Prato-Previde, E., Marshall-Pescini, S., & Valsecchi, P. (2008). Is your choice my choice` The owners effect on pet dogs? ( Canis lupus familiaris ) performance in a food choice task. Anim. Cogn., 11(1), 167–174.
Abstract: Abstract This study investigates the influence of owners on their dogs performance in a food choice task using either different or equal quantities of food. Fifty-four pet dogs were tested in three different conditions. In Condition 1 we evaluated their ability to choose between a large and small amount of food (quantity discrimination task). In Condition 2 dogs were again presented with a choice between the large and small food quantity, but only after having witnessed their owner favouring the small quantity. In Condition 3 dogs were given a choice between two equally small quantities of food having witnessed their owner favouring either one or the other. A strong effect of the owner on the dogs`` performance was observed. In Condition 1 dogs as a group chose significantly more often the large food quantity, thus showing their ability to solve the quantity discrimination task. After observing their owner expressing a preference for the small food quantity they chose the large quantity of food significantly less than in the independent choice situation. The tendency to conform to the owner`s choice was higher when the dogs had to choose between equally small quantities of food (Condition 3) rather than between a large and a small one (Condition 2). These results provide evidence that dogs can be influenced by their owners even when their indications are clearly in contrast with direct perceptual information, thus leading dogs to ultimately make counterproductive choices.
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Quaranta, A., Siniscalchi, M., Frate, A., & Vallortigara, G. (2004). Paw preference in dogs: relations between lateralised behaviour and immunity. Behavioural Brain Research, 153(2), 521–525.
Abstract: Paw use in a task consisting of the removal of a piece of adhesive paper from the snout was investigated in 80 mongrel and pure-bred domestic dogs (Canis familiaris). Population lateralisation was observed, but in opposite directions in the two sexes (animals were not desexed): males preferentially used their left paw, females their right paw. The relationship between immune function and paw preference was then investigated. Some immune parameters (total number of white blood cells including lymphocytes, granulocytes and monocytes; leukocyte formula; total proteins; γ-globulins) were investigated in a sample of left-pawed (n=6), right-pawed (n=6) and ambidextrous (n=6) dogs. The results showed that the percentage of lymphocytes was higher in left-pawed than in right-pawed and ambidextrous dogs, whereas granulocytes percentage was lower in left-pawed than in right-pawed and ambidextrous dogs. Moreover, total number of lymphocytes cells was higher in left-pawed than in right-pawed and ambidextrous dogs, whereas the number of γ-globulins was lower in left-pawed than in right-pawed and ambidextrous dogs. These findings represent the first evidence that brain asymmetry modulates immune responses in dogs.
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Reid, P. J. (2009). Adapting to the human world: Dogs' responsiveness to our social cues. Behav. Process., 80(3), 325–333.
Abstract: Dogs are more skilful than a host of other species at tasks which require they respond to human communicative gestures in order to locate hidden food. Four basic interpretations for this proficiency surface from distilling the research findings. One possibility is that dogs simply have more opportunity than other species to learn to be responsive to human social cues. A different analysis suggests that the domestication process provided an opening for dogs to apply general cognitive problem-solving skills to a novel social niche. Some researchers go beyond this account and propose that dogs' co-evolution with humans equipped them with a theory of mind for social exchanges. Finally, a more prudent approach suggests that sensitivity to the behaviours of both humans and conspecifics would be particularly advantageous for a social scavenger like the dog. A predisposition to attend to human actions allows for rapid early learning of the association between gestures and the availability of food.
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Riedel, J., Buttelmann, D., Call, J., & Tomasello, M. (2006). Domestic dogs (Canis familiaris) use a physical marker to locate hidden food. Anim. Cogn., 9(1), 27–35.
Abstract: Dogs can use the placement of an arbitrary marker to locate hidden food in an object-choice situation. We tested domestic dogs (Canis familiaris) in three studies aimed at pinning down the relative contributions of the human's hand and the marker itself. We baited one of two cups (outside of the dogs' view) and gave the dog a communicative cue to find the food. Study 1 systematically varied dogs' perceptual access to the marker placing event, so that dogs saw either the whole human, the hand only, the marker only, or nothing. Follow-up trials investigated the effect of removing the marker before the dog's choice. Dogs used the marker as a communicative cue even when it had been removed prior to the dog's choice and attached more importance to this cue than to the hand that placed it although the presence of the hand boosted performance when it appeared together with the marker. Study 2 directly contrasted the importance of the hand and the marker and revealed that the effect of the marker diminished if it had been associated with both cups. In contrast touching both cups with the hand had no effect on performance. Study 3 investigated whether the means of marker placement (intentional or accidental) had an effect on dogs' choices. Results showed that dogs did not differentiate intentional and accidental placing of the marker. These results suggest that dogs use the marker as a genuine communicative cue quite independently from the experimenter's actions.
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Rumiantsev, S. N. (1973). [Biological function of Clostridium tetani toxin (ecological and evolutionary aspects)]. Zh Evol Biokhim Fiziol, 9(5), 474–480.
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Saigo, S. (1981). Kinetic and equilibrium studies of alkaline isomerization of vertebrate cytochromes c. Biochim Biophys Acta, 669(1), 13–20.
Abstract: Equilibria and kinetics of alkaline isomerization of seven ferricytochromes c from vertebrates were studied by pH-titration and pH-jump methods in the pH region of 7-12. In the equilibrium behavior, no significant difference was detected among the cytochromes c, whereas marked differences in the kinetic behavior were observed. According to the kinetic behavior of the isomerization, the cytochromes c examined fall into three classes: Group I (horse, sheep, dog and pigeon cytochromes c), Group II (tuna and bonito cytochromes c) and Group III (rhesus monkey cytochrome c). The kinetic results are interpreted in terms of the sequential scheme: Neutral form in equilibrium with fast Transient form in equilibrium with slow Alkaline form where the neutral and alkaline forms are the species stable at neutral and alkaline pH, respectively, and the transient form is a kinetic intermediate. From comparison of the primary sequences of the seven cytochromes c and the classification of these cytochromes c, it is concluded that the amino acid substitution Phe/Tyr at the 46-th position has a major influence on the kinetic behavior. In Group II and III cytochromes c, the ionization of Tyr-46 is suggested to bring about loosening of the heme crevice and thus facilitate the ligand replacement involved in the isomerization.
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Scheider, L., Kaminski, J., Call, J., & Tomasello, M. (2013). Do domestic dogs interpret pointing as a command? Animal Cognition, 16(3), 361–372.
Abstract: Domestic dogs comprehend human gestural communication flexibly, particularly the pointing gesture. Here, we examine whether dogs interpret pointing informatively, that is, as simply providing information, or rather as a command, for example, ordering them to move to a particular location. In the first study a human pointed toward an empty cup. In one manipulation, the dog either knew or did not know that the designated cup was empty (and that the other cup actually contained the food). In another manipulation, the human (as authority) either did or did not remain in the room after pointing. Dogs ignored the human’s gesture if they had better information, irrespective of the authority’s presence. In the second study, we varied the level of authority of the person pointing. Sometimes this person was an adult, and sometimes a young child. Dogs followed children’s pointing just as frequently as they followed adults’ pointing (and ignored the dishonest pointing of both), suggesting that the level of authority did not affect their behavior. Taken together these studies suggest that dogs do not see pointing as an imperative command ordering them to a particular location. It is still not totally clear, however, if they interpret it as informative or in some other way.
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Schwab, C., & Huber, L. (2006). Obey or not obey? Dogs (Canis familiaris) behave differently in response to attentional states of their owners. J Comp Psychol, 120(3), 169–175.
Abstract: Sixteen domestic dogs (Canis familiaris) were tested in a familiar context in a series of 1-min trials on how well they obeyed after being told by their owner to lie down. Food was used in 1/3 of all trials, and during the trial the owner engaged in 1 of 5 activities. The dogs behaved differently depending on the owner's attention to them. When being watched by the owner, the dogs stayed lying down most often and/or for the longest time compared with when the owner read a book, watched TV, turned his or her back on them, or left the room. These results indicate that the dogs sensed the attentional state of their owners by judging observable behavioral cues such as eye contact and eye, head, and body orientation.
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Selby, L. A., Marienfeld, C. J., & Pierce, J. O. (1970). The effects of trace elements on human and animal health. J Am Vet Med Assoc, 157(11), 1800–1808.
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Shalaby, A. M. (1969). Host-preference observations on Anopheles culicifacies (Diptera: Culicidae) in Gujarat State, India. Ann Entomol Soc Am, 62(6), 1270–1273.
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