Focus on People and the Science Will Follow: Motivating Forces for Professional Movement in Stem Cell Research.

The migration of researchers across geographic borders, or "brain drain" as it is commonly called, remains an important issue for governments around the world as loss or gain of highly qualified personnel in research can have substantial social, economic and political consequences. In the present study we seek to examine the forces that drive international professional migration of stem cell (SC) researchers, for which variation of SC policy in different jurisdictions has previously been implicated as a driving force. Structured interviews were carried out with a purposive sample of SC researchers in the professoriate who had made international moves after postdoctoral work between the years 2001-2014, or were actively anticipating a future move. Participants were asked to rank motivators of international movement on a 5-point Likert scale and prompted to elaborate on their answers. The results suggest that career considerations, availability of research funding, and personal considerations are of high importance to the participants when considering an international move, while the permissiveness or restrictiveness SC research policy is of comparably lower importance. Participants also expressed that international movements are beneficial to scientific careers overall. The findings have important implications for policy and strategies to attract and retain members of the SC research community.

High titer ethanol production from simultaneous enzymatic saccharification and fermentation of aspen at high solids: a comparison between SPORL and dilute acid pretreatments.

Native aspen (Populus tremuloides) was pretreated using sulfuric acid and sodium bisulfite (SPORL) and dilute sulfuric acid alone (DA). Simultaneous enzymatic saccharification and fermentation (SSF) was conducted at 18% solids using commercial enzymes with cellulase loadings ranging from 6 to 15 FPU/g glucan and Saccharomyces cerevisiae Y5. Compared with DA pretreatment, the SPORL pretreatment reduced the energy required for wood chip size-reduction, and reduced mixing energy of the resultant substrate for solid liquefaction. Approximately 60% more ethanol was produced from the solid SPORL substrate (211 L/ton wood at 59 g/L with SSF efficiency of 76%) than from the solid DA substrate (133 L/ton wood at 35 g/L with SSF efficiency 47%) at a cellulase loading of 10 FPU/g glucan after 120 h. When the cellulase loading was increased to 15 FPU/g glucan on the DA substrate, the ethanol yield still remained lower than the SPORL substrate at 10 FPU/g glucan.

Rheology of dilute acid hydrolyzed corn stover at high solids concentration.

The rheological properties of acid hydrolyzed corn stover at high solids concentration (20-35 wt.%) were investigated using torque rheometry. These materials are yield stress fluids whose rheological properties can be well represented by the Bingham model. Yield stresses increase with increasing solids concentration and decrease with increasing hydrolysis reaction temperature, acid concentration, and rheometer temperature. Plastic viscosities increase with increasing solids concentration and tend to decrease with increasing reaction temperature and acid concentration. The solids concentration dependence of the yield stress is consistent with that reported for other fibrous systems. The changes in yield stress with reaction conditions are consistent with observed changes in particle size. This study illustrates that torque rheometry can be used effectively to measure rheological properties of concentrated biomass.

Cavitation in ciliary body melanoma.

PURPOSE: To report a case of a cystic ciliary body melanoma that appeared clinically as a solid mass. METHODS: A 59-year-old woman underwent an iridocyclectomy for removal of a ciliary body melanoma in the right eye. The tumor was analyzed histopathologically for acid mucopolysaccharide production. RESULTS: Histopathology identified a ciliary body melanoma with cystic cavities. Contents of the cystic spaces did not stain with alcian blue. Histologic findings suggested exudation, cavitary necrosis, or both rather than acid mucopolysaccharide production as pathogenic factors for cyst formation. CONCLUSION: Cystic cavities can develop in a solid, malignant tumor and therefore should not be considered signs of a benign lesion.

Evaluation of a DNA probe assay (Gen-Probe PACE 2) as the test of cure for Neisseria gonorrhoeae genital infections.

A DNA probe (Gen-Probe PACE 2) detects portions of viable and nonviable organisms, and test results could remain positive after effective treatment of genital Neisseria gonorrhoeae infection. Twenty patients underwent test-of-cure studies 6 to 11 days after standard treatment for gonorrhea; in each case the DNA probe finding was negative. The Gen-Probe PACE 2 probe is reliable for test-of-cure study as early as 6 days after treatment.