Quantum-classical correspondence in spin-boson equilibrium states at arbitrary coupling

It is known that the equilibrium properties of nanoscale systems can deviate significantly from standard thermodynamics due to their coupling to an environment. For the generalized $\theta$-angled spin-boson model, here we derive an explicit form of the classical mean force equilibrium state. Taking the large spin limit of the quantum spin-boson model, we demonstrate that the quantum-classical correspondence is maintained at arbitrary coupling strength. This correspondence gives insight into the conditions for a quantum system to be well-approximated by its classical counterpart. We further demonstrate that, counterintuitively, previously identified environment-induced 'coherences' in the equilibrium state of weakly coupled quantum spins, do not disappear in the classical case. Finally, we categorise various coupling regimes, from ultra-weak to ultra-strong, and find that the same value of coupling strength can either be 'weak' or 'strong', depending on whether the system is quantum or classical. Our results shed light on the interplay of quantum and mean force corrections in equilibrium states of the spin-boson model, and will help draw the quantum to classical boundary in a range of fields, such as magnetism and exciton dynamics

Exploring potential risk factors of antimicrobial use in beef cattle.

Livestock species are major contributors to the increase of antimicrobial (AM) resistance which is a worldwide concern for both human and animal health. The over-use of AM is widely acknowledged, however, unlike pigs, poultry and dairy cattle, knowledge on potential risk factors affecting AM usage (AMU) in beef industry is limited. Hence, this study aimed to investigate the impact of farm, breed, sex and season of arrival of purchased beef cattle on AMU in Italian beef cattle. Data on 1063 batches were collected from January 2016 to April 2019 from specialised beef fattening farms located in the north of Italy. Information on breed, sex, date of arrival, performance traits and AM agents used on farm was collected, and the treatment incidence 100 (TI100) indexes per batch were calculated using the defined daily dose animal estimated according to Italian summaries of product characteristics. Factors affecting TI100 indexes were investigated using a cross-classified multilevel model. Farms largely differed in terms of AMU. Males had greater AMU than females (P < 0.001), likely due to their higher susceptibility to disease. Statistically significant differences were observed between seasons of arrival with summer and spring having lower TI100 indexes than winter and autumn (P < 0.001). Indeed, winter is commonly linked to an increase in respiratory diseases in beef cattle. Finally, the TI100it indexes tended to be different among breeds with Blonde d'Aquitaine and Limousine having greater AMU compared to the other breeds. Results of this study provided valuable information on potential risk factors of AMU in beef production which may be useful to address its reduction. For instance, the development of tailored management strategies for specific breeds, targeted approaches to improve the health of males as well as greater care towards batches purchased in winter are possible advice to implement on-farm for a more responsible AM stewardship

The Disturbed Habitat and Its Effects on the Animal Population

Changes in the “habitat” may interfere with the normal functioning of all biological systems. The existence of relationships between environmental changes and health in humans and animal species is well known and it has become generally accepted that poor health affects the animal’s natural behaviors and animal welfare and, consequently, food safety and animal production quality. Microclimate alterations, husbandry-management conditions, quality of human-animal interactions, feeding systems, and rearing environment represent the main factors that could negatively affect animal welfare and may produce behavioral, biochemical, endocrine, and pathological modifications in domestic and wild animals. Particularly, high stress levels can reduce the immune system response and promote infectious diseases. Adverse socio-environmental factors can represent a major stimulus to the development of different pathologies. This chapter will discuss the main pathological modifications described in domestic and wild animals due to “disturbed habitat” paying more attention to critical points detected in standard breeding systems

The use of antimicrobials in Italian heavy pig fattening farms

Data on antimicrobial use (AMU) in heavy pig production (>150 kg) are limited. The aim of this study was to investigate the AMU in this production. Data from 2015 were collected for 143 fattening farms. The AMU was estimated through a treatment index per 100 days (TI100) using the defined daily dose animal for Italy (DDDAit). When possible, a comparison with the European Medicines Agency's defined daily doses for animals (DDDvet) was performed. The median TI100 was 10.7 (range, 0.2-49.5). Group treatments represented 94.6% of overall consumption. The AMU calculated using DDDAit and DDDvet were strongly correlated (rho = 0.976; p < 0.001). The AMU was negatively correlated with injectables use (rho = -0.46, p < 0.001) and positively correlated with oral products (rho = 0.21, p = 0.014), premixes (rho = 0.26, p = 0.002), and mortality (rho = 0.18; p = 0.027). Farm size was negatively correlated with AMU (rho = -0.29, p < 0.001). Smaller farms were more frequently above the median TI100 (odds ratio = 2.3, 95% confidence interval = 1.2-4.7), suggesting that they may have lower biosecurity and management standards. The results of this study should provide useful insights for the development of an Italian monitoring system

Monitoring of Farm-Level Antimicrobial Use to Guide Stewardship: Overview of Existing Systems and Analysis of Key Components and Processes

peer-reviewedThe acknowledgment of antimicrobial resistance (AMR) as a major health challenge in humans, animals and plants, has led to increased efforts to reduce antimicrobial use (AMU). To better understand factors influencing AMR and implement and evaluate stewardship measures for reducing AMU, it is important to have sufficiently detailed information on the quantity of AMU, preferably at the level of the user (farmer, veterinarian) and/or prescriber or provider (veterinarian, feed mill). Recently, several countries have established or are developing systems for monitoring AMU in animals. The aim of this publication is to provide an overview of known systems for monitoring AMU at farm-level, with a descriptive analysis of their key components and processes. As of March 2020, 38 active farm-level AMU monitoring systems from 16 countries were identified. These systems differ in many ways, including which data are collected, the type of analyses conducted and their respective output. At the same time, they share key components (data collection, analysis, benchmarking, and reporting), resulting in similar challenges to be faced with similar decisions to be made. Suggestions are provided with respect to the different components and important aspects of various data types and methods are discussed. This overview should provide support for establishing or working with such a system and could lead to a better implementation of stewardship actions and a more uniform communication about and understanding of AMU data at farm-level. Harmonization of methods and processes could lead to an improved comparability of outcomes and less confusion when interpreting results across systems. However, it is important to note that the development of systems also depends on specific local needs, resources and aims

A particular truncation of the covariant vacuum in loop quantum gravity: semiclassical analysis and cosmological interpretation

Our current understanding of the physical world is based on the framework of the quantum theory of fields (QFT) and on the classical theory of general relativity (GR). Both of them have received countless experimental confirmations, however, the two theories are at odds with each other: QFT is formulated on a fixed, nondynamical spacetime, while in GR the spacetime is a dynamical entity, affected by the presence of matter. In this scenario, one possibility to reconcile GR and QFT is to construct an encompassing quantum theory of the gravitational field, in which the latter couples with the matter fields by means of a quantum version of the Einstein equations. This Master thesis fits into the theoretical framework of Loop Quantum Gravity (LQG) [1], which is one of the most promising, tentative theories of quantum gravity (QG). LQG is based on two pillars. The first is the background independence, which is assumed as a guiding principle of the quantization procedure, instead as something to recover a posteriori. The second is a minimalist point of view, in which the only elements of QG are quantum mechanics and GR, merged according to mathematical consistency. The main result of the theory is the appearance of an inherent notion of 3D space with quantum mechanical, geometrical properties and fundamentally discrete at the Planck scale. In this context, our work is an attempt of linking LQG with the semiclassical level of a QFT on a classical background, in a particular case. After a thorough review of the path leading from GR to LQG, we consider the quantum state studied numerically in [2]. This is a particular truncation of the so-called covariant vacuum, therefore, it is an approximate solution of the quantum Einstein equations. In the first part, we argue that this truncation of the covariant vacuum can be interpreted as the quantum state of a closed Friedmann-Lemaˆıtre-Robertson-Walker (FLRW) spacetime [3], filled with a sort of background of gravitational radiation, in its early expansion phase. This prediction relies on the quantum geometrical properties of the state and on some strong assumptions, which are carefully discussed. On the basis of the previous result, in the second part we consider a massless spin 2 quantum field (the graviton) on a closed FLRW background. We find the expression for the leading behaviour of the entanglement entropy of the field inside a closed 2-surface [4], which is a measure of the quantum correlations existing between the points inside the surface and the points outside. We conclude by discussing the possible match of this expression with the numerical results of [2], concerning the entanglement entropy of a quantum of space with respect to the rest of the system. [1] Rovelli, C., and Smolin, L. Loop Space Representation of Quantum General Relativity. Nucl. Phys. B 331 (1990), 80–152. [2] Gozzini, F., and Vidotto, F. Primordial fluctuations from quantum gravity. Front. Astron. Space Sci. (Jun 2019). [3] Weinberg, S. Cosmology. Cosmology. OUP Oxford, 2008. [4] Solodukhin, S. N. Entanglement entropy of black holes. Living Reviews in Relativity 14, 1 (oct 2011)

The spectrum of mutatine for the diagnosis of vanishing white matter disease.

Vanishing white matter disease (VWM; MIM #603896), also known as childhood ataxia with central nervous system hypomyelination (CACH) syndrome, is an autosomal recessive transmitted leukoencephalopathy related to mutations in each of the 5 genes (EIF2B1, EIF2B2, EIF2B3, EIF2B4 and EIF2B5) encoding for the 5 subunits of eukaryotic translation initiation factor 2B (eIF2B), essential for protein synthesis. VWM is characterised by ataxia, spasticity, variable optic atrophy and intermittent episodes of acute regression of clinical and neurological status. Another key step in diagnosis, besides clinical picture and gene sequencing, is magnetic resonance imaging (MRI), which typically shows a progressive rarefaction of the brain white matter, and its replacement by cerebrospinal fluid (CSF). In the present paper we summarise the up-to-date knowledge about VWM and include the full list of known mutations

Large scale phenotypic characterisation of Hierophis viridiflavus (Squamata: Serpentes): climatic and environmental drivers suggest the role of evolutionary processes in a polymorphic species

Colour variability is largely widespread in the animal world as it is tightly associated with fitness and survivorship. Therefore, the drivers and implications of such variability have been of great interest for zoologists in the past decades. Reptiles are excellent models to investigate colour variations and expression under different conditions. Here, we focused on melanism occurrence in the two main lineages of Hierophis viridiflavus at the scale of the species distribution, by extracting available data from iNaturalist, a citizen science network, with the aim of detecting any pure effect of climate or local habitat on colour expression. Our analyses highlighted that habitat does not explain differences in phenotypes, whereas marked effects of geographic and climatic variables were detected. However, the observed climatic effects could be a proxy of the geographical distribution of the two groups, and thus the high occurrence of bright colourations in western populations of the eastern lineage could be addressed to an ongoing event of asymmetric gene flow in contact zones. The current distribution of phenotypes could be the outcome of the evolutionary history of the species combined with the geological history of the Mediterranean region. This investigation, though, is only preliminary and molecular analyses on highly variable regions of the genome are mandatory to address this issue