Liquid marbles containing petroleum and their properties

Liquid marbles （non-stick droplets） containing crude petroleum are reported. Liquid marbles were ob- tained by use of fluorinated decyl polyhedral oligomeric silsequioxane （FD-POSS） powder. Marbles containing crude petroleum remained stable on a broad diversity of solid and liquid supports. The effective surface tension of marbles filled with petroleum was established. The mechanism of friction of the marbles is discussed. Actuation of liquid marbles containing crude petroleum with an electric field is presented.

Barter Trade Exchange to the Rescue of the Tourism and Travel Industry

South Africa＇s tourism and travel industry is a key sector in its economy as well as a significant job creator. The recent global economic turmoil is threatening the tourism industry; at the same time, global experts claim that tourism may be a key to overcoming economic difficulties and play a vital role in the green new deal. The purpose of the study is to introduce a new strategic option that has become increasingly attractive for troubled businesses-barter. While the study focuses on the advantages of this concept＇s recent refinements for South Africa＇s tourism and travel industry, its findings are also applicable to other countries. A survey of small and medium-sized enterprises （SME） from Europe and Turkey, as well as graduate students at an Israeli university, demonstrate the gap between familiarity with barter processes and their advantages and the actual scale of barter transactions in the supply chain, in order to enhance the economic performance of their tourism enterprises as well as the entire economy, providing evidence for the potential of adapting old proven concepts to the modem digital world.

Whole-Plant Live Imaging of Reactive Oxygen Species

Reactive oxygen species(ROS)are key regulators of numerous subcellular,cellular,and systemic signals.They function in plants as an integral part of many different hormonal,physiological,and developmental pathways,as well as play a critical role in defense and acclimation responses to different biotic and abiotic conditions.Although many ROS imaging techniques have been developed and utilized in plants,a wholeplant imaging platform for the dynamic detection of ROS in mature plants is lacking.Here we report a robust and straightforward method for the whole-plant live imaging of ROS in mature plants grown in soil.This new method could be used to study local and systemic ROS signals in different genetic variants,conduct phenotyping studies to identify new pathways for ROS signaling,monitor the stress level of different plants and mutants,and unravel novel routes of ROS integration into stress,growth regulation,and development in plants.We demonstrate the utility of this new method for studying systemic ROS signals in different A rabidopsis mutants and wound responses in cereals such as wheat and corn.

Protein kinase A inhibition induces EPAC-dependent acrosomal exocytosis in human sperm

To in teract with the egg, the spermatozo on must un dergo several biochemical and motility modifications in the female reproductive tract, collectively called capacitation. Only capacitated sperm can undergo acrosomal exocytosis, near or on the egg, a process that allows the sperm to penetrate and fertilize the egg. In the present study, we investigated the invoIvement of cyclic adenosine monophosphate (cAMP)-dependent processes on acrosomal exocytosis. Inhibition of protein kinase A (PKA) at the end of capacitation induced acrosomal exocytosis. This process is cAMP-dependent;however, the addition of relatively high concentration of the membrane-permeable 8-bromo-cAMP (8Br-cAMP, 0.1 mmol l^-1) analog induced significant inhibition of the acrosomal exocytosis. The induction of acrosomal exocytosis by PKA inhibition was significantly inhibited by an exchange protein directly activated by cAMP (EPAC) ESI09 inhibitor. The EPAC selective substrate activated AE at relatively low concentrations (0.02-0.1 μmol l^1), whereas higher concerttrations (>5 pmol l^-1) were inhibitory to the AE induced by PKA inhibition. Inhibition of PKA revealed about 50% increase in intracellular cAMP levels, conditions under which EPAC can be activated to induce the AE. Induction of AE by activating the actin severing?protein, gelsolin, which causes F-actin dispersion, was inhibited by the EPAC inhibitor. The AE induced by PKA inhibition was mediated by phospholipase C activity but not by the Ca^2+-channel, CatSper. Thus, inhibition of PKA at the end of the capacitation process induced EPAC/phospholipase C-dependent acrosomal exocytosis. EPAC mediates F-actin depolymerization an d/or activation of effectors down stream to F-actin breakdown that lead to acrosomal exocytosis.