| 1. |
- Ronquist, Fredrik, et al.
(författare)
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Completing Linnaeus’s inventory of the Swedish insect fauna: only 5,000 species left?
- 2020
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 15:3
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Tidskriftsartikel (refereegranskat)abstract
- Despite more than 250 years of taxonomic research, we still have only a vague idea about the true size and composition of the faunas and floras of the planet. Many biodiversity inventories provide limited insight because they focus on a small taxonomic subsample or a tiny geographic area. Here, we report on the size and composition of the Swedish insect fauna, thought to represent roughly half of the diversity of multicellular life in one of the largest European countries. Our results are based on more than a decade of data from the Swedish Taxonomy Initiative and its massive inventory of the country’s insect fauna, the Swedish Malaise Trap Project The fauna is considered one of the best known in the world, but the initiative has nevertheless revealed a surprising amount of hidden diversity: more than 3,000 new species (301 new to science) have been documented so far. Here, we use three independent methods to analyze the true size and composition of the fauna at the family or subfamily level: (1) assessments by experts who have been working on the most poorly known groups in the fauna; (2) estimates based on the proportion of new species discovered in the Malaise trap inventory; and (3) extrapolations based on species abundance and incidence data from the inventory. For the last method, we develop a new estimator, the combined non-parametric estimator, which we show is less sensitive to poor coverage of the species pool than other popular estimators. The three methods converge on similar estimates of the size and composition of the fauna, suggesting that it comprises around 33,000 species. Of those, 8,600 (26%) were unknown at the start of the inventory and 5,000 (15%) still await discovery. We analyze the taxonomic and ecological composition of the estimated fauna, and show that most of the new species belong to Hymenoptera and Diptera groups that are decomposers or parasitoids. Thus, current knowledge of the Swedish insect fauna is strongly biased taxonomically and ecologically, and we show that similar but even stronger biases have distorted our understanding of the fauna in the past. We analyze latitudinal gradients in the size and composition of known European insect faunas and show that several of the patterns contradict the Swedish data, presumably due to similar knowledge biases. Addressing these biases is critical in understanding insect biomes and the ecosystem services they provide. Our results emphasize the need to broaden the taxonomic scope of current insect monitoring efforts, a task that is all the more urgent as recent studies indicate a possible worldwide decline in insect faunas.
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| 2. |
- Shovsky, Oleksandr, et al.
(författare)
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Adsorption Characteristics of Stoichiometric and Nonstoichiometric Molecular Polyelectrolyte Complexes on Silicon Oxynitride Surfaces
- 2011
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Ingår i: Langmuir. - : American Chemical Society (ACS). - 0743-7463 .- 1520-5827. ; 27:3, s. 1044-1050
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Tidskriftsartikel (refereegranskat)abstract
- Adsorption properties of stoichiometric and nonstoichiometric polyelectrolyte complexes (PECs) have been investigated by means of dual polarization interferometry (DPI) and X-ray photoelectron spectroscopy (XPS). Poly(sodium styrenesulfonate) (NaPSS) of molecular weight 4300 g/mol was used as polyanion, and two bottle-brush copolymers possessing different molar ratios of the cationic segment methacryloxyethyltrimethylammonium chloride (METAC) and the nonionic segment poly(ethylene oxide) methyl ether methacrylate (PEO(45)MEMA) were used as polycations. They are referred to as PEO(45)MEMA:METAC-25 and PEO(45)MEMA:METAC-50, where the last digits denote the mol % of charged main-chain segments. The time evolution of the adsorbed amount, thickness, and refractive index of the PEC layers were determined in aqueous solution using DPI. We demonstrate that cationic, uncharged, and negatively charged complexes adsorb to negatively charged silicon oxynitride and that maximum adsorption is achieved when small amounts of PSS are present in the complexes. The surface composition of the adsorbed PEC layers was estimated from XPS measurements that demonstrated very low content of NaPSS. On the basis of these data, the PEC adsorption mechanism is discussed and the competition between PSS and negative surface sites for association with the cationic polyelectrolyte is identified as a key issue.
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| 3. |
- Shovskyy, Oleksandr, 1978-, et al.
(författare)
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Formation and Stability of Water-Soluble Molecular Polyelectrolyte Complexes : Effects of Charge Density, Mixing Ratio and Polyelectrolyte Concentration
- 2009
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Ingår i: Langmuir. - : American Chemical Society (ACS). - 0743-7463 .- 1520-5827. ; 25:11, s. 6113-6121
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Tidskriftsartikel (refereegranskat)abstract
- The formation of complexes with stoichiometric (1:1) as well as nonstoichiometric (2:1) and (1:2) compositions between oppositely charged synthetic polyelectrolytes carrying strong ionic groups and significantly different molecular weights is reported in this contribution. Poly(sodium styrenesulfonate) (NaPSS) was used as polyanion, and a range of copolymers with various molar ratios of the poly(methacryloxyethyltrimethylammonium) chloride, poly(METAC), and the nonionic poly(ethylene oxide) ether methacrylate, poly(PEO45MEMA), were used as polycations. Formation and stability of PECs have been investigated by dynamic and static light scattering (LS), turbidity, and electrophoretic mobility measurements as a function of polyelectrolyte solution concentration, charge density of the cationic polyelectrolyte, and mixing ratio. The data obtained demonstrate that in the absence of PEO45 side chains the 100% charged polymer (polyMETAC) formed insoluble PECs with PSS that precipitate from solution when exact stoichiometry is achieved. In nonstoichiometric complexes (1:2) and (2:1) large colloidally stable aggregates were formed. The presence of even a relatively small amount of PEO45 side chains (25%) in the cationic copolymer was sufficient for preventing precipitation of the formed stoichiometric and nonstoichiometric complexes. These PEC’s are sterically stabilized by the PEO45 chains. By further increasing the PEO45 side-chain content (50 and 75%) of the cationic copolymer, small, water-soluble molecular complexes could be formed. The data suggest that PSS molecules and the charged backbone of the cationic brush form a compact core, and with sufficiently high PEO45 chain density (above 25%) molecular complexes are formed that are stable over prolonged times.
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| 4. |
- Varga, Oleksandr, et al.
(författare)
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First record of the genus Aplomerus Provancher, 1886 (Hymenoptera: Ichneumonidae: Xoridinae) from the Oriental region, with descriptions of two new species.
- 2014
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Ingår i: Zootaxa. - : Magnolia Press. - 1175-5326 .- 1175-5334. ; :3815, s. 591-9
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Tidskriftsartikel (refereegranskat)abstract
- The genus Aplomerus Provancher, 1886 (Hymenoptera, Ichneumonidae) is a small genus of the subfamily Xoridinae. Two new species from Asia, A. orientalis Varga & Reshchikov sp. n. from Thailand and A. phamae Broad sp. n. from Vietnam, are described and illustrated. An identification key for Asian species is provided. These are the first records of the genus from the Oriental region and increases the known number of Aplomerus species to eight, with a disjunct distribution of North America, Japan and south-east Asia.
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