Sub-diffraction imaging on standard microscopes through photobleaching microscopy with non-linear processing.

Visualization of organelles and molecules at nanometer resolution is revolutionizing the biological sciences. However, such technology is still limited for many cell biologists. We present here a novel approach using photobleaching microscopy with non-linear processing (PiMP) for sub-diffraction imaging. Bleaching of fluorophores both within the single-molecule regime and beyond allows visualization of stochastic representations of sub-populations of fluorophores by imaging the same region over time. Our method is based on enhancing the probable positions of the fluorophores underlying the images. The random nature of the bleached fluorophores is assessed by calculating the deviation of the local actual bleached fluorescence intensity to the average bleach expectation as given by the overall decay of intensity. Subtracting measured from estimated decay images yields differential images. Non-linear enhancement of maxima in these diffraction-limited differential images approximates the positions of the underlying structure. Summing many such processed differential images yields a super-resolution PiMP image. PiMP allows multi-color, three-dimensional sub-diffraction imaging of cells and tissues using common fluorophores and can be implemented on standard wide-field or confocal systems.

Super Divya, an Interactive Digital Storytelling Instructional Comic Series to Sustain Facilitation Skills of Labor and Delivery Nurse Mentors in Bihar, India-A Pilot Study.

To improve the quality of intrapartum care in public health facilities of Bihar, India, a statewide quality improvement program was implemented. Nurses participated in simulation sessions to improve their clinical, teamwork, and communication skills. Nurse mentors, tasked with facilitating these sessions, received training in best practices. To support the mentors in the on-going facilitation of these trainings, we developed a digital, interactive, comic series starring "Super Divya", a simulation facilitation superhero. The objective of these modules was to reinforce key concepts of simulation facilitation in a less formal and more engaging way than traditional didactic lessons. This virtual platform offers the flexibility to watch modules frequently and at preferred times. This pilot study involved 205 simulation educators who were sent one module at a time. Shortly before sending the first module, nurses completed a baseline knowledge survey, followed by brief surveys after each module to assess change in knowledge. Significant improvements in knowledge were observed across individual scores from baseline to post-survey. A majority found Super Divya modules to be acceptable and feasible to use as a learning tool. However, a few abstract concepts in the modules were not well-understood, suggesting that more needs to be done to communicate their core meaning of these concepts.

HDAC6 is a Bruchpilot deacetylase that facilitates neurotransmitter release.

Presynaptic densities are specialized structures involved in synaptic vesicle tethering and neurotransmission; however, the mechanisms regulating their function remain understudied. In Drosophila, Bruchpilot is a major constituent of the presynaptic density that tethers vesicles. Here, we show that HDAC6 is necessary and sufficient for deacetylation of Bruchpilot. HDAC6 expression is also controlled by TDP-43, an RNA-binding protein deregulated in amyotrophic lateral sclerosis (ALS). Animals expressing TDP-43 harboring pathogenic mutations show increased HDAC6 expression, decreased Bruchpilot acetylation, larger vesicle-tethering sites, and increased neurotransmission, defects similar to those seen upon expression of HDAC6 and opposite to hdac6 null mutants. Consequently, reduced levels of HDAC6 or increased levels of ELP3, a Bruchpilot acetyltransferase, rescue the presynaptic density defects in TDP-43-expressing flies as well as the decreased adult locomotion. Our work identifies HDAC6 as a Bruchpilot deacetylase and indicates that regulating acetylation of a presynaptic release-site protein is critical for maintaining normal neurotransmission.

ELP3 controls active zone morphology by acetylating the ELKS family member Bruchpilot.

Elongator protein 3 (ELP3) acetylates histones in the nucleus but also plays a role in the cytoplasm. Here, we report that in Drosophila neurons, ELP3 is necessary and sufficient to acetylate the ELKS family member Bruchpilot, an integral component of the presynaptic density where neurotransmitters are released. We find that in elp3 mutants, presynaptic densities assemble normally, but they show morphological defects such that their cytoplasmic extensions cover a larger area, resulting in increased vesicle tethering as well as a more proficient neurotransmitter release. We propose a model where ELP3-dependent acetylation of Bruchpilot at synapses regulates the structure of individual presynaptic densities and neurotransmitter release efficiency.