90 research outputs found

    Connecting species’ geographical distributions to environmental variables: range maps versus observed points of occurrence

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    Connecting the geographical occurrence of a species with underlying environmental variables is fundamental for many analyses of life history evolution and for modeling species distributions for both basic and practical ends. However, raw distributional information comes principally in two forms: points of occurrence (specific geographical coordinates where a species has been observed), and expert-prepared range maps. Each form has potential short-comings: range maps tend to overestimate the true occurrence of a species, whereas occurrence points (because of their frequent non-random spatial distribution) tend to underestimate it. Whereas previous comparisons of the two forms have focused on how they may differ when estimating species richness, less attention has been paid to the extent to which the two forms actually differ in their representation of a species’ environmental associations. We assess such differences using the globally distributed avian order Galliformes (294 species). For each species we overlaid range maps obtained from IUCN and point-of-occurrence data obtained from GBIF on global maps of four climate variables and elevation. Over all species, the median difference in distribution centroids was 234 km, and median values of all five environmental variables were highly correlated, although there were a few species outliers for each variable. We also acquired species’ elevational distribution mid-points (mid-point between minimum and maximum elevational extent) from the literature; median elevations from point occurrences and ranges were consistently lower (median −420 m) than mid-points. We concluded that in most cases occurrence points were likely to produce better estimates of underlying environmental variables than range maps, although differences were often slight. We also concluded that elevational range mid-points were biased high, and that elevation distributions based on either points or range maps provided better estimates

    Plasmodium falciparum (Haemosporodia: Plasmodiidae) and O'nyong-nyong virus development in a transgenic Anopheles gambiae (Diptera: Culicidae) strain

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    Transgenic Anopheles gambiae Giles (Diptera: Culicidae) mosquitoes have been developed that confer sexual sterility on males that carry a transgene encoding a protein which cuts ribosomal DNA. A relevant risk concern with transgenic mosquitoes is that their capacity to transmit known pathogens could be greater than the unmodified form. In this study, the ability to develop two human pathogens in these transgenic mosquitoes carrying a homing endonuclease which is expressed in the testes was compared with its nontransgenic siblings. Infections were performed with Plasmodium falciparum (Welch) and o'nyong-nyong virus (ONNV) and the results between the transgenic and nontransgenic sibling females were compared. There was no difference observed with ONNV isolate SG650 in intrathoracic infections or the 50% oral infectious dose measured at 14 d postinfection or in mean body titers. Some significant differences were observed for leg titers at the medium and highest doses for those individuals in which virus titer could be detected. No consistent difference was observed between the transgenic and nontransgenic comparator females in their ability to develop P. falciparum NF54 strain parasites. This particular transgene caused no significant effect in the ability of mosquitoes to become infected by these two pathogens in this genetic background. These results are discussed in the context of risk to human health if these transgenic individuals were present in the environment

    eHabitat, a multi-purpose Web Processing Service for ecological modeling

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    The number of interoperable research infrastructures has increased significantly with the growing awareness of the efforts made by the Global Earth Observation System of Systems (GEOSS). One of the Societal Benefit Areas (SBA) that is benefiting most from GEOSS is biodiversity, given the costs of monitoring the environment and managing complex information, from space observations to species records including their genetic characteristics. But GEOSS goes beyond simple data sharing to encourage the publishing and combination of models, an approach which can ease the handling of complex multi-disciplinary questions. It is the purpose of this paper to illustrate these concepts by presenting eHabitat, a basic Web Processing Service (WPS) for computing the likelihood of finding ecosystems with equal properties to those specified by a user. When chained with other services providing data on climate change, eHabitat can be used for ecological forecasting and becomes a useful tool for decision-makers assessing different strategies when selecting new areas to protect. eHabitat can use virtually any kind of thematic data that can be considered as useful when defining ecosystems and their future persistence under different climatic or development scenarios. The paper will present the architecture and illustrate the concepts through case studies which forecast the impact of climate change on protected areas or on the ecological niche of an African bird

    1960: Abilene Christian College Lectures - Full Text

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    Table of Contents: Theme Speeches: Christian Faith in the Modern World Basis of Faith - Leonard Mullens - 9 Authority in Christianity - John T. Smithson, Jr. - 27 Origin and Preservation of the Bible - Neil R. Lightfoot - 44 Alleged Discrepancies of the Bible - David H. Bobo - 62 The Unity of the Bible - Jack Meyer - 91 Faith and Reason - Joe Sanders - 115 The Reasonableness of Supernaturalism - Virgil Trout - 126 The Present Statue of the Doctrine of Organic Evolution - J.D. Thomas - 146 The Nature of Man - Roy F. Osborne, Jr. - 181 Modern Challenges to Christian Morals - Carl Spain - 199 The Christ, Whose Son is He? - Gordon Teel - 232 Special Speeches Teaching the Word of God in Korea - L. Haskell Chessfire - 255 The Influence of Christian Education - Judge Jack Pope - 276 Mission Opportunities in the Far East - Harry Robert Fox - 288 Mission Work in Austria - Robert Skelton - 303 Report from Switzerland - Heinrich Blum - 313 The Work in Nigeria - Rees Byrant - 320 The Training of Evangelists in Foreign Fields - Reiner Kallus - 331 Christian Scholarships - Everett Ferguson - 340 Evangelizing the World - A.R. Holton - 349 Panel Discussions The Significance of the Dead Sea Scrolls The Scrolls and the Text of the Bible - Paul Rotenberry - 357 The Relation between the Religion of the Essenes and that of Early Christians - Jay Smith - 366 Biblical Interpretation Expediency and Pattern Authority - J.W. Roberts - 381 Examples in Pattern Authority - Thomas B. Warren - 392 Mental Health and Sin The Present State of Mental Health Knowledge - Donald R. Sime - 409 The Relationship of Mental Health Problems to Sin - Paul Easley - 421 The Teenager The Problems of Youth - Mack Wayne Craig - 432 Influences for Good - Wyatt Sawyer - 443 The Benefits of Abilene Christian College To the Church - Hulen Jackson - 451 To The Home - Robert S. Bell - 459 \u27To the Community - Louie Welch - 465 Expenses At Abilene Christian College - James C. Kerr - 469 The Graduate School at Abilene Christian College What I Am Getting Now in the ACC Graduate Program - Harold Vanderpool - 475 How the ACC Graduate Program Has Stood Up - Everett Ferguson - 481 What the ACC Graduate Program Ought To Be - Frank Pack - 486 The Importance to the Church of the ACC Graduate Program A.R. Holton - 490 Beware: Large File Size Uploaded by Jackson Hage

    Avian Use of Perennial Biomass Feedstocks as Post-Breeding and Migratory Stopover Habitat

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    Increased production of biomass crops in North America will require new agricultural land, intensify the cultivation of land already under production and introduce new types of biomass crops. Assessing the potential biodiversity impacts of novel agricultural systems is fundamental to the maintenance of biodiversity in agricultural landscapes, yet the consequences of expanded biomass production remain unclear. We evaluate the ability of two candidate second generation biomass feedstocks (switchgrass, Panicum virgatum, and mixed-grass prairie) not currently managed as crops to act as post-breeding and fall migratory stopover habitat for birds. In total, we detected 41 bird species, including grassland specialists and species of state and national conservation concern (e.g. Henslow's Sparrow, Ammodramus henslowii). Avian species richness was generally comparable in switchgrass and prairie and increased with patch size in both patch types. Grassland specialists were less abundant and less likely to occur in patches within highly forested landscapes and were more common and likely to occur in larger patches, indicating that this group is also area-sensitive outside of the breeding season. Variation in the biomass and richness of arthropod food within patches was generally unrelated to richness and abundance metrics. Total bird abundance and that of grassland specialists was higher in patches with greater vegetation structural heterogeneity. Collectively, we find that perennial biomass feedstocks have potential to provide post-breeding and migratory stopover habitat for birds, but that the placement and management of crops will be critical factors in determining their suitability for species of conservation concern. Industrialization of cellulosic bioenergy production that results in reduced crop structural heterogeneity is likely to dramatically reduce the suitability of perennial biomass crops for birds

    Measuring floral resource availability for insect pollinators in temperate grasslands – a review

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    Abstract. 1. The relationship between pollinators and flowering plants plays a crucial role in the function of terrestrial ecosystems. Although pollinators use floral nectar and pollen as food resources, no general methodology for floral resource availability estimates exists. 2. A brief review is provided on floral resource sampling methods frequently used in pollination studies. The focus is on how representative vegetation samples are both spatially and temporally, and how these are constrained by sampling effort. 3. Field studies investigating flowering plant abundance for insect pollinators in temperate grasslands were selected. We categorised the reviewed studies according to aims, sampling units, and count variables used and provide a descriptive summary on methodology. We also searched for trade-offs between different aspects of sampling investment. 4. One hundred and fifty-eight pollination studies were reviewed. Large methodolog- ical differences were found, and vegetation sampling was presented in many studies insufficiently. Sampling covered a small proportion (median: 0.69%) of the study sites, with long intervals (median: 30 days), and most studies lasted only a few years. The most often used count variables were indirect proxies of floral resources. Negative relation- ships were found in some of the different aspects of sampling, e.g. the proportion of site covered with sampling decreased with increasing site area. 5. By tailoring sampling methods to specific research questions, research effort should be optimally allocated to obtain proper spatio-temporal resolution and data coverage. Guidelines were suggested to design sampling, e.g. to increase coverage and frequency. Further field work on optimising sampling techniques is mandatory
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