Impact of AFM-induced nano-pits in a-Si:H films on silicon crystal growth

Conductive tips in atomic force microscopy (AFM) can be used to localize field-enhanced metal-induced solid-phase crystallization (FE-MISPC) of amorphous silicon (a-Si:H) at room temperature down to nanoscale dimensions. In this article, the authors show that such local modifications can be used to selectively induce further localized growth of silicon nanocrystals. First, a-Si:H films by plasma-enhanced chemical vapor deposition on nickel/glass substrates are prepared. After the FE-MISPC process, yielding both conductive and non-conductive nano-pits in the films, the second silicon layer at the boundary condition of amorphous and microcrystalline growth is deposited. Comparing AFM morphology and current-sensing AFM data on the first and second layers, it is observed that the second deposition changes the morphology and increases the local conductivity of FE-MISPC-induced pits by up to an order of magnitude irrespective of their prior conductivity. This is attributed to the silicon nanocrystals (<100 nm) that tend to nucleate and grow inside the pits. This is also supported by micro-Raman spectroscopy

Book Review: Cohen A.C. 2021: Design, Operation and Control of Insect Rearing Systems. Science, Technology, and Infrastructure.

Cohen A.C. 2021: Design, Operation and Control of Insect Rearing Systems. Science, Technology, and Infrastructure. CRC Press, Boca Raton, xxv + 394 pp., 297 color and 63 b/w illustrations. ISBN 9781138571259. Price GBP 170.00 (hardback), GBP 119.00 (e-book)

Towards a functional classification of poorly known tropical insects: The case of rhinoceros beetles (Coleoptera, Dynastinae) in Panama

The population dynamics of most tropical insects are unknown and long-term monitoring programmes are urgently needed to evaluate a possible insect decline in the tropics. In this context, functional groups can be used effectively to summarise time-series for species-rich taxa. Neotropical dung beetles have often been catalogued into functional groups, but close relatives also of ecological significance, the Dynastinae, are awaiting such a classification. Here, we examine the functional groups of Dynastinae at the regional (Panama: 147 species) and local (Barro Colorado Island, BCI: 56 species) scales. Our optimum classification of Panamanian species distinguished five groups, one of which is probably artificial and accounts for species ecologically poorly known. Ecological attributes or species traits mainly influencing the delineation of groups were geographical distribution, body length, seasonal aggregation, larval food and whether the adult may be present in decaying wood. Our analyses indicated that (1) missing trait values and the high percentage of ‘cryptic’ species (25%) influenced the delineation of groups; (2) the dendrogram similarity of functional groups versus phylogenetic tree was low, although some traits were phylogenetically conserved; and (3) the overall structure of functional groups was conserved when comparing regional and local data, suggesting no drastic loss of functional groups locally. To proceed with the functional classification of poorly known tropical insects, we recommend a cautious selection of traits a priori, inclusion of ‘cryptic’ species recognised by DNA barcoding, and building phylogenies, which may allow a careful taxonomic imputation to complete species-traits matrices

On the phylogenetic position and systematics of extant and fossil Aclopinae (Coleoptera: Scarabaeidae)

The Aclopinae is a small subfamily within the family Scarabaeidae. It currently comprises five extant genera with 28 species, and eight fossil genera with 25 species. The systematic position of Aclopinae within the family Scarabaeidae is uncertain, particularly because representative species of Aclopinae have been absent in previous phylogenetic studies. Here we performed phylogenetic analyses using morphological and molecular data to investigate the phylogenetic position of fossil and extant Aclopinae. For this objective, we expanded and revised a former morphological data matrix (composed of 68 characters) including all extant genera of Aclopinae. We complemented our morphological investigations with a molecular phylogenetic analysis based on four genes of several extant taxa of Aclopinae and a wide sample of diverse Scarabaeoidea. Our phylogenetic analyses show that all the type species of the fossil genera formerly included within Aclopinae do not belong within the extant Aclopinae clade and support both the exclusion of those fossil taxa and the monophyly of the extant genera of Aclopinae: Aclopus Erichson, Desertaclopus Ocampo & Mondaca, Gracilaclopus Ocampo & Mondaca, Neophanaeognatha Allsopp and Phanaeognatha Hope. Our results also show that the fossil taxa Prophaenognatha robusta Bai et al. and Ceafornotensis archratiras Woolley are closely related to Ochodaeidae, while the remaining type species of fossils formerly included in Aclopinae (Cretaclopus longipes (Ponomarenko), Holcorobeus vittatus Nikritin, Juraclopus rodhendorfi Nikolajev, Mesaclopus mongolicus (Nikolajev), and Mongolrobeus zherikhini Nikolajev) belong to a distinct lineage closely related to Diphyllostomatidae. Based on these results, the subfamily Aclopinae appears monophyletic and sister to the ?pleurostict? lineage. Consequently, we propose the following changes to the current classification of the fossil taxa: Holcorobeus monreali (Gómez-Pallerola) belongs to Carabidae (incertae sedis) as proposed by the original author, and we place Ceafornotensis Woolley, Cretaclopus Nikolajev, Holcorobeus Nikritin, Juraclopus Nikolajev, Mesaclopus Nikolajev, Mongolrobeus Nikolajev and Prophaenognatha Bai et al. in Scarabaeoidea (incertae sedis). Furthermore, we provide an identification key to, and diagnoses of, the genera, illustrations of diagnostic characters and checklists of their included species. The evolutionary perspective presented provides new insights into the evolution of the pleurostict condition in Scarabaeoidea and the biogeography of this group, which is now regarded as Gondwanan, probably evolving during the Cretaceous and not from the upper Jurassic as previously assumed.Fil: Neita Moreno, Jhon César. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Provincia de Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Universidad Nacional de Cuyo. Instituto Argentino de Investigaciones de las Zonas Áridas; Argentina. Instituto de Investigaciones de Recursos Biológicos Alexander Von Humboldt; ColombiaFil: Agrain, Federico Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Provincia de Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Universidad Nacional de Cuyo. Instituto Argentino de Investigaciones de las Zonas Áridas; ArgentinaFil: Eberle, Jonas. Zoologisches Forschungsmuseum Alexander Koenig; AlemaniaFil: Ahrens, Dirk. Zoologisches Forschungsmuseum Alexander Koenig; AlemaniaFil: Pereyra, Vanina Antonella. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Provincia de Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Universidad Nacional de Cuyo. Instituto Argentino de Investigaciones de las Zonas Áridas; Argentin