Морфология спор Parahemionitis arifolia (Cheilanthoideae, Pteridaceae)

A study of spores of the single species of the genus Parahemionitis Panigrahi was performed using the method of scanning electronic microscopy (SEM). Spores of Parahemionitis arifolia (Burm. f.) Panigrahi are tetrahedral trilete, roundish-triangular in polar position, with micro-wrinkled exospore and sculptured perispore. Sculpture of perispore is cristate-reticulate, cristae are quite regularly distributed and form reticulum with small mostly closed polygonal luminae of different shape. Laesura arms are often obscured by numerous cristae. Size of spores is 53–63 × 40–42 μm. Spores of P. arifolia are similar in perispore sculpture with those of species of some cheilanthoid ferns

Морфология спор Taenitis, Syngramma и Austrogramme (Pteridoideae, Pteridaceae) из Юго-Восточной Азии и Океании. II

This paper continues consideration of the spores of three paleotropical fern genera – Taenitis, Syn-gramma, and Austrogramme (Pteridoideae, Pteridaceae) from South-Eastern Asia and Oceania. At the second stage, we carried out a comparative scanning electron microscopy study of spores of three species of Austrogramme, four species of Syngramma, and six species of Taenitis and added information about previously studied spores of seven species of these genera. Spores of all examined species are trilete, tetrahedral or tetrahedral-globose with convex to hemispherical distal side and plane, convex or conical proximal side. The spores of Austrogramme species are the smallest, simplest in ornamentation and similar to each other. Sculpture of the proximal and distal sides are microver-rucate, the surface of the spores is covered by granular deposits. Spores of most Syngramma species are very similar to spores of Austrogramme species in shape and surface sculpture: their distal and proximal surfaces are microverrucate, whereas the spores of S. borneensis and S. cartilagidens have the low-tuberculate sculpture. Spores of Taenitis species are very different from the spores of Austrogramme and Syngramma. Seven of nine studied species have spores with well-expressed cingulum (T. blechnoides, T. cordata, T. diversifolia, T. interrupta, T. luzonica, T. obtusa, and T. re -quiniana), three species (T. cordata, T. hookeri, and T. pinnata) have spores with prominent laesural ridges. The spores have well-expressed ornamentation – tuberculate, baculate, rugate, tuberculate-rugate. The most conspicuous char-acter of the ornamentation of spore surfaces is the presence of rodlets associated with sculpture elements. The dens-est rodlets are characteristic of Taenitis diversifolia, T. luzonica, T. obtusa, and T. requiniana. Spore size (equatorial diameter) ranges on average between 22 μm and 37 μm in Austrogramme, between 27 μm and 41 μm in Syngramma, and between 26 and 51 μm in Taenitis specie

Measurement of Z0 decays to hadrons, and a precise determination of the number of neutrino species

We have made a precise measurement of the cross section for e+e--->Z0-->hadrons with the L3 detector at LEP, covering the range from 88.28 to 95.04 GeV. From a fit to the Z0 mass, total width, and the hadronic cross section to be MZ0=91.160 +/- 0.024 (experiment) +/-0.030(LEP) GeV, [Gamma]Z0=2.539+/-0.054 GeV, and [sigma]h(MZ0)=29.5+/-0.7 nb. We also used the fit to the Z0 peak cross section and the width todetermine [Gamma]invisible=0.548+/-0.029 GeV, which corresponds to 3.29+/-0.17 species of light neutrinos. The possibility of four or more neutrino flavors is thus ruled out at the 4[sigma] confidence level.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/28683/3/0000500.pd

Морфология спор Parahemionitis arifolia (Cheilanthoideae, Pteridaceae)

A study of spores of the single species of the genus Parahemionitis Panigrahi was performed using the method of scanning electronic microscopy (SEM). Spores of Parahemionitis arifolia (Burm. f.) Panigrahi are tetrahedral trilete, roundish-triangular in polar position, with micro-wrinkled exospore and sculptured perispore. Sculpture of perispore is cristate-reticulate, cristae are quite regularly distributed and form reticulum with small mostly closed polygonal luminae of different shape. Laesura arms are often obscured by numerous cristae. Size of spores is 53–63 × 40–42 μm. Spores of P. arifolia are similar in perispore sculpture with those of species of some cheilanthoid ferns

Autocatalysis in thermal decomposition of polymers

Possibility of replicating polymer decomposition by a single global reaction greatly simplifies pyrolysis modeling. Apparent kinetic parameters are normally derived from the microscale experiments with linear heating program, and the n-th order reaction is routinely assumed thereby strongly affecting the numerical values of the kinetic parameters. In this work, we demonstrate inconsistency of the n-th order reaction assumption and reveal the autocatalytic behavior in thermal degradation of polyethylene, polystyrene and polycarbonate. The autocatalysis manifests itself in non-monotonicity of the conversion function, which markedly increases in a wide range of conversions. Although the iso-conversional approach makes it possible to explicitly recover the conversion function from the measurements, this option has not been used in most of the previous studies. Meanwhile, proper approximation of the experimentally derived conversion function results in excellent replication of the measured reaction rates, with the same kinetic parameters, in a range of the heating rates. Thus developed thermal decomposition kinetic models are provided in this paper for three kinds of polyethylene (LDPE, HDPE, and UHMWPE), seven kinds of polystyrene, polycarbonate, and two kinds of polymethylmethacrylate with different molecular weights. Although the pyrolysis of the polymers with different molecular weights proceeds differently, no systematic correlation of the pyrolysis characteristics (conversion-averaged apparent activation energy, heat of combustion, peak reaction rates and temperatures etc.) with the molecular weight has been observed for polystyrene. Peak reaction rates and temperatures varied in opposite directions for polyethylene and polymethylmethacrylate

11<i>H</i>-Benzo[4,5]imidazo[1,2-<i>a</i>]indol-11-one as a New Precursor of Azomethine Ylides: 1,3-Dipolar Cycloaddition Reactions with Cyclopropenes and Maleimides

The possibility of generating azomethine ylides from 11H-benzo[4,5]imidazo[1,2-a]indol-11-one and amino acids is shown for the first time. Based on the cycloaddition reactions of these azomethine ylides with cyclopropenes and maleimides, cyclopropa[a]pyrrolizines, 3-azabicyclo[3.1.0]hexanes, and pyrrolo[3,4-a]pyrrolizines spiro-fused with a benzo[4,5]imidazo[1,2-a]indole fragment were synthesized. Spirocyclic compounds were obtained in moderate to good yields, albeit with poor diastereoselectivity. Density functional theory calculations were performed to obtain an insight into the mechanism of the 1,3-dipolar cycloaddition of 11H-benzo[4,5]imidazo[1,2-a]indol-11-one-derived azomethine ylides to cyclopropenes. The cytotoxic activity of some of the obtained cycloadducts against the human erythroleukemia (K562) cell line was evaluated in vitro by MTS-assay

Allium pallasii and A. caricifolium - Surprisingly Diverse Old Steppe Species, Showing a Clear Geographical Barrier in the Area of Lake Zaysan

Polymorph Allium pallasii s.l. from monotypic A. sect. Pallasia was studied using a wide spectrum of methods and divided into two clearly morphologically, geographically, cytologically and genetically isolated species: A. pallasii s. str.—North-East Kazakhstan, Western Siberia, and the Altai Mountains; A. caricifolium—Kyrgyzstan, Northwest China, South-East Kazakhstan until Zaysan Lake in the east. Despite serious genetic differences, both species are sisters and are related to species of the A. sect. Codonoprasum (Subg. Allium). Allium caricifolium differs from A. pallasii s. str. by taller stems, dense inflorescence, and with filaments longer than perianth. The possible phylogenetic reasons for the separation of these species are discussed. A nomenclature analysis of synonyms was carried out

Formation and consumption of NO in H-2 + O-2 + N-2 flames doped with NO or NH3 at atmospheric pressure

Flat premixed burner-stabilized H-2 + O-2 + N-2 flames, neat or doped with 300-1000 ppm of NO or NH3, were studied experimentally using molecular-beam mass-spectrometry and simulated numerically. Spatial profiles of temperature and concentrations of stable species, H-2, O-2, H2O, NO, NH3, and of H and OH radicals obtained at atmospheric pressure in lean (phi = 0.47), near-stoichiometric (phi = 1.1) and rich (phi = 2.0) flames are reported. Good agreement between measured and calculated structure of lean and near-stoichiometric flames was found. Significant discrepancy between simulated and measured profiles of NO concentration was observed in the rich flames. Sensitivity and reaction path analyses revealed reactions responsible for the discrepancy. Modification to the model was proposed to improve an overall agreement with the experiment. (C) 2009 The Combustion Institute. Published by Elsevier Inc. All rights reserved

Odontogenic mediastinitis: intensive therapy experience (clinical observation)

Mediastinitis as complications of traumas and esophagus perforations are ill-controlled and characterized with high mortality. Yet clinical characteristics and therapeutic controllability of contact odontogenic mediastinitis are not covered enough in medical literature. Aim of the study was to investigate clinical characteristics and to analyze treatment results of odontogenic purulent mediastinitis according to data of pilot monocenter observational study. Materials and methods. The results of treatment of the patients with odontogenic mediastinitis were analyzed in groups: panmediastinitis (8 participants) and posterior upper mediastinitis (12 participants). The following indexes were compared: body temperature, content of C-reactive protein, leucocytes, thrombocytes, creatinine, 24-hour and cumulative fluid electrolyte balance reproduced in hospitals of any equipment levels with using of criteria of nonparametric statistics for excluding of false positive results. Results. Causative agents of the infectious process were found in 65 % of patients in bacteriological study. The mortality was 5 %; the process controllability in conditions of described techniques of anesthesiology and intensive therapy has been shown, the danger of infusive overload of the interstitium of the lungs has been demonstrated

Hotspot and conservation gap analysis of endemic vascular plants in the Altai Mountain Country based on a new global conservation assessment

The Altai Mountains of Central and North Asia are biologically rich and comprise a wide range of ecosystems and phytogeographical regions. According to the latest checklist, a total of 321 endemic vascular plant species, including 217 endemic and 104 subendemic taxa, have been recognized in the Altai Mountain Country (AMC). In this study, we conducted species risk assessment, distribution evaluation and conservation gap analysis for the endemic vascular flora of the AMC. The conservation status of 217 endemic species was assessed at the global level using the ConR package. As a result, 197 species were evaluated as potentially threatened, of which 101 are critically endangered (CR), 72 species are endangered (EN), and 24 species are vulnerable (VU). The remaining 20 species were evaluated as not threatened. Furthermore, the AMC was divided into 350 grid cells, with a grid cell size of 50 × 50 km2, for the spatial assessments of the endemic vascular plants. A total of 2657 unique georeferenced occurrences of endemic species were found and analyzed with three endemism indices, species richness (SR), weighted endemism (WE), and corrected weighted endemism (CWE), to quantify geographic patterns and centers of endemism across the whole AMC. The results showed that the endemic species are spread across 186 grid cells and distributed unevenly within the AMC. According to the conservation gap analysis, the main hotspots of endemism (i.e., SR and WE indices) were found at high elevations in the Russian Altai, while the CWE points to the Kazakh Altai as a hotspot, and many such hotspots are currently afforded no formal protections