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Nelson, D. M., Gardner, I. A., Chiles, R. F., Balasuriya, U. B., Eldridge, B. F., Scott, T. W., et al. (2004). Prevalence of antibodies against Saint Louis encephalitis and Jamestown Canyon viruses in California horses. Comp Immunol Microbiol Infect Dis, 27(3), 209–215.
Abstract: Jamestown Canyon (JC) and Saint Louis encephalitis (SLE) viruses are mosquito-transmitted viruses that have long been present in California. The objective of this study was to determine the seroprevalence of these two viruses in horses prior to the introduction of West Nile (WN) virus. Approximately 15% of serum samples collected in 1998 from 425 horses on 44 equine operations horses throughout California had serum antibodies to JC virus, whereas antibodies were not detected to SLE virus. The results indicate that horses in California were commonly infected prior to 1998 with mosquito-transmitted Bunyaviruses that are identical or closely related to JC virus, but not with SLE virus. The different seroprevalence of SLE and JC viruses in horses likely reflects the unique ecology of each virus, and it is predicted that WN virus will have a wider distribution in California than closely related SLE virus.
Keywords: Animals; Antibodies, Viral/*blood; California/epidemiology; Encephalitis Virus, California/*immunology/isolation & purification; Encephalitis Virus, St. Louis/*immunology/isolation & purification; Encephalitis, St. Louis/epidemiology/immunology/*veterinary/virology; Female; Horse Diseases/epidemiology/immunology/*virology; Horses; Logistic Models; Male; Neutralization Tests/veterinary; Polyomavirus Infections/epidemiology/immunology/*veterinary/virology; Questionnaires; Seroepidemiologic Studies; Tumor Virus Infections/epidemiology/immunology/*veterinary/virology
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Nicol, C. J., Yoon, M., Ward, J. M., Yamashita, M., Fukamachi, K., Peters, J. M., et al. (2004). PPARgamma influences susceptibility to DMBA-induced mammary, ovarian and skin carcinogenesis. Carcinogenesis, 25(9), 1747–1755.
Abstract: Peroxisome proliferator-activated receptor gamma (PPARgamma), a member of the nuclear receptor superfamily, plays a role in adipocyte differentiation, type II diabetes, macrophage response to inflammation and is suggested to influence carcinogen-induced colon cancer. Studies done in vitro and in vivo also revealed that PPARgamma ligands might promote differentiation and/or regression of mammary tumors. To directly evaluate the role of PPARgamma in mammary carcinogenesis, PPARgamma wild-type (+/+) or heterozygous (+/-) mice were administered 1 mg 7,12-dimethylbenz[a]anthracene (DMBA) by gavage once a week for 6 weeks and followed for a total of 25 weeks. Compared with congenic PPARgamma(+/+) littermate controls, PPARgamma(+/-) mice had early evidence for increased susceptibility to DMBA-mediated carcinogenesis based on a 1.6-fold increase in the percentage of mice with skin papillomas, as well as a 1.7-fold increase in the numbers of skin papillomas per mouse (P < 0.05). Similarly, PPARgamma(+/-) mice also had a 1.5-fold decreased survival rate (P = 0.059), and a 1.7-fold increased incidence of total tumors per mouse (P < 0.01). Moreover, PPARgamma(+/-) mice had an almost 3-fold increase in mammary adenocarcinomas (P < 0.05), an over 3-fold increase in ovarian granulosa cell carcinomas (P < 0.05), an over 3-fold increase in malignant tumors (P < 0.02) and a 4.6-fold increase in metastatic incidence. These results are the first to demonstrate an increased susceptibility in vivo of PPARgamma haploinsufficiency to DMBA-mediated carcinogenesis and suggest that PPARgamma may act as a tumor modifier of skin, ovarian and breast cancers. The data also support evidence suggesting a beneficial role for PPARgamma-specific ligands in the chemoprevention of mammary, ovarian and skin carcinogenesis.
Keywords: 9,10-Dimethyl-1,2-benzanthracene/*toxicity; Animals; DNA Primers/chemistry; Disease Susceptibility; Female; Heterozygote; Humans; Mammary Neoplasms, Experimental/chemically induced/*pathology; Mice; Ovarian Neoplasms/chemically induced/*pathology; RNA, Messenger/genetics/metabolism; Receptors, Cytoplasmic and Nuclear/genetics/*physiology; Reverse Transcriptase Polymerase Chain Reaction; Skin Neoplasms/chemically induced/*pathology; Survival Rate; Transcription Factors/genetics/*physiology; Zinc Fingers
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Flack, J. C., Jeannotte, L. A., & de Waal, F. B. M. (2004). Play signaling and the perception of social rules by juvenile chimpanzees (Pan troglodytes). J Comp Psychol, 118(2), 149–159.
Abstract: Prescriptive social rules are enforced statistical regularities. The authors investigated whether juvenile chimpanzees (Pan troglodytes) recognize and use enforced statistical regularities to guide dyadic play behavior. They hypothesized (a) that proximity of adults, especially mothers of younger play partners, to play bouts will increase the play signaling of older partners and (b) that when juvenile-juvenile play bouts occur in proximity to adults, older partners will play at a lower intensity than when no adults are present. They found that older and younger partners increase their play signaling in the presence of the mothers of younger partners, particularly as the intensity of play bouts increases. In contrast to their hypothesis, older partners played more roughly when the mothers of younger partners were in proximity. These results suggest that juvenile chimpanzees increase play signaling to prevent termination of the play bouts by mothers of younger partners.
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Robitaille, J., Brouillette, C., Lemieux, S., Perusse, L., Gaudet, D., & Vohl, M. C. (2004). Plasma concentrations of apolipoprotein B are modulated by a gene-diet interaction effect between the LFABP T94A polymorphism and dietary fat intake in French-Canadian men. Mol Genet Metabol, 82(4), 296–303.
Abstract: Hyperapobetalipoproteinemia is a common feature of the metabolic syndrome and could result from the interaction between genetic and dietary factors. The objective of this study was to verify whether dietary fat intake interacts with the T94A polymorphism of the liver fatty acid-binding protein (LFABP) gene to modulate plasma apolipoprotein (apo) B levels. Dietary fat and saturated fat intakes were obtained by a dietitian-administered food frequency questionnaire and the LFABP T94A genotype was determined by a PCR-RFLP based method in 623 French-Canadian men recruited through the Chicoutimi Lipid Clinic (279 T94/T94, 285 T94/A94, and 59 A94/A94). The LFABP T94A polymorphism was not associated with plasma apo B levels when fat intake was not taken into consideration. However, in a model including the polymorphism, fat intake expressed as a percentage of total energy intake, the interaction term and covariates, the variance in apo B concentrations was partly explained by the LFABP T94A polymorphism (5.24%, p=0.01) and by the LFABP T94A * fat interaction (6.25%, p=0.005). Results were similar when saturated fat replaced fat intake in the model (4.49%, p=0.02 for LFABP T94A and 6.43%, p=0.004 for the interaction). Moreover, in men consuming more than 30% of energy from fat, the odds ratio for having plasma apo B levels above 1.04 g/L for A94 carriers was of 0.40 (p=0.02) compared to T94/T94 homozygotes. Results were similar for carriers of the A94 allele consuming more than 10% of energy from saturated fat (OR: 0.32, p=0.005). In conclusion, T94/T94 exhibit higher apo B levels whereas carriers of the A94 allele seem to be protected against high apo B levels when consuming a high fat and saturated fat diet. These findings reinforce the importance to take into account gene-diet interactions in the prevention and management of the metabolic syndrome.
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Paz-y-Miño C. G., Bond, A. B., Kamil, A. C., & Balda, R. P. (2004). Pinyon jays use transitive inference to predict social dominance. Nature, 430(7001), 778–781.
Abstract: Living in large, stable social groups is often considered to favour the evolution of enhanced cognitive abilities, such as recognizing group members, tracking their social status and inferring relationships among them. An individual's place in the social order can be learned through direct interactions with others, but conflicts can be time-consuming and even injurious. Because the number of possible pairwise interactions increases rapidly with group size, members of large social groups will benefit if they can make judgments about relationships on the basis of indirect evidence. Transitive reasoning should therefore be particularly important for social individuals, allowing assessment of relationships from observations of interactions among others. Although a variety of studies have suggested that transitive inference may be used in social settings, the phenomenon has not been demonstrated under controlled conditions in animals. Here we show that highly social pinyon jays (Gymnorhinus cyanocephalus) draw sophisticated inferences about their own dominance status relative to that of strangers that they have observed interacting with known individuals. These results directly demonstrate that animals use transitive inference in social settings and imply that such cognitive capabilities are widespread among social species.
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Friedrich, A. M., & Zentall, T. R. (2004). Pigeons shift their preference toward locations of food that take more effort to obtain. Behav. Process., 67(3), 405–415.
Abstract: Although animals typically prefer to exert less effort rather than more effort to obtain food, the present research shows that requiring greater effort to obtain food at a particular location appears to increase the value of that location. In Experiment 1, pigeons' initial preference for one feeder was significantly reduced by requiring 1 peck to obtain food from that feeder and requiring 30 pecks to obtain food from the other feeder. In Experiment 2, a similar decrease in preference was not found when pigeons received reinforcement from both feeders independently of the amount of effort required. These results are consistent with the within-trial contrast effect proposed by in which the relative hedonic value of a reward depends on the state of the animal immediately prior to the reward. The greater the improvement from that prior state the greater the value of the reinforcer.
Keywords: Animals; *Behavior, Animal; *Choice Behavior; Columbidae; *Exertion; *Feeding Behavior; Reward
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Zentall, T. R., Weaver, J. E., & Clement, T. S. (2004). Pigeons group time intervals according to their relative duration. Psychon Bull Rev, 11(1), 113–117.
Abstract: In the present research, we asked whether pigeons tended to judge time intervals not only in terms of their absolute value but also relative to a duration from which they must be discriminated (i.e., longer or shorter). Pigeons were trained on two independent temporal discriminations. In one discrimination, sample durations of 2 and 8 sec were associated with, for example, red and green hue comparisons, respectively, and in the other discrimination, sample durations of 4 and 16 sec were associated with vertical and horizontal line comparisons, respectively. If pigeons are trained on a temporal discrimination and tested with intermediate durations, the subjective midpoint typically occurs close to the geometric mean of the two trained values. The 4- and 8-sec values were selected to be the geometric mean of the two values in the other discrimination. When a 4-sec test sample was presented with the comparisons from the 2- and 8-sec discrimination, the pigeons preferred the comparison associated with the shorter sample. Similarly, when an 8-sec test sample was presented with the comparisons from the 4- and 16-sec discrimination, the pigeons preferred the comparison associated with the longer sample. Thus, a relative grouping effect was found. That is, durations that should have produced indifferent choice were influenced by their relative durations (shorter than or longer than the alternative) during training.
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Harman, F. S., Nicol, C. J., Marin, H. E., Ward, J. M., Gonzalez, F. J., & Peters, J. M. (2004). Peroxisome proliferator-activated receptor-delta attenuates colon carcinogenesis. Nat Med, 10(5), 481–483.
Abstract: Peroxisome proliferator-activated receptor-delta (PPAR-delta; also known as PPAR-beta) is expressed at high levels in colon tumors, but its contribution to colon cancer is unclear. We examined the role of PPAR-delta in colon carcinogenesis using PPAR-delta-deficient (Ppard(-/-)) mice. In both the Min mutant and chemically induced mouse models, colon polyp formation was significantly greater in mice nullizygous for PPAR-delta. In contrast to previous reports suggesting that activation of PPAR-delta potentiates colon polyp formation, here we show that PPAR-delta attenuates colon carcinogenesis.
Keywords: Animals; Azoxymethane/toxicity; Colonic Neoplasms/etiology/genetics/*prevention & control; Colonic Polyps/etiology/genetics/pathology/prevention & control; Disease Models, Animal; Mice; Mice, Knockout; Mice, Mutant Strains; Phenotype; Receptors, Cytoplasmic and Nuclear/deficiency/genetics/*physiology; Transcription Factors/deficiency/genetics/*physiology
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Parr, L. A. (2004). Perceptual biases for multimodal cues in chimpanzee (Pan troglodytes) affect recognition. Anim. Cogn., 7(3), 171–178.
Abstract: The ability of organisms to discriminate social signals, such as affective displays, using different sensory modalities is important for social communication. However, a major problem for understanding the evolution and integration of multimodal signals is determining how humans and animals attend to different sensory modalities, and these different modalities contribute to the perception and categorization of social signals. Using a matching-to-sample procedure, chimpanzees discriminated videos of conspecifics' facial expressions that contained only auditory or only visual cues by selecting one of two facial expression photographs that matched the expression category represented by the sample. Other videos were edited to contain incongruent sensory cues, i.e., visual features of one expression but auditory features of another. In these cases, subjects were free to select the expression that matched either the auditory or visual modality, whichever was more salient for that expression type. Results showed that chimpanzees were able to discriminate facial expressions using only auditory or visual cues, and when these modalities were mixed. However, in these latter trials, depending on the expression category, clear preferences for either the visual or auditory modality emerged. Pant-hoots and play faces were discriminated preferentially using the auditory modality, while screams were discriminated preferentially using the visual modality. Therefore, depending on the type of expressive display, the auditory and visual modalities were differentially salient in ways that appear consistent with the ethological importance of that display's social function.
Keywords: Acoustic Stimulation; *Animal Communication; Animals; Auditory Perception/physiology; Cues; Discrimination Learning/*physiology; Facial Expression; Female; Male; Pan troglodytes/*psychology; Perceptual Masking/*physiology; Photic Stimulation; Recognition (Psychology)/*physiology; Visual Perception/physiology; *Vocalization, Animal
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de Waal, F. B. M. (2004). Peace lessons from an unlikely source. PLoS. Biol., 2(4), E101.
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