932 research outputs found
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Effects of urbanisation and landscape heterogeneity mediated by feeding guild and body size in a community of coprophilous beetles
Although the impacts of urbanisation on biodiversity are well studied, the precise response of some invertebrate groups remains poorly known. Dung-associated beetles are little studied in an urban context, especially in temperate regions. We considered how landscape heterogeneity, assessed at three spatial scales (250, 500 and 1000 metre radius), mediates the community composition of coprophilous beetles on a broad urban gradient. Beetles were sampled using simple dung-baited traps, placed at 48 sites stratified across three distance bands around a large urban centre in England. The most urban sites hosted the lowest abundance of saprophagous beetles, with a lower mean body length relative to the least urban sites. Predicted overall species richness and the richness of saprophagous species were also lowest at the most urban sites. Ordination analyses followed by variation partitioning revealed that landscape heterogeneity across the urban gradient explained a small but significant proportion of community composition. Heterogeneity data for a 500-metre radius around each site provided the best fit with beetle community data. Larger saprophagous species were associated with lower amounts of manmade surface and improved grassland. Some individual species, particularly predators, appeared to be positively associated with urban or urban fringe sites. This study is probably the first to examine the response of the whole coprophilous beetle community to urbanisation. Our results suggest that the response of this community to urbanisation matches expectations based on other taxonomic groups, whilst emphasising the complex nature of this response, with some smaller-bodied species potentially benefitting from urbanisation
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New distributional record of Anthrenus dorsatus Mulsant & Rey, 1868 (Coleoptera, Dermestidae) on the island of Mallorca, Spain
The carpet beetle Anthrenus dorsatus has previously been recorded from North Africa and Malta. During a recent visit to the island of Mallorca several Anthrenus species were collected which included a number of Anthrenus dorsatusspecimens. This record adds a new species both to the island of Mallorca and to the Spanish checklist. These records extend our knowledge of the distribution of A. dorsatus and provide more evidence of range expansion in the pimpinel-lae species group across Europe, possibly because of global climate change
X-ray Searches for Axions from Super Star Clusters
Axions may be produced in abundance inside stellar cores and then convert
into observable X-rays in the Galactic magnetic fields. We focus on the
Quintuplet and Westerlund 1 super star clusters, which host large numbers of
hot, young stars including Wolf-Rayet stars; these stars produce axions
efficiently through the axion-photon coupling. We use Galactic magnetic field
models to calculate the expected X-ray flux locally from axions emitted from
these clusters. We then combine the axion model predictions with archival
Nuclear Spectroscopic Telescope Array (NuSTAR) data from 10 - 80 keV to search
for evidence of axions. We find no significant evidence for axions and
constrain the axion-photon coupling GeV for masses eV at 95\%
confidence.Comment: 8+18 pages, 3+21 figures, version published in PRL. Supplementary
Data at https://github.com/bsafdi/axionSS
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Linking mesoscale landscape heterogeneity and biodiversity: gardens and tree cover significantly modify flower-visiting beetle communities
Context
Maintaining biodiversity in multifunction landscapes is a significant challenge. Planning for the impacts of change requires knowledge of how species respond to landscape heterogeneity. Some insect groups are known to respond to heterogeneity at the mesoscale, defined here as hundreds of metres. However, for many taxa these effects are poorly known.
Objectives
To identify key elements of mesoscale landscape heterogeneity influencing community composition in flower-visiting beetles, and whether landscape explains any variation in beetle communities beyond that driven by immediate habitat cover.
Methods
Flower-visiting beetles were sampled from 36 transects, laid out using a 6 km2 grid located in southern Britain. Landscape heterogeneity was measured for 30 and 200 m buffers around the transects and the relative response of beetle communities to each assessed using ordination analyses followed by variation partitioning.
Results
The composition of immediately adjacent habitat (30 m) and mesoscale landscape heterogeneity (200 m) explained unique portions of the variation in flower-visiting beetle communities. A number of species, including those affiliated with deadwood habitats, were positively linked to tree cover in the surrounding mesoscale landscape. Gardens covered a smaller area than trees but modified beetle communities to the same extent.
Conclusions
The local abundance of some flower-visiting beetles is modified by the composition of the surrounding landscape. Results highlight the importance of tree cover for maintaining insect biodiversity in agricultural landscapes, while suggesting that gardens associated with small urban areas may have a disproportionate influence on biodiversity
Flipping an Agricultural Teaching Methods Course at a Non-Land Grant University
The purpose of this study was to analyze undergraduate students’ perceptions of experiencing a flipped classroom in a teaching methods course at a Non-Land Grant Public Institution. The flipped classroom moves lectures and online videos outside of the classroom and uses class time for learning activities that promote problem-solving and discussion. Basic qualitative methods were used to provide flexibility, rich description, and the emergence of common patterns and themes. Participants reported the online lectures were beneficial and provided order and structure to the learning process. Personal responsibility emerged as a subtheme with mixed responses. Some participants felt it was the responsibility of the students to watch the videos and make sure they understood, while others felt it was too much responsibility on the students. All participants acknowledged that online lectures were a valuable tool for delivering content knowledge. All participants reported the online lectures, combined with the learning activities during class meetings, deepened their knowledge of teaching and learning application and skill development. Overall, participants felt the flipped classroom approach was a confidence booster due to the use of class time to practice their teaching skills. Participants recognized the flipped classroom as an effective teaching approach
Timing of extension in the Pioneer metamorphic core complex with implications for the spatial-temporal pattern of Cenozoic extension and exhumation in the northern U.S. Cordillera
The Pioneer core complex (PCC) in central Idaho lies along a transition between Early Eocene and ca. 40 Ma core complexes to the north and south, respectively. Thus, the age of extensional development of the PCC is important in understanding the spatial-temporal patterns of core-complex development in the North American Cordillera. New results, including structural observations and U-Pb zircon (SHRIMP and ICPMS) geochronology, constrain the early extensional history of the footwall for the first time. High-temperature strain with a top-WNW shear-sense is pervasive throughout metamorphic rocks of the northwestern footwall. An isoclinally folded dike yields a crystallization age of ∼48-47 Ma, whereas a crosscutting dike yielded an age of 46 Ma. Metamorphic rocks are also intruded by the ∼50-48 Ma Pioneer intrusive suite (PIS), a W-dipping granodiorite sheet displaying a magmatic fabric. Northwest-trending lineations are locally visible and also defined by anisotropy of magnetic susceptibility, indicating that during emplacement, the PIS was undergoing similarly oriented extensional strain as the enclosing metamorphic rocks. Therefore, WNW-directed extension spanning this structural section occurred between ∼50 and 46 Ma. Following emplacement of crosscutting 46 Ma dikes, deformation was partitioned into the WNW-directed Wildhorse detachment. Motion on the detachment occurred between ∼38 and 33 Ma, as documented by previous 40Ar/ 39Ar thermochronology. It is not clear, however, whether extension was continuous through the interval between these two time periods. Although Early Eocene extension in the PCC was synchronous with extension in core complexes to the north, rates of footwall exhumation in central Idaho were much lower. This southward slowing is compatible with N-S differences in inferred subduction zone geometry/kinematics and in the internal character of the orogenic wedge
Design and Preliminary Testing of the International Docking Adapter's Peripheral Docking Target
The International Docking Adapter's Peripheral Docking Target (PDT) was designed to allow a docking spacecraft to judge its alignment relative to the docking system. The PDT was designed to be compatible with relative sensors using visible cameras, thermal imagers, or Light Detection and Ranging (LIDAR) technologies. The conceptual design team tested prototype designs and materials to determine the contrast requirements for the features. This paper will discuss the design of the PDT, the methodology and results of the tests, and the conclusions pertaining to PDT design that were drawn from testing
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