29 research outputs found
Activity, habitat use, feeding behavior, and diet of four sympatric species of Serranidae (Actinopterygii: Perciformes) in southeastern Brazil
Contextual Metadata in Digital Aggregations: Application of Collection-Level Subject Metadata and Its Role in User Interactions and Information Retrieval
Article discussing a study of contextual metadata in digital aggregations. Results of this study prove importance of provision of collection-level metadata in general and subject metadata in particular to enhance user experiences and information retrieval in digital libraries
Support for maternal manipulation of developmental nutrition in a facultatively eusocial bee, Megalopta genalis (Halictidae)
Developmental maternal effects are a potentially important source of phenotypic variation, but they can be difficult to distinguish from other environmental factors. This is an important distinction within the context of social evolution, because if variation in offspring helping behavior is due to maternal manipulation, social selection may act on maternal phenotypes, as well as those of offspring. Factors correlated with social castes have been linked to variation in developmental nutrition, which might provide opportunity for females to manipulate the social behavior of their offspring. Megalopta genalis is a mass-provisioning facultatively eusocial sweat bee for which production of males and females in social and solitary nests is concurrent and asynchronous. Female offspring may become either gynes (reproductive dispersers) or workers (non-reproductive helpers). We predicted that if maternal manipulation plays a role in M. genalis caste determination, investment in daughters should vary more than for sons. The mass and protein content of pollen stores provided to female offspring varied significantly more than those of males, but volume and sugar content did not. Sugar content varied more among female eggs in social nests than in solitary nests. Provisions were larger, with higher nutrient content, for female eggs and in social nests. Adult females and males show different patterns of allometry, and their investment ratio ranged from 1.23 to 1.69. Adult body weight varied more for females than males, possibly reflecting increased variation in maternal investment in female offspring. These differences are consistent with a role for maternal manipulation in the social plasticity observed in M. genalis
Helper Response to Experimentally Manipulated Predation Risk in the Cooperatively Breeding Cichlid Neolamprologus pulcher
Background
We manipulated predation risk in a field experiment with the cooperatively breeding cichlid Neolamprologus pulcher by releasing no predator, a medium- or a large-sized fish predator inside underwater cages enclosing two to three natural groups. We assessed whether helpers changed their helping behaviour, and whether within-group conflict changed, depending on these treatments, testing three hypotheses: ‘pay-to-stay’ PS, ‘risk avoidance’ RA, or (future) reproductive benefits RB. We also assessed whether helper food intake was reduced under risk, because this might reduce investments in other behaviours to save energy.
Methodology/Principal Findings
Medium and large helpers fed less under predation risk. Despite this effect helpers invested more in territory defence, but not territory maintenance, under the risk of predation (supporting PS). Experimentally covering only the breeding shelter with sand induced more helper digging under predation risk compared to the control treatment (supporting PS). Aggression towards the introduced predator did not differ between the two predator treatments and increased with group member size and group size (supporting PS and RA). Large helpers increased their help ratio (helping effort/breeder aggression received, ‘punishment’ by the dominant pair in the group) in the predation treatments compared to the control treatment, suggesting they were more willing to PS. Medium helpers did not show such effects. Large helpers also showed a higher submission ratio (submission/ breeder aggression received) in all treatments, compared to the medium helpers (supporting PS).
Conclusions/Significance
We conclude that predation risk reduces helper food intake, but despite this effect, helpers were more willing to support the breeders, supporting PS. Effects of breeder punishment suggests that PS might be more important for large compared to the medium helpers. Evidence for RA was also detected. Finally, the results were inconsistent with RB
Utility of an OAI Service Provider Search Portal
The Open Archives Initiative (OAI) Protocol for Metadata Harvesting (PMH) facilitates efficient interoperability between digital collections, in particular by enabling service providers to construct, with relatively modest effort, search portals that present aggregated metadata to specific communities. This paper describes the experiences of the University of Illinois at Urbana-Champaign Library as an OAI service provider. We discuss the creation of a search portal to an aggregation of metadata describing cultural heritage resources. We examine several key challenges posed by the aggregated metadata and present preliminary findings of a pilot study of the utility of the portal for a specific community (student teachers). We also comment briefly on the potential for using text analysis tools to uncover themes and relationships within the aggregated metadata.Research presented here funded by the Mellon Foundationpublished or submitted for publicationis peer reviewe
IDEALS Digital Preservation: Current Status and Future Directions
Ensuring that IDEALS is indeed worthy of the trust of the faculty, students, and staff of the institution requires careful and deliberate planning and ongoing attention to digital preservation. With this in mind, this white paper provides a roadmap for the implementation of a comprehensive digital preservation management program for IDEALS. Specifically, this paper: Presents the current state of digital preservation for the pilot stage (through Spring 2007) of IDEALS; Specifies the minimum requirements for the ongoing production???level service (Summer 2007 and forward); Recommends that IDEALS pursues certification as a Trusted Digital Repository for endorsement by the IDEALS Working Group and Steering Committee; and Identifies the next steps for moving towards compliance as a Trusted Digital Repository.unpublishednot peer reviewe
Findings Pertaining to the Framework of Guidance for Building Good Digital Collections
This white paper details our findings to date relevant to the Framework of Guidance for Building Good Digital Collections. We provide sixteen recommendations to NISO suggesting potential ways to improve the impact and/or utility of the Framework itself. For selected recommendations, we identify complementary research opportunities for IMLS; these appear as boxed text alongside each relevant recommendation. We base our comments and recommendations largely on observations of practice gleaned over the first three plus years of the IMLS Digital Collections and Content project.IMLS National Leadership Grant LG-02-02-0281unpublishednot peer reviewe
Metadata for Special Collections in CONTENTdm: How to Improve Interoperability of Unique Fields Through OAI-PMH
Collection curators develop locally defined unique fields to support local requirements. As per the guidelines of the Open Archives Initiative Protocol for Metadata Harvesting (OAI-PMH), Simple Dublin Core is the minimum requirement for exposing metadata to aggregators. Oftentimes the level of specificity of unique local fields is not
translated well to Dublin Core, which may hinder the interoperability of the item metadata record. This paper researched 21 digital collections that were hosted in CONTENTdm. The objective was to explore the use and issues of unique fields in local context and recommend best practices that will increase the interoperability of metadata for special collections.published or submitted for publicationis peer reviewe
Harvesting cultural heritage metadata using the OAI protocol
In July of 2001, with funding from the Andrew W. Mellon Foundation, the University of Illinois at Urbana-Champaign undertook a project to test the efficacy of using the Open Archives Initiative Protocol for Metadata Harvesting to construct a search and discovery service focused on information resources in the domain of cultural heritage. To date, the Illinois project has indexed over two million Dublin Core metadata records contributed by 38 metadata repositories in the museum, academic library, and digital library project communities. These records describe a mix of digital and analog primary content. Our analysis of these metadata records demonstrates wide divergence in descriptive metadata practices and the use and interpretation of Dublin Core metadata elements. Differences are particularly notable by community. This article provides an overview of the Illinois project, presents quantitative data about divergent metadata practices and element usage patterns, and details implications for metadata providers and harvesting services.The University of Illinois Open Archives Initiative Metadata Harvesting Project, including the research described in this article, was funded by a grant from the Andrew W. Mellon Foundation.published or submitted for publicationis peer reviewe