, derivation extended, cosine billiard adde

Potential of multi-species livestock farming to improve the sustainability of livestock farms: A review.

Diversified farming systems are proposed as a major mechanism to address the many sustainability issues of today's agriculture. Multi-species livestock farming, i.e. keeping two or more animal species simultaneously on the same farm, is an option that has received little attention to date. Moreover, most studies of multi-species livestock farming are limited, usually focusing on selected dimensions of farm sustainability and addressing lower organizational levels (i.e. within the farm) and rather limited time horizons (e.g. a few weeks in a grazing season). Thus, a comprehensive assessment of multi-species livestock farming in terms of farm sustainability is lacking. In this context, we outline and discuss potential benefits and limitations of multi-species livestock farming for livestock farm sustainability from existing literature and list issues on multi-species livestock farming requiring further research. We show that multi-species livestock farming has the potential to improve the three dimensions of sustainability reviewed - economic viability for farmers, environmental soundness and social acceptability by being respectful of animals and humans - as long as locally relevant farming practices are implemented, especially an appropriate stocking rate during grazing. If relevant practices are not observed, multi-species livestock farming may produce undesirable effects, such as competition for resource acquisition during grazing, parasitic cross-infection and more intense work peaks. Therefore, we identify four focal research areas for multi-species livestock farming. First, characterizing the management of multi-species livestock farms. To do this, we suggest considering the integration of production enterprises (e.g. cattle and sheep enterprises) within the farm from three perspectives: farming practices (e.g. grazing management), work organization and sales. Second, exploring the complementarity of livestock species on multi-species livestock farms. This is especially true for species combinations that have been largely ignored (e.g. ruminants and monogastrics), even though they may have potential due to complementary diet compositions and resource-acquisition strategies. Third, assessing the sustainability of multi-species livestock farm scenarios (current or alternative) according to the management practices and production conditions, which requires adapting existing methods/models or developing new ones. Fourth, characterizing conditions for success and obstacles for multi-species livestock farming along the value chain from production to consumption, considering stakeholders' objectives, work habits and constraints. Increasing understanding should help prioritize actions and organize them to scale up multi-species livestock farming

Experimentally induced incomplete burst fractures - a novel technique for calf and human specimens

Background: Fracture morphology is crucial for the clinical decision-making process preceding spinal fracture treatment. The presented experimental approach was designed in order to ensure reproducibility of induced fracture morphology. Results: The presented method resulted in fracture morphology, found in clinical classification systems like the Magerl classification. In the calf spine samples, 70% displayed incomplete burst fractures corresponding to type A3.1 and A3.2 fractures. In all human samples, superior incomplete burst fractures (Magerl A3.1) were identified by an independent radiologist and spine surgeon. Conclusions: The presented set up enables the first experimental means to reliably model and study distinct incomplete burst fracture patterns in an in vitro setting. Thus, we envisage this protocol to facilitate further studies on spine fracture treatment of incomplete burst fractures

A hybrid finite element and surrogate modelling approach for simulation and monitoring supported TBM steering

The paper proposes a novel computational method for real-time simulation and monitoring-based predictions during the construction of machine-driven tunnels to support decisions concerning the steering of tunnel boring machines (TBMs). The proposed technique combines the capacity of a process-oriented 3D simulation model for mechanized tunnelling to accurately describe the complex geological and mechanical interactions of the tunnelling process with the computational efficiency of surrogate (or meta) models based on artificial neural networks. The process-oriented 3D simulation model with updated model parameters based on acquired monitoring data during the advancement process is used in combination with surrogate models to determine optimal tunnel machine-related parameters such that tunnelling-induced settlements are kept below a tolerated level within the forthcoming process steps. The performance of the proposed strategy is applied to the Wehrhahn-line metro project in Düsseldorf, Germany and compared with a recently developed approach for real-time steering of TBMs, in which only surrogate models are used

Multi-species livestock farming

This CORE Organic Practice Abstract gives practical recommendations for multi-species livestock farming, which has the potential to improve the three dimensions of sustainability – economic viability for farmers, environmental soundness, and social acceptability – by being respectful of animals and humans, as long as locally relevant farming practices are implemented, especially an appropriate stocking rate during grazing

Motor, cognitive and mobility deficits in 1000 geriatric patients : protocol of a quantitative observational study before and after routine clinical geriatric treatment – the ComOn-study

© The Author(s). 2020 Open Access. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.Background: Motor and cognitive deficits and consequently mobility problems are common in geriatric patients. The currently available methods for diagnosis and for the evaluation of treatment in this vulnerable cohort are limited. The aims of the ComOn (COgnitive and Motor interactions in the Older populatioN) study are (i) to define quantitative markers with clinical relevance for motor and cognitive deficits, (ii) to investigate the interaction between both motor and cognitive deficits and (iii) to assess health status as well as treatment outcome of 1000 geriatric inpatients in hospitals of Kiel (Germany), Brescia (Italy), Porto (Portugal), Curitiba (Brazil) and Bochum (Germany). Methods: This is a prospective, explorative observational multi-center study. In addition to the comprehensive geriatric assessment, quantitative measures of reduced mobility and motor and cognitive deficits are performed before and after a two week's inpatient stay. Components of the assessment are mobile technology-based assessments of gait, balance and transfer performance, neuropsychological tests, frailty, sarcopenia, autonomic dysfunction and sensation, and questionnaires to assess behavioral deficits, activities of daily living, quality of life, fear of falling and dysphagia. Structural MRI and an unsupervised 24/7 home assessment of mobility are performed in a subgroup of participants. The study will also investigate the minimal clinically relevant change of the investigated parameters. Discussion: This study will help form a better understanding of symptoms and their complex interactions and treatment effects in a large geriatric cohort.info:eu-repo/semantics/publishedVersio

Rotierende oder gemeinsame Beweidung mit zwei Tierarten - eine Chance?

Alle Nutztiere sind mit Parasiten belastet. Je nach Parasitenart und Grad des Befalls komm es zu gesundheitlichen Beeinträchtigungen oder Leistungseinbußen. Forscher haben untersucht, ob eine gemeinsame Beweidung - etwa Schafe mit Rindern - gegen Wurmbefall hilft

Experimentally induced incomplete burst fractures - a novel technique for calf and human specimens

Abstract Background Fracture morphology is crucial for the clinical decision-making process preceding spinal fracture treatment. The presented experimental approach was designed in order to ensure reproducibility of induced fracture morphology. Results The presented method resulted in fracture morphology, found in clinical classification systems like the Magerl classification. In the calf spine samples, 70% displayed incomplete burst fractures corresponding to type A3.1 and A3.2 fractures. In all human samples, superior incomplete burst fractures (Magerl A3.1) were identified by an independent radiologist and spine surgeon. Conclusions The presented set up enables the first experimental means to reliably model and study distinct incomplete burst fracture patterns in an in vitro setting. Thus, we envisage this protocol to facilitate further studies on spine fracture treatment of incomplete burst fractures.</p

Diversified farming systems for improved sustainability of agriculture: potentialities and challenges

1 – Introduction Responding to the many sustainability issues related to modern industrial agriculture (air, soil and water pollution, biodiversity loss, etc.), the diversity argument was brought forward by scientists (Kremen et al., 2012). Diversified farming systems intentionally include functional agrobiodiversity, i.e. crops, seeded and permanent pastures, rangelands and animal genotypes and species chosen by the farmer to manage his farm. These systems presumably provide ecosystem services while reducing the input needed for production. Agrobiodiversity is also assumed to strengthen the robustness and resilience of livestock farming systems. Because of their inherent complexity, research on diversified farming systems is limited. Literature on the topic mainly consists of review articles that gather and integrate field- and herd-scale results at the farm level (Frison et al., 2011; Lin, 2011; Mijatovic et al., 2012) without addressing threshold effects driven by the scale change. Moreover, these articles largely focus on biotechnical issues and only take limited account of the socio-economic aspects of livestock farming (e.g. presence vs. absence of a local value chain) that contribute to the success or failure of diversified systems. The proof of concept thus seems rather limited so far. We need to increase our understanding of the potential benefits and challenges of diversified farming systems. We focus on organic multi-species livestock farms, i.e. livestock farms integrating two or more animal species, possibly with integrated crop production. We review the theoretical advantages of mixed livestock farming and conclude on how studying diversified farming systems challenges the concepts and methods that have long been used to design and analyze conventional livestock systems. 2 – Theoretical framework Sustainability in the context of organic multi-species livestock farms is understood as a multi-dimensional concept that involves trade-offs among the following dimensions: resource use efficiency, resource conservation, self-reliance, productivity, profitability, human welfare, animal welfare and resilience to hazards. In this paper, we review the literature according to these dimensions. 3 – Results – Discussion The majority of papers studying multi-species livestock farming suggest that it improves productivity per animal and per unit area (d’Alexis et al., 2014). However, it is usually only one species that benefits from mixed grazing (e.g. lambs when grazed with cattle). Improved productivity is related to a higher resource use efficiency and to facilitation processes. Mixed grazing allows each species to express its food preferences and can enhance herbage use. For instance, sheep graze herbage close to cattle dungs that have high nutrient content and dry matter digestibility and is usually avoided by cattle (de Rancourt et al., 1980). In addition, multi-species farming systems may provide health benefits to the animals. It has been shown that mixed grazing of cattle and sheep reduces the number of strongyles well adapted for sheep (Arundel and Hamilton, 1975; Jordan et al., 1998) and thereby improve sheep performance and possibly sheep welfare. On the other hand, multi-species farming systems may increase the risks of transmission of bacterial and viral diseases, e.g. dermatitis (Rogdo et al., 2012). A special threat may arise from diseases with high mutation rates transmitted horizontally, e.g. among sheep and goats. Self-reliance is promoted when transfers of by-products occur from one farm enterprise to another and thereby avoid purchase of costly feed inputs. This is the case for piglets fed with whey from cattle, sheep or goat milk processing into cheese (Maswaure and Mandisodza, 1995). Despite these potential savings and above-mentioned benefits of multi-species livestock farms, their profitability is not necessarily higher than that of specialized farms. Economic results are, however, usually more stable thus improving farm resilience against economic or climatic hazards (Mischler, 2019). 4 – Conclusions Based on available literature, multi-species livestock farming appears as a promising option for improved sustainability in agriculture. However, this literature remains rather limited and we have identified two main knowledge gaps which may hinder the upscaling of multi-species livestock farming. First, multi-species livestock farms may be much more complex to manage thus increasing workload and making farmer welfare more critical, but this aspect has been little studied so far. Second, little information is available on how interactions among species (or farm enterprises) are managed, although these interactions appear to be key drivers of farm efficiency and resilience. Further research is thus needed to increase our knowledge of the technical, economic and environmental performances of multi-species livestock farms according to the management practices implemented. This research challenges the current concepts and methods of agricultural science that are mainly suited to specialized farms. Analytical frameworks to assess the integration among species or farm enterprises should better consider the farming practices but also how farm work is organized to deal with this diversity. Another key issue is how sales management does (or does not) take advantage of economies of scope allowed by the diversity of productions