Refinement of international recommendations for cubicles,based on the identification of associations between cubicle characteristics and dairy cow welfare measures

Maladjusted cubicles for dairy cattle may cause increased skin alterations, lameness, and dirtiness. The International Commission of Agricultural and Biosystems Engineering has produced several recommendations for cubicle design, but a previous study showed that not all of them seem efficient. Here, we aim to refine and complete these recommendations. We collected data on 76 dairy farms (2,404 cows). We modeled the association between combinations of cubicle properties (e.g., type of bedding litter) and dimensions (e.g., cubicle width) relative to cow size, and prevalence of cow skin alterations, lameness, and dirtiness. We used weighted multivariable logistic regression models to predict the presence of skin alteration on the carpus; the neck, shoulder, and back; the flank, side, and udder; and the tarsus or hindquarters. We also evaluated the presence of lameness as well as the dirtiness of the lower hind legs including hocks; the hindquarters, upper hind legs, and flank; the cow rear including tail; and the udder. The risk factors highlighted led us to recommend (1) position cubicles in a way that leaves more than 1 m of clearance from any obstacle in front of the cubicle; (2) if there is an obstacle on the lateral plane (i.e., where the cubicle partition is) in front ahead of the cow, put the obstacle in front of the fore knees; (3) if there is an obstacle in front of the cow on the median plane (e.g., neck or front rail), the position the obstacle between 1.25 and 1.5 of the cow length from the curb and between 1.0 and 1.25 of its height; (4) use curb height between 0.11 and 0.15 of cow height with no sharp edges on the curb; (5) use round or at least has no sharp edges brisket board; (6) use a stone-free soil instead of concrete or use a mattress thicker than 1 cm, with microrelief, and a soft fixing area at the curb, (7) litter with straw (rather than nothing or sawdust) and keep it dry. This risk factor analysis should be followed by experiments in controlled environments to further validate these conclusions and used to update the International Commission of Agricultural and Biosystems Engineering recommendations.     

Physicochemical characterization of Au/CeO2 solids. Part 2: The impregnation preparation method

Au/CeO₂ solids with different gold contents were prepared using the impregnation method. Electron microscopy (SEM and TEM) studies indicated the formation of both nanoparticles and large gold particles on the surface of the ceria support. SEM and XRD analyses revealed that the number and size of large particles increases with the gold content in the solid. The XPS technique showed that 90% of the total gold is in the metallic form Au⁰ while the remaining 10% were cationic gold species Au⁺. These latter were formed following calcination under dry air at 400 °C and are located in the proximity of the O²⁻ and/or Cl⁻ present on the support. These Au⁺ species are present at the edge of gold particles and they were reduced into metallic gold when the solid was vacuum treated (5–7.10⁻⁴ mbar) at 400 °C for 1 h. When air was adsorbed at room temperature on the latter vacuum treated solids, two EPR signals were obtained. The first one was assigned to O₂⁻ species whereas attributing the second signal was difficult and required a more detailed investigation that will be presented in a forthcoming work.     

Zipping effect on omniphobic surfaces for controlled deposition of minute amounts of fluid or colloids

When a drop sits on a highly liquid-repellent surface (super-hydrophobic or super-omniphobic) made of periodic micrometer-sized posts, its contact-line can recede with very weak mechanical retention providing that the liquid stays on top of the microsized posts. Occurring in both sliding and evaporation processes, the achievement of low-contact-angle hysteresis (low retention) is required for discrete microfluidic applications involving liquid motion or self-cleaning; however, careful examination shows that during receding, a minute amount of liquid is left on top of the posts lying at the receding edge of the drop. For the first time, the heterogeneities of these deposits along the drop-receding contact-line are underlined. Both nonvolatile liquid and particle-laden water are used to quantitatively characterize what rules the volume distribution of deposited liquid. The experiments suggest that the dynamics of the liquid de-pinning cascade is likely to select the volume left on a specific post, involving the pinch-off and detachment of a liquid bridge. In an applied prospective, this phenomenon dismisses such surfaces for self-cleaning purposes, but offers an original way to deposit controlled amounts of liquid and (bio)-particles at well-targeted locations.     

AMZ Driverless: The full autonomous racing system

This paper presents the algorithms and system architecture of an autonomous racecar. The introduced vehicle is powered by a software stack designed for robustness, reliability, and extensibility. To autonomously race around a previously unknown track, the proposed solution combines state of the art techniques from different fields of robotics. Specifically, perception, estimation, and control are incorporated into one high‐performance autonomous racecar. This complex robotic system, developed by AMZ Driverless and ETH Zürich, finished first overall at each competition we attended: Formula Student Germany 2017, Formula Student Italy 2018 and Formula Student Germany 2018. We discuss the findings and learnings from these competitions and present an experimental evaluation of each module of our solution.     

Tensile behaviour of magnesia-spinel refractories: Comparison of tensile and wedge splitting tests

In some industrial applications, the need to improve the thermal shock resistance of refractories by optimisation of their microstructural design is of major importance. Refractories with enhanced thermal shock resistance usually present a rather low resistance to crack initiation but high resistance to crack propagation (rising R-curves), as well as a mechanical behaviour deviating from pure linear elastic fracture mechanics (LEFM), often qualified as nonlinear. The present work aimed at studying the influence of thermal micro-damage within the microstructure released during the cooling process on the nonlinearity of the mechanical behaviour in tension. The two-phase composites considered were magnesia-spinel refractories with different spinel inclusions content allowing to modulate the micro-damage level. Two different destructive mechanical tests, namely tensile and wedge splitting tests, were performed and their results were compared. The influence of thermal damage on different relevant mechanical parameters was investigated, and a quantitative correlation analysis between these parameters was proposed.     

Self-similar correlation function in brain resting-state functional magnetic resonance imaging

Adaptive behaviour, cognition and emotion are the result of a bewildering variety of brain spatio-temporal activity patterns. An important problem in neuroscience is to understand the mechanism by which the human brain''s 100 billion neurons and 100 trillion synapses manage to produce this large repertoire of cortical configurations in a flexible manner. In addition, it is recognized that temporal correlations across such configurations cannot be arbitrary, but they need to meet two conflicting demands: while diverse cortical areas should remain functionally segregated from each other, they must still perform as a collective, i.e. they are functionally integrated. Here, we investigate these large-scale dynamical properties by inspecting the character of the spatio-temporal correlations of brain resting-state activity. In physical systems, these correlations in space and time are captured by measuring the correlation coefficient between a signal recorded at two different points in space at two different times. We show that this two-point correlation function extracted from resting-state functional magnetic resonance imaging data exhibits self-similarity in space and time. In space, self-similarity is revealed by considering three successive spatial coarse-graining steps while in time it is revealed by the 1/f frequency behaviour of the power spectrum. The uncovered dynamical self-similarity implies that the brain is spontaneously at a continuously changing (in space and time) intermediate state between two extremes, one of excessive cortical integration and the other of complete segregation. This dynamical property may be seen as an important marker of brain well-being in both health and disease.