Objective comparison of particle tracking methods

Particle tracking is of key importance for quantitative analysis of intracellular dynamic processes from time-lapse microscopy image data. Because manually detecting and following large numbers of individual particles is not feasible, automated computational methods have been developed for these tasks by many groups. Aiming to perform an objective comparison of methods, we gathered the community and organized an open competition in which participating teams applied their own methods independently to a commonly defined data set including diverse scenarios. Performance was assessed using commonly defined measures. Although no single method performed best across all scenarios, the results revealed clear differences between the various approaches, leading to notable practical conclusions for users and developers

In-situ yeast fermentation to enhance bioconversion of coconut endosperm waste into larval biomass of hermetia illucens: statistical augmentation of larval lipid content

The aim of this study was to spur the lipid accumulation by larvae of Hermetia illucens or black soldier fly (BSFL) via feeding with yeast fermented medium. The Saccharomyces cerevisiae, a single cell yeast, was introduced at different concentrations (0.02, 0.1, 0.5, 1.0, 2.5 wt %) to execute an in-situ fermentation on coconut endosperm waste. The rearing of BSFL was started simultaneously and the rearing was stopped once the BSFL reached the fifth instar. With the increasing of yeast concentration, the rearing duration of BSFL was shortened from 15.5 to 13.5 days. Moreover, it was found that at 0.5 to 1.0 wt % yeast concentration, the lipid yield and lipid productivity of BSFL were statistically enhanced to their highest peaks, namely, at 49.4% and 0.53 g/day, respectively. With regard to biodiesel composition, BSFL-derived biodiesel contained mainly C12:0, C14:0, C16:0 and C18:1. The higher amount of saturated fatty acids could strengthen the oxidative stability biodiesel produced as compared with non-edible oils or microalgal lipid. At last, the addition of yeast was also found to improve the waste reduction index of coconut endosperm waste (CEW) from 0.31 to 0.40 g/day, heralding the capability of BSFL to valorize organic waste via bioconversion into its biomass to serve as a feedstock for biodiesel production

Down-Regulation of ZnT8 Expression in INS-1 Rat Pancreatic Beta Cells Reduces Insulin Content and Glucose-Inducible Insulin Secretion

The SLC30A8 gene codes for a pancreatic beta-cell-expressed zinc transporter, ZnT8. A polymorphism in the SLC30A8 gene is associated with susceptibility to type 2 diabetes, although the molecular mechanism through which this phenotype is manifest is incompletely understood. Such polymorphisms may exert their effect via impacting expression level of the gene product. We used an shRNA-mediated approach to reproducibly downregulate ZnT8 mRNA expression by >90% in the INS-1 pancreatic beta cell line. The ZnT8-downregulated cells exhibited diminished uptake of exogenous zinc, as determined using the zinc-sensitive reporter dye, zinquin. ZnT8-downregulated cells showed reduced insulin content and decreased insulin secretion (expressed as percent of total insulin content) in response to hyperglycemic stimulus, as determined by insulin immunoassay. ZnT8-depleted cells also showed fewer dense-core vesicles via electron microscopy. These data indicate that reduced ZnT8 expression in cultured pancreatic beta cells gives rise to a reduced insulin response to hyperglycemia. In addition, although we provide no direct evidence, these data suggest that an SLC30A8 expression-level polymorphism could affect insulin secretion and the glycemic response in vivo

Microalgae Lipid Characterization

To meet the growing interest of utilizing microalgae biomass in the production of biofuels and nutraceutical and pharmaceutical lipids, we need suitable analytical methods and a comprehensive database for their lipid components. The objective of the present work was to demonstrate methodology and provide data on fatty acid composition, lipid class content and composition, characteristics of the unsaponifiables, and type of chlorophylls of five microalgae. Microalgae lipids were fractionated into TAG, FFA, and polar lipids using TLC, and the composition of fatty acids in total lipids and in each lipid class, hydrocarbons, and sterols were determined by GC-MS. Glyco- and phospholipids were profiled by LC/ESI-MS. Chlorophylls and their related metabolites were qualified by LC/APCI-MS. The melting and crystallization profiles of microalgae total lipids and their esters were analyzed by DSC to evaluate their potential biofuel applications. Significant differences and complexities of lipid composition among the algae tested were observed. The compositional information is valuable for strain selection, downstream biomass fractionation, and utilization

Inhibition of cell motility by troglitazone in human ovarian carcinoma cell line

<p>Abstract</p> <p>Background</p> <p>Troglitazone (TGZ) is a potential anticancer agent. Little is known about the effect of this agent on cancer cell migration.</p> <p>Methods</p> <p>Human ovarian carcinoma cell line, ES-2 cells were treated with various concentrations of TGZ. Cell migration was evaluated by wound-healing and Boyden chamber transwell experiments. PPARγ expression was blocked by PPARγ small interfering RNA. The effects of TGZ on phosphorylation of FAK, PTEN, Akt were assessed by immunoblotting using phospho-specific antibodies. The cellular distribution of paxillin, vinculin, stress fiber and PTEN was assessed by immunocytochemistry.</p> <p>Results</p> <p>TGZ dose- and time-dependently impaired cell migration through a PPARγ independent manner. TGZ treatment impaired cell spreading, stress fiber formation, tyrosine phosphorylation of focal adhesion kinase (FAK), and focal adhesion assembly in cells grown on fibronectin substratum. TGZ also dose- and time-dependently suppressed FAK autophosphorylation and phosphorylation of the C-terminal of PTEN (a phosphatase). At concentration higher than 10 μM, TGZ caused accumulation of PTEN in plasma membrane, a sign of PTEN activation.</p> <p>Conclusion</p> <p>These results indicate that TGZ can suppress cultured ES-2 cells migration. Our data suggest that the anti-migration potential of TGZ involves in regulations of FAK and PTEN activity.</p

Automatic Morphological Subtyping Reveals New Roles of Caspases in Mitochondrial Dynamics

Morphological dynamics of mitochondria is associated with key cellular processes related to aging and neuronal degenerative diseases, but the lack of standard quantification of mitochondrial morphology impedes systematic investigation. This paper presents an automated system for the quantification and classification of mitochondrial morphology. We discovered six morphological subtypes of mitochondria for objective quantification of mitochondrial morphology. These six subtypes are small globules, swollen globules, straight tubules, twisted tubules, branched tubules and loops. The subtyping was derived by applying consensus clustering to a huge collection of more than 200 thousand mitochondrial images extracted from 1422 micrographs of Chinese hamster ovary (CHO) cells treated with different drugs, and was validated by evidence of functional similarity reported in the literature. Quantitative statistics of subtype compositions in cells is useful for correlating drug response and mitochondrial dynamics. Combining the quantitative results with our biochemical studies about the effects of squamocin on CHO cells reveals new roles of Caspases in the regulatory mechanisms of mitochondrial dynamics. This system is not only of value to the mitochondrial field, but also applicable to the investigation of other subcellular organelle morphology

Doing race: how secondary school pupils in mainly white schools construct 'race'

This article examines how ‘race’ impacts upon the lives of young people who attend secondary schools in a mainly white British area of the United Kingdom. Schools Stand up 2 Racism (SSu2R), a Big Lottery research project, brought together a community partner – the Cheshire, Halton and Warrington Race and Equality Centre – and a team from Manchester Metropolitan University to investigate racism in Cheshire secondary schools. In an area where the population is over 93% ‘white British’, the sense that ‘there's nothing to be racist about in this school’ (Year 8 pupil) was found to be common. The three-year SSu2R study used a multimethod approach to study how students ‘do race’ in these schools, where the silent advocacy of a ‘colour-blind’ approach is promulgated through the popular rhetoric of ‘everyone is unique’ and ‘we should treat everyone the same’. Race is tackled only tangentially through the curriculum, accompanied by silences that close down discussion. Perhaps unsurprisingly given this context, forms of everyday racism are endemic and yet mostly unnoticed by staff or students. The article uses Bourdieu's concepts of ‘doxa’ and ‘the game’ to examine the nature of this silence