1,936 research outputs found
Units of Evidence for Analyzing Subdisciplinary Difference in Data Practice Studies
Digital libraries (DLs) are adapting to accommodate research data
and related services. The complexities of this new content spans
the elements of DL development, and there are questions
concerning data selection, service development, and how best to
align these with local, institutional initiatives for
cyberinfrastructure, data-intensive research, and data stewardship.
Small science disciplines are of particular relevance due to the
prevalence of this mode of research in the academy, and the
anticipated magnitude of data production. To support data
acquisition into DLs – and subsequent data reuse – there is a need
for new knowledge on the range and complexities inherent in
practice-data-curation arrangements for small science research.
We present a flexible methodological approach crafted to generate
data units to analyze these relationships and facilitate crossdisciplinary
comparisons.Library Services (LG-06-07-0032-07) and National Science Foundation (OCI-0830976).is peer reviewe
Life History of Elsinoe panici
Elsinoe panici Tiffany and Mathre is widespread on native Panicum virgatum L. in Iowa. In June Sphaceloma (imperfect stage) conidia develop from acervuli on overwintered stromata of wind-dispersed leaf litter and culms. Germ cubes penetrate between epidermal cells of young leaves, and 2 wk later tiny yellowish, subepidermal stromata are visible. Secondary conidia develop from acervuli on these stromata within 2 wk and are spread to adjacent leaves. Stromata become black, raised, shiny, ovoid-elongate patches, composed of thick-walled pseudoparenchymatous cells. Chlorosis or necrosis does not develop around the stromata. Stromata are visible on all leaves throughout the season. Acervuli, appearing as white spots in black stromata, open by irregular tears in the epidermis. Ascostromata develop on lower leaves infrequently from late July into September. They are tan-bronze, raised, ovoid-elongate, softer, and more loosely structured than stromata. Asci mature at different times. Ascospores are discharged from the bitunicate asci and germinate directly by budding or by germ tubes
Plant pathogens as biological agents for the control of weeds
Weed control is by far the most pervasive and costly need in agriculture, both in underdevel oped as well as in technologically advanced production systems. In 1994, losses due to weeds in U.S. agriculture—including herbi cide costs and yield losses—amounted to over $ 15 billion, and about 96% of the more than 21 million acres of row crops grown in Iowa received at least one chemical herbicide appli cation. Pesticide use statistics reveal that more herbicides are used than any other class of pesticide. Despite the extensive use of herbi cides, certain weed species continue to cause problems in agriculture, and current control strategies for some of these are inadequate. Among these weeds are johnsongrass (Sor ghum halapense), the morning glorys (Ipomoea spp.), nutsedges (Cyperus esculentus), shattercane (Sorghum bicolor), and velvetleaf (Abutillon theophrasti)
The Influence of Signaling Conspecific and Heterospecific Neighbors on Eavesdropper Pressure
The study of tradeoffs between the attraction of mates and the attraction of eavesdropping predators and parasites has generally focused on a single species of prey, signaling in isolation. In nature, however, animals often signal from mixed-species aggregations, where interactions with heterospecific group members may be an important mechanism modulating tradeoffs between sexual and natural selection, and thus driving signal evolution. Although studies have shown that conspecific signalers can influence eavesdropper pressure on mating signals, the effects of signaling heterospecifics on eavesdropper pressure, and on the balance between natural and sexual selection, are likely to be different. Here, we review the role of neighboring signalers in mediating changes in eavesdropper pressure, and present a simple model that explores how selection imposed by eavesdropping enemies varies as a function of a signaling aggregation\u27s species composition, the attractiveness of aggregation members to eavesdroppers, and the eavesdroppers\u27 preferences for different member types. This approach can be used to model mixed-species signaling aggregations, as well as same-species aggregations, including those with non-signaling individuals, such as satellites or females. We discuss the implications of our model for the evolution of signal structure, signaling behavior, mixed-species aggregations, and community dynamics
Development of Fungal Calcium Oxalate Crystals Associated with the Basidiocarps of Geastrum Minus (Lycoperdales)
Calcium oxalate crystals were observed on facing peridial surfaces of developing basidiocarps of Geastrum minus. Five crystal forms were characterized by their outward shapes and X-ray diffraction patterns: Form One, small bipyramids (COD); Form Two, crystals with split tips (COD); Form Three, crystals with oriented overgrowths (COD); Form Four, large bipyramids (COD); and Form Five, rosettes of plate-like crystals (COM). Forms One and Two were first to appear after peridia separated in unopened basidiocarps, whereas Forms Three, Four and Five were present on exposed peridia of opened basidiocarps. Based on time of appearance during basidiocarp development and crystallography of each form, we believe Form One gives rise to Forms Two, Three and Four. Form Five may arise from dissolution and recrystallization of pre-existing forms. Farinose or asperate basidiocarps of eight other species of Geastrum showed no crystals, indicating that only G. minus forms crystals. Comparison of the five forms with crystals on old basidiocarps indicates Form Four is predominant. The functional value of the crystals is discussed and they are compared with crystal forms found in human and animal urinary tracts
Waste Corn as a Source of Inoculum of Aspergillus Flavus, the Cause of Aflatoxin
Aspergillus Flavus occurs worldwide in diverse habitats on a variety of plant and animal substrates. In the United States, contamination of susceptible crops particularly maize, peanuts, cottonseed, and tree nuts has become a major health concern because of the development of the carcinogen, aflatoxin. Extensive research into all aspects of the biology of A. flavus over the past twenty years still has left many unanswered but very basic questions about the ecology of this important organism
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The microbiome in patients with atopic dermatitis.
As an interface with the environment, the skin is a complex ecosystem colonized by many microorganisms that coexist in an established balance. The cutaneous microbiome inhibits colonization with pathogens, such as Staphylococcus aureus, and is a crucial component for function of the epidermal barrier. Moreover, crosstalk between commensals and the immune system is now recognized because microorganisms can modulate both innate and adaptive immune responses. Host-commensal interactions also have an effect on the developing immune system in infants and, subsequently, the occurrence of diseases, such as asthma and atopic dermatitis (AD). Later in life, the cutaneous microbiome contributes to the development and course of skin disease. Accordingly, in patients with AD, a decrease in microbiome diversity correlates with disease severity and increased colonization with pathogenic bacteria, such as S aureus. Early clinical studies suggest that topical application of commensal organisms (eg, Staphylococcus hominis or Roseomonas mucosa) reduces AD severity, which supports an important role for commensals in decreasing S aureus colonization in patients with AD. Advancing knowledge of the cutaneous microbiome and its function in modulating the course of skin disorders, such as AD, might result in novel therapeutic strategies
Scalar capital as ingredient of success in conservation governance: evidence from Melanesia
Problems of scale abound in the governance of complex social-ecological systems. Conservation governance, for example, typically occurs at a single scale, but needs to inform governance and action at other scales to be truly effective at achieving social and ecological outcomes. This process is conventionally conceived as unidirectional - either scaling down or scaling up - in the way it both exploits and creates the natural, social, human, institutional, and financial resources and benefits that are collectively known as conservation 'capital'. Here we analyse multiscale conservation governance and the different types of capital that impede or facilitate its effectiveness. Comparative analysis of conservation planning in Papua New Guinea and the Solomon Islands, through in-depth document review, key informant interview, and participant observation, reveals limited evidence of unidirectional processes. Instead, we observe multidirectional scaling pathways, cultivated by the following six scale-explicit characteristics of effective conservation governance: 1) multiscale understanding, 2) scale jumping, 3) scaled leadership characteristics, 4) scaled stakeholder engagement, 5) scaled policy frameworks, and 6) scaled institutional settings. While the latter four are familiar concepts, though not always recognised as explicitly scalar, we know little about the first two attributes of conservation governance. Based on this novelty and relevance, we propose a new form of capital - 'scalar capital' - to complement natural, social, human, institutional, and financial capitals as both input and outcome of effective conservation governance. We find that scalar capital facilitates flows of different resources (data, conservation objectives, practitioner experience, institutional support, and funding) in multiple directions. Critically, we present empirical evidence that conservation governance can foster scalar capital to improve outcomes across multiple scales
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