Entanglement negativity in quantum field theory

We develop a systematic method to extract the negativity in the ground state of a 1+1 dimensional relativistic quantum field theory, using a path integral formalism to construct the partial transpose rho_A^{T_2} of the reduced density matrix of a subsystem A=A1 U A2, and introducing a replica approach to obtain its trace norm which gives the logarithmic negativity E=ln||\rho_A^{T_2}||. This is shown to reproduce standard results for a pure state. We then apply this method to conformal field theories, deriving the result E\sim(c/4) ln(L1 L2/(L1+L2)) for the case of two adjacent intervals of lengths L1, L2 in an infinite system, where c is the central charge. For two disjoint intervals it depends only on the harmonic ratio of the four end points and so is manifestly scale invariant. We check our findings against exact numerical results in the harmonic chain.Comment: 4 pages, 5 figure

What Does Sustainability Mean? Perceptions of Future Professionals across Disciplines

Given the negative externalities of the traditional productive system, sustainable development has become a productive alternative that attempts to improve the quality of life of present and future generations. The aim of this research was to understand the degree of perception and knowledge of sustainability of university students attending different courses, who represent future Argentinian professionals. A survey was conducted on a representative sample of those enrolled in the faculties of Agricultural, Economic, and Social Sciences of the National University of Lomas de Zamora, Buenos Aires. The results showed that, in terms of awareness, the environmental dimension of sustainability stands out above the others. Sustainability involves preserving natural resources, favoring biodiversity, reducing environmental risks, and finding a balance between the development of humanity and care for the environment. Only 10% of the respondents identified the three sustainability dimensions contemporaneously, and most of these individuals were not informed through university courses. No substantial differences were found in the knowledge of sustainability among students of different faculties. Universities, as trainers of professionals and leaders, should further develop the subject in their curricula, to improve knowledge of sustainability, so that graduates can better face future professional challenges. Similarly, students should strive to know about sustainability and its components to defend and improve it in all areas of work

Perceptions and preconceptions about chicken and pork meat: A qualitative exploratory study of Argentine consumers in the metropolitan area of Buenos Aires

In the past, the Argentine livestock production system was based on the extensive breeding that used pastures. However, technological progress and the use of land for soybean production are leading to a strong intensification of beef production, with a negative impact on the environment. According to FAO data, Argentina has the third highest meat consumption in the world, half of which is beef. A change in diet is a long and difficult process. The first step in favor of the environment could be the replacement of beef with other types of meat that have a lower impact on the environment, such as chicken and pork. The purpose of this study is to understand the causes limiting the preference for these alternatives and to identify useful tools to encourage their consumption. The results show that the interviewed Argentine consumers in the Metropolitan Area of Buenos Aires have preconceptions about these two types of meat, such as the fact that hormones are still used in the chicken production system, that pork has higher cholesterol content than other meats, and that it carries diseases. These products are instead appreciated for their practicality of use, especially when purchased in portions, and they are not only tasty but also cheap

The root towards more circularized animal production systems: From animal to territorial metabolism

This paper deals with a relevant topic in the literature on sustainable management of animal farms, concerning the transition towards circular methods of animal production. The paper aims to put forward an original analytical multilevel perspective overlapping different dimensions at either micro, meso, and macro level. Starting from the Malthusian analysis on depletion of natural resources, with risks of the fragility of the natural and economic systems, the paper points out the importance of moving away from intensive methods of production, by adopting more circularized approaches based on resources efficiency. The application of circular economy approaches to animal production is theorized through the concept of territorial metabolism involving not only internal resources (at the animal farm level) but also territorial resources. The paper underlines the critical points of the transition, which is labeled as a socio-technical transition in that it involves not only technical issues but also social aspects. Critical points are addressed through consumers\u2019 acceptance of products drawn on circular approaches and political support to transition, through political tools which are boosted in recent documents of the European Union, like the Green Deal and Farm to Fork strategy

Application of Raman and Brillouin Scattering Phenomena in Distributed Optical Fiber Sensing

We present a review of the basic operating principles and measurement schemes of standalone and hybrid distributed optical fiber sensors based on Raman and Brillouin scattering phenomena. Such sensors have been attracting a great deal of attention due to the wide industrial applications they offer, ranging from energy to oil and gas, transportation and structural health monitoring. In distributed sensors, the optical fiber itself acts as a sensing element providing unique measurement capabilities in terms of sensing distance, spatial resolution and number of sensing points. The most common configuration exploits optical time domain reflectometry, in which optical pulses are sent along the sensing fiber and the backscattered light is detected and processed to extract physical parameters affecting its intensity, frequency, phase, polarization or spectral content. Raman and Brillouin scattering effects allow the distributed measurement of temperature and strain over tens of kilometers with meter-scale spatial resolution. The measurement is immune to electromagnetic interference, suitable for harsh environments and highly attractive whenever large industrial plants and infrastructures have to be continuously monitored to prevent critical events such as leakages in pipelines, fire in tunnels as well as structural problems in large infrastructures like bridges and rail tracks. We discuss the basic sensing mechanisms based on Raman and Brillouin scattering effects used in distributed measurements, followed by configurations commonly used in optical fiber sensors. Hybrid configurations which combine Raman and Brillouin-based sensing for simultaneous strain and temperature measurements over the same fiber using shared resources will also be addressed. We will also discuss advanced techniques based on pulse coding used to overcome the tradeoff between sensing distance and spatial resolution affecting both types of sensors, thereby allowing measurements over tens of kilometers with meter-scale spatial resolution, and address recent advances in measurement schemes employing the two scattering phenomena

Influence of fine fraction on breakage of binary granular materials

Understanding the stress transmission mechanisms and breakage of soils composed of a fine and coarse fractions is critical for the design of many geotechnical structures such as pile driving and large embankment dams. A series of strain controlled one-dimensional compression laboratory experiments were carried out using glass beads to investigate the effect of the fine faction on the macroscopic response of the material. A wide range of stress varying from 10 to 250MPa was considered. Glass beads with diameters between 0.5 and 4mm were used to form granular mixtures with fines content ranging from 0 to 100%. This study shows the potential of strain controlled testing to provide further insights into the fabric evolution of granular materials undergoing grain breakage. When compared to conventional load controlled testing, the force:displacement curve obtained during strain controlled testes provides a better correlation between the macroscopic response and the grain-scale phenomena. The response of mono-sized samples is used as a reference to better understand the contribution of both the coarse and the fine factions to the behaviour of the mixture. Preliminary results have suggested that as breakage progresses, the grain size distribution evolves towards a fine fraction threshold value, beyond which the behaviour is governed by the fine component. Previously proposed relative breakage parameters are also used to demonstrate the influence of the fine faction in the final grading of the material. These finding, also supported by recent numerical studies, can provide valuable guidance for geotechnical practice

The root towards more circularized animal production systems: From animal to territorial metabolism

This paper deals with a relevant topic in the literature on sustainable management of animal farms, concerning the transition towards circular methods of animal production. The paper aims to put forward an original analytical multilevel perspective overlapping different dimensions at either micro, meso, and macro level. Starting from the Malthusian analysis on depletion of natural resources, with risks of the fragility of the natural and economic systems, the paper points out the importance of moving away from intensive methods of production, by adopting more circularized approaches based on resources efficiency. The application of circular economy approaches to animal production is theorized through the concept of territorial metabolism involving not only internal resources (at the animal farm level) but also territorial resources. The paper underlines the critical points of the transition, which is labeled as a socio-technical transition in that it involves not only technical issues but also social aspects. Critical points are addressed through consumers’ acceptance of products drawn on circular approaches and political support to transition, through political tools which are boosted in recent documents of the European Union, like the Green Deal and Farm to Fork strategy

Molecular marketing, personalised information and willingness-to-pay for functional foods: Vitamin D enriched eggs

Increasingly, the health claims made by food products focus on the marketing of specific molecular enrichments. Research exploring consumers’ willingness to pay (WTP) for health claims assumes that individuals hold perfect information on the benefits of the enrichment, and that their valuations depend solely on whether or not they need to improve their health. While health interventions are aimed at individuals at higher health risk, consumers may be unaware of the health risks that they face, limiting the effectiveness of a generic targeting strategy. Using an orthogonal experimental design, we explore the impact of two factors on the WTP for vitamin D enrichment in eggs: whether the information is person-specific or generic; and the presence of a health claim explaining the vitamin D enrichment. Results indicate that it is the provision of information, not the health claim, that influences WTP. Both generic and personalised information lead to similar increases in the WTP for vitamin D enrichment. While we only observe a direct effect of generic information on the WTP for vitamin D enrichment, personal information may also operate by increasing the perceived risk of vitamin D deficiency. Our results support the use of personalised health information during the choice task as a means of increasing the sales of healthy products

Precision Farming: Barriers of Variable Rate Technology Adoption in Italy

Research dealing with the adoption of various precision agriculture technologies has shown that guidance and recording tools are more widespread than reactive ones (such as variable rate technology), with much lower utilization rates in European case studies. This study aims to analyze the propensity to innovate variable rate technologies among young Italian farmers. A cluster analysis was carried out revealing four groups. The first two groups represent non-adopters who think technological innovation is very complex from a technical point of view, as well as not very accessible as capital-intensive technology. The third and fourth groups represent adopters. The third reports an early level of adoption, still considering the cost of access a major barrier to technology implementation. The fourth, on the other hand, shows a more intensive level and considers the lack of institutional support a major limitation. The cluster with the most intensive adoption is characterized by the youngest age group, the farms with the largest size, and a prevalence of female entrepreneurs. The need for management training in day-to-day business operations upon adoption is detected for all groups. This paper identified relevant drivers and barriers in characterizing the adopting farm of variable rate technologies. Results may offer insights to the policy maker to better calibrate support interventions

Entanglement entropy and quantum field theory: a non-technical introduction

In these proceedings we give a pedagogical and non-technical introduction to the Quantum Field Theory approach to entanglement entropy. Particular attention is devoted to the one space dimensional case, with a linear dispersion relation, that, at a quantum critical point, can be effectively described by a two-dimensional Conformal Field Theory.Comment: 10 Pages, 2 figures. Talk given at the conference "Entanglement in Physical and information sciences", Centro Ennio de Giorgi, Pisa, December 200