A phylogenetic and monographic study of Oxypolis, Ptilimnium, and closely related genera (Apiaceae)

A phylogenetic and monographic study of Oxypolis, Ptilimnium, and closely related genera in the North American endemics clade of tribe Oenantheae (Apiaceae) was carried out. Sequences from the nuclear ribosomal DNA internal transcribed spacer (ITS) region and the chloroplast DNA trnQ-5'rps16 and 3'rps16-5'trnK intergeneric spacer regions were used to estimate the phylogenetic relationships of Oxypolis, Ptilimnium, and closely related genera. The sequence data were analyzed using maximum parsimony, maximum likelihood and Bayesian methods. Results of the phylogenetic analyses showed that neither Oxypolis nor Ptilimnium was monophyletic. In the analyses, each genus was separated into two strongly supported clades that corresponded to differences in leaf morphology within the groups. While most species of Oxypolis and Ptilimnium have compound leaves, others share a unique leaf morphology known as rachis leaves. Rachis leaves are linear, terete, hollow, and septate and are equivalent to the rachis of a pinnately compound leaf in which the pinnae are not expressed. Fruit anatomical characters were explored and were also found to support these splits. Based on the analyses of the molecular data (ITS and cpDNA sequences) and the corroboration of morphological and fruit anatomical data, new circumscriptions for the genera Oxypolis and Ptilimnium were formalized. The two polyphyletic genera (Oxypolis and Ptilimnium) were split, two genera (Tiedemannia and Harperella) were resurrected, and new combinations were made. In addition to these generic level questions, the results of the phylogenetic analyses were used to examine a number of interspecific and infraspecific relationships within Oxypolis and Ptilimnium. As a result, the species P. texense was resurrected, P. ahlesii was placed in synonymy under P. capillaceum, and a case was made for the recognition of O. filiformis subsp. greenmanii. Also, a nomenclatural issue concerning the correct name for the species Oxypolis ternata was resolved. Finally, taxonomic treatments including keys, species and genus descriptions, and brief taxonomic discussions are presented for the following genera: Ptilimnium, Tiedemannia, Harperella, Limnosciadium, Cynosciadium, and Oxypolis. These treatments adopt the newly reinstated genera Harperella and Tiedemannia and include the closely related genera Cynosciadium and Limnosciadium. Treatments are written according to the Flora of North America Guide for Contributors for publication in Volume 13 of the Flora of North America series

Senora : Spanish Waltz

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Probing Electron Correlation via Attosecond XUV Pulses in the Two-Photon Double Ionization of Helium

Recent experimental developments of high-intensity, short-pulse XUV light sources are enhancing our ability to study electron-electron correlations. We perform time-dependent calculations to investigate the so-called "sequential" regime (photon energy above 54.4 eV) in the two-photon double ionization of helium. We show that attosecond pulses allow to induce and probe angular and energy correlations of the emitted electrons. The final momentum distribution reveals regions dominated by the Wannier ridge break-up scenario and by post-collision interaction.Comment: 4 pages, 5 figure

Universal features in sequential and nonsequential two-photon double ionization of helium

We analyze two-photon double ionization of helium in both the nonsequential and sequential regime. We show that the energy spacing between the two emitted electrons provides the key parameter that controls both the energy and the angular distribution and reveals the universal features present in both the nonsequential and sequential regime. This universality, i.e., independence of photon energy, is a manifestation of the continuity across the threshold for sequential double ionization. For all photon energies, the energy distribution can be described by a universal shape function that contains only the spectral and temporal information entering second-order time-dependent perturbation theory. Angular correlations and distributions are found to be more sensitive to the photon energy. In particular, shake-up interferences have a large effect on the angular distribution. Energy spectra, angular distributions parameterized by the anisotropy parameters, and total cross sections presented in this paper are obtained by fully correlated time-dependent ab initio calculations.Comment: 12 pages, 8 figure

Viola sagittata Ait.

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The Incidence and Clinical Relevance of Graft Hypertrophy After Matrix-Based Autologous Chondrocyte Implantation

Background: Graft hypertrophy is the most common complication of periosteal autologous chondrocyte implantation (p-ACI). Purpose: The aim of this prospective study was to analyze the development, the incidence rate, and the persistence of graft hypertrophy after matrix-based autologous chondrocyte implantation (mb-ACI) in the knee joint within a 2-year postoperative course. Study Design: Case series; Level of evidence, 4. Methods: Between 2004 and 2007, a total of 41 patients with 44 isolated cartilage defects of the knee were treated with the mb-ACI technique. The mean age of the patients was 35.8 years (standard deviation [SD], 11.3 years), and the mean body mass index was 25.9 (SD, 4.2; range, 19-35.3). The cartilage defects were arthroscopically classified as Outerbridge grades III and IV. The mean area of the cartilage defect measured 6.14 cm2 (SD, 2.3 cm2). Postoperative clinical and magnetic resonance imaging (MRI) examinations were conducted at 3, 6, 12, and 24 months to analyze the incidence and course of the graft. Results: Graft hypertrophy developed in 25% of the patients treated with mb-ACI within a postoperative course of 1 year; 16% of the patients developed hypertrophy grade 2, and 9% developed hypertrophy grade 1. Graft hypertrophy occurred primarily in the first 12 months and regressed in most cases within 2 years. The International Knee Documentation Committee (IKDC) and visual analog scale (VAS) scores improved during the postoperative follow-up time of 2 years. There was no difference between the clinical results regarding the IKDC and VAS pain scores and the presence of graft hypertrophy. Conclusion: The mb-ACI technique does not lead to graft hypertrophy requiring treatment as opposed to classic p-ACI. The frequency of occurrence of graft hypertrophy after p-ACI and mb-ACI is comparable. Graft hypertrophy can be considered as a temporary excessive growth of regenerative cartilage tissue rather than a true graft hypertrophy. It is therefore usually not a persistent or systematic complication in the treatment of circumscribed cartilage defects with mb-ACI

Viola pedata L.

https://thekeep.eiu.edu/herbarium_specimens_byname/20659/thumbnail.jp

Cumulant expansion for the treatment of light–matter interactions in arbitrary material structures

This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in The Journal of Chemical Physics 152.3 (2020): 034108 and may be found at https://aip.scitation.org/toc/jcp/152/3Strong coupling of quantum emitters with confined electromagnetic modes of nanophotonic structures may be used to change optical, chemical, and transport properties of materials, with significant theoretical effort invested toward a better understanding of this phenomenon. However, a full theoretical description of both matter and light is an extremely challenging task. Typical theoretical approaches simplify the description of the photonic environment by describing it as a single mode or few modes. While this approximation is accurate in some cases, it breaks down strongly in complex environments, such as within plasmonic nanocavities, and the electromagnetic environment must be fully taken into account. This requires the quantum description of a continuum of bosonic modes, a problem that is computationally hard. We here investigate a compromise where the quantum character of light is taken into account at modest computational cost. To do so, we focus on a quantum emitter that interacts with an arbitrary photonic spectral density and employ the cumulant, or cluster, expansion method to the Heisenberg equations of motion up to first, second, and third order. We benchmark the method by comparing it with exact solutions for specific situations and show that it can accurately represent dynamics for many parameter rangesThis work was funded by the European Research Council through Grant No. ERC-2016-StG-714870 and the Spanish Ministry for Science, Innovation, and Universities—Agencia Estatal de Investigación through Grant Nos. RTI2018-099737-B-I00, PCI2018-093145 (through the QuantERA program of the European Commission), and MDM-2014-0377 (through the María de Maeztu program for Units of Excellence in R&D