At the leading edge of healing embryonic epithelium, cables of actin filaments appear to extend from cell to cell, forming a ring around the wound circumference. It has been hypothesized that this actin filament cable functions as a contractile 'purse string' to facilitate wound closure. We have observed this cable in large, circular healing epithelial wounds in corneas of adult mice. To elucid...

When a liquid drop falls from a fluid source with a slow flow rate, it remains attached to the source by an elongating liquid filament until the filament pinches off. For many fluids, this pinch-off occurs first near the end of the filament, where the filament joins to the liquid drop. For other fluids, the filament pinches off at one or more interior points. In this paper, we study the motion ...

OBJECTIVE The undergraduate medical curriculum has been overcrowded with core learning outcomes with no formal exposure to plastic surgery. The aim of this study was to compare medical students from two educational settings for the basic understanding, preferred learning method, and factors influencing a career choice in plastic surgery. DESIGN AND SETTING A prospective cohort study based on ...

OBJECTIVE To describe the geographic and temporal trends in cosmetic facial plastic surgery procedure costs and frequency during the last decade and to evaluate factors that may influence changes in the demand for cosmetic procedures. METHODS A survey sent to every (N = 1727) active fellow, member, or associate of the American Academy of Facial Plastic and Reconstructive Surgery assessing the...

Achieving a level of technical skill and confidence in surgical operations is the main goal of plastic surgical training. Operating rooms were accepted as the practical teaching venues of the traditional apprenticeship model. However, increased patient population, time, and ethical and legal considerations made preoperation room practical work a must for plastic surgical training. There are sev...

BACKGROUND Exposure to plastic surgery during medical school is limited. Most interested applicants form their perceptions of careers in this surgical specialty during elective rotations. OBJECTIVE To investigate the perceptions of Canadian medical students considering a career in plastic surgery. The results obtained were then compared with current Canadian plastic surgery residents' percept...

Rad51 and Rad54 proteins are important for the repair of double-stranded DNA (dsDNA) breaks by homologous recombination in eukaryotes. Rad51 assembles on single-stranded DNA (ssDNA) to form a helical nucleoprotein filament that performs homologous pairing with dsDNA; Rad54 stimulates this pairing substantially. Here, we demonstrate that Rad54 acts in concert with the mature Rad51-ssDNA filament...

RecA and its homologs help maintain genomic integrity through recombination. Using single-molecule fluorescence assays and hidden Markov modeling, we show the most direct evidence that a RecA filament grows and shrinks primarily one monomer at a time and only at the extremities. Both ends grow and shrink, contrary to expectation, but a higher binding rate at one end is responsible for direction...

RecA proteins form a long stable filament on a single-stranded DNA and catalyze strand exchange reaction. The stability of RecA filament changes dramatically with pH, yet its detailed mechanism is not known. Here, using a single molecule assay, we determined the binding and dissociation rates of RecA monomers at the filament ends at various pH. The pH-induced rate changes were moderate but occu...

This paper presents one efficient automatic detection method for filament disappearance. The method was applied to the Big Bear Solar Observatory (BBSO) fulldisk Hα images. The initial step is to detect the filament pixels by the threshold method. Then, using a regiongrowing method, we merge the adjacent detected pixels to obtain all filament areas. Based on these two steps, an automatic filame...