Timing of hydrogen cyanamide application to grapevine buds

One major factor limiting the application of hydrogen cyanamide (H<sub>2</sub>CN<sub>2</sub>) is the difficulty in deciding when to apply, since mistiming may lead to bud and crop damage. Since an effective method for monitoring the developmental stage of dormant buds is not yet available, minimizing such a risk involves the regional evaluation of application timing. For three successive years, several H<sub>2</sub>CN<sub>2</sub> application dates were evaluated in cv. Perlette vineyards in the Jordan valley in Israel. The level and uniformity of bud break did not differ significantly among the application dates tested. However, major effects of the application date on cluster number, cluster size and yield were found. The sensitivity of the reproductive meristem to H<sub>2</sub>CN<sub>2</sub> is discussed

Compartmental Genomics in Living Cells Revealed by Single-Cell Nanobiopsy

The ability to study the molecular biology of living single cells in heterogeneous cell populations is essential for next generation analysis of cellular circuitry and function. Here, we developed a single-cell nanobiopsy platform based on scanning ion conductance microscopy (SICM) for continuous sampling of intracellular content from individual cells. The nanobiopsy platform uses electrowetting within a nanopipette to extract cellular material from living cells with minimal disruption of the cellular milieu. We demonstrate the subcellular resolution of the nanobiopsy platform by isolating small subpopulations of mitochondria from single living cells, and quantify mutant mitochondrial genomes in those single cells with high throughput sequencing technology. These findings may provide the foundation for dynamic subcellular genomic analysis

Dynamic Control of Nanoprecipitation in a Nanopipette

Studying the earliest stages of precipitation at the nanoscale is technically challenging but quite valuable as such phenomena reflect important processes such as crystallization and biomineralization. Using a quartz nanopipette as a nanoreactor, we induced precipitation of an insoluble salt to generate oscillating current blockades. The reversible process can be used to measure both kinetics of precipitation and relative size of the resulting nanoparticles. Counter ions for the highly water-insoluble salt zinc phosphate were separated by the pore of a nanopipette and a potential applied to cause ion migration to the interface. By analyzing the kinetics of pore blockage, two distinct mechanisms were identified: a slower process due to precipitation from solution, and a faster process attributed to voltage-driven migration of a trapped precipitate. We discuss the potential of these techniques in studying precipitation dynamics, trapping particles within a nanoreactor, and electrical sensors based on nanoprecipitation