Methodology of the biological risk classification of animal pathogens in Belgium

The biological hazards posed by micro-organisms have lead to their categorisation into risk groups and the elaboration of classification lists. Current classification systems rely on criteria defined by the World Health Organization, which cover the severity of the disease the micro-organism might cause, its ability to spread and the availability of prophylaxis or efficient treatment. Animal pathogens are classified according to the definitions of the World Organization of Animal Health, which also consider economic aspects of disease. In Europe, classification is often directly linked to containment measures. The Belgian classification system however, only considers the inherent characteristics of the micro-organism, not its use, making the risk classification independent of containment measures. A common classification list for human and animal pathogens has been developed in Belgium using as comprehensive an approach as possible. Evolution of scientific knowledge will demand regular updating of classification lists. This paper describes the Belgian risk classification system and the methodology that was used for its peer-reviewed revision (with a focus on animal pathogens)

Relational Contracts and Trust in a High-Tech Industry

We study how informal buyer-supplier relationships in the German automotive industry affect procurement. Using unique data from a survey focusing on these, we show that more trust, the belief that the trading partner acts to maintain the mutual relationship, is associated with both higher quality of the automotive parts and more competition among suppliers. Yet both effects hold only for parts involving unsophisticated technology, not when technology is sophisticated. We rationalize these findings within a relational contracting model that critically focuses on changes in the bargaining power, due to differences in the costs of switching suppliers

Blinking fluorescent probes for tubulin nanoscopy in living and fixed cells

Here we report a small molecule tubulin probe for single-molecule localization microscopy (SMLM), stimulated emission depletion (STED) microscopy and MINFLUX nanoscopy, which can be used in living and fixed cells. We explored a series of taxane derivatives containing spontaneously blinking far-red dye hydroxymethyl silicon–rhodamine (HMSiR) and found that the linker length profoundly affects the probe permeability and off-targeting in living cells. The best performing probe, HMSiR-tubulin, is composed of cabazitaxel and the 6′-regioisomer of HMSiR bridged by a C6 linker. Microtubule diameter of ≤50 nm was routinely measured in SMLM experiments on living and fixed cells. HMSiR-tubulin allows a complementary use of different nanoscopy techniques for investigating microtubule functions and developing imaging methods. For the first time, we resolved the inner microtubule diameter of 16 ± 5 nm by optical nanoscopy and thereby demonstrated the utility of a self-blinking dye for MINFLUX imaging

STRUCTURING OF ELECTRODE SURFACES WITH LIGAND-FREE NANOPARTICLES VIA ELECTROPHORETIC DEPOSITION- FUNDAMENTALS AND IN VIVO APPLICATIONS

Electrodes for neural stimulation and recording are highly relevant in modern medicine, e.g. for the treatment of movement disorders. As these electrodes have to be implanted directly into the patient´s brain, impaired biocompatibility as well as reduced performance due to increased impedance upon tissue contact are serious problems. Strategies to improve the efficiency of electrodes entail the implementation of defined nanoscopic structures to the electrode surface, which increase the surface area and improve the current flow by possible edge effects1. In this context electrophoretic deposition (EPD) of nanoparticles (NP) constitutes an efficient and feasible way for surface structuring as in contrast to e.g. ablative laser machining, electric field lines are naturally ordered perpendicular to the implant´s surface, so that electrophoretic deposition is well compatible to shaped implants and curved surfaces. In this work an EPD process for the structuring of Pt electrode surfaces with NP is systematically investigated. Reference NP from a modern synthesis route named pulsed laser ablation in liquids (PLAL)2 are utilized as they possess a high surface charge density in order to ease their movement in an electric field. The electrophoretic velocity of these NP was examined and found to be linearly-correlated with the electric field strength, while the slope is dictated by the NP´s surface charge density (zeta-potential).3, 4 On the other hand the PLAL-generated NP are, by design, completely free of organic ligand, which significantly affected their deposition in an EPD setup. It was found that the deposited mass linearly increased with process time, yielding a well scalable process, while on the other hand control experiments with ligands showed a saturation of the deposited mass due to electrochemical shielding of the surface by charged ligands.4 It was furthermore demonstrated that the EPD process with ligand-free NP could also be done in a continuous flow-through setup suitable for the parallel structuring of multiple electrodes.5 Interestingly, the deposition velocity was not size dependent as particle size distributions prior to and after EPD were identical.5 In consecutive experiments, the surface properties like coverage, oxidation, wettability6 and impedance of the electrode materials were evaluated and correlated with the EPD process parameters electric field strength, colloid concentration and deposition time. As a result a detailed map was obtained, which allows a defined tuning of Pt surface properties by Pt NP EPD. Finally, the impedance of electrodes coated with ligand-free Pt NP were evaluated in long term stimulation experiments with rats. The NP coating could stabilize the impedance of the electrodes in vivo, while it continuously increased in non-coated controls.7 Furthermore, the coated electrodes exhibited excellent biocompatibility similar to the controls7 while no significant NP desorption from the surface was found upon mechanical tear. 1. X. F. F. Wei and W. M. Grill, J. Neural Eng., 2005, 2, 139-147. 2. V. Amendola and M. Meneghetti, Phys. Chem. Chem. Phys., 2013, 15, 3027-3046. 3. A. Menendez-Manjon, J. Jakobi, K. Schwabe, J. K. Krauss and S. Barcikowski, J. Laser Micro Nanoeng., 2009, 4, 95-99. 4. C. Streich, S. Koenen, M. Lelle, K. Peneva and S. Barcikowski, Appl. Surf. Sci., 2015, 348, 92-99. 5. S. Koenen, R. Streubel, J. Jakobi, K. Schwabe, J. K. Krauss and S. Barcikowski, J. Electrochem. Soc., 2015, 162, D174-D179. 6. A. Heinemann, S. Koenen, K. Schwabe, C. Rehbock and S. Barcikowski, Key engineering materials, 2015, 654, 218-223. 7. S. D. Angelov, S. Koenen, J. Jakobi, H. E. Heissler, M. Alam, K. Schwabe, S. Barcikowski and J. K. Krauss, J. Nanobiotechnol., 2016, 14

Epigenetic predictors of all-cause mortality are associated with objective measures of neighborhood disadvantage in an urban population

BACKGROUND: Neighborhood characteristics are robust predictors of overall health and mortality risk for residents. Though there has been some investigation of the role that molecular indicators may play in mediating neighborhood exposures, there has been little effort to incorporate newly developed epigenetic biomarkers into our understanding of neighborhood characteristics and health outcomes. METHODS: Using 157 participants of the Detroit Neighborhood Health Study with detailed assessments of neighborhood characteristics and genome-wide DNA methylation profiling via the Illumina 450K methylation array, we assessed the relationship between objective neighborhood characteristics and a validated DNA methylation-based epigenetic mortality risk score (eMRS). Associations were adjusted for age, race, sex, ever smoking, ever alcohol usage, education, years spent in neighborhood, and employment. A secondary model additionally adjusted for personal neighborhood perception. We summarized 19 neighborhood quality indicators assessed for participants into 9 principal components which explained over 90% of the variance in the data and served as metrics of objective neighborhood quality exposures. RESULTS: Of the nine principal components utilized for this study, one was strongly associated with the eMRS (β = 0.15; 95% confidence interval = 0.06-0.24; P = 0.002). This principal component (PC7) was most strongly driven by the presence of abandoned cars, poor streets, and non-art graffiti. Models including both PC7 and individual indicators of neighborhood perception indicated that only PC7 and not neighborhood perception impacted the eMRS. When stratified on neighborhood indicators of greenspace, we observed a potentially protective effect of large mature trees as this feature substantially attenuated the observed association. CONCLUSION: Objective measures of neighborhood disadvantage are significantly associated with an epigenetic predictor of mortality risk, presenting a potential novel avenue by which neighborhood-level exposures may impact health. Associations were independent of an individual's perception of their neighborhood and attenuated by neighborhood greenspace features. More work should be done to determine molecular risk factors associated with neighborhoods, and potentially protective neighborhood features against adverse molecular effects

Posttraumatic stress disorder in the World Mental Health Surveys

Background: Traumatic events are common globally; however, comprehensive population-based cross-national data on the epidemiology of posttraumatic stress disorder (PTSD), the paradigmatic trauma-related mental disorder, are lacking. Methods: Data were analyzed from 26 population surveys in the World Health Organization World Mental Health Surveys. A total of 71 083 respondents ages 18+ participated. The Composite International Diagnostic Interview assessed exposure to traumatic events as well as 30-day, 12-month, and lifetime PTSD. Respondents were also assessed for treatment in the 12 months preceding the survey. Age of onset distributions were examined by country income level. Associations of PTSD were examined with country income, world region, and respondent demographics. Results: The cross-national lifetime prevalence of PTSD was 3.9% in the total sample and 5.6% among the trauma exposed. Half of respondents with PTSD reported persistent symptoms. Treatment seeking in high-income countries (53.5%) was roughly double that in low-lower middle income (22.8%) and upper-middle income (28.7%) countries. Social disadvantage, including younger age, female sex, being unmarried, being less educated, having lower household income, and being unemployed, was associated with increased risk of lifetime PTSD among the trauma exposed. Conclusions: PTSD is prevalent cross-nationally, with half of all global cases being persistent. Only half of those with severe PTSD report receiving any treatment and only a minority receive specialty mental health care. Striking disparities in PTSD treatment exist by country income level. Increasing access to effective treatment, especially in low- and middle-income countries, remains critical for reducing the population burden of PTSD