High efficiency protoplast isolation from in vitro cultures and hairy roots of Maesa lanceolata

In vitro cultures of the medicinal plant Maesa lanceolata were established to enable the cultivation ofplant material for the production of protoplasts. Callus cultures were initiated using leaves collectedfrom shoot cultures and the root tips from hairy root cultures obtained upon Agrobacterium rhizogenestransformation. For the isolation of protoplasts, the different explant material of M. lanceolata wasexposed to an enzyme mixture consisting of 1.5% cellulase, 0.5% macerozyme R-10 and 0.5 M mannitol.About 6 x 106 protoplasts g-1 fresh weight were obtained from leaf material and 5 x 105 protoplasts g-1fresh weight from callus. To obtain high amounts of hairy root protoplasts, the cultures were pretreatedwith the auxin indole-3-butyric acid (IBA) that stimulated the formation of novel root tips. Usingthe dissected root tips as starting material, 8 x 105 protoplasts g-1 fresh weight were obtained perpreparation. The protoplast isolation method will enable further studies on the transformation andfusion of protoplasts from M. lanceolata.Key words: Maesa lanceolata, in vitro conservation, tissue culture, protoplast isolation

Решение задач многокритериальной оптимизации с использованием генетических алгоритмов

В данной работе представлены существующие подходы и методы применения генетических алгоритмов для решения задач многокритериальной оптимизации. Предложены математическая модель и алгоритмы решения многокритериальной задачи выбора стратегии развития производственной системы. Представлены также результаты применения для решения этой задачи метода присваивания рангов Голдберга и гибридного генетического алгоритма.Представлені існуючи підходи і методи застосування генетичних алгоритмів для рішення залач багатокритеріальної оптимізації. Запропоновано математичну модель і алгоритми розв’язку багатокритеріальної задачі вибору стратегії розвитку виробничої системи. Навелено результати застосування для розв’язку цієї задачі методу надання рангів Голдберга і гібридного генетичного алгоритму.This paper describes the existing approaches and methods of application of genetic algorithms for multiobjective optimization. The mathematical model and algorithms for solving multiobjective optimization problems in management have been proposed. Experimental results of application of the hybrid genetic algorithms for solving combinatorial optimization problems have been presented

Vascular uptake of rehydration fluids in hypohydrated men at rest and exercise

The purpose of this study was to formulate and to evaluate rehydration drinks, which would restore total body water and plasma volume (PV), for astronauts to consume before and during extravehicular activity, a few hours before reentry, and immediately after landing. In the first experiment (rest, sitting), five healthy men (23-41 yr), previously dehydrated for 24 hr., drank six (1a, 2, 4, 5, 6, 7) fluid formulations (one each at weekly intervals) and then sat for 70 min. Pre-test PV were measured with Evans blue dye and changes in PV were calculated with the hematocrit-hemoglobin transformation equation. This rest experiment simulated hypohydrated astronauts preparing for reentry. The second experiment (exercise, supine) followed the same protocol except four healthy men (30-46 yr) worked for 70 min. in the supine position on a cycle ergometer at a mean load of 71+/-1 percent of their peak aerobic work capacity. This exercise experiment simulated conditions for astronauts with reduced total body water engaging in extravehicular activity

The industrialization of ablation: a highly standardized and reproducible workflow for radiofrequency ablation of atrial fibrillation

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Production of Diploid Male Gametes in Arabidopsis by Cold-Induced Destabilization of Postmeiotic Radial Microtubule Arrays

Whole-genome duplication through the formation of diploid gametes is a major route for polyploidization, speciation, and diversification in plants. The prevalence of polyploids in adverse climates led us to hypothesize that abiotic stress conditions can induce or stimulate diploid gamete production. In this study, we show that short periods of cold stress induce the production of diploid and polyploid pollen in Arabidopsis (Arabidopsis thaliana). Using a combination of cytological and genetic analyses, we demonstrate that cold stress alters the formation of radial microtubule arrays at telophase II and consequently leads to defects in postmeiotic cytokinesis and cell wall formation. As a result, cold-stressed male meiosis generates triads, dyads, and monads that contain binuclear and polynuclear microspores. Fusion of nuclei in binuclear and polynuclear microspores occurs spontaneously before pollen mitosis I and eventually leads to the formation of diploid and polyploid pollen grains. Using segregation analyses, we also found that the majority of cold-induced dyads and triads are genetically equivalent to a second division restitution and produce diploid gametes that are highly homozygous. In a broader perspective, these findings offer insights into the fundamental mechanisms that regulate male gametogenesis in plants and demonstrate that their sensitivity to environmental stress has evolutionary significance and agronomic relevance in terms of polyploidization

Charge catastrophe and dielectric breakdown during exposure of organic thin films to low-energy electron radiation

Quantum Matter and Optic

Nanoscale measurements of unoccupied band dispersion in few-layer graphene

The properties of any material are fundamentally determined by its electronic band structure. Each band represents a series of allowed states inside a material, relating electron energy and momentum. The occupied bands, that is, the filled electron states below the Fermi level, can be routinely measured. However, it is remarkably difficult to characterize the empty part of the band structure experimentally. Here, we present direct measurements of unoccupied bands of monolayer, bilayer and trilayer graphene. To obtain these, we introduce a technique based on low-energy electron microscopy. It relies on the dependence of the electron reflectivity on incidence angle and energy and has a spatial resolution ∼10 nm. The method can be easily applied to other nanomaterials such as van der Waals structures that are available in small crystals only.Quantum Matter and Optic

Packing and covering immersion models of planar subcubic graphs

A graph $H$ is an immersion of a graph $G$ if $H$ can be obtained by some sugraph $G$ after lifting incident edges. We prove that there is a polynomial function $f:\Bbb{N}\times\Bbb{N}\rightarrow\Bbb{N}$, such that if $H$ is a connected planar subcubic graph on $h>0$ edges, $G$ is a graph, and $k$ is a non-negative integer, then either $G$ contains $k$ vertex/edge-disjoint subgraphs, each containing $H$ as an immersion, or $G$ contains a set $F$ of $f(k,h)$ vertices/edges such that $G\setminus F$ does not contain $H$ as an immersion