Modulation of aggression in male mice: influence of group size and cage size

Aggression in group-housed male mice is known to be influenced by both cage size and group size. However, the interdependency of these two parameters has not been studied yet. In this study, the level of aggression in groups of three, five, or eight male BALB/c mice housed in cages with a floor size of either 80 or 125 cm2/animal was estimated weekly after cage cleaning for a period of 14 weeks. Furthermore, urine corticosterone levels, food and water intake, body weight, and number of wounds were measured weekly. At the end of the experiment, tyrosine hydroxylase (TH) activity, testosterone levels, and weight of spleen, thymus, testes, and seminal vesicles were determined. Results indicate a moderate increase of intermale aggression in larger cages when compared to the smaller cages. Aggression in groups of eight animals was considerably higher than in groups of three animals. The increase of agonistic behavior was observed both in dominant and subordinate animals. Physiological parameters indicate differences in stress levels between dominant and subordinate animals. It is concluded that aggressive behavior in group-housed male BALB/c mice is best prevented by housing the animals in small groups of three to five animals, while decreasing floor size per animal may be used as a temporary solution to decrease high levels of aggression in an existing social group.

Model selection with estimated factors and idiosyncratic components

This paper provides consistent information criteria for the selection of forecasting models which use a subset of both the idiosyncratic and common factor components of a big dataset. This hybrid model approach has been explored by recent empirical studies to relax the strictness of pure factor-augmented model approximations, but no formal model selection procedures have been developed. The main difference to previous factor-augmented model selection procedures is that we must account for estimation error in the idiosyncratic component as well as the factors. Our main contribution is to show the conditions required for selection consistency of a class of information criteria which reflect this additional source of estimation error. We show that existing factor-augmented model selection criteria are inconsistent in circumstances where N is of larger order than root-T, where N and T are the cross-section and time series dimensions of the dataset respectively, and that the standard BIC is inconsistent regardless of the relationship between N and T. We therefore propose a new set of information criteria which guarantee selection consistency in the presence of estimated idiosyncratic components. The properties of these new criteria are explored through a Monte Carlo simulation study. The paper concludes with an empirical application to long-horizon exchange rate forecasting using a recently proposed model with country-specific idiosyncratic components from a panel of global exchange rates

The sources of management innovation: when firms introduce new management practices

Management innovation is the introduction of management practices new to the firm and intended to enhance firm performance. Building on the organizational reference group literature, this article shows that management innovation is a consequence of a firm's internal context and of the external search for new knowledge. Furthermore the article demonstrates a trade-off between context and search, in that there is a negative effect on management innovation associated with their joint occurrence. Finally the article shows that management innovation is positively associated with firm performance in the form of subsequent productivity growth

Numerical and experimental analysis of micro HAWTs designed for wind tunnel applications

In this paper the authors describe a design and optimization process of micro HAWTs using a numerical and experimental approach. An in-house 1D BEM model was used to obtain a first geometrical draft. It allowed to quickly optimize blade geometry to maximize energy production as well. As these models are quite sensitive to airfoil coefficients, above all at low Reynolds numbers, an accurate 3D CFD model was developed to support and validate the 1D BEM design, analyzing and fixing the discrepancies between model output. The 3D CFD model was developed and optimized using ANSYS Fluent solver and a RANS transition turbulence model. This allowed to correctly reproduce the transition and stall phenomena that characterize the aerodynamic behavior of micro wind turbines, solving the issues related to low Reynolds flows. The procedure was completed, thus building two micro HAWTs with different scales, testing them in the subsonic wind tunnel of the University of Catania. Wind tunnel features, experimental set-up and testing procedures are presented in the paper. Through the comparison of numerical CFD and experimental test results, a good compatibility was found. This allowed the authors to analyze and compare numerical calculation results and verify blockage effects on the prototypes as well

Early and non-intrusive lameness detection in dairy cows using 3-dimensional video

ABSTRACTLameness is a major issue in dairy herds and its early and automated detection offers animal welfare benefits together with high potential commercial savings for farmers. Current advancements in automated detection have not achieved a sensitive measure for classifying early lameness. A novel proxy for lameness using 3-dimensional (3D) depth video data to analyse the animal’s gait asymmetry is introduced. This dynamic proxy is derived from the height variations in the hip joint during walking. The video capture setup is completely covert and it facilitates an automated process. The animals are recorded using an overhead 3D depth camera as they walk freely in single file after the milking session. A 3D depth image of the cow’s body is used to automatically track key regions such as the hooks and the spine. The height movements are calculated from these regions to form the locomotion signals of this study, which are analysed using a Hilbert transform. Our results using a 1-5 locomotion scoring (LS) system on 22 Holstein Friesian dairy cows, a threshold could be identified between LS 1 and 2 (and above). This boundary is important as it represents the earliest point in time at which a cow is considered lame, and its early detection could improve intervention outcome thereby minimising losses and reducing animal suffering. Using a linear Support Vector Machine (SVM) binary classification model, the threshold achieved an accuracy of 95.7% with a 100% sensitivity (detecting lame cows) and 75% specificity (detecting non-lame cows)

The Experimental Hut: Hosting Vectors

publication-status: Publishedtypes: ArticleThis is a preprint version of the article and is available in ERIC according to journal policy as outlined in SHERPA/RoMEO. The definitive version is available at www3.interscience.wiley.comIn southeast Tanzania, ten canvass huts raised on wooden foundations occupy a plot of cleared rice field. Designed to simulate malaria transmission on the domestic scale, the experimental hut is constructed in the fashion of indigenous homes (complete with villagers, paid to spend the night) but is structurally modified to render mosquito behaviours visible. The experiment’s domestic camouflage provides the setting for multiple, and reciprocal, hostings: between parasite, mosquito and man, and between villagers, volunteers and scientists. This paper explores the valences of hospitality when the ‘home’ becomes a site of experimentation, and the cosmopoltian encounters these experiments entail

Perceptions of, and reactions to, environmental heat: a brief note on issues of concern in relation to occupational health

Average temperatures around the world are already increasing, and climate change projections suggest that global mean temperatures will continue to rise. As the effects, and projected effects, of climate change are becoming clearer, it is more apparent that the health effects of heat exposure will need further investigation. The risks associated with heat exposure are especially relevant to understandings of occupational health for people involved in labouring or agricultural work in low-income countries. This review is a partial look at the ways in which issues surrounding heat exposure and occupational health have been treated in some of the available literature. This literature focuses on military-related medical understandings of heat exposure as well as heat exposure in working environments. The ways that these issues have been treated throughout the literature reflect the ways in which technologies of observation are intertwined with social attitudes. The effects of heat on the health of working people, as well as identification of risk groups, will require further research in order to promote prophylactic measures as well as to add to understandings of the actual and potential consequences of climatic change

How big is big enough? Toward a sustainable future by examining alternatives to the conventional economic growth paradigm

This study addresses how the sustainability crisis may be overcome by using alternatives to the conventional economic growth paradigm. Based on a literature review, the paper identifies and discusses three alternatives, namely negative, zero and positive economic growth. These alternatives are compared from a feasibility and policy perspective in relation to the transition toward sustainable development. The three alternatives are associated with very far‐reaching sets of policies that have different focal points with regard to how the paradigm shift from the conventional growth paradigm can be realized. All these alternatives, however, challenge the effectiveness of market forces. The shortcomings of the alternatives (resistance to voluntary transition with negative or zero growth, no proper consideration of the rebound effect for positive growth) hinder the transition and must be further addressed by policy‐makers in public and private sectors, as well as by civil society