Mass calibration and Relative Humidity compensation requirements for optical portable particulate matter monitors : the IMPASHS (Impact of smoke-free policies in EU Member States) WP2 preliminary results

Better knowledge of particulate matter (PM) concentrations needs portable, reliable, user friendly, low cost, real time mass analyzers of PM2.5 and PM10. Optical Particle Counters (OPC) measuring mass have manufacturer calibration specific gravity “K” factor referred to polystyrene latex particles which are completely different than those of the real world, therefore they require specific calibrations. Measurements are also subject to Relative Humidity (RH) heavy interference.Fundação para a Ciência e a Tecnologia (FCT

SmokeHaz: systematic reviews and meta-analyses of the effects of smoking on respiratory health

Background: Smoking tobacco increases the risk of respiratory disease in adults and children, but communicating the magnitude of these effects in a scientific manner that is accessible and usable by public and policymakers presents a challenge. We have therefore summarised scientific data on the impact of smoking on respiratory diseases to provide the content for a unique resource, SmokeHaz. Methods: We conducted systematic reviews and meta-analyses of longitudinal studies (published to 2013) identified from electronic databases, grey literature, and experts. Random effect meta-analyses were used to pool the findings. Results: We included 216 papers. Among adult smokers, we confirmed substantially increased risks of lung cancer (Risk Ratio (RR) 10.92, 95% CI 8.28-14.40; 34 studies), COPD (RR 4.01, 95% CI 3.18-5.05; 22 studies) and asthma (RR 1.61, 95% CI 1.07-2.42; 8 studies). Exposure to passive smoke significantly increased the risk of lung cancer in adult non-smokers; and increased the risks of asthma, wheeze, lower respiratory infections, and reduced lung function in children. Smoking significantly increased the risk of sleep apnoea, and asthma exacerbations in adult and pregnant populations; and active and passive smoking increased the risk of tuberculosis. Conclusions: These findings have been translated into easily digestible content and published on the SmokeHaz website (www.smokehaz.eu)

Unique microglia recovery population revealed by single-cell RNAseq following neurodegeneration

Abstract Microglia are brain immune cells that constantly survey their environment to maintain homeostasis. Enhanced microglial reactivity and proliferation are typical hallmarks of neurodegenerative diseases. Whether specific disease-linked microglial subsets exist during the entire course of neurodegeneration, including the recovery phase, is currently unclear. Taking a single-cell RNA-sequencing approach in a susceptibility gene-free model of nerve injury, we identified a microglial subpopulation that upon acute neurodegeneration shares a conserved gene regulatory profile compared to previously reported chronic and destructive neurodegeneration transgenic mouse models. Our data also revealed rapid shifts in gene regulation that defined microglial subsets at peak and resolution of neurodegeneration. Finally, our discovery of a unique transient microglial subpopulation at the onset of recovery may provide novel targets for modulating microglia-mediated restoration of brain health

Following development of belowground sugar beet traits with MagneticResonance Imaging (MRI) and Positron Emission Tomography (PET)

Both structural and functional properties of belowground organs are critical for development and yield of plants, but compared to the shoot, these are much more difficult to observe due to soil opacity. With the yield relevant organ situated belowground sugar beet is even more affected by this difficulty than other crops. The beet shows a complex tissue structure with several cambia active in parallel that are tightly linked with its function in storing photoassimilates in the form of sucrose. Additionally the development of traits during the growth period such as morphology, anatomy, sugar content and photoassimilate allocation within the beet cannot be addressed with destructive sampling techniques. Nevertheless, these are key factors for sugar yield. Here, we show application of Magnetic Resonance imaging (MRI) to investigate on a routine basis the development of structural traits such as beet diameter, biomass and width of cambia rings in plants potted in an agricultural soil mixed with sand. Functional traits such as sugar content and petiole xylem flow velocity were investigated regularly during the same time periods of up to four months. Individual tissues could be identified using MRI T2-maps with the aid of light microscopy at final harvest allowing the study of the development of tissues such as cambia, phloem or storage parenchyma in the cambial rings. Different Genotypes, commercial varieties as well as such of contrasting sugar content from KWS material were compared. For studying photoassimilate allocation we applied Positron Emission Tomography (PET) using carbon isotope 11C as a tracer. We show 3D PET maps of Radioactivity in the beet tracing the routes of photoassimilate translocation from the leaves into the beet. This revealed translocation pattern and their dynamics during three month of growth. These data are further used for fitting simple transport models, to estimate assimilate transport velocity and assimilate storage along the transport pathway in specific sections of the beet. Together these approaches have the potential to yield unique insights into sugar beet belowground development. Thereby they will shed new light on processes like sugar storage or stress responses in the beet

Phloem Import and Storage Metabolism Are Highly Coordinated by the Low Oxygen Concentrations within Developing Wheat Seeds

We studied the influence of the internal oxygen concentration in seeds of wheat (Triticum aestivum) on storage metabolism and its relation to phloem import of nutrients. Wheat seeds that were developing at ambient oxygen (21%) were found to be hypoxic (2.1%). Altering the oxygen supply by decreasing or increasing the external oxygen concentration induced parallel changes in the internal oxygen tension. However, the decrease in internal concentration was proportionally less than the reduction in external oxygen. This indicates that decreasing the oxygen supply induces short-term adaptive responses to reduce oxygen consumption of the seeds. When external oxygen was decreased to 8%, internal oxygen decreased to approximately 0.5% leading to a decrease in energy production via respiration. Conversely, increasing the external oxygen concentration above ambient levels increased the oxygen content as well as the energy status of the seeds, indicating that under normal conditions the oxygen supply is strongly limiting for energy metabolism in developing wheat seeds. The intermediate metabolites of seed storage metabolism were not substantially affected when oxygen was either increased or decreased. However, at subambient external oxygen concentrations (8%) the metabolic flux of carbon into starch and protein, measured by injecting (14)C-Suc into the seeds, was reduced by 17% and 32%, respectively, whereas no significant effect was observed at superambient (40%) oxygen. The observed decrease in biosynthetic fluxes to storage compounds is suggested to be part of an adaptive response to reduce energy consumption preventing excessive oxygen consumption when oxygen supply is limited. Phloem transport toward ears exposed to low (8%) oxygen was significantly reduced within 1 h, whereas exposing ears to elevated oxygen (40%) had no significant effect. This contrasts with the situation where the distribution of assimilates has been modified by removing the lower source leaves from the plant, resulting in less assimilates transported to the ear in favor of transport to the lower parts of the plant. Under these conditions, with two strongly competing sinks, elevated oxygen (40%) did lead to a strong increase in phloem transport to the ear. The results show that sink metabolism is affected by the prevailing low oxygen concentrations in developing wheat seeds, determining the import rate of assimilates via the phloem

phenoPET – Results from the Plant Scanner

Within the German Plant Phenotyping Network (DPPN), we developed a novel PET scanner based on Philips Digital Photon Counters (DPCs, or dSiPMs = digital Silicon Photomultipliers). The scanner is dedicated for plant research and provides functional information on carbon transport within the plant. To this end the detector ring is oriented horizontally. It provides a Field-of-View of 18 cm dia. and 20 cm in height. The read-out electronics cluster hits from different photodetector pixels when they originate from the same scintillation event. These single events are written via USB 3.0 with up to 300 MB/s to the computer system. Crystal identification, energy discrimination and coincidence detection is realized in software. The spatial resolution in the center Field-of-View (CFOV) could be estimated to approx. 1.6 mm from measurements of a dedicated hot rod phantom. Preliminary sensitivity measurements result in a peak sensitivity of 4.04% (ΔE = 250-750 keV) in the CFOV and a Coincidence Resolving Time of 298 ps could be achieved

A new fate mapping system reveals context-dependent random or clonal expansion of microglia

Microglia constitute a highly specialized network of tissue-resident immune cells that is important for the control of tissue homeostasis and the resolution of diseases of the CNS. Little is known about how their spatial distribution is established and maintained in vivo. Here we establish a new multicolor fluorescence fate mapping system to monitor microglial dynamics during steady state and disease. Our findings suggest that microglia establish a dense network with regional differences, and the high regional turnover rates found challenge the universal concept of microglial longevity. Microglial self-renewal under steady state conditions constitutes a stochastic process. During pathology this randomness shifts to selected clonal microglial expansion. In the resolution phase, excess disease-associated microglia are removed by a dual mechanism of cell egress and apoptosis to re-establish the stable microglial network. This study unravels the dynamic yet discrete self-organization of mature microglia in the healthy and diseased CNS

Molecular epidemiology of MRSA in 13 ICUs from eight European countries

Objectives: The European epidemiology of MRSA is changing with the emergence of community-associated MRSA (CA-MRSA) and livestock-associated MRSA (LA-MRSA). In this study,we investigated the molecular epidemiology of MRSA during 2 years in 13 ICUs in France, Greece, Italy, Latvia, Luxemburg, Portugal, Slovenia and Spain. Methods: Surveillance cultures for MRSA from nose and wounds were obtained on admission and twice weekly from all patients admitted to an ICU for ≥3 days. The first MRSA isolate per patient was genotyped in a central laboratory by MLST, spa typing, agr typing and SCCmec (sub)typing. Risk factors for patients with an unknown history of MRSA colonization were identified. Results: Overall, 14390 ICU patients were screened, of whom 8519 stayed in an ICU for ≥3 days. Overall MRSA admission prevalence was 3.9% and ranged from 1.0% to 7.0% for individual ICUs. Overall MRSA acquisition rate was 2.5/1000 patient days at risk and ranged from 0.2 to 8/1000 patient days at risk per ICU. In total, 557 putative MRSA isolates were submitted to the central laboratory for typing, of which 511 (92%) were confirmed as MRSA. Each country had a distinct epidemiology, with ST8-IVc (UK-EMRSA-2/-6, USA500) being most prevalent, especially in France and Spain, and detected in ICUs in five of eight countries. Seventeen (3%) and three (70 years and hospitalization within 1 year prior to ICU admission. Conclusions: The molecular epidemiology of MRSA in 13 European ICUs in eight countries was homogeneous within, but heterogeneous between, countries. CA-MRSA and LA-MRSA genotypes and Panton-Valentine leucocidin-producing isolates were detected sporadically