4,664 research outputs found

    Effect of woodstack structure on invertebrate abundance and diversity

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    Reduced quantities of dead wood in managed forests have resulted in a reduction in the abundance and diversity of saproxylic invertebrates to the extent that many are now considered red list species. To mitigate against this loss, one conservation measure is the provision of dead wood, in the form of piles of chopped logs, i.e. ‘woodstacks’. The heterogeneity and volume of dead wood habitat is considered to be an important component of habitat suitability. However, the value of different woodstack types to invertebrate conservation has rarely been quantified and there is little consensus on how to best to survey the invertebrate fauna of woodstacks. This study used both sticky traps and pitfall traps to sample the invertebrate fauna of three types of sycamore woodstack. Woodstacks were made from 10 logs, 20 logs and 10 scorched logs plus a control woodstack made of unplasticised polyvinyl chloride (uPVC) plastic piping and observed over a 4-week period. A total of 1446 invertebrates from 16 orders, including 127 Coleoptera, were caught during the sampling period. A generalized linear model was used to analyse invertebrate abundance between woodstack and between trap types, and diversity was determined using Shannon diversity indices and analysed using a two-way Analysis of Variance (ANOVA). The woodstack type had no effect on the abundance of invertebrates. However, Shannon diversity was highest on the scorched woodstacks, with little difference between the 10 and 20 log stacks and the control uPVC woodstacks. However, closer inspection of orders revealed the uPVC woodstacks to have the lowest abundance and diversity of Coleoptera. This study suggests that constructing woodstacks can provide suitable habitat for a variety of invertebrates. However, these invertebrates may have simply used the structures for shelter and the true value with saproxylic invertebrates could not be measured in this 4-week study. To fully appreciate the conservation value of woodstacks will require longer term studies that examine how and when saproxylic invertebrates use dead and decaying wood

    Additive decompositions for rings of modular forms

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    We study rings of integral modular forms for congruence subgroups as modules over the ring of integral modular forms for the full modular group. In many cases these modules are free or decompose at least into well-understood pieces. We apply this to characterize which rings of modular forms are Cohen--Macaulay and to prove finite generation results. These theorems are based on decomposition results about vector bundles on the compactified moduli stack of elliptic curves.Comment: Complete revision. Comments welcome. arXiv admin note: text overlap with arXiv:1609.0926

    Chemical effects in ion mixing of a ternary system (metal-SiO_2)

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    The mixing of Ti, Cr, and Ni thin films with SiO_2 by low‐temperature (−196–25 °C) irradiation with 290 keV Xe has been investigated. Comparison of the morphology of the intermixed region and the dose dependences of net metal transport into SiO_2 reveals that long range motion and phase formation probably occur as separate and sequential processes. Kinetic limitations suppress chemical effects in these systems during the initial transport process. Chemical interactions influence the subsequent phase formation

    Countershading in Seabirds

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    The Intensity Profile of the Solar Supergranulation

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    We have measured the average radial (cell center to network boundary) profile of the continuum intensity contrast associated with supergranular flows using data from the Precision Solar Photometric Telescope (PSPT) at the Mauna Loa Solar Observatory (MLSO). After removing the contribution of the network flux elements by the application of masks based on Ca II K intensity and averaging over more than 10^5 supergranular cells, we find a ~ 0.1% decrease in red and blue continuum intensity from the supergranular cell centers outward, corresponding to a ~ 1.0 K decrease in brightness temperature across the cells. The radial intensity profile may be caused either by the thermal signal associated with the supergranular flows or a variation in the packing density of unresolved magnetic flux elements. These are not unambiguously distinguished by the observations, and we raise the possibility that the network magnetic fields play an active role in supergranular scale selection by enhancing the radiative cooling of the deep photosphere at the cell boundaries.Comment: Accepted to Ap

    Near-Earth Ion Irradiation Effects on Functional Ceramic Materials: A Combined Experimental-Monte Carlo Approach

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    The near-Earth space radiation environment is a complex system that creates a harmful environment for materials to operate in. Motivated by the search for using optical defects as an indicator of radiation damage, five single-crystal functional ceramic materials were selected to undergo ion irradiation at conditions found in the near-Earth space environment. Due to the complex nature of ion irradiation effects in ceramic materials, a host of calculations and experimental characterization methods were used. Calculations using the 2013 SRIM code were used to evaluate the ion projected range and the type and number of defects (vacancies) created by ion irradiation. Structural characterization by Raman spectroscopy was combined with results from UV-visible spectroscopy, radioluminescence, and thermoluminescence to determine changes induced by ion irradiation. This work revealed that the structure and optical properties are sensitive to ion irradiation and can be experimentally characterized by the methods used

    A Framework for the Economic Analysis of Ditch System Management Alternatives

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    Replaced with revised version of paper 05/10/06.Land Economics/Use,

    Gender diversity and research productivity in accounting and finance at Australian and New Zealand HEIs

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    This study has two main objectives. First, it refreshes investigations into research productivity within the accounting and finance domains across Australian and New Zealand higher education institutions from 2011 to 2022. Second, it reflects on affirmative action in Australia, arguing that its impact on women's experiences should extend beyond mere numerical measures. Analysing 48 top journals reveals a steady increase in research output with notable contributions from the University of New South Wales, Monash University, the University of Sydney, the University of Melbourne, and the University of Queensland. Authors with five or more publications rank in the top 5%, highlighting the difficulty of achieving prolific publishing. Significantly, gender diversity improved, with female authorship rising from 19.27% to 31.73%, indicating a shift towards more inclusive research environments. However, a persistent gender gap among highly published authors suggests ongoing challenges. The study also examines job mobility among top contributors, offering insights into career progression within the academic community. Overall, the findings provide new insights into research productivity, the impact of affirmative action on gender diversity, and career mobility within the academic field of accounting and finance
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