Evaluating the coefficient of thermal expansion of additive manufactured AlSi10Mg using microwave techniques

In this paper we have used laser powder bed fusion (PBF) to manufacture and characterize metal microwave components. Here we focus on a 2.5 GHz microwave cavity resonator, manufactured by PBF from the alloy AlSi10Mg. Of particular interest is its thermal expansion coefficient, especially since many microwave applications for PBF produced components will be in satellite systems where extreme ranges of temperature are experienced. We exploit the inherent resonant frequency dependence on cavity geometry, using a number of TM cavity modes, to determine the thermal expansion coefficient over the temperature range 6–450 K. Our results compare well with literature values and show that the material under test exhibits lower thermal expansion when compared with a bulk aluminium alloy alternative (6063)

Evaluating the coefficient of thermal expansion of additive manufactured AlSi10Mg using microwave techniques

In this paper we have used laser powder bed fusion (PBF) to manufacture and characterize metal microwave components. Here we focus on a 2.5 GHz microwave cavity resonator, manufactured by PBF from the alloy AlSi10Mg. Of particular interest is its thermal expansion coefficient, especially since many microwave applications for PBF produced components will be in satellite systems where extreme ranges of temperature are experienced. We exploit the inherent resonant frequency dependence on cavity geometry, using a number of TM cavity modes, to determine the thermal expansion coefficient over the temperature range 6–450 K. Our results compare well with literature values and show that the material under test exhibits lower thermal expansion when compared with a bulk aluminium alloy alternative (6063)

Indigenous plants promote insect biodiversity in urban greenspaces

The contribution of urban greenspaces to support biodiversity and provide benefits for people is increasingly recognized. However, ongoing management practices favor vegetation oversimplification, often limiting greenspaces to lawns and tree canopy rather than multi-layered vegetation that includes under- and midstorey, and the use of nonnative species. These practices hinder the potential of greenspaces to sustain indigenous biodiversity, particularly for taxa like insects that rely on plants for food and habitat. Yet, little is known about which plant species may maximize positive outcomes for taxonomically and functionally diverse insect communities in greenspaces. Additionally, while cities are expected to experience high rates of introductions, quantitative assessments of the relative occupancy of indigenous vs. introduced insect species in greenspace are rare, hindering understanding of how management may promote indigenous biodiversity while limiting the establishment of introduced insects. Using a hierarchically replicated study design across 15 public parks, we recorded occurrence data from 552 insect species on 133 plant species, differing in planting design element (lawn, midstorey, and tree canopy), midstorey growth form (forbs, lilioids, graminoids, and shrubs) and origin (nonnative, native, and indigenous), to assess (1) the relative contributions of indigenous and introduced insect species and (2) which plant species sustained the highest number of indigenous insects. We found that the insect community was overwhelmingly composed of indigenous rather than introduced species. Our findings further highlight the core role of multi-layered vegetation in sustaining high insect biodiversity in urban areas, with indigenous midstorey and canopy representing key elements to maintain rich and functionally diverse indigenous insect communities. Intriguingly, graminoids supported the highest indigenous insect richness across all studied growth forms by plant origin groups. Our work highlights the opportunity presented by indigenous understory and midstorey plants, particularly indigenous graminoids, in our study area to promote indigenous insect biodiversity in urban greenspaces. Our study provides a blueprint and stimulus for architects, engineers, developers, designers, and planners to incorporate into their practice plant species palettes that foster a larger presence of indigenous over regionally native or nonnative plant species, while incorporating a broader mixture of midstorey growth forms

Ecological Niche Modelling and nDNA Sequencing Support a New, Morphologically Cryptic Beetle Species Unveiled by DNA Barcoding

DNA sequencing techniques used to estimate biodiversity, such as DNA barcoding, may reveal cryptic species. However, disagreements between barcoding and morphological data have already led to controversy. Species delimitation should therefore not be based on mtDNA alone. Here, we explore the use of nDNA and bioclimatic modelling in a new species of aquatic beetle revealed by mtDNA sequence data. The aquatic beetle fauna of Australia is characterised by high degrees of endemism, including local radiations such as the genus Antiporus. Antiporus femoralis was previously considered to exist in two disjunct, but morphologically indistinguishable populations in south-western and south-eastern Australia. We constructed a phylogeny of Antiporus and detected a deep split between these populations. Diagnostic characters from the highly variable nuclear protein encoding arginine kinase gene confirmed the presence of two isolated populations. We then used ecological niche modelling to examine the climatic niche characteristics of the two populations. All results support the status of the two populations as distinct species. We describe the south-western species as Antiporus occidentalis sp.n. In addition to nDNA sequence data and extended use of mitochondrial sequences, ecological niche modelling has great potential for delineating morphologically cryptic species

FIGURE 4 in A new and likely extinct species of Antilissus Sharp, 1879 (Coleoptera: Zopheridae Colydiinae) from Makauwahi Cave, Kauai, Hawaiian Islands

FIGURE 4. Antilissus aper, Sharp, 1879: A. Historical specimen of A. aper from Oahu (Labels: Kaumuahona, 6.17.17, Oahu; J.C. Bridwell, collector; Bobea; Antilissus aper, Sharp, 1879 det.?; BPBM ENT, 2004012430); B. Subfossil specimen of A. aper from Makauwahi Cave sequence (Sample: BAC-NW 2009 PHD).Published as part of Porch, Nick, 2020, A new and likely extinct species of Antilissus Sharp, 1879 (Coleoptera: Zopheridae Colydiinae) from Makauwahi Cave, Kauai, Hawaiian Islands, pp. 135-141 in Zootaxa 4868 (1) on page 139, DOI: 10.11646/zootaxa.4868.1.8, http://zenodo.org/record/441742

FIGURE 2 in A new and likely extinct species of Antilissus Sharp, 1879 (Coleoptera: Zopheridae Colydiinae) from Makauwahi Cave, Kauai, Hawaiian Islands

FIGURE 2. Type series prothoraces of Antilissus makauwahi from Makauwahi Cave. All paratypes other than the holotype. A-D, F. BAW-NW Pit, 2009 square GG74, 'Sump' 4.0–4.5 metres depth. E. Holotype of A. makauwahi. Scale bar = 0.5 mm.Published as part of Porch, Nick, 2020, A new and likely extinct species of Antilissus Sharp, 1879 (Coleoptera: Zopheridae Colydiinae) from Makauwahi Cave, Kauai, Hawaiian Islands, pp. 135-141 in Zootaxa 4868 (1) on page 138, DOI: 10.11646/zootaxa.4868.1.8, http://zenodo.org/record/441742

FIGURE 1 in A new and likely extinct species of Antilissus Sharp, 1879 (Coleoptera: Zopheridae Colydiinae) from Makauwahi Cave, Kauai, Hawaiian Islands

FIGURE 1. Holotype Antilissus makauwahi articulated prothorax and head, dorsal (left) and ventral (right) - (Hawaiian Islands, Kauai, Makauwahi Cave, BAW-NW Pit, Bucket auger sample, 3.3–3.6 metres depth). Scale bar = 0.5 mm.Published as part of Porch, Nick, 2020, A new and likely extinct species of Antilissus Sharp, 1879 (Coleoptera: Zopheridae Colydiinae) from Makauwahi Cave, Kauai, Hawaiian Islands, pp. 135-141 in Zootaxa 4868 (1) on page 137, DOI: 10.11646/zootaxa.4868.1.8, http://zenodo.org/record/441742

Climate space, bioclimatic envelopes and coexistence methods for the reconstruction of past climates : a method using Australian beetles and significance for Quaternary reconstruction

If Quaternary palaeoclimatic reconstructions are to be adequately contextualised, it is vital that the nature of modern datasets and the limitations this places on interpreting Quaternary climates are made explicit - such issues are too infrequently considered. This paper describes a coexistence method for the reconstruction of past temperature and precipitation parameters in Australia, using fossil beetles. It presents the context for Quaternary palaeoclimatic reconstruction in terms of climate space, bioclimatic envelope data derived from modern beetle distributions, and the palaeoclimatic limitations of bioclimatic envelope-based reconstructions. Tests in modern climate space, using bioclimatic envelope data for 734 beetle taxa and 54 site-based assemblages from across the continent, indicate that modern seasonal, especially summer, temperatures and precipitation are accurately and, in the case of temperature, precisely reconstructed. The limitations of modern climate space, especially in terms of the limited seasonal variation in thermal regimes and subsequent lack of cold winters in the Australian region, renders winter predictions potentially unreliable when applied to the Quaternary record. Crow