Fast invasives fastly become faster: invasive plants align largely with the fast side of the plant economics spectrum

1. Invasive plants generally align with the fast side of the plant's trait economics spectrum, characterized by fast nutrient acquisition, growth and reproduction. However, there are numerous and notable exceptions, including woody invasives. 2. The generalization that invasives are fast is driven by the high occurrence of invasive ruderal species colonizing nutrient-rich disturbed habitats, a consequence of anthropogenic disturbance usually going hand-in-hand with biological introductions. 3. Successful invasive plans have shown a remarkable ability to rapidly adapt to the new regions where they are introduced. These changes predominantly involve increased resource acquisition, growth and reproduction, aligning them even further with the fast side of the plant economics spectrum. 4. Common garden experiments with invasive model systems provide valuable insights about the speed and direction of adaptive responses to different climates, helping us to predict general plant responses to global change. 5. Synthesis. Invasive plant species commonly present fast nutrient acquisition, growth and reproduction, but this general pattern is mostly driven by ruderal species. Still, common garden experiments comparing populations from distant world regions show a clear trend for already fast invasive plants to rapidly adapt towards even faster traits in their non-native regions

Invasive neo-species and how to name them

Range-expansion and speciation are not new to life on Earth, but they have been scarcely observed contemporarily and, likely, never over several continents simultaneously. Evidence of incipient reproductive isolation between native and non-native regions of some invasive alien species indicates that invasive speciation is closer than we expected. Some neo-allopatric populations are likely to qualify as distinguishable subspecies already. Given their trajectory, whether they will become new species is not an if, but a when. I present two decision tables to help to (1) assess the coining of new invasive species or subspecies with the current taxonomical approach or (2), introduce the term “neo” to name invasive neo-species resulting from synchronous allopatric speciation from a single, known, living ancestor. This later case can be exemplified with the hypothetical case: “Gingko biloba neo americana”, “G. biloba neo europea”, etc

Surgery untying of coloured knots

For p=3 and for p=5 we prove that there are exactly p equivalence classes of p-coloured knots modulo (+/-1)--framed surgeries along unknots in the kernel of a p-colouring. These equivalence classes are represented by connect-sums of n left-hand (p,2)-torus knots with a given colouring when n=1,2,...,p. This gives a 3-colour and a 5-colour analogue of the surgery presentation of a knot.Comment: This is the version published by Algebraic & Geometric Topology on 24 May 200

Understanding the three and four-leg inverter Space Vector

This paper shows a new point of view of the classical voltage space vectors and its implications on three and four-leg converters. It is easy to find in the literature, authors using bi-dimensional and threedimensional representations of the converter states. Nonetheless, the literature rarely specifies what these spaces represent. Therefore, this paper proposes a wide analysis of the state voltages and its references for three-leg, three-leg four-wire and four-leg inverters, in favour of understanding the space vector behaviour under three and four-wire scenarios.Postprint (published version

Perceptual Color Image Smoothing via a New Region-Based PDE Scheme

In this paper, we present a new color image regularization method using a rotating smoothing filter. This approach combines a pixel classification method, which roughly determines if a pixel belongs to a homogenous region or an edge with an anisotropic perceptual edge detector capable of computing two precise diffusion directions. Using a now classical formulation, image regularization is here treated as a variational model, where successive iterations of associated PDE (Partial Differential Equation) are equivalent to a diffusion process. Our model uses two kinds of diffusion: isotropic and anisotropic diffusion. Anisotropic diffusion is accurately controlled near edges and corners, while isotropic diffusion is applied to smooth regions either homogeneous or corrupted by noise. A comparison of our approach with other regularization methods applied on real images demonstrate that our model is able to efficiently restore images as well as handle diffusion, and at the same time preserve edges and corners well

Neotypification for five names linked to Arenaria (Caryophyllaceae) for the endemic flora of Peru and Bolivia

The names Arenaria mattfeldii, A. pallens, A. peruviana, A. pintaudii, and A. stuebelii (Caryophyllaceae, Arenarieae) from Peru and Bolivia were studied and neotypified based on specimens preserved at B and P

The genus Paronychia (Caryophyllaceae) in South America. Nomenclatural review and taxonomic notes with the description of a new species from North Peru

All the names in Paronychia described from South America are investigated. Five names (P. arbuscula, P. brasiliana subsp. brasiliana var. pubescens, P. coquimbensis, P. hieronymi, and P. mandoniana) are lecto- or neotypified on specimens preserved at GOET, K, LP, and P. The typification of nine names, first proposed by Chaudhri in 1968 as the “holotype” are corrected according to Art. 9.10 of ICN. Three second-step typifications (Art. 9.17 of ICN) are proposed for P. camphorosmoides, P. communis, and P. hartwegiana. The following nomenclatural changes are proposed: P. arequipensis comb. et stat. nov. (basionym: P. microphylla subsp. microphylla var. arequepensis), P. compacta nom. nov. pro P. andina (Philippi non Gray; Art. 53.1 of ICN), P. jujuyensis comb. et stat. nov. (basionym: P. hieronymi subsp. hieronymi var. jujuyensis), P. compacta subsp. boliviana comb. nov. (basionym: P. andina subsp. boliviana), and P. compacta subsp. purpurea comb. nov. (basionym: P. andina subsp. purpurea). A new species (P. glabra sp. nov.) is proposed based on our examination of live plants and herbarium specimens. P. johnstonii subsp. johnstonii var. scabrida is synonymized (syn. nov.) with P. johnstonii. Finally, P. argyrocoma subsp. argyrocoma is excluded from South America since it was based on misidentified specimens (deposited at MO) of P. andina subsp. andina. A total of 30 species (43 taxa including subspecies, varieties, subvarieties, and forms) are recognized, highlighting that for some (Paronychia chilensis, P. communis, P. setigera) we provisionally accept Chaudhri’s infraspecific classification, since the high phenotypic variability of these taxa is quite complicated and further investigations need to solve their taxonomy