Anatomy of the adventitious roots of Philodendron (Araceae) and its importance for the systematics of the genus

2020 ◽  
Vol 33 (2) ◽  
pp. 207
Author(s):  
Rafaela de Oliveira Ferreira ◽  
Ana Cristina Campos Borges ◽  
Juan Augusto Rodrigues dos Campos ◽  
Artur Manoel Leite Medeiros ◽  
Cassia Mônica Sakuragui ◽  
...  
Keyword(s):  
Cross Sections ◽  
Related Species ◽  
Adventitious Roots ◽  
Related Genus ◽  
Phylogenetic Hypothesis ◽  
The Common

The genus Philodendron Schott comprises the following three currently accepted subgenenera: P. subg. Philodendron, P. subg. Pteromischum and P. subg. Meconostigma; however, these lack a well-defined classification. In the present study, we examined anatomically samples of adventitious roots in species of the group, so as to establish aspects relevant for taxonomic purposes. The anatomical analyses emphasised the characteristics of the steles in cross-sections of the root samples from regions near the apex to the most mature zones. A species of a closely related genus Adelonema, namely A. crinipes, was included in the study to clarify the results. Our results indicated notable differences in the species of the subgenus Meconostigma, mainly in terms of the presence (and variations) of a lobed stele, whereas the cylindrical stele stood out among the common characteristics in P. subg. Philodendron, P. subg. Pteromischum and the related species A. crinipes. Moreover, the characteristics shared by P. subg. Philodendron and P. subg. Pteromischum corroborated the phylogenetic hypothesis that these two taxa were more closely related to one another than to P. subg. Meconostigma.

Corrigendum to: Anatomy of the adventitious roots of Philodendron (Araceae) and its importance for the systematics of the genus

2020 ◽  
Author(s):  
Rafaela de Oliveira Ferreira ◽  
Ana Cristina Campos Borges ◽  
Juan Augusto Rodrigues dos Campos ◽  
Artur Manoel Leite Medeiros ◽  
Cassia Mônica Sakuragui ◽  
...  
Keyword(s):  
Cross Sections ◽  
Related Species ◽  
Adventitious Roots ◽  
Related Genus ◽  
Phylogenetic Hypothesis ◽  
The Common

The genus Philodendron Schott comprises the following three currently accepted subgenenera: P. subg. Philodendron, P. subg. Pteromischum and P. subg. Meconostigma; however, these lack a well-defined classification. In the present study, we examined anatomically samples of adventitious roots in species of the group, so as to establish aspects relevant for taxonomic purposes. The anatomical analyses emphasised the characteristics of the steles in cross-sections of the root samples from regions near the apex to the most mature zones. A species of a closely related genus Adelonema, namely A. crinipes, was included in the study to clarify the results. Our results indicated notable differences in the species of the subgenus Meconostigma, mainly in terms of the presence (and variations) of a lobed stele, whereas the cylindrical stele stood out among the common characteristics in P. subg. Philodendron, P. subg. Pteromischum and the related species A. crinipes. Moreover, the characteristics shared by P. subg. Philodendron and P. subg. Pteromischum corroborated the phylogenetic hypothesis that these two taxa were more closely related to one another than to P. subg. Meconostigma.

scholarly journals Evolutionary Spread and Recombination of Porcine Endogenous Retroviruses in the Suiformes

2005 ◽  
Vol 79 (1) ◽  
pp. 649-654 ◽  
Author(s):  
Marcus Niebert ◽  
Ralf R. Tönjes
Keyword(s):  
Long Terminal Repeat ◽  
Related Species ◽  
Sus Scrofa ◽  
Endogenous Retroviruses ◽  
Phylogenetic Distance ◽  
African Origin ◽  
Closely Related Species ◽  
Separate Event ◽  
Porcine Endogenous Retroviruses ◽  
The Common

ABSTRACT Different Suiformes with increasing phylogenetic distance to the common pig (Sus scrofa) were assayed for the presence of porcine endogenous retroviruses (PERV) in general (pol gene), while the distribution of long terminal repeat (LTR) types (with or without repeats in U3) and env genes (classes A, B, and C) were determined in detail. PERV was not detectable in the most distantly related species, while classes PERV-A and PERV-B are present in Suiformes originating in the Pliocene epoch, and class PERV-C was detectable only in S. scrofa and in closely related species originating in the Holocene epoch. This distribution pattern of PERV classes is in line with our previous study on the age of PERV (45) and suggests an African origin of about 7.5 million years ago (MYA) and a gradual spread of PERV through the Suiformes. It seems likely that PERV-C originated more recently (1.5 to 3.5 MYA) by recombination with a homologue of unknown descent, while the origin of the repeatless LTR was a separate event approximately 3.5 MYA.

scholarly journals Comparative transcriptomics of the venoms of continental and insular radiations of West African cones

2020 ◽  
Vol 287 (1929) ◽  
pp. 20200794
Author(s):  
Samuel Abalde ◽  
Manuel J. Tenorio ◽  
Carlos M. L. Afonso ◽  
Rafael Zardoya
Keyword(s):  
Related Species ◽  
Common Ancestor ◽  
West African ◽  
Generic Level ◽  
Closely Related Species ◽  
Functional Convergence ◽  
Venom Glands ◽  
Phylogenetic Framework ◽  
The Common ◽  
Secreted Peptides

The transcriptomes of the venom glands of 13 closely related species of vermivorous cones endemic to West Africa from genera Africonus and Varioconus were sequenced and venom repertoires compared within a phylogenetic framework using one Kalloconus species as outgroup. The total number of conotoxin precursors per species varied between 108 and 221. Individuals of the same species shared about one-fourth of the total conotoxin precursors. The number of common sequences was drastically reduced in the pairwise comparisons between closely related species, and the phylogenetical signal was totally eroded at the inter-generic level (no sequence was identified as shared derived), due to the intrinsic high variability of these secreted peptides. A common set of four conotoxin precursor superfamilies (T, O1, O2 and M) was expanded in all studied cone species, and thus, they are considered the basic venom toolkit for hunting and defense in the West African vermivorous cone snails. Maximum-likelihood ancestral character reconstructions inferred shared conotoxin precursors preferentially at internal nodes close to the tips of the phylogeny (between individuals and between closely related species) as well as in the common ancestor of Varioconus . Besides the common toolkit, the two genera showed significantly distinct catalogues of conotoxin precursors in terms of type of superfamilies present and the abundance of members per superfamily, but had similar relative expression levels indicating functional convergence. Differential expression comparisons between vermivorous and piscivorous cones highlighted the importance of the A and S superfamilies for fish hunting and defense.

New method for determining correction factors for pin-in-paste solder volumes

2017 ◽  
Vol 29 (1) ◽  
pp. 2-9 ◽  
Author(s):  
Oliver Krammer ◽  
Bertalan Varga ◽  
Karel Dušek
Keyword(s):  
Explicit Expression ◽  
Cross Sections ◽  
New Method ◽  
Solder Paste ◽  
Correction Factors ◽  
Surface Evolver ◽  
Volume Calculation ◽  
Content Type ◽  
The Common ◽  
Approach Zero

Purpose This paper aims to present a new method to calculate the appropriate volume of solder paste necessary for the pin-in-paste (PIP) technology. By the aid of this volume calculation, correction factors have been determined, which can be used to correct the solder fillet volume obtained by an explicit expression. Design/methodology/approach The method is based on calculating the optimal solder fillet shape and profile for through-hole (TH) components with given geometrical sizes. To calculate this optimal shape of the fillet, a script was written in Surface Evolver. The volume calculations were performed for different fillet radiuses (0.4-1.2 mm) and for different component lead geometries (circular and square cross-sections). Finally, the volume obtained by the Evolver calculations was divided by the volume obtained by an explicit expression, and correction factors were determined for the varying parameters. Findings The results showed that the explicit expression underestimates the fillet volume necessary for the PIP technology significantly (15-35 per cent). The correction factors for components with circular leads ranged between 1.4 and 1.59, whereas the correction factors for square leads ranged between 1.1 and 1.27. Applying this correction can aid in depositing the appropriate solder paste volume for TH components. Originality/value Determining the correct volume of solder paste necessary for the PIP technology is crucial to eliminate the common soldering failure of TH components (e.g. voiding or non-wetted solder pads). The explicit expression, which is widely used for volume calculation in this field, underestimates the necessary volume significantly. The new method can correct this estimation, and can aid the industry to approach zero-defect manufacturing in the PIP technology.

scholarly journals Development of the computerized decision-making support system for the prevention and revealing of dangerous zones of flooding

2019 ◽  
Vol 97 ◽  
pp. 05040 ◽  
Author(s):  
Farrukh Shaazizov ◽  
Bakhtiyar Uralov ◽  
Elyor Shukurov ◽  
Aydar Nasrulin
Keyword(s):  
Cross Sections ◽  
Calculation Method ◽  
Visual Inspection ◽  
Wave Speed ◽  
Emergency Situation ◽  
Technical Condition ◽  
The Common ◽  
The Given ◽  
Modern Condition ◽  
Partial Destruction

In considered article the results are presented of the carried out researches on high-mountainous lakes of the Tashkent area. Visual inspection of a modern condition of natural dams of considered high-mountainous lakes of the Tashkent oblast is carried out. On the basis of the analysis of visual inspection it is possible to note, that the common technical condition of natural dams of the submitted high-mountainous lakes safe and does not represent danger to downstream situated territories. It was carried out the modeling of occurrence of emergency situation on high-mountainous lakes of the Tashkent oblast in case of full or partial destruction of natural dams. By an available calculation method of flooding waves are determined its key parameters, height of a wave, speed of distribution of a wave of break on the certain distances and reaching time the given wave up to the certain distances. On the basis of calculation method have been calculated and put on cross-sections of the rivers Pskem and Kocy zones of possible flooding in full and partial destruction of dams of high-mountainous lakes. Results of the carried out calculations have been put on the digital map, created on platform ArcView 3.2a.

Efficiency of visual strength grading of timber with respect to origin, species, cross section, and grading rules: a critical evaluation of the common standards

Holzforschung ◽  
2014 ◽  
Vol 68 (2) ◽  
pp. 203-216 ◽  
Author(s):  
Peter Stapel ◽  
Jan-Willem G. van de Kuilen
Keyword(s):  
Mechanical Properties ◽  
Cross Section ◽  
Cross Sections ◽  
Critical Evaluation ◽  
International Standards ◽  
National Standards ◽  
Visual Grading ◽  
Source Areas ◽  
The Common ◽  
Machine Strength

Abstract Strength grading is essential for the efficient use of structural timber. Although international standards exist for machine strength grading, visual grading is still regulated based on national rules, which are expected to allow safe and economic grading results. Although there are large differences in the graded output because the species, the cross section, and the origin of the timber influence the results, some of these standards are considered to be applicable universally. The present article demonstrates how the chosen standards influence the grading results. Depending on the parameters, the yields or the mechanical properties are low compared with the declared values. The results also show the efficiency and applicability of different national standards for strength grading of timber from various origins. Furthermore, it is recommended to reconsider the existing limits for source areas and cross sections given in the standard EN 1912.

Revision of the genus Hemicladus Buquet, 1857 with a special focus on the species from French Guiana (Coleoptera: Cerambycidae: Lamiinae)

Zootaxa ◽  
2010 ◽  
Vol 2358 (1) ◽  
pp. 39
Author(s):  
GÉRARD LUC Tavakilian ◽  
JULIEN TOUROULT ◽  
PIERRE-HENRI DALENS
Keyword(s):  
Related Species ◽  
French Guiana ◽  
New Combination ◽  
Special Focus ◽  
Related Genus ◽  
Distribution Maps

Hemicladus buqueti Tavakilian, Touroult & Dalens sp. n. is described from French Guiana and compared to the related species H. dejeanii Buquet, 1857, also present in French Guiana. Distributional data are presented for these two species and summarised in distribution maps. Lectotypes are designated for H. dejeanii Buquet, 1857 and H. thomsonii Buquet, 1857. H. decoratus Fuchs, 1955 is transferred to the related genus Eumimesis Bates, 1866 to give the new combination E. decoratus (Fuchs, 1955), comb. nov. An updated key to the species of Hemicladus Buquet, 1857 is presented.

scholarly journals Determination of meteoroid physical properties from tristatic radar observations

2008 ◽  
Vol 26 (8) ◽  
pp. 2217-2228 ◽  
Author(s):  
J. Kero ◽  
C. Szasz ◽  
A. Pellinen-Wannberg ◽  
G. Wannberg ◽  
A. Westman ◽  
...  
Keyword(s):  
Cross Sections ◽  
Equation Of Motion ◽  
Momentum Equation ◽  
Radar System ◽  
Radar Target ◽  
Radar Cross Sections ◽  
The Common ◽  
Head Echo ◽  
Uhf Radar

Abstract. In this work we give a review of the meteor head echo observations carried out with the tristatic 930 MHz EISCAT UHF radar system during four 24 h runs between 2002 and 2005 and compare these with earlier observations. A total number of 410 tristatic meteors were observed. We describe a method to determine the position of a compact radar target in the common volume monitored by the three receivers and demonstrate its applicability for meteor studies. The inferred positions of the meteor targets have been utilized to estimate their velocities, decelerations and directions of arrival as well as their radar cross sections with unprecedented accuracy. The velocity distribution of the meteoroids is bimodal with peaks at 35–40 km/s and 55–60 km/s, and ranges from 19–70 km/s. The estimated masses are between 10−9–10−5.5 kg. There are very few detections below 30 km/s. The observations are clearly biased to high-velocity meteoroids, but not so biased against slow meteoroids as has been presumed from previous tristatic measurements. Finally, we discuss how the radial deceleration observed with a monostatic radar depends on the meteoroid velocity and the angle between the trajectory and the beam. The finite beamwidth leads to underestimated meteoroid masses if radial velocity and deceleration of meteoroids approaching the radar are used as estimates of the true quantities in a momentum equation of motion.

Аэродинамический высокопроизводительный распылитель жидких реагентов на основе сопла Лаваля

2020 ◽  
Vol 13 (5) ◽  
pp. 264-274
Author(s):  
Р.В. Клейманов ◽  
С.Е. Александров
Keyword(s):  
Flow Rate ◽  
Cross Sections ◽  
Vapor Deposition ◽  
High Performance ◽  
Laval Nozzle ◽  
Chemical Vapor ◽  
High Flow ◽  
Wide Range ◽  
The Common ◽  
Internal Body

Авторами статьи предлагается высокопроизводительное устройство для подачи жидкого реагента в установку для химического осаждения высокочистого кварца в пламени. Подача жидкого кремнийсодержащего реагента осуществляется путем преобразования его в аэрозоль при помощи аэродинамического распылителя с плоским соплом Лаваля с внутренним телом. Разработанная конструкция позволяет достичь больших расходов жидкого реагента путем изменения сечений сопла для регулировки скорости газа-распылителя. Предложенная конструкция отличается более высокой технологичностью и простотой изменения расхода реагента в широких пределах, в отличие от распространенных коаксиальных конструкций сопел. The authors propose a high-performance device for supplying a liquid reagent for the chemical vapor deposition of high-purity quartz. The liquid silicon-containing reagent is supplied by converting it into an aerosol using an aerodynamic nebulizer with a flat Laval nozzle incorporating an internal body. The developed design allows of achieving a high flow rate of the liquid reagent by changing the nozzle cross-sections so as to adjust the speed of the nebulizer gas. The proposed design features higher manufacturability and simple adjustment of the reagent flow rate over a wide range, as distinct from the common coaxial nozzle designs.

A new saprotrophic species of Amanita (Amanitaceae, Agaricales) from Inner Mongolia, China

Phytotaxa ◽  
2021 ◽  
Vol 527 (4) ◽  
pp. 284-292
Author(s):  
XIAOLIANG LIU ◽  
TOLGOR BAU ◽  
ZHU L. YANG
Keyword(s):  
Related Species ◽  
Internal Transcribed Spacer ◽  
Inner Mongolia ◽  
Northeast China ◽  
Large Subunit ◽  
Sand Dunes ◽  
Morphological Characteristics ◽  
The Common

A new saprotrophic species in Amanita sect. Lepidella, A. orientisororia, was discovered on lawn and sand dunes in Northeast China. This species was macroscopically characterized by a small white pileus, conical to subconical to pyramidal volval remnants on pileal surface, large broadly ellipsoid to ellipsoid basidiospores measuring 9–13×7–9.5 μm, and the common presence of clamps in all parts of basidiomata. It was described and compared with related species in the genus, based on morphological characteristics and phylogenetic evidence inferred from sequences of the nuclear ribosomal internal transcribed spacer (ITS) and the large subunit of the nuclear ribosomal region (nrLSU).

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