Search results for "Maran"

Gluten-Free Alternative Grains: Nutritional Evaluation and Bioactive Compounds

2019

Interest in gluten-free grains is increasing, together with major incidences of celiac disease in the last years. Since to date, knowledge of the nutritional and bioactive compounds profile of alternative gluten-free grains is limited, we evaluated the content of water-soluble (thiamine and riboflavin) and liposoluble vitamins, such as carotenoids and tocols (tocopherols and tocotrienols), of gluten-free minor cereals and also of pseudocereals. The analysed samples showed a high content of bioactive compounds

Simulation of the influence of gas flow on melt convection and phase boundaries in FZ silicon single crystal growth

2015

Abstract Axisymmetric calculations of inert gas flow in a floating zone puller are carried out using an open source software package OpenFOAM. Transient axisymmetric melt flow in liquid silicon and quasi-stationary shape of silicon phase boundaries are calculated using a specialized program FZone. Additional heat losses at silicon surfaces caused by the gas flow are taken into account for argon and helium, while maintaining the height of molten zone by adjusting inductor current. Cooling causes an increase of electromagnetic force, heat sources and more intense melt flow, while crystallization interface deflection decreases. The shear stress of gas flow is found to be an order of magnitude …

Analytical Study of the Thermal Induced Oscillations Known as Heartbeats

1998

Abstract A laser beam traveling horizontally at a short distance below the free surface of an absorbing solution exhibits various oscillatory states (periodic, quasiperiodic, and chaotic) which depend on both the buoyancy (Archimedes force) and the thermal coefficient of the surface tension (Marangoni effect). The beam oscillations have been called “heartbeats.” In this work, the heartbeats were produced by pumping 1-(2-pyridylazo)-2-naphthol (PAN) solutions in silicone oil with an Ar+continuous-wave laser beam. The relationships between PAN concentration and the other parameters that control the oscillatory behavior were studied. The frequency of the oscillations sensitively varied with sm…

Setting-up tension in the style of Marantaceae

2008

The Marantaceae stand out from other plant families through their unique style movement which is combined with a highly derived form of secondary pollen presentation. Although known for a long time, the mechanism underlying the movement is not yet understood. In this paper, we report an investigation into the biomechanical principles of this movement. For the first time we experimentally confirm that, in Maranta noctiflora, longitudinal growth of the maturing style within the 'straitjacket' of the hooded staminode involves both arresting of the style before tripping and building up of potential for the movement. The longer the style grows in relation to the enclosing hooded staminode, the m…

Five new species of Marantaceae endemic to Gabon

2012

ABSTRACT Five new species of African Marantaceae are described and illustrated from two locations in Gabon, Marantochloa alba A. C. Ley, sp. nov., M. grandiflora A. C. Ley, sp. nov., M. montsdecristalii A. C. Ley, sp. nov. and Thaumatococcus flavus A. C. Ley, sp. nov. from the mountainous area of Monts de Cristal, north east of the capital Libreville, as well as Hypselodelphys lopei A. C. Ley, sp. nov. from the central part of Gabon in secondary forest near La Lope and Mikongo. New keys to the genera Marantochloa Brongn. & Gris., Thaumatococcus Benth. and Hypselodelphys (K. Schum.) Milne.-Redh. are provided.

Insights Into the Inside - A Quantitative Histological Study of the Explosively Moving Style in Marantaceae.

2018

This study aims to identify the histological basis for the extraordinary, fast movement of the style in Marantaceae. Although this explosive pollination mechanism was subject of many studies, quantitative measurements to document volumetric changes have never been conducted. Based on physical parameters and limitations (poroelastic time), the movement itself is by far too fast to be explained by turgor changes solely. Therefore, we address the hypothesis that the style contains elastic structures to store energy allowing the fast movement. We provide an experimental approach in Goeppertia bachemiana to identify histological differences of styles in various states, i.e., steady, unreleased, …

Insights Into the Inside – A Quantitative Histological Study of the Explosively Moving Style in Marantaceae

2018

This study aims to identify the histological basis for the extraordinary, fast movement of the style in Marantaceae. Although this explosive pollination mechanism was subject of many studies, quantitative measurements to document volumetric changes have never been conducted. Based on physical parameters and limitations (poroelastic time), the movement itself is by far too fast to be explained by turgor changes solely. Therefore, we address the hypothesis that the style contains elastic structures to store energy allowing the fast movement. We provide an experimental approach in Goeppertia bachemiana to identify histological differences of styles in various states, i.e., steady, unreleased, …

Hydrodynamical aspects of the floating zone silicon crystal growth process

2014

Abstract 3D numerical modeling of dopant transport in the melt is carried out for the 100 mm floating zone silicon single crystal growth process. The axis-symmetric shape of the molten zone is calculated with the program FZone considering the coil and the high frequency (HF) electromagnetic (EM) field in 3D. Time dependent melt flow, temperature and dopant concentration fields are modeled using a specialized solver based on the open source code library OpenFOAM ® . The influence of the Marangoni coefficient in the boundary conditions on the melt velocity field is analyzed. The obtained shapes of the crystallization interface and resistivity profiles in the grown crystal are compared with ex…

2015

The explosive pollination mechanism of the prayer plants (Marantaceae) is unique among plants. After a tactile stimulus by a pollinator, the style curls up rapidly and mediates pollen exchange. It is still under discussion whether this explosive movement is released electrophysiologically, i.e. by a change in the membrane potential (as in Venus flytrap), or purely mechanically. In the present study, electrophysiological experiments are conducted to clarify the mechanism. Artificial release experiments (chemical and electrical) and electrophysiological measurements were conducted with two phylogenetically distant species, Goeppertia bachemiana (E. Morren) Borchs. & S. Suarez and Donax cannif…

Triterpene Saponins from the Roots of Achyranthes bidentata

2001

Three saponins, oleanolic acid-28- O -s-D-glucopyranoside (1), chikusetsusaponin V (2), and 3- O -s-D-glucopyranosyl-oleanolic acid-28- O -s-D-glucopyranoside (3) were isolated from the roots of Achyranthes bidentata Blume (Amaranthaceae). No activity was shown in the granulocyte phagocytosis test nor in the test of the potentiation of the cytotoxicity of cisplatin in human colon cancer cells. This is the first report of compounds 1, 2 and 3 isolated from Achyranthes species. Furthermore, the NMR data of 2 completed the partially published data.