Effects of Behavior-Based Driver Feedback Systems on Commercial Long Haul Operator Safety

There are large economic and societal costs to commercial motor vehicle crashes. A majority of crashes are precipitated due to driver-related factors. Behavior-based systems that influence drivers with feedback from safety managers can help reduce driver-related risk factors. These systems harness the experience and knowledge of managers along with advanced driver telematics that monitor and record driver behaviors to positively influence driver safety. Safety solutions that focus on modifying driver behaviors thus hold promise for improving the safety record of commercial trucking. In this study, one such feedback system was examined by analyzing data from a commercial trucking fleet, treating the system deployment as a natural experiment. This made it possible, without experimental intervention, to compare drivers before and after system introduction, and to compare drivers that were subject to this system with those that drove with no supervisor feedback. Adverse event data were obtained for drivers in the fleet and weekly event rates were calculated taking into account driving exposure (in miles). Results show that drivers improved after receiving safety feedback and significantly more so than drivers that did not receive feedback

Long-term effects of sulfidized silver nanoparticles in sewage sludge on soil microflora

The use of silver nanoparticles (AgNPs) in consumer products such as textiles leads to their discharge into wastewater and consequently to a transfer of the AgNPs to soil ecosystems via biosolids used as fertilizer. In urban wastewater systems (e.g., sewer, wastewater treatment plant [WWTP], anaerobic digesters) AgNPs are efficiently converted into sparingly soluble silver sulfides (Ag2S), mitigating the toxicity of the AgNPs. However, long-term studies on the bioavailability and effects of sulfidized AgNPs on soil microorganisms are lacking. Thus we investigated the bioavailability and long-term effects of AgNPs (spiked in a laboratory WWTP) on soil microorganisms. Before mixing the biosolids into soil, the sludges were either anaerobically digested or directly dewatered. The effects on the ammonium oxidation process were investigated over 140 d. Transmission electron microscopy (TEM) suggested an almost complete sulfidation of the AgNPs analyzed in all biosolid samples and in soil, with Ag2S predominantly detected in long-term incubation experiments. However, despite the sulfidation of the AgNPs, soil ammonium oxidation was significantly inhibited, and the degree of inhibition was independent of the sludge treatment. The results revealed that AgNPs sulfidized under environmentally relevant conditions were still bioavailable to soil microorganisms. Consequently, Ag2S may exhibit toxic effects over the long term rather than the short term

Humanized mouse model: Hematopoietic stemcell transplantation and tracking using short tandem repeat technology

Introduction Models of mice carrying a human immune system, so-called humanized mice, are used increasingly as preclinical models to bridge the gap between model organisms and human beings. Challenges of the humanized mouse model include finding suitable sources for human hematopoietic stem cells (HSC) and reaching sufficient engraftment of these cells in immunocompromised mice. Methods In this study, we compared the use of CD34(+)HSC from cord blood (CB) vs HSC from adult mobilized peripheral blood. Furthermore, we developed a simple and highly specific test for donor identification in humanized mice by applying the detection method of short tandem repeats (STR). Results It was found that, in vitro, CB-derived and adult HSC show comparable purity, viability, and differentiation potential in colony-forming unit assays. However, in vivo, CB-derived HSC engrafted to a significantly higher extent in NOD.Cg-Prkdc(scid)IL2r gamma(tm1Wjl)/SzJ (NSG) mice than adult HSC. Increasing the cell dose of adult HSC or using fresh cells without cryopreservation did not improve the engraftment rate. Interestingly, when using adult HSC, the percentage of human cells in the bone marrow was significantly higher than that in the peripheral blood. Using the STR-based test, we were able to identify and distinguish human cells from different donors in humanized mice and in a humanized allogeneic transplantation model. Conclusion From these findings, we conclude that adult mobilized HSC are less suitable for generating a humanized immune system in mice than CB-derived cells

Humanized mouse model: Hematopoietic stemcell transplantation and tracking using short tandem repeat technology

Introduction Models of mice carrying a human immune system, so-called humanized mice, are used increasingly as preclinical models to bridge the gap between model organisms and human beings. Challenges of the humanized mouse model include finding suitable sources for human hematopoietic stem cells (HSC) and reaching sufficient engraftment of these cells in immunocompromised mice. Methods In this study, we compared the use of CD34(+)HSC from cord blood (CB) vs HSC from adult mobilized peripheral blood. Furthermore, we developed a simple and highly specific test for donor identification in humanized mice by applying the detection method of short tandem repeats (STR). Results It was found that, in vitro, CB-derived and adult HSC show comparable purity, viability, and differentiation potential in colony-forming unit assays. However, in vivo, CB-derived HSC engrafted to a significantly higher extent in NOD.Cg-Prkdc(scid)IL2r gamma(tm1Wjl)/SzJ (NSG) mice than adult HSC. Increasing the cell dose of adult HSC or using fresh cells without cryopreservation did not improve the engraftment rate. Interestingly, when using adult HSC, the percentage of human cells in the bone marrow was significantly higher than that in the peripheral blood. Using the STR-based test, we were able to identify and distinguish human cells from different donors in humanized mice and in a humanized allogeneic transplantation model. Conclusion From these findings, we conclude that adult mobilized HSC are less suitable for generating a humanized immune system in mice than CB-derived cells

Comparison of hematopoietic stem cells derived from fresh and cryopreserved whole cord blood in the generation of humanized mice.

To study the function and maturation of the human hematopoietic and immune system without endangering individuals, translational human-like animal models are needed. We compare the efficiency of CD34(+) stem cells isolated from cryopreserved cord blood from a blood bank (CCB) and fresh cord blood (FCB) in generating highly engrafted humanized mice in NOD-SCID IL2Rγ(null) (NSG) rodents. Interestingly, the isolation of CD34(+) cells from CCB results in a lower yield and purity compared to FCB. The purity of CD34(+) isolation from CCB decreases with an increasing number of mononuclear cells that is not evident in FCB. Despite the lower yield and purity of CD34(+) stem cell isolation from CCB compared to FCB, the overall reconstitution with human immune cells (CD45) and the differentiation of its subpopulations e.g., B cells, T cells or monocytes is comparable between both sources. In addition, independent of the cord blood origin, human B cells are able to produce high amounts of human IgM antibodies and human T cells are able to proliferate after stimulation with anti-CD3 antibodies. Nevertheless, T cells generated from FCB showed increased response to restimulation with anti-CD3. Our study reveals that the application of CCB samples for the engraftment of humanized mice does not result in less engraftment or a loss of differentiation and function of its subpopulations. Therefore, CCB is a reasonable alternative to FCB and allows the selection of specific genotypes (or any other criteria), which allows scientists to be independent from the daily changing birth rate

Humanized mice generated functional human B and T cells.

<p>(A, B) The concentration of human IgM and IgG in the plasma of humanized mice was determined by cytometric bead array 19–21 weeks after intrahepatic transplantation of CD34⁺ cells from CCB or FCB. (C) Spleen cells were labeled with CFDA-SE and cultured for 5 d in the presence (dark gray bars) or absence (gray bars) of an anti-CD3 antibody. Proliferation of cells was determined by flow cytometry. Box plots depict median and 5–95% percentile. Level of significance is given.</p

The purity of CD34⁺ separation decreases with an increasing number of MNC in CCB.

<p>MNC were isolated from CCB or FCB by washing with DNAse buffer or Ficoll-paque density gradient centrifugation as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0046772#s2" target="_blank">materials and methods</a>. CD34⁺ stem cells were isolated from MNC by a positive magnetic separation of CD34⁺ cells and the purity was determined by flow cytometry. The correlations between the number of MNC and the purity of the CD34⁺ separation for CCB (A; no significance) and FCB (B) are shown. Correlations were evaluated using GraphPad Prism software and the Spearman rank correlation coefficient method.</p

Differences and parallelism in the purity of CD34⁺ -cell-purifications from FCB and blood bank CCB.

<p>(A) MNC were isolated from FCB and blood bank CCB by washing with DNAse buffer or Ficoll-paque density gradient centrifugation as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0046772#s2" target="_blank">materials and methods</a>. CD34⁺ stem cells were isolated from MNC by a positive magnetic separation of CD34+ cells and the purity was analyzed by flow cytometry. Dot plots depict the percentage of CD34⁺ cells of one representative separation from CCB and FCB (lower panels). The quadrant was set according to the isotype controls (upper panels). (B) The bar chart depicts the percentage of CD34⁺ cells after isolation of CD34⁺ cells from 26 CCB and 37 FCB samples. Box plots depict median and 5–95% percentile. Level of significance is given. n. s. = no significance.</p

Differences and parallelism in the yield of CD34⁺ -cell-purifications from FCB and blood bank CCB.

<p>(A) MNC were isolated from CCB or FCB by washing with DNAse buffer or Ficoll-paque density gradient centrifugation as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0046772#s2" target="_blank">materials and methods</a>. The total number of MNC per 10 ml cord blood is shown. (B) CD34⁺ cells were isolated from MNC by a positive magnetic separation of CD34⁺ cells. The number of CD34⁺ cells per 10 ml cord blood is shown.</p