396 research outputs found
Testing differential use of payoff-biased social learning strategies in children and chimpanzees
Various non-human animal species have been shown to exhibit behavioural traditions. Importantly, this research has been guided by what we know of human culture, and the question of whether animal cultures may be homologous or analogous to our own culture. In this paper, we assess whether models of human cultural transmission are relevant to understanding biological fundamentals by investigating whether accounts of human payoff-biased social learning are relevant to chimpanzees (Pan troglodytes). We submitted 4- and 5-year-old children (N = 90) and captive chimpanzees (N = 69) to a token–reward exchange task. The results revealed different forms of payoff-biased learning across species and contexts. Specifically, following personal and social exposure to different tokens, children's exchange behaviour was consistent with proportional imitation, where choice is affected by both prior personally acquired and socially demonstrated token–reward information. However, when the socially derived information regarding token value was novel, children's behaviour was consistent with proportional observation; paying attention to socially derived information and ignoring their prior personal experience. By contrast, chimpanzees' token choice was governed by their own prior experience only, with no effect of social demonstration on token choice, conforming to proportional reservation. We also find evidence for individual- and group-level differences in behaviour in both species. Despite the difference in payoff strategies used, both chimpanzees and children adopted beneficial traits when available. However, the strategies of the children are expected to be the most beneficial in promoting flexible behaviour by enabling existing behaviours to be updated or replaced with new and often superior ones
Robust retention and transfer of tool construction techniques in chimpanzees (Pan troglodytes)
Long-term memory can be critical to a species’ survival in environments with seasonal and even longer-term cycles of resource availability. The present, longitudinal study investigated whether complex tool behaviors used to gain an out-of-reach reward, following a hiatus of about 3 years and 7 months since initial experiences with a tool use task, were retained and subsequently executed more quickly by experienced than by naïve chimpanzees. Ten of the 11 retested chimpanzees displayed impressive long-term procedural memory, creating elongated tools using the same methods employed years previously, either combining 2 tools or extending a single tool. The complex tool behaviors were also transferred to a different task context, showing behavioral flexibility. This represents some of the first evidence for appreciable long-term procedural memory, and improvements in the utility of complex tool manufacture in chimpanzees. Such long-term procedural memory and behavioral flexibility have important implications for the longevity and transmission of behavioral traditions
Improving design education at Kanazawa Intitute of Technology
A Task Force made up of a multicultural group of visiting professors at KIT, worked together with Japanese counterparts to develop materials to Improve Design Education At Kanazawa Institute of Technology (IDEA-KIT), Japan. The IDEA-KIT Task Force decided to use the Design Engineering Process that we teach to address the problem related to improving design education. The Task Force mission was to identify problems and needs in Engineering Design Education (EDE), to develop design specifications for educational materials to meet these needs, to generate a large number of concepts for ways to satisfy the design specifications, and select the best and most feasible ones for development to a level appropriate for classroom use in the autumn quarter of 1999. To facilitate implementation at KIT, all materials developed were to be modular, easy to use for both the faculty and students, and provide guidance in managing courses and standardising practices.As with any new programme, there were significant challenges in developing and implementing the EDE programme at KIT. While some challenges were anticipated, most did not show their true difficulty until experience in running the programme was available
Chance mechanisms affecting the burden of metastases
BACKGROUND: The burden of cancer metastases within an individual is commonly used to clinically characterize a tumor's biological behavior. Assessments like these implicitly assume that spurious effects can be discounted. Here the influence of chance on the burden of metastasis is studied to determine whether or not this assumption is valid. METHODS: Monte Carlo simulations were performed to estimate tumor burdens sustained by individuals with cancer, based upon empirically derived and validated models for the number and size distributions of metastases. Factors related to the intrinsic metastatic potential of tumors and their host microenvironments were kept constant, to more clearly demonstrate the contribution from chance. RESULTS: Under otherwise identical conditions, both the simulated numbers and the sizes of metastases were highly variable. Comparable individuals could sustain anywhere from no metastases to scores of metastases, and the sizes of the metastases ranged from microscopic to macroscopic. Despite the marked variability in the number and sizes of the metastases, their respective growth times were rather more narrowly distributed. In such situations multiple occult metastases could develop into fully overt lesions within a comparatively short time period. CONCLUSION: Chance can have a major effect on the burden of metastases. Random variability can be so great as to make individual assessments of tumor biology unreliable, yet constrained enough to lead to the apparently simultaneous appearance of multiple overt metastases
Flocculation of influenza virus by specific anti-neuraminidase antibody
1. Flocculation of purified preparations of influenza virus has been demonstrated to occur in the presence of low dilutions of specific anti-neuraminidase sera. High dilutions of the sera caused microscopic aggregation of virions. It is suggested that the effects of anti-neuraminidase antibody on the replication of influenza virus observed in vitro could be caused by antibody binding virions to infected cells, rather than by inhibition of neuraminidase enzymic activity.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/41680/1/705_2005_Article_BF01253756.pd
Evaluation of citrus fiber as a natural alternative to sodium tripolyphosphate in marinated boneless broiler chicken breast and inside beef skirt (transversus abdominis)
Objective This research was conducted to evaluate the effects of citrus fiber (CF) as a natural alternative to sodium tripolyphosphate (STPP) in marinated broiler boneless chicken breast and inside beef skirt on overall retention rate, shear force, and consumer sensory attributes. Methods Five different marinade formulations were targeted to include 0.9% salt, either 0.25% or 0.50% STPP or CF and water on a finished product basis. Water and salt only were considered the negative control (CON). Chicken breasts (n = 14) and inside beef skirt (n = 14) were randomly assigned to a treatment, raw weights recorded and then placed in a vacuum tumbler. Marinated weights were recorded, individually packed, and randomly assigned to either retail display for 10-day retention rate, shear force analysis, cook loss, or consumer sensory panel. Results Pickup percentage, and overall retention was similar among treatments for chicken breast and inside beef skirt. Citrus fiber treatments resulted in higher cooking loss compared to the CON in chicken breast; though, CF050 resulted in similar cooking loss compared to STPP025 in inside beef skirt. No differences were found in sensory attributes for chicken breast, however, WBSF data showed CF025 was tougher than CF050, STPP050, and CON. Inside beef skirt with CF050 were least liked overall by the consumer panel. Conclusion Citrus fiber included in marinades at a lower percentage rate can produce similar texture characteristics, and sensory properties compared with those marinated with STPP
Analysis of Myogenic and Candidate Disease Biomarkers in FSHD Muscle Cells
The UMMS Wellstone Program is a foundation and NIH-funded cooperative research center focusing on identifying biomarkers for facioscapulohumeral muscular dystrophy (FSHD) to gain insight into the molecular pathology of the disease and to develop potential therapies. FSHD is characterized by progressive wasting of skeletal muscles, with weakness often initiating in facial muscles and muscles supporting the scapula and upper arms. While the genetics associated with FSHD are complex, the major form of the disease, FSHD1, is linked to contraction of the D4Z4 repeat region located at chromosome 4q. Recently, a transcript encoded at the distal end of the repeat region, Dux4-fl, normally expressed in embryonic stem cells and germ cells, was also detected in differentiated muscle cells and biopsies from FSHD subjects, giving rise to the hypothesis that DUX4-FL function contributes to muscle weakness.
We established a repository of high quality, well-characterized primary and immortalized muscle cell strains from FSHD and control subjects in affected families to provide biomaterials for cell and molecular studies to the FSHD research community. qPCR and immunostaining analyses demonstrate similar growth and differentiation characteristics in cells from FSHD and control subjects within families. We detected Dux4-fl transcript and protein in FSHD cells as recently described; interestingly, we also detected Dux4-fl in muscle cells from a subset of control individuals, suggesting that any Dux4-fl-mediated myopathy would require additional modifying elements. Microarray analysis of FSHD and control muscle cells demonstrated that several genes were upregulated in FSHD cells, including genes that were concurrently identified as downstream targets of Dux4-fl and as candidate FSHD disease genes. Future studies will further characterize the RNA and protein expression of candidate disease genes in cells from FSHD and control subjects, including nonmanifesting subjects with the D4Z4 lesion but no muscle weakness, and utilizing whole transcriptome sequencing (RNAseq) to identify additional candidates
Rapid cultural adaptation can facilitate the evolution of large-scale cooperation
Over the past several decades, we have argued that cultural evolution can facilitate the evolution of large-scale cooperation because it often leads to more rapid adaptation than genetic evolution, and, when multiple stable equilibria exist, rapid adaptation leads to variation among groups. Recently, Lehmann, Feldman, and colleagues have published several papers questioning this argument. They analyze models showing that cultural evolution can actually reduce the range of conditions under which cooperation can evolve and interpret these models as indicating that we were wrong to conclude that culture facilitated the evolution of human cooperation. In the main, their models assume that rates of cultural adaption are not strong enough compared to migration to maintain persistent variation among groups when payoffs create multiple stable equilibria. We show that Lehmann et al. reach different conclusions because they have made different assumptions. We argue that the assumptions that underlie our models are more consistent with the empirical data on large-scale cultural variation in humans than those of Lehmann et al., and thus, our models provide a more plausible account of the cultural evolution of human cooperation in large groups
Wild redfronted lemurs (Eulemur rufifrons) use social information to learn new foraging techniques
Recent research has claimed that traditions are not a unique feature of human culture, but that they can be found in animal societies as well. However, the origins of traditions in animals studied in the wild are still poorly understood. To contribute comparative data to begin filling this gap, we conducted a social diffusion experiment with four groups of wild redfronted lemurs (Eulemur rufifrons). We used a ‘two-option’ feeding box, where these Malagasy primates could either pull or push a door to get access to a fruit reward to study whether and how these two behavioural traits spread through the groups. During a pre-training phase, two groups were presented with boxes in which one technique was blocked, whereas two groups were presented with unblocked boxes. During a subsequent unconstrained phase, all four groups were confronted with unblocked boxes. Nearly half of the study animals were able to learn the new feeding skill and individuals who observed others needed fewer unsuccessful task manipulations until their first successful action. Animals in the two groups with pre-training also discovered the corresponding alternative technique but preferred the seeded technique. Interestingly, animals in the two groups without pre-training discovered both techniques, and one group developed a group preference for one technique whereas the other did not. In all groups, some animals also scrounged food rewards. In conclusion, redfronted lemurs appear to use social information in acquiring a novel task, and animals in at least in one group without training developed a group preference for one technique, indicating that they have the potential to develop behavioural traditions and conformity
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