Systematic approach to Delta L=1 processes in thermal leptogenesis

In this work we study the contribution to leptogenesis from Delta L=1 decay and scattering processes mediated by the Higgs with quarks in the initial and final states using the formalism of non-equilibrium quantum field theory. Starting from fundamental equations for correlators of the quantum fields we derive quantum-corrected Boltzmann and rate equations for the total lepton asymmetry improved in that they include quantum-statistical effects and medium corrections to the quasiparticle properties. To compute the collision term we take into account one- and two-loop contributions to the lepton self-energy and use the extended quasiparticle approximation for the Higgs two-point function. The resulting CP-violating and washout reaction densities are numerically compared to the conventional ones.Comment: 16 pages, 13 figure

Evaluation Of Rocker Sole Shapes For Rigid Ankle Foot Orthoses

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Toward Robust Sensing for Autonomous Vehicles: An Adversarial Perspective

Autonomous Vehicles rely on accurate and robust sensor observations for safety critical decision-making in a variety of conditions. Fundamental building blocks of such systems are sensors and classifiers that process ultrasound, RADAR, GPS, LiDAR and camera signals~\cite{Khan2018}. It is of primary importance that the resulting decisions are robust to perturbations, which can take the form of different types of nuisances and data transformations, and can even be adversarial perturbations (APs). Adversarial perturbations are purposefully crafted alterations of the environment or of the sensory measurements, with the objective of attacking and defeating the autonomous systems. A careful evaluation of the vulnerabilities of their sensing system(s) is necessary in order to build and deploy safer systems in the fast-evolving domain of AVs. To this end, we survey the emerging field of sensing in adversarial settings: after reviewing adversarial attacks on sensing modalities for autonomous systems, we discuss countermeasures and present future research directions

Network coding meets multimedia: a review

While every network node only relays messages in a traditional communication system, the recent network coding (NC) paradigm proposes to implement simple in-network processing with packet combinations in the nodes. NC extends the concept of "encoding" a message beyond source coding (for compression) and channel coding (for protection against errors and losses). It has been shown to increase network throughput compared to traditional networks implementation, to reduce delay and to provide robustness to transmission errors and network dynamics. These features are so appealing for multimedia applications that they have spurred a large research effort towards the development of multimedia-specific NC techniques. This paper reviews the recent work in NC for multimedia applications and focuses on the techniques that fill the gap between NC theory and practical applications. It outlines the benefits of NC and presents the open challenges in this area. The paper initially focuses on multimedia-specific aspects of network coding, in particular delay, in-network error control, and mediaspecific error control. These aspects permit to handle varying network conditions as well as client heterogeneity, which are critical to the design and deployment of multimedia systems. After introducing these general concepts, the paper reviews in detail two applications that lend themselves naturally to NC via the cooperation and broadcast models, namely peer-to-peer multimedia streaming and wireless networkin

Soil phosphorus (P) budgets, P availability and P use efficiencies in conventional and organic cropping systems of the DOK trial

Cropping systems rely on the provision of adequate amounts of phosphorus (P) to enable stable crop yields. A balanced application of P is necessary to avoid reduced crop yields (in case of too low application rates), but also to avoid P losses to other ecosystems (in case of too high application rates). While in conventional cropping systems the use of synthetic P fertilizers is common practice, organic cropping systems mostly rely on organic P inputs such as farmyard manure or compost. We aimed to answer if different cropping systems attain balanced P application rates in the long run, and how plant P availability is affected by different cropping systems and forms of fertilizers applied

Phosphorus Transformations in an Oxisol under contrasting land-use systems: The role of the soil microbial biomass

It is generally assumed that phosphorus (P) availability for plant growth on highly weathered and P-deficient tropical soils may depend more on biologically mediated organic P (Po) turnover processes than on the release of adsorbed inorganic P (Pi). However, experimental evidence showing the linkages between Po, microbial activity, P cycling and soil P availability is scarce. To test whether land-use systems with higher soil Po are characterized by greater soil biological activity and increased P mineralization, we analyzed the partitioning of P among various organic and inorganic P fractions in soils of contrasting agricultural land-use systems and related it to biological soil properties. Isotopic labeling was used to obtain information on the turnover of P held in the microbial biomass. Soil samples were taken from grass-legume pasture (GL), continuous rice (CR) and native savanna (SAV) which served as reference. In agreement with estimated P budgets (+277, +70 and 0 kg P ha−1 for CR, GL and SAV, respectively), available P estimated using Bray-2 and resin extraction declined in the order CR > GL > SAV. Increases in Bray-2 and resin Pi were greater in CR than GL relative to total soil P increase. Organic P fractions were significantly less affected by P inputs than inorganic fractions, but were a more important sink in GL than CR soils. Extractable microbial P (Pchl) was slightly higher in GL (6.6 mg P kg−1) than SAV soils (5.4 mg P kg−1), and significantly lowest in CR (2.6 mg P kg−1). Two days after labeling the soil with carrier free 33P, 25, 10 and 2% of the added 33P were found in Pchl in GL, SAV and CR soils, respectively, suggesting a high and rapid microbial P turnover that was highest in GL soils. Indicators of P mineralization were higher in GL than CR soils, suggesting a greater transformation potential to render Po available. Legume-based pastures (GL) can be considered as an important land-use option as they stimulate P cycling. However, it remains to be investigated whether crops planted in pasture-crop rotations could benefit from the enhanced Po cycling in grass-legume soils. Furthermore, there is need to develop and test a direct method to quantify Po mineralization in these system

AVALIAÇÃO DO DESEMPENHO DE TÉCNICAS PARA MELHORIA DA FORMULAÇÃO MECID EM PROBLEMAS DE AUTOVALOR

A técnica de Integração Direta (MECID) já se mostrou uma vertente adequada do Método dos Elementos de Contorno para resolver problemas expressos por equações diferenciais parciais, que apresentam termos que não são dados por operadores auto-adjuntos ou requeiram a utilização de uma solução fundamental que não é correlata ao problema proposto. Já foi utilizado anteriormente, de forma bem sucedida, em problemas governados pelas Equações de Poisson e de Helmholtz. Porém, todo método numérico passa por inúmeros processos de melhoria e essas visam aprimorar os resultados apresentados, adaptá-lo à solução de uma nova família de problemas, diminuir o seu custo computacional e até mesmo simplificá-lo matematicamente. Buscando melhorar a qualidade dos resultados apresentados pelo MECID, testam-se dois expedientes diferentes com essa finalidade: primeiramente, a utilização de diferentes famílias de Funções de Base Radial para analisar quais são as funções que permitem a obtenção de melhor precisão nos resultados; em segundo lugar, a utilização de um esquema de regularização do tipo proposto por Hadamard para remover a singularidade que ocorre no núcleo das integrais a serem interpoladas pela MECID, eliminando assim a necessidade de conjuntos distintos de pontos, um para interpolação e outro para geração de pontos fonte. A avaliação dos procedimentos é feita confrontando-se valores numéricos com os analíticos na solução de problemas bidimensionais de autovalor bem conhecidos