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Schnabel, C. L., Babasyan, S., Freer, H., & Wagner, B. (2017). Quantification of equine immunoglobulin A in serum and secretions by a fluorescent bead-based assay. Veterinary Immunology and Immunopathology, 188, 12–20.
Abstract: Abstract Only few quantitative reports exist about the concentrations and induction of immunoglobulin A (IgA) in mucosal secretions of horses. Despite this, it is widely assumed that IgA is the predominant immunoglobulin on mucosal surfaces in the horse. Here, two new monoclonal antibodies (mAbs) against equine IgA, clones 84-1 and 161-1, were developed and characterized in detail. Both IgA mAbs specifically bound monomeric and dimeric equine IgA in different applications, such as Western blots and fluorescent bead-based assays. Cross-reactivity with other equine immunoglobulin isotypes was not observed. The new IgA mAb 84-1 was used in combination with the previously characterized anti-equine IgA mAb BVS2 for the development and validation of a fluorescent bead-based assay to quantify total IgA in equine serum and various secretions. The IgA assay's linear detection ranged from 64 pg/ml to 1000 ng/ml. For the quantification of IgA in serum or in secretions an IgA standard was purified from serum or nasal wash fluid (secretory IgA), respectively. The different standards were needed for accurate IgA quantification in the respective samples taking the different signal intensities of monomeric and dimeric IgA on the florescent bead-based assay into account. IgA was quantified by the bead-based assay established here in different equine samples of healthy adult individuals. In serum the median total IgA was 0.45 mg/ml for Thoroughbred horses (TB, n = 10) and 1.16 mg/ml in Icelandic horses (ICH, n = 12). In nasopharyngeal secretions of TB (n = 7) 0.13 mg/ml median total IgA was measured, and 0.25 mg/ml for ICH (n = 12). Saliva of ICH (n = 6) contained a median of 0.15 mg/ml, colostrum of Warmbloods (n = 8) a median of 1.89 mg/ml IgA. Compared to IgG1 and IgG4/7 quantified in the same samples, IgA appeared as the major immunoglobulin isotype in nasopharyngeal secretions and saliva while it is a minor isotype in serum and colostrum. The newly developed monoclonal antibodies against equine IgA and the resulting bead-based assay for quantification of total IgA can notably improve the evaluation of mucosal immunity in horses.
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Rosati, A. G. (2017). Foraging Cognition: Reviving the Ecological Intelligence Hypothesis. Trends in Cognitive Sciences, 21(9), 691–702.
Abstract: What are the origins of intelligent behavior? The demands associated with living in complex social groups have been the favored explanation for the evolution of primate cognition in general and human cognition in particular. However, recent comparative research indicates that ecological variation can also shape cognitive abilities. I synthesize the emerging evidence that ?foraging cognition? ? skills used to exploit food resources, including spatial memory, decision-making, and inhibitory control ? varies adaptively across primates. These findings provide a new framework for the evolution of human cognition, given our species? dependence on costly, high-value food resources. Understanding the origins of the human mind will require an integrative theory accounting for how humans are unique in both our sociality and our ecology.
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Henry, S., Fureix, C., Rowberry, R., Bateson, M., & Hausberger, M. (2017). Do horses with poor welfare show 'pessimistic' cognitive biases? Sci. Nat., 104(1), 8.
Abstract: This field study tested the hypothesis that domestic horses living under putatively challenging-to-welfare conditions (for example involving social, spatial, feeding constraints) would present signs of poor welfare and co-occurring pessimistic judgement biases. Our subjects were 34 horses who had been housed for over 3 years in either restricted riding school situations (e.g. kept in single boxes, with limited roughage, ridden by inexperienced riders; N = 25) or under more naturalistic conditions (e.g. access to free-range, kept in stable social groups, leisure riding; N = 9). The horses' welfare was assessed by recording health-related, behavioural and postural indicators. Additionally, after learning a location task to discriminate a bucket containing either edible food ('positive' location) or unpalatable food ('negative' location), the horses were presented with a bucket located near the positive position, near the negative position and halfway between the positive and negative positions to assess their judgement biases. The riding school horses displayed the highest levels of behavioural and health-related problems and a pessimistic judgment bias, whereas the horses living under more naturalistic conditions displayed indications of good welfare and an optimistic bias. Moreover, pessimistic bias data strongly correlated with poor welfare data. This suggests that a lowered mood impacts a non-human species' perception of its environment and highlights cognitive biases as an appropriate tool to assess the impact of chronic living conditions on horse welfare.
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Kiliç, S., & Cantürk, G. (2017). Car Accident Due to Horse Crossing the Motorway: Two Case Reports. Bull. Leg. Med., 22.
Abstract: Basic Commercial Court in Ankara wanted a report from our department of forensic medicine about two injury cases due to animal vehicle collision. The reports should include the disability rate and the duration of unfunctionality. After the examination we prepared the reports. Both vehicle collisions happened due to free ranging horse crossing the motorway. Both cases had different types of injury due to trauma. Vehicle collision due to horse crossing the motorway is rarely met in Turkey.
Our first case is a man that had upper extremity and facial injury. He uses prothesis due to ear amputation. He has a scar tissue on the right side of his face and left forearm. The other case is three-years-old boy that had cranial bone fracture and cranial hematoma. He has also hemiparesis of the right side of body. Both cases have neurologic sequels but they have no psychiatric sequels. In literature, animal vehicle collisions involve lots of animal species such as kangaroo, deer, camel and moose. Animal vehicle collision involving the horses is rarely met. Forensic medicine specialists should state the causal link between traumatic events and disabilities in order to help justice. Our aim to present the current two cases is investigation of injuries of animal related collision and makes forensic medicine specialists pay attention to the subject of preparing reports about such cases. |
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Rogers, L. J. (2017). A Matter of Degree: Strength of Brain Asymmetry and Behaviour. Symmetry, 9(4).
Abstract: Research on a growing number of vertebrate species has shown that the left and right sides of the brain process information in different ways and that lateralized brain function is expressed in both specific and broad aspects of behaviour. This paper reviews the available evidence relating strength of lateralization to behavioural/cognitive performance. It begins by considering the relationship between limb preference and behaviour in humans and primates from the perspectives of direction and strength of lateralization. In birds, eye preference is used as a reflection of brain asymmetry and the strength of this asymmetry is associated with behaviour important for survival (e.g., visual discrimination of food from non-food and performance of two tasks in parallel). The same applies to studies on aquatic species, mainly fish but also tadpoles, in which strength of lateralization has been assessed as eye preferences or turning biases. Overall, the empirical evidence across vertebrate species points to the conclusion that stronger lateralization is advantageous in a wide range of contexts. Brief discussion of interhemispheric communication follows together with discussion of experiments that examined the effects of sectioning pathways connecting the left and right sides of the brain, or of preventing the development of these left-right connections. The conclusion reached is that degree of functional lateralization affects behaviour in quite similar ways across vertebrate species. Although the direction of lateralization is also important, in many situations strength of lateralization matters more. Finally, possible interactions between asymmetry in different sensory modalities is considered.
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Knolle, F., Goncalves, R. P., & Morton, A. J. (2017). Sheep recognize familiar and unfamiliar human faces from two-dimensional images. Royal Society Open Science, 4(11).
Abstract: One of the most important human social skills is the ability to recognize faces. Humans recognize familiar faces easily, and can learn to identify unfamiliar faces from repeatedly presented images. Sheep are social animals that can recognize other sheep as well as familiar humans. Little is known, however, about their holistic face-processing abilities. In this study, we trained eight sheep (Ovis aries) to recognize the faces of four celebrities from photographic portraits displayed on computer screens. After training, the sheep chose the 'learned-familiar' faces rather than the unfamiliar faces significantly above chance. We then tested whether the sheep could recognize the four celebrity faces if they were presented in different perspectives. This ability has previously been shown only in humans. Sheep successfully recognized the four celebrity faces from tilted images. Interestingly, there was a drop in performance with the tilted images (from 79.22 ± 7.5% to 66.5 ± 4.1%) of a magnitude similar to that seen when humans perform this task. Finally, we asked whether sheep could recognize a very familiar handler from photographs. Sheep identified the handler in 71.8 ± 2.3% of the trials without pretraining. Together these data show that sheep have advanced face-recognition abilities, comparable with those of humans and non-human primates.
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Leadbeater, E., & Dawson, E. H. (2017). A social insect perspective on the evolution of social learning mechanisms. Proc. Natl. Acad. Sci. U.S.A., 114(30), 7838–7845.
Abstract: The social world offers a wealth of opportunities to learn from others, and across the animal kingdom individuals capitalize on those opportunities. Here, we explore the role of natural selection in shaping the processes that underlie social information use, using a suite of experiments on social insects as case studies. We illustrate how an associative framework can encompass complex, context-specific social learning in the insect world and beyond, and based on the hypothesis that evolution acts to modify the associative process, suggest potential pathways by which social information use could evolve to become more efficient and effective. Social insects are distant relatives of vertebrate social learners, but the research we describe highlights routes by which natural selection could coopt similar cognitive raw material across the animal kingdom.
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Marneweck, C., Jürgens, A., & Shrader, A. M. (2017). Dung odours signal sex, age, territorial and oestrous state in white rhinos. Proc. R. Soc. Lond. B, 284(1846).
Abstract: Mammals commonly communicate olfactorily via urine. However, the extent to which they communicate via dung, another waste product, is unknown. Behavioural studies suggest that mammals can obtain information from dung odours but are unclear about the information transmitted. Moreover, an understanding of the volatile organic compounds (VOCs) released from dung is limited. To address this, we analysed the odours emitted from the dung of free-ranging white rhinos, and found that 2,3-dimethylundecane signalled an individual's sex, heptanal discriminated age class, nonane defined male territorial status and 2,6-dimethylundecane indicated female oestrous state. To validate these findings, we artificially reproduced key elements of the territorial and oestrous odour profiles (i.e. profiles likely to elicit behavioural responses from receivers). We then exposed free-ranging territorial males to these odours. In response, males elicited behaviours associated with the specific odours (e.g. territorial male (potential threat): reduced latency in assuming vigilance; oestrous female (potential mate): increased investigation). These results indicate that the VOCs identified from the dung of free-ranging individuals do transmit key information. Moreover, as white rhinos of all ages and sexes defecate communally, middens probably act as information centres. Furthermore, as many other mammals defecate communally, olfactory communication via dung odours is likely a widespread phenomenon.
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Baragli, P., Demuru, E., Scopa, C., & Palagi, E. (2017). Are horses capable of mirror self-recognition? A pilot study. Plos One, 12(5), e0176717.
Abstract: Mirror Self-Recognition (MSR) unveils complex cognitive, social and emotional skills and it has been found only in humans and few other species, such as great apes, dolphins, elephants and magpies. In this pilot study, we tested if horses show the capacity of MSR. Four subjects living socially under naturalistic conditions were selected for the experiment. We adopted the classical mark test, which consists in placing a coloured mark on an out-of-view body part, visible only through mirror inspection. If the animal considers the image as its own, it will use its reflection to detect the mark and will try to explore it. We enhanced the classical paradigm by introducing a double-check control. Only in the presence of the reflecting surface, animals performed tactile and olfactory exploration of the mirror and looked behind it. These behaviors suggest that subjects were trying to associate multiple sensory cues (visual, tactile and olfactory) to the image in the mirror. The lack of correspondence between the collected stimuli in front of the mirror and the response to the colored mark lead us to affirm that horses are able to perceive that the reflected image is incongruent when compared with the memorized information of a real horse. However, without replication of data, the self-directed behavior towards the colored marks showed by our horses cannot be sufficient per se to affirm that horses are capable of self-recognition.
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Valenchon, M., Lévy, F., Moussu, C., & Lansade, L. (2017). Stress affects instrumental learning based on positive or negative reinforcement in interaction with personality in domestic horses. Plos One, 12(5), e0170783.
Abstract: The present study investigated how stress affects instrumental learning performance in horses (Equus caballus) depending on the type of reinforcement. Horses were assigned to four groups (N = 15 per group); each group received training with negative or positive reinforcement in the presence or absence of stressors unrelated to the learning task. The instrumental learning task consisted of the horse entering one of two compartments at the appearance of a visual signal given by the experimenter. In the absence of stressors unrelated to the task, learning performance did not differ between negative and positive reinforcements. The presence of stressors unrelated to the task (exposure to novel and sudden stimuli) impaired learning performance. Interestingly, this learning deficit was smaller when the negative reinforcement was used. The negative reinforcement, considered as a stressor related to the task, could have counterbalanced the impact of the extrinsic stressor by focusing attention toward the learning task. In addition, learning performance appears to differ between certain dimensions of personality depending on the presence of stressors and the type of reinforcement. These results suggest that when negative reinforcement is used (i.e. stressor related to the task), the most fearful horses may be the best performers in the absence of stressors but the worst performers when stressors are present. On the contrary, when positive reinforcement is used, the most fearful horses appear to be consistently the worst performers, with and without exposure to stressors unrelated to the learning task. This study is the first to demonstrate in ungulates that stress affects learning performance differentially according to the type of reinforcement and in interaction with personality. It provides fundamental and applied perspectives in the understanding of the relationships between personality and training abilities.
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