1,639 research outputs found
Unravelling the function of community-level organization
No full textFirst paragraph: Multi-level and fission-fusion social systems are relatively uncommon across the animal kingdom: most group-living species live in at least temporarily stable social groups, where all members of the group form a relatively cohesive group. However, there are two major deviations from this scheme. In some species, small cohesive (usually reproductive) units, such as families or one-male units with attached females and offspring, aggregate regularly with other small cohesive units, thereby forming higher level groupings. This type of multi-layered sociality has e.g. been shown for African and Asian elephants (Moss &Poole 1983, Wittemyer et al. 2005; de Silva et al., 2011), zebras (Rubenstein & Hack 2004), whales (Baird 2000, Whitehead et al. 1991), prairie dogs (Hoogland 1995), horses (Linklater 2000), parrots (Wanker et al., 1998) and several primate taxa, including the African papionins Papio hamadryas and Theropithecus and some Asian colobines (notably Rhinopithecus, Nasalis and Pygathrix). In all these cases, the small unit is the stable social unit with higher level groupings being built out of these smaller units; multi-level sociality is thus achieved via a bottom-up mechanism with small stable groups flexibly aggregating into larger, more fluid groupings (of which several layers can exist)
Pacific Rim Magazine 2011
No full textThe 2011 issue of Pacific Rim Magazine includes the cover stories "Dayton Boots' Canadian Sale," "Angus An Gets Grilled," "Mars to Venus: Thailand's Third Gender," and "David Y. H. Lui.
Pacific Rim Magazine 2013
No full textThe 2013 Issue of Pacific Rim Magazine includes the cover stories "Into the Unknown: Should an Aging LGBTQ Community Have a Home of its Own," "Urban Pioneers: Farms Blossom in the City," "Working for Buddha: Three Professionals put Peace into Practice," "A Reel Mystery: Japan's Lost Kong," "Fooling the Phantom: Stephen Sumner Helps Amputees Find Relief," and "Impossible Choices: An Inside View of the Challenges Facing Foreign Nannies in Canada.
Opposite effects of maternal and paternal grandmothers on infant survival in historical Krummhörn
No full textOn the basis of church register entries from the Krummhörn region (Ostfriesland, Germany, 1720-1874) we looked at the question whether the existence or non-existence of grandmothers had an impact on the reproductive success of a family. We found that fertility (measured by intervals between births) was not influenced by grandmothers. However, maternal grandmothers tended to reduce infant mortality when the children were between six and twelve months of age. During these six months, the relative risk of dying was approximately 1.8 times higher if the maternal grandmother was dead at the time of the child’s birth compared to if she was alive. Interestingly, the existence of paternal grandmothers approximately doubled the relative risk of infant mortality during the first month of life. We interpret this as being the result of a tense relationship between mother- and daughter- in-laws. We found that Krummhörn grandmothers could be both helpful and a hindrance at the same time. Geographic proximity tended to increase the effects found. If this ambivalent impact of grandmothers on familial reproduction could be generalized beyond the Krummhörn population, the hypothesis that the evolution of the postgenerative life span could be explained by grandmotherly kin-effects would have to be stated more precisely: the costs of social stress in the male descendency would have to be subtracted from the benefits of aid and assistance in the female descendency. At any rate, the Krummhörn data do not offer a role model for grandmothers who provide unconditional assistance, an effort which in itself could have explained the evolutionary extension of the human life span.
Helping-at-the-nest and sex-biased parental investment in a Hungarian Gypsy population
No full textN.B. Professor Dunbar is now based at the Institute of Social and Cultural Anthropology at the University of Oxford
Implementing a New Trade Paradigm: Opportunities for Agricultural Trade Regionalism in the Pacific Rim
No full textThe objective of this paper is to analyze the economic implications for American food producers, consumers, and society of alternative Pacific Rim free trade region (FIR) configurations.International Relations/Trade,
Cognitive constraints on the structure and dynamics of social networks
No full textEveryday social activities take place within an environment peopled by a specific set of individuals (our social network). The author reviews the evidence that our social world is both limited in size and highly structured. This structuring consists of a series of circles of acquaintanceship, the successive layers of which progressively include more individuals with whom we have less intense relationships. Although these layers have very consistent typical sizes, there is considerable individual variation because of individual differences in gender, personality, and social-cognitive abilities. The author considers some of the implications of these structural components for the way in which we organize our social lives. © 2008 American Psychological Association
Modular Neural Networks for Video Prediction
No full textModular neural networks have received an upsurge of attention lately owing to their unique modular design and potential capacity to decompose complex dynamics and learn interactions among causal variables. Inspired by this potential, we employ the recently introduced Recurrent Independent Mechanisms (RIMs) in the downstream video prediction task. RIMs consist of several modular recurrent units and modular hidden states which are called RIM cells. Those modules are connected by two attention mechanisms. Through experiments, we show that RIMs perform better or comparably with related baselines. From modular recurrent units to modular image representations, we push the modularity further to explore how much the performance can benefit from it. We extend RIMs architecture on both the encoder and decoder sides to allow for object-centric (OC) feature representation learning in video prediction, resulting in an end-to-end architecture we refer to as OC-RIMs. Our qualitative evaluations demonstrate that every RIM cell in OC-RIMs now attends to a certain object within the input scene at any specific moment. As a result, OC-RIMs offer considerable quantitative performance improvement in video prediction over comparable baselines across two datasets.We perform extensive ablation studies to validate the design choices of every module of RIMs. We empirically show that most modules work as expected. However, the sparse activation greatly detriments the prediction performance, which is against the claims in the paper where RIMs were proposed. On the other hand, RIM cells are expected to work near-independently. But experiments show that the use of communication mechanism leads to heavy co-adaptation between cells, i.e., RIM cells fail to make any reasonable predictions independently. Those issues have raised our concerns about the design of RIMs. Finally, we point out some future work directions to address these deficiencies.Project Github Repository - https://github.com/sentient-codebot/RIM-MovingMNISTElectrical Engineerin
Some effective techniques for naive Bayes text classification
No full textWhile naive Bayes is quite effective in various data mining tasks, it shows a disappointing result in the automatic text classification problem. Based on the observation of naive Bayes for the natural language text, we found a serious problem in the parameter estimation process, which causes poor results in text classification domain. In this paper, we propose two empirical heuristics: per-document text normalization and feature weighting method. While these are somewhat ad hoc methods, our proposed naive Bayes text classifier performs very well in the standard benchmark collections, competing with state-of-the-art text classifiers based on a highly complex learning method such as SVM.This work was partly supported by the JSPS Postdoctoral Fellowship Program and the Okumura Group at Tokyo Institute of Technology. H.-C. Rim was the corresponding author
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