Progenitor cells in human myeloid leukemia : in vitro studies with PHA supplemented colony cultures

In the past decade, in vitro colony culture methods have been developed to study cellular proliferation and differentiation in hematopoiesis. The application of these culture methods in human myeloid leukemia revealed several disturbances in the hematopoietic stem cell campartment of these neeplastic diseases. It has been the general finding that acute leukemia cells lack the ability to produce colanies in the culture systems designed for the growth of progenitor cells in normal hematopoiesis. Our investigations intended to develop a colony culture system specific for leukemie progenitor cells and to characterize these cells in order to get some insight into pathophysiological events in leukernia

Experiments Participation Act:Know what works for whom

In recent years (1 October 2017 - 31 December 2019), six municipalities have conducted experiments in the assistance under the Temporary Decree Experiments Participation Act. The aim was to improve the implementation of the Participation Act through less control and coercion and more room for own direction, extra guidance and customization. The municipalities have asked the research institutes to scientifically investigate the results of these experiments. In order to be able to compare, the researchers used the same questionnaire in all six municipalities, the same outcome measures were used and the analysis model is also the same. However, because the experiments are designed at the municipal level, the differences between the municipalities and the experiments implemented are too big to really be able to combine the data. For a complete comparison and interpretation of the six experiments, we refer to the local final reports. The experiments, however, each individually, but above all in conjunction, provide relevant information for (future) policy that can fuel the discussion about the future of social security in the Netherlands. That is why we decided to write this joint semi-trailer to provide an initial insight into the broader outcomes on a selection of outcome measures. After a brief summary of the conclusions, we will discuss the various experiments and some important outcome measures in more detail

The Oxytricha trifallax Mitochondrial Genome

The Oxytricha trifallax mitochondrial genome contains the largest sequenced ciliate mitochondrial chromosome (∼70 kb) plus a ∼5-kb linear plasmid bearing mitochondrial telomeres. We identify two new ciliate split genes (rps3 and nad2) as well as four new mitochondrial genes (ribosomal small subunit protein genes: rps- 2, 7, 8, 10), previously undetected in ciliates due to their extreme divergence. The increased size of the Oxytricha mitochondrial genome relative to other ciliates is primarily a consequence of terminal expansions, rather than the retention of ancestral mitochondrial genes. Successive segmental duplications, visible in one of the two Oxytricha mitochondrial subterminal regions, appear to have contributed to the genome expansion. Consistent with pseudogene formation and decay, the subtermini possess shorter, more loosely packed open reading frames than the remainder of the genome. The mitochondrial plasmid shares a 251-bp region with 82% identity to the mitochondrial chromosome, suggesting that it most likely integrated into the chromosome at least once. This region on the chromosome is also close to the end of the most terminal member of a series of duplications, hinting at a possible association between the plasmid and the duplications. The presence of mitochondrial telomeres on the mitochondrial plasmid suggests that such plasmids may be a vehicle for lateral transfer of telomeric sequences between mitochondrial genomes. We conjecture that the extreme divergence observed in ciliate mitochondrial genomes may be due, in part, to repeated invasions by relatively error-prone DNA polymerase-bearing mobile elements

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

Experimenten Participatiewet: Weten wat werkt voor wie

In recent years (1 October 2017 - 31 December 2019), six municipalities have conducted experiments in the assistance under the Temporary Decree Experiments Participation Act. The aim was to improve the implementation of the Participation Act through less control and coercion and more room for own direction, extra guidance and customization. The municipalities have asked the research institutes to scientifically investigate the results of these experiments. In order to be able to compare, the researchers used the same questionnaire in all six municipalities, the same outcome measures were used and the analysis model is also the same. However, because the experiments are designed at the municipal level, the differences between the municipalities and the experiments implemented are too big to really be able to combine the data. For a complete comparison and interpretation of the six experiments, we refer to the local final reports. The experiments, however, each individually, but above all in conjunction, provide relevant information for (future) policy that can fuel the discussion about the future of social security in the Netherlands. That is why we decided to write this joint semi-trailer to provide an initial insight into the broader outcomes on a selection of outcome measures. After a brief summary of the conclusions, we will discuss the various experiments and some important outcome measures in more detail