WorldWideScience

Sample records for airborne bacterial quantification

  1. Urban greenness influences airborne bacterial community composition.

    Science.gov (United States)

    Mhuireach, Gwynne; Johnson, Bart R; Altrichter, Adam E; Ladau, Joshua; Meadow, James F; Pollard, Katherine S; Green, Jessica L

    2016-11-15

    Urban green space provides health benefits for city dwellers, and new evidence suggests that microorganisms associated with soil and vegetation could play a role. While airborne microorganisms are ubiquitous in urban areas, the influence of nearby vegetation on airborne microbial communities remains poorly understood. We examined airborne microbial communities in parks and parking lots in Eugene, Oregon, using high-throughput sequencing of the bacterial 16S rRNA gene on the Illumina MiSeq platform to identify bacterial taxa, and GIS to measure vegetation cover in buffer zones of different diameters. Our goal was to explore variation among highly vegetated (parks) versus non-vegetated (parking lots) urban environments. A secondary objective was to evaluate passive versus active collection methods for outdoor airborne microbial sampling. Airborne bacterial communities from five parks were different from those of five parking lots (p=0.023), although alpha diversity was similar. Direct gradient analysis showed that the proportion of vegetated area within a 50m radius of the sampling station explained 15% of the variation in bacterial community composition. A number of key taxa, including several Acidobacteriaceae were substantially more abundant in parks, while parking lots had higher relative abundance of Acetobacteraceae. Parks had greater beta diversity than parking lots, i.e. individual parks were characterized by unique bacterial signatures, whereas parking lot communities tended to be similar to each other. Although parks and parking lots were selected to form pairs of nearby sites, spatial proximity did not appear to affect compositional similarity. Our results also showed that passive and active collection methods gave comparable results, indicating the "settling dish" method is effective for outdoor airborne sampling. This work sets a foundation for understanding how urban vegetation may impact microbial communities, with potential implications for designing

  2. Development and calibration of real-time PCR for quantification of airborne microorganisms in air samples

    Science.gov (United States)

    An, Hey Reoun; Mainelis, Gediminas; White, Lori

    This manuscript describes the coupling of bioaerosol collection and the use of real-time PCR (RT-PCR) to quantify the airborne bacteria. The quantity of collected bacteria determined by RT-PCR is compared with conventional quantification techniques, such as culturing, microscopy and airborne microorganism counting by using optical particle counter (OPC). Our data show that an experimental approach used to develop standard curves for use with RT-PCR is critical for accurate sample quantification. Using universal primers we generated 12 different standard curves which were used to quantify model organism Escherichia coli (Migula) Catellani from air samples. Standard curves prepared using a traditional approach, where serially diluted genomic DNA extracted from pure cultured bacteria were used in PCR reaction as a template DNA yielded significant underestimation of sample quantities compared to airborne microorganism concentration as measured by an OPC. The underestimation was especially pronounced when standard curves were built using colony forming units (CFUs). In contrast, the estimate of cell concentration in an air sample by RT-PCR was more accurate (˜60% compared to the airborne microorganism concentration) when the standard curve was built using aerosolized E. coli. The accuracy improved even further (˜100%) when air samples used to build the standard curves were diluted first, then the DNA extracted from each dilution was amplified by the RT-PCR—to mimic the handling of air samples with unknown and possibly low concentration. Therefore, our data show that standard curves used for quantification by RT-PCR needs to be prepared using the same environmental matrix and procedures as handling of the environmental sample in question. Reliance on the standard curves generated with cultured bacterial suspension (a traditional approach) may lead to substantial underestimation of microorganism quantities in environmental samples.

  3. Elemental quantification of airborne particulate matter in Bandung and Lembang area

    International Nuclear Information System (INIS)

    Sutisna; Achmad Hidayat; Dadang Supriatna

    2004-01-01

    ELEMENTAL QUANTIFICATION OF AIRBORNE PARTICULATE MATTER IN BANDUNG AND LEMBANG REGION: The contaminated airborne particulates by toxic gases and elements have a potential affect to the human health. Some toxic elements related to air pollution have carcinogenic affect. The quantification of those elements is important to monitor a level of pollutant contained in the airborne particulate. The aim of this work is to analyze the air particulate sample using instrumental neutron activation analysis and other related technique. Two sampling points of Bandung and Lembang that represent and urban and rural area respectively have been chosen to collect the air particulate sample. The samplings were carried out using Gent Stacked Filter Unit Sampler for 24 hours, and two cellulose filters of 8 μm and 0.45 μm pore size were used. Trace elements in the sample collected were determined using NAA based on a comparative method. Elemental distribution on PM 2.5 and PM 10 fraction of airborne particulate was analyzed, the enrichment factor was calculated using Al as reference elements, and the black carbons contents were determined using FEL Smoke Stain Reflectometer analyzed. The results are presented and discussed. (author)

  4. Pig Farmers’ Homes Harbor More Diverse Airborne Bacterial Communities Than Pig Stables or Suburban Homes

    Directory of Open Access Journals (Sweden)

    Ditte V. Vestergaard

    2018-05-01

    Full Text Available Airborne bacterial communities are subject to conditions ill-suited to microbial activity and growth. In spite of this, air is an important transfer medium for bacteria, with the bacteria in indoor air having potentially major consequences for the health of a building’s occupants. A major example is the decreased diversity and altered composition of indoor airborne microbial communities as a proposed explanation for the increasing prevalence of asthma and allergies worldwide. Previous research has shown that living on a farm confers protection against development of asthma and allergies, with airborne bacteria suggested as playing a role in this protective effect. However, the composition of this beneficial microbial community has still not been identified. We sampled settled airborne dust using a passive dust sampler from Danish pig stables, associated farmers’ homes, and from suburban homes (267 samples in total and carried out quantitative PCR measurements of bacterial abundance and MiSeq sequencing of the V3–V4 region of bacterial 16S rRNA genes found in these samples. Airborne bacteria had a greater diversity and were significantly more abundant in pig stables and farmers’ homes than suburban homes (Wilcoxon rank sum test P < 0.05. Moreover, bacterial taxa previously suggested to contribute to a protective effect had significantly higher relative and absolute abundance in pig stables and farmers’ homes than in suburban homes (ALDEx2 with P < 0.05, including Firmicutes, Peptostreptococcaceae, Prevotellaceae, Lachnospiraceae, Ruminococcaceae, Ruminiclostridium, and Lactobacillus. Pig stables had significantly lower airborne bacterial diversity than farmers’ homes, and there was no discernable direct transfer of airborne bacteria from stable to home. This study identifies differences in indoor airborne bacterial communities that may be an important component of this putative protective effect, while showing that pig stables

  5. Airborne Bacterial Communities in Three East Asian Cities of China, South Korea, and Japan.

    Science.gov (United States)

    Lee, Jae Young; Park, Eun Ha; Lee, Sunghee; Ko, GwangPyo; Honda, Yasushi; Hashizume, Masahiro; Deng, Furong; Yi, Seung-Muk; Kim, Ho

    2017-07-17

    The global diversity of airborne bacteria has not yet been studied, despite its importance in human health and climate change. Here, we focused on the diversity of airborne bacteria and their correlations with meteorological/environmental conditions in China, South Korea, and Japan. Beijing (China) had more diverse airborne bacteria, followed by Seoul (South Korea) and Nagasaki (Japan), and seasonal variations were observed. Beijing and Seoul had more diverse airborne bacteria during the winter, whereas Nagasaki showed greater diversity during the summer. According to principal component analysis and Bray-Curtis similarity, higher similarity was observed between Beijing and Seoul than between Seoul and Nagasaki during all seasons except summer. Among meteorological/environmental variables, temperature and humidity were highly correlated with the diversity of airborne bacteria on the measurement day, whereas wind speeds and the frequency of northwest winds were highly correlated for 2-3-day moving averages. Thus, proximity and resuspension could enhance bacterial diversity in East Asian cities.

  6. Airborne bacterial communities in residences: similarities and differences with fungi.

    Directory of Open Access Journals (Sweden)

    Rachel I Adams

    Full Text Available Genetic analysis of indoor air has uncovered a rich microbial presence, but rarely have both the bacterial and fungal components been examined in the same samples. Here we present a study that examined the bacterial component of passively settled microbes from both indoor and outdoor air over a discrete time period and for which the fungal component has already been reported. Dust was allowed to passively settle in five common locations around a home - living room, bedroom, bathroom, kitchen, and balcony - at different dwellings within a university-housing complex for a one-month period at two time points, once in summer and again in winter. We amplified the bacterial 16S rRNA gene in these samples and analyzed them with high-throughput sequencing. Like fungal OTU-richness, bacterial OTU-richness was higher outdoors then indoors and was invariant across different indoor room types. While fungal composition was structured largely by season and residential unit, bacterial composition varied by residential unit and room type. Bacteria from putative outdoor sources, such as Sphingomonas and Deinococcus, comprised a large percentage of the balcony samples, while human-associated taxa comprised a large percentage of the indoor samples. Abundant outdoor bacterial taxa were also observed indoors, but the reverse was not true; this is unlike fungi, in which the taxa abundant indoors were also well-represented outdoors. Moreover, there was a partial association of bacterial composition and geographic distance, such that samples separated by even a few hundred meters tended have greater compositional differences than samples closer together in space, a pattern also observed for fungi. These data show that while the outdoor source for indoor bacteria and fungi varies in both space and time, humans provide a strong and homogenizing effect on indoor bacterial bioaerosols, a pattern not observed in fungi.

  7. Airborne bacterial assemblage in a zero carbon building: A case study.

    Science.gov (United States)

    Leung, M H Y; Tong, X; Tong, J C K; Lee, P K H

    2018-01-01

    Currently, there is little information pertaining to the airborne bacterial communities of green buildings. In this case study, the air bacterial community of a zero carbon building (ZCB) in Hong Kong was characterized by targeting the bacterial 16S rRNA gene. Bacteria associated with the outdoor environment dominated the indoor airborne bacterial assemblage, with a modest contribution from bacteria associated with human skin. Differences in overall community diversity, membership, and composition associated with short (day-to-day) and long-term temporal properties were detected, which may have been driven by specific environmental genera and taxa. Furthermore, time-decay relationships in community membership (based on unweighted UniFrac distances) and composition (based on weighted UniFrac distances) differed depending on the season and sampling location. A Bayesian source-tracking approach further supported the importance of adjacent outdoor air bacterial assemblage in sourcing the ZCB indoor bioaerosol. Despite the unique building attributes, the ZCB microbial assemblage detected and its temporal characteristics were not dissimilar to that of conventional built environments investigated previously. Future controlled experiments and microbial assemblage investigations of other ZCBs will undoubtedly uncover additional knowledge related to how airborne bacteria in green buildings may be influenced by their distinctive architectural attributes. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  8. Absolute quantification method and validation of airborne snow crab allergen tropomyosin using tandem mass spectrometry.

    Science.gov (United States)

    Abdel Rahman, Anas M; Lopata, Andreas L; Randell, Edward W; Helleur, Robert J

    2010-11-29

    Measuring the levels of the major airborne allergens of snow crab in the workplace is very important in studying the prevalence of crab asthma in workers. Previously, snow crab tropomyosin (SCTM) was identified as the major aeroallergen in crab plants and a unique signature peptide was identified for this protein. The present study advances our knowledge on aeroallergens by developing a method of quantification of airborne SCTM by using isotope dilution mass spectrometry. Liquid chromatography tandem mass spectrometry was developed for separation and analysis of the signature peptides. The tryptic digestion conditions were optimized to accomplish complete digestion. The validity of the method was studied using international conference on harmonization protocol, Where 2-9% for CV (precision) and 101-110% for accuracy, at three different levels of quality control. Recovery of the spiked protein from PTFE and TopTip filters was measured to be 99% and 96%, respectively. To further demonstrate the applicability and the validity of the method for real samples, 45 kg of whole snow crab were processed in an enclosed (simulated) crab processing line and air samples were collected. The levels of SCTM ranged between 0.36-3.92 μg m(-3) and 1.70-2.31 μg m(-3) for butchering and cooking stations, respectively. Crown Copyright © 2010. Published by Elsevier B.V. All rights reserved.

  9. The effect of mobile laminar airflow units on airborne bacterial contamination during neurosurgical procedures.

    Science.gov (United States)

    von Vogelsang, Ann-Christin; Förander, Petter; Arvidsson, Martin; Löwenhielm, Peter

    2018-03-23

    Surgical site infections (SSIs) after neurosurgery are potentially life threatening and entails great costs. SSI can occur from airborne bacteria in the operating room (OR), and ultraclean air is desired during infection-prone clean procedures. Door openings and the number of persons present in the OR affects the air quality. Mobile laminar airflow (MLAF) units, with horizontal laminar airflow, have previously shown to effectively reduce airborne bacterial contamination. To assess the effect of MLAF units on airborne bacterial contamination during neurosurgical procedures. In a quasi-experimental design, bacteria carrying particles (colony forming units, CFU) during neurosurgical procedures were measured with active air sampling in ORs with conventional turbulent ventilation, and with additional MLAF units. The MLAF units were shifted between ORs monthly. CFU count and bacterial species detection were conducted after incubation. Data was collected over a period of 18 months. A total of 233 samples were collected during 45 neurosurgical procedures. The use of MLAF units significantly reduced the numbers of CFU in the surgical site area (Pneurosurgery to ultraclean air levels. MLAF units can be a valuable addition when the main OR ventilation system is unable to produce ultraclean air in infection prone clean neurosurgery. Copyright © 2018. Published by Elsevier Ltd.

  10. Morphology, chemical composition, and bacterial concentration of airborne particulate matter in rabbit farms

    Directory of Open Access Journals (Sweden)

    Elisa Adell

    2012-12-01

    Full Text Available Livestock houses are major sources of airborne particulate matter (PM, which can originate from manure, feed, feathers, skin and bedding and may contain and transport microorganisms. Improved knowledge of particle size, morphology, chemical and microbiological composition of PM in livestock houses can help identify major sources of PM and contribute to the development of appropriate source-specific reduction techniques. In rabbit production systems, however, there is limited information on specific particle characteristics. The objective of this study was to characterise airborne PM in rabbit farms in terms of morphology, chemical compositions and bacterial concentration in different size fractions. Size-fractioned PM was sampled in the air of 2 rabbit farms, 1 for fattening rabbits and 1 for reproductive does, using a virtual cascade impactor, which simultaneously collected total suspended PM (TSP, PM10 and PM2.5 size fractions. Airborne PM samples were examined by light microscopy and scanning electron microscopy combined with energy dispersive X-ray analysis. Representative samples from potential sources of PM were also collected and examined. Additionally, a methodology to extract bacteria from the collected samples of airborne PM was developed to determine the bacterial concentration per PM size fraction. Results showed that airborne PM in rabbit farms is highly complex in particle morphology, especially in size. Broken skin flakes, disintegrated particles from feed or faecal material from mechanical fracture are the main sources of airborne PM in rabbit farms. Major elements found in rabbit airborne PM were S, Ca, Mg, Na and Cl. Bacterial concentrations ranged from 1.7×104 to 1.6×106 colony forming units (CFU/m3 (TSP; from 3.6×103 to 3.0×104 CFU/m3 (PM10; and from 3.1×103 to 1.6×104 CFU/m3 (PM2.5. Our results will improve the knowledge on essential particle characteristics necessary to understand PM’s origin in rabbit farms and

  11. Assessment of bacterial pathogens in fresh rainwater and airborne particulate matter using Real-Time PCR

    Science.gov (United States)

    Kaushik, Rajni; Balasubramanian, Rajasekhar

    2012-01-01

    Bacterial pathogens in airborne particulate matter (PM) and in rainwater (RW) were detected using a robust and sensitive Real-Time PCR method. Both RW and PM were collected simultaneously in the tropical atmosphere of Singapore, which were then subjected to analysis for the presence of selected bacterial pathogens and potential pathogen of health concern ( Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and Aeromonas hydrophila). These pathogens were found to be prevalent in both PM and RW samples with E. coli being the most prevalent potential pathogen in both types of samples. The temporal distribution of these pathogens in PM and RW was found to be similar to each other. Using the proposed microbiological technique, the atmospheric deposition (dry and wet deposition) of bacterial pathogens to lakes and reservoirs can be studied in view of growing concerns about the outbreak of waterborne diseases.

  12. A comparison of airborne bacterial fallout between orthopaedic and vascular surgery.

    Science.gov (United States)

    Stather, P; Salji, M; Hassan, S-U; Abbas, M; Ahmed, A; Mills, H; Elston, T; Backhouse, C; Howard, A; Choksy, S

    2017-04-01

    INTRODUCTION The objective of the study was to compare bacterial fallout during vascular prosthesis insertion and orthopaedic major joint replacement performed in conventional and laminar flow ventilation, respectively. MATERIALS AND METHODS A prospective single-centre case control study of 21 consecutive elective vascular procedures involving prosthetic graft insertion and 24 consecutive elective orthopaedic major joint replacements were tested for degree of bacterial fallout using agar settle plates. Preparation time, waiting time and total procedure duration were collected at the time of surgery, and bacterial colony counts on the agar settle plates from airborne bacterial fallout were counted after an incubation period. RESULTS Bacterial fallout count in vascular prosthetic graft insertion was 15-fold greater than in orthopaedic prosthetic joint insertion (15, (IQR 15) vs 1, (IQR 3) respectively, P fallout counts during the procedure (P = 0.9). CONCLUSIONS Vascular surgical theatres have significantly higher bacterial fallout compared with orthopaedic theatres. This may be partly explained by orthopaedic surgery being routinely performed in laminar flow ventilation, a practice which has not been widely adopted for vascular surgery, in which prosthetic infection may also result in significant mortality and morbidity.

  13. Discriminating bacterial spores from inert airborne particles by classification of optical scattering patterns

    Science.gov (United States)

    Crosta, Giovanni F.; Pan, Yongle; Videen, Gorden

    2014-05-01

    Scattering patterns are made available by the TAOS (Two-dimensional Angle-resolved Optical Scattering) method, which consists of detecting micrometer-sized single airborne aerosol particles and collecting the intensity of the light they scatter from a pulsed, monochromatic laser beam. TAOS patterns have been classified by a learning machine, the training stage of which depends on many control parameters. Patterns due to single bacterial spores (Bq class) have to be discriminated from those produced by outdoor aerosol particles (Kq set) and diesel soot aggregates (sq set), where both Kq and sq are assumed not to contain patterns of bacterial origin. This work describes two directions along which classification continues to develop: the enlargement of the control parameter set and the simultaneous processing of two areas (sectors) selected from the TAOS pattern. The latter algorithm is meant to make the classifier sensitive to simmetry exhibited by some patterns. The available classification scheme is summarized, as well as the rule by which discrimination is rated off-line. Discrimination based on one pattern sector alone scores fewer than 15% false negatives (misclassified Bq patterns) and false positives from Kq and sq. Discrimination based on the symmetry of two pattern sectors fails to recognize 30% of the Bq (bacterial) patterns, whereas positives from sq (diesel) patterns drop to zero. The issue of false positives is briefly discussed in relation to the fraction of airborne bacteria found in aerosols.

  14. Kynetic resazurin assay (KRA) for bacterial quantification of foodborne pathogens

    Science.gov (United States)

    Arenas, Yaxal; Mandel, Arkady; Lilge, Lothar

    2012-03-01

    Fast detection of bacterial concentrations is important for the food industry and for healthcare. Early detection of infections and appropriate treatment is essential since, the delay of treatments for bacterial infections tends to be associated with higher mortality rates. In the food industry and in healthcare, standard procedures require the count of colony-forming units in order to quantify bacterial concentrations, however, this method is time consuming and reports require three days to be completed. An alternative is metabolic-colorimetric assays which provide time efficient in vitro bacterial concentrations. A colorimetric assay based on Resazurin was developed as a time kinetic assay (KRA) suitable for bacterial concentration measurements. An optimization was performed by finding excitation and emission wavelengths for fluorescent acquisition. A comparison of two non-related bacteria, foodborne pathogens Escherichia coli and Listeria monocytogenes, was performed in 96 well plates. A metabolic and clonogenic dependence was established for fluorescent kinetic signals.

  15. Spatio-temporal variability of airborne bacterial communities and their correlation with particulate matter chemical composition across two urban areas.

    Science.gov (United States)

    Gandolfi, I; Bertolini, V; Bestetti, G; Ambrosini, R; Innocente, E; Rampazzo, G; Papacchini, M; Franzetti, A

    2015-06-01

    The study of spatio-temporal variability of airborne bacterial communities has recently gained importance due to the evidence that airborne bacteria are involved in atmospheric processes and can affect human health. In this work, we described the structure of airborne microbial communities in two urban areas (Milan and Venice, Northern Italy) through the sequencing, by the Illumina platform, of libraries containing the V5-V6 hypervariable regions of the 16S rRNA gene and estimated the abundance of airborne bacteria with quantitative PCR (qPCR). Airborne microbial communities were dominated by few taxa, particularly Burkholderiales and Actinomycetales, more abundant in colder seasons, and Chloroplasts, more abundant in warmer seasons. By partitioning the variation in bacterial community structure, we could assess that environmental and meteorological conditions, including variability between cities and seasons, were the major determinants of the observed variation in bacterial community structure, while chemical composition of atmospheric particulate matter (PM) had a minor contribution. Particularly, Ba, SO4 (2-) and Mg(2+) concentrations were significantly correlated with microbial community structure, but it was not possible to assess whether they simply co-varied with seasonal shifts of bacterial inputs to the atmosphere, or their variation favoured specific taxa. Both local sources of bacteria and atmospheric dispersal were involved in the assembling of airborne microbial communities, as suggested, to the one side by the large abundance of bacteria typical of lagoon environments (Rhodobacterales) observed in spring air samples from Venice and to the other by the significant effect of wind speed in shaping airborne bacterial communities at all sites.

  16. Quantification of a bacterial secondary metabolite by SERS combined with SLM extraction for bioprocess monitoring

    DEFF Research Database (Denmark)

    Morelli, Lidia; Andreasen, Sune Zoëga; Jendresen, Christian Bille

    2017-01-01

    and combined it with surface enhanced Raman scattering (SERS) sensing for the screening of a biological process, namely for the quantification of a bacterial secondary metabolite, p-coumaric acid (pHCA), produced by Escherichia coli. The microfluidic device proved to be robust and reusable, enabling efficient....... The obtained data showed good correlation with HPLC analysis....

  17. Exploring biodiversity in the bacterial community of the Mediterranean phyllosphere and its relationship with airborne bacteria.

    Science.gov (United States)

    Vokou, Despoina; Vareli, Katerina; Zarali, Ekaterini; Karamanoli, Katerina; Constantinidou, Helen-Isis A; Monokrousos, Nikolaos; Halley, John M; Sainis, Ioannis

    2012-10-01

    We studied the structure and diversity of the phyllosphere bacterial community of a Mediterranean ecosystem, in summer, the most stressful season in this environment. To this aim, we selected nine dominant perennial species, namely Arbutus unedo, Cistus incanus, Lavandula stoechas, Myrtus communis, Phillyrea latifolia, Pistacia lentiscus, Quercus coccifera (woody), Calamintha nepeta, and Melissa officinalis (herbaceous). We also examined the extent to which airborne bacteria resemble the epiphytic ones. Genotype composition of the leaf and airborne bacteria was analysed by using denaturing gradient gel electrophoresis profiling of a 16S rDNA gene fragment; 75 bands were cloned and sequenced corresponding to 28 taxa. Of these, two were found both in the air and the phyllosphere, eight only in the air, and the remaining 18 only in the phyllosphere. Only four taxa were found on leaves of all nine plant species. Cluster analysis showed highest similarity for the five evergreen sclerophyllous species. Aromatic plants were not grouped all together: the representatives of Lamiaceae, bearing both glandular and non-glandular trichomes, formed a separate group, whereas the aromatic and evergreen sclerophyllous M. communis was grouped with the other species of the same habit. The epiphytic communities that were the richest in bacterial taxa were those of C. nepeta and M. officinalis (Lamiaceae). Our results highlight the remarkable presence of lactic acid bacteria in the phyllosphere under the harsh conditions of the Mediterranean summer, the profound dissimilarity in the structure of bacterial communities in phyllosphere and air, and the remarkable differences of leaf microbial communities on neighbouring plants subjected to similar microbial inocula; they also point to the importance of the leaf glandular trichome in determining colonization patterns.

  18. Quantification of total phosphorothioate in bacterial DNA by a bromoimane-based fluorescent method.

    Science.gov (United States)

    Xiao, Lu; Xiang, Yu

    2016-06-01

    The discovery of phosphorothioate (PT) modifications in bacterial DNA has challenged our understanding of conserved phosphodiester backbone structure of cellular DNA. This exclusive DNA modification in bacteria is not found in animal cells yet, and its biological function in bacteria is still poorly understood. Quantitative information about the bacterial PT modifications is thus important for the investigation of their possible biological functions. In this study, we have developed a simple fluorescence method for selective quantification of total PTs in bacterial DNA, based on fluorescent labeling of PTs and subsequent release of the labeled fluorophores for absolute quantification. The method was highly selective to PTs and not interfered by the presence of reactive small molecules or proteins. The quantification of PTs in an E. coli DNA sample was successfully achieved using our method and gave a result of about 455 PTs per million DNA nucleotides, while almost no detectable PTs were found in a mammalian calf thymus DNA. With this new method, the content of phosphorothioate in bacterial DNA could be successfully quantified, serving as a simple method suitable for routine use in biological phosphorothioate related studies. Copyright © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. In situ real-time measurement of physical characteristics of airborne bacterial particles

    Science.gov (United States)

    Jung, Jae Hee; Lee, Jung Eun

    2013-12-01

    Bioaerosols, including aerosolized bacteria, viruses, and fungi, are associated with public health and environmental problems. One promising control method to reduce the harmful effects of bioaerosols is thermal inactivation via a continuous-flow high-temperature short-time (HTST) system. However, variations in bioaerosol physical characteristics - for example, the particle size and shape - during the continuous-flow inactivation process can change the transport properties in the air, which can affect particle deposition in the human respiratory system or the filtration efficiency of ventilation systems. Real-time particle monitoring techniques are a desirable alternative to the time-consuming process of microscopic analysis that is conventionally used in sampling and particle characterization. Here, we report in situ real-time optical scattering measurements of the physical characteristics of airborne bacteria particles following an HTST process in a continuous-flow system. Our results demonstrate that the aerodynamic diameter of bacterial aerosols decreases when exposed to a high-temperature environment, and that the shape of the bacterial cells is significantly altered. These variations in physical characteristics using optical scattering measurements were found to be in agreement with the results of scanning electron microscopy analysis.

  20. Spatial variability in airborne bacterial communities across land-use types and their relationship to the bacterial communities of potential source environments.

    Science.gov (United States)

    Bowers, Robert M; McLetchie, Shawna; Knight, Rob; Fierer, Noah

    2011-04-01

    Although bacteria are ubiquitous in the near-surface atmosphere and they can have important effects on human health, airborne bacteria have received relatively little attention and their spatial dynamics remain poorly understood. Owing to differences in meteorological conditions and the potential sources of airborne bacteria, we would expect the atmosphere over different land-use types to harbor distinct bacterial communities. To test this hypothesis, we sampled the near-surface atmosphere above three distinct land-use types (agricultural fields, suburban areas and forests) across northern Colorado, USA, sampling five sites per land-use type. Microbial abundances were stable across land-use types, with ∼10(5)-10(6) bacterial cells per m(3) of air, but the concentrations of biological ice nuclei, determined using a droplet freezing assay, were on average two and eight times higher in samples from agricultural areas than in the other two land-use types. Likewise, the composition of the airborne bacterial communities, assessed via bar-coded pyrosequencing, was significantly related to land-use type and these differences were likely driven by shifts in the sources of bacteria to the atmosphere across the land-uses, not local meteorological conditions. A meta-analysis of previously published data shows that atmospheric bacterial communities differ from those in potential source environments (leaf surfaces and soils), and we demonstrate that we may be able to use this information to determine the relative inputs of bacteria from these source environments to the atmosphere. This work furthers our understanding of bacterial diversity in the atmosphere, the terrestrial controls on this diversity and potential approaches for source tracking of airborne bacteria.

  1. Direct quantification of airborne nanoparticles composition by TXRF after collection on filters

    Science.gov (United States)

    Motellier, S.; Lhaute, K.; Guiot, A.; Golanski, L.; Geoffroy, C.; Tardif, F.

    2011-07-01

    Direct TXRF analysis of nanoparticles deposited on filters was evaluated. Standard filters spiked with known amounts of NP were produced using an atomizer which generates an aerosol from a NP containing-liquid suspension. Polycarbonate filters provided the highest fluorescence signals and black polycarbonate filters containing chromium were further selected, Cr being used as internal standard for elemental quantification of the filter contaminants. Calibration curves were established for various NP (TiO2, ZnO, CeO2, Al2O3). Good linearity was observed. Low limits of detection were in the tens to the hundreds of ngs per filter, the method being less adapted to Al2O3 due to the poor TXRF sensitivity for light elements. The analysis of MW-CNTs was attempted by quantification of their metal (Fe) catalyst impurities. Problems like CNT dispersion in liquids, quantification of the deposited quantity and high Fe-background contamination.

  2. Thermal resistance of naturally occurring airborne bacterial spores. [Viking spacecraft dry heat decontamination simulation

    Science.gov (United States)

    Puleo, J. R.; Bergstrom, S. L.; Peeler, J. T.; Oxborrow, G. S.

    1978-01-01

    Simulation of a heat process used in the terminal dry-heat decontamination of the Viking spacecraft is reported. Naturally occurring airborne bacterial spores were collected on Teflon ribbons in selected spacecraft assembly areas and subsequently subjected to dry heat. Thermal inactivation experiments were conducted at 105, 111.7, 120, 125, 130, and 135 C with a moisture level of 1.2 mg of water per liter. Heat survivors were recovered at temperatures of 135 C when a 30-h heating cycle was employed. Survivors were recovered from all cycles studied and randomly selected for identification. The naturally occurring spore population was reduced an average of 2.2 to 4.4 log cycles from 105 to 135 C. Heating cycles of 5 and 15 h at temperature were compared with the standard 30-h cycle at 111.7, 120, and 125 C. No significant differences in inactivation (alpha = 0.05) were observed between 111.7 and 120 C. The 30-h cycle differs from the 5- and 15-h cycles at 125 C. Thus, the heating cycle can be reduced if a small fraction (about 0.001 to 0.0001) of very resistant spores can be tolerated.

  3. High temporal variability in airborne bacterial diversity and abundance inside single-family residences.

    Science.gov (United States)

    Emerson, J B; Keady, P B; Clements, N; Morgan, E E; Awerbuch, J; Miller, S L; Fierer, N

    2017-05-01

    Our homes are microbial habitats, and although the amounts and types of bacteria in indoor air have been shown to vary substantially across residences, temporal variability within homes has rarely been characterized. Here, we sought to quantify the temporal variability in the amounts and types of airborne bacteria in homes, and what factors drive this variability. We collected filter samples of indoor and outdoor air in 15 homes over 1 year (approximately eight time points per home, two per season), and we used culture-independent DNA sequencing approaches to characterize bacterial community composition. Significant differences in indoor air community composition were observed both between homes and within each home over time. Indoor and outdoor air community compositions were not significantly correlated, suggesting that indoor and outdoor air communities are decoupled. Indoor air communities from the same home were often just as different at adjacent time points as they were across larger temporal distances, and temporal variation correlated with changes in environmental conditions, including temperature and relative humidity. Although all homes had highly variable indoor air communities, homes with the most temporally variable communities had more stable, lower average microbial loads than homes with less variable communities. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  4. Assessing genetic structure and diversity of airborne bacterial communities by DNA fingerprinting and 16S rDNA clone library

    Science.gov (United States)

    Maron, Pierre-Alain; Lejon, David P. H.; Carvalho, Esmeralda; Bizet, Karine; Lemanceau, Philippe; Ranjard, Lionel; Mougel, Christophe

    The density, genetic structure and diversity of airborne bacterial communities were assessed in the outdoor atmosphere. Two air samples were collected on the same location (north of France) at two dates (March 2003 (sample1) and May 2003 (sample 2)). Molecular culture -independent methods were used to characterise airborne bacterial communities regardless of the cell culturability. The automated-ribosomal intergenic spacer analysis (A-RISA) was performed to characterise the community structure in each sample. For both sampling dates, complex A-RISA patterns were observed suggesting a highly diverse community structure, comparable to those found in soil, water or sediment environments. Furthermore, differences in the genetic structure of airborne bacterial communities were observed between samples 1 and 2 suggesting an important variability in time. A clone library of 16S rDNA directly amplified from air DNA of sample 1 was constructed and sequenced to analyse the community composition and diversity. The Proteobacteria group had the greatest representation (60%), with bacteria belonging to the different subdivisions α- (19%), β-(21%), γ-(12%) and δ-(8%). Firmicute and Actinobacteria were also well represented with 14% and 12%, respectively. Most of the identified bacteria are known to be commonly associated with soil or plant environments suggesting that the atmosphere is mainly colonised transiently by microorganisms from local sources, depending on air fluxes.

  5. A comparison of conventional methods for the quantification of bacterial cells after exposure to metal oxide nanoparticles.

    Science.gov (United States)

    Pan, Hongmiao; Zhang, Yongbin; He, Gui-Xin; Katagori, Namrata; Chen, Huizhong

    2014-08-21

    Due to potential interference of nanoparticles on bacterial quantification, there is a challenge to develop a fast, accurate and reproducible method for bacterial quantification. Currently various bacterial quantification methods are used by researchers performing nanoparticles study, but there has been no efficacy evaluation of these methods. Here we study interference of nanoparticles on three most commonly used conventional bacterial quantification methods, including colony counting to determine the colony-forming units (CFU), spectrophotometer method of optical density (OD) measurement, and flow cytometry (FCM). Three oxide nanoparticles including ZnO, TiO2, and SiO2 and four bacterial species including Salmonella enterica serovar Newport, Staphylococcus epidermidis, Enterococcus faecalis, and Escherichia coli were included in the test. Results showed that there is no apparent interference of the oxide nanoparticles on quantifications of all four bacterial species by FCM measurement; CFU counting is time consuming, less accurate and not suitable for automation; and the spectrophotometer method using OD measurement was the most unreliable method to quantify and detect the bacteria in the presence of the nanoparticles. In summary, FCM measurement proved to be the best method, which is suitable for rapid, accurate and automatic detection of bacteria in the presence of the nanoparticles.

  6. Quantification of a bacterial secondary metabolite by SERS combined with SLM extraction for bioprocess monitoring.

    Science.gov (United States)

    Morelli, Lidia; Andreasen, Sune Zoëga; Jendresen, Christian Bille; Nielsen, Alex Toftgaard; Emnéus, Jenny; Zór, Kinga; Boisen, Anja

    2017-11-20

    During the last few decades, great advances have been reached in high-throughput design and building of genetically engineered microbial strains, leading to a need for fast and reliable screening methods. We developed and optimized a microfluidic supported liquid membrane (SLM) extraction device and combined it with surface enhanced Raman scattering (SERS) sensing for the screening of a biological process, namely for the quantification of a bacterial secondary metabolite, p-coumaric acid (pHCA), produced by Escherichia coli. The microfluidic device proved to be robust and reusable, enabling efficient removal of interfering compounds from the real samples, reaching more than 13-fold up-concentration of the donor at 10 μL min -1 flow rate. With this method, we quantified pHCA directly from the bacterial supernatant, distinguishing between various culture conditions based on the pHCA production yield. The obtained data showed good correlation with HPLC analysis.

  7. Direct quantification of airborne nanoparticles composition by TXRF after collection on filters

    Energy Technology Data Exchange (ETDEWEB)

    Motellier, S; Lhaute, K; Guiot, A; Golanski, L; Tardif, F [CEA Grenoble, DRT, LITEN, DTNM, Laboratory of Nanochemistry and Nanosafety, 17 Avenue des Martyrs, Cedex 9, F-38054 Grenoble (France); Geoffroy, C, E-mail: sylvie.motellier@cea.fr [Elexience, 9 rue des petits ruisseaux, BP 61, 91371 Verrieres-le-Buisson Cedex (France)

    2011-07-06

    Direct TXRF analysis of nanoparticles deposited on filters was evaluated. Standard filters spiked with known amounts of NP were produced using an atomizer which generates an aerosol from a NP containing-liquid suspension. Polycarbonate filters provided the highest fluorescence signals and black polycarbonate filters containing chromium were further selected, Cr being used as internal standard for elemental quantification of the filter contaminants. Calibration curves were established for various NP (TiO{sub 2}, ZnO, CeO{sub 2}, Al{sub 2}O{sub 3}). Good linearity was observed. Low limits of detection were in the tens to the hundreds of ngs per filter, the method being less adapted to Al{sub 2}O{sub 3} due to the poor TXRF sensitivity for light elements. The analysis of MW-CNTs was attempted by quantification of their metal (Fe) catalyst impurities. Problems like CNT dispersion in liquids, quantification of the deposited quantity and high Fe-background contamination.

  8. Background Radiance Estimation for Gas Plume Quantification for Airborne Hyperspectral Thermal Imaging

    Directory of Open Access Journals (Sweden)

    Ramzi Idoughi

    2016-01-01

    Full Text Available Hyperspectral imaging in the long-wave infrared (LWIR is a mean that is proving its worth in the characterization of gaseous effluent. Indeed the spectral and spatial resolution of acquisition instruments is steadily decreasing, making the gases characterization increasingly easy in the LWIR domain. The majority of literature algorithms exploit the plume contribution to the radiance corresponding to the difference of radiance between the plume-present and plume-absent pixels. Nevertheless, the off-plume radiance is unobservable using a single image. In this paper, we propose a new method to retrieve trace gas concentration from airborne infrared hyperspectral data. More particularly the outlined method improves the existing background radiance estimation approach to deal with heterogeneous scenes corresponding to industrial scenes. It consists in performing a classification of the scene and then applying a principal components analysis based method to estimate the background radiance on each cluster stemming from the classification. In order to determine the contribution of the classification to the background radiance estimation, we compared the two approaches on synthetic data and Telops Fourier Transform Spectrometer (FTS Imaging Hyper-Cam LW airborne acquisition above ethylene release. We finally show ethylene retrieved concentration map and estimate flow rate of the ethylene release.

  9. Airborne Quantification of Methane Emissions in the San Francisco Bay Area of California

    Science.gov (United States)

    Guha, A.; Newman, S.; Martien, P. T.; Young, A.; Hilken, H.; Faloona, I. C.; Conley, S.

    2017-12-01

    The Bay Area Air Quality Management District, the San Francisco Bay Area's air quality regulatory agency, has set a goal to reduce the region's greenhouse gas (GHG) emissions 80% below 1990 levels by 2050, consistent with the State of California's climate protection goal. The Air District maintains a regional GHG emissions inventory that includes emissions estimates and projections which influence the agency's programs and regulatory activities. The Air District is currently working to better characterize methane emissions in the GHG inventory through source-specific measurements, to resolve differences between top-down regional estimates (Fairley and Fischer, 2015; Jeong et al., 2016) and the bottom-up inventory. The Air District funded and participated in a study in Fall 2016 to quantify methane emissions from a variety of sources from an instrumented Mooney aircraft. This study included 40 hours of cylindrical vertical profile flights that combined methane and wind measurements to derive mass emission rates. Simultaneous measurements of ethane provided source-apportionment between fossil-based and biological methane sources. The facilities sampled included all five refineries in the region, five landfills, two dairy farms and three wastewater treatment plants. The calculated mass emission rates were compared to bottom-up rates generated by the Air District and to those from facility reports to the US EPA as part of the mandatory GHG reporting program. Carbon dioxide emission rates from refineries are found to be similar to bottom-up estimates for all sources, supporting the efficacy of the airborne measurement methodology. However, methane emission estimates from the airborne method showed significant differences for some source categories. For example, methane emission estimates based on airborne measurements were up to an order of magnitude higher for refineries, and up to five times higher for landfills compared to bottom-up methods, suggesting significant

  10. Amplicon sequencing for the quantification of spoilage microbiota in complex foods including bacterial spores.

    Science.gov (United States)

    de Boer, Paulo; Caspers, Martien; Sanders, Jan-Willem; Kemperman, Robèr; Wijman, Janneke; Lommerse, Gijs; Roeselers, Guus; Montijn, Roy; Abee, Tjakko; Kort, Remco

    2015-01-01

    Spoilage of food products is frequently caused by bacterial spores and lactic acid bacteria. Identification of these organisms by classic cultivation methods is limited by their ability to form colonies on nutrient agar plates. In this study, we adapted and optimized 16S rRNA amplicon sequencing for quantification of bacterial spores in a canned food matrix and for monitoring the outgrowth of spoilage microbiota in a ready-to-eat food matrix. The detection limit of bar-coded 16S rRNA amplicon sequencing was determined for the number of bacterial spores in a canned food matrix. Analysis of samples from a canned food matrix spiked with a mixture of equinumerous spores from the thermophiles, Geobacillus stearothermophilus and Geobacillus thermoglucosidans, and the mesophiles, Bacillus sporothermodurans, Bacillus cereus, and Bacillus subtilis, led to the detection of these spores with an average limit of 2 × 10(2) spores ml(-1). The data were normalized by setting the number of sequences resulting from DNA of an inactivated bacterial species, present in the matrix at the same concentration in all samples, to a fixed value for quantitative sample-to-sample comparisons. The 16S rRNA amplicon sequencing method was also employed to monitor population dynamics in a ready-to-eat rice meal, incubated over a period of 12 days at 7 °C. The most predominant outgrowth was observed by the genera Leuconostoc, Bacillus, and Paenibacillus. Analysis of meals pre-treated with weak acids showed inhibition of outgrowth of these three genera. The specificity of the amplicon synthesis was improved by the design of oligonucleotides that minimize the amplification of 16S rRNA genes from chloroplasts originating from plant-based material present in the food. This study shows that the composition of complex spoilage populations, including bacterial spores, can be monitored in complex food matrices by bar-coded amplicon sequencing in a quantitative manner. In order to allow sample

  11. Model structural uncertainty quantification and hydrogeophysical data integration using airborne electromagnetic data (Invited)

    DEFF Research Database (Denmark)

    Minsley, Burke; Christensen, Nikolaj Kruse; Christensen, Steen

    estimates of model structural uncertainty are then combined with hydrologic observations to assess the impact of model structural error on hydrologic calibration and prediction errors. Using a synthetic numerical model, we describe a sequential hydrogeophysical approach that: (1) uses Bayesian Markov chain...... Monte Carlo (McMC) methods to produce a robust estimate of uncertainty in electrical resistivity parameter values, (2) combines geophysical parameter uncertainty estimates with borehole observations of lithology to produce probabilistic estimates of model structural uncertainty over the entire AEM...... of airborne electromagnetic (AEM) data to estimate large-scale model structural geometry, i.e. the spatial distribution of different lithological units based on assumed or estimated resistivity-lithology relationships, and the uncertainty in those structures given imperfect measurements. Geophysically derived...

  12. Model structural uncertainty quantification and hydrologic parameter and prediction error analysis using airborne electromagnetic data

    DEFF Research Database (Denmark)

    Minsley, B. J.; Christensen, Nikolaj Kruse; Christensen, Steen

    electromagnetic (AEM) data. Our estimates of model structural uncertainty follow a Bayesian framework that accounts for both the uncertainties in geophysical parameter estimates given AEM data, and the uncertainties in the relationship between lithology and geophysical parameters. Using geostatistical sequential......Model structure, or the spatial arrangement of subsurface lithological units, is fundamental to the hydrological behavior of Earth systems. Knowledge of geological model structure is critically important in order to make informed hydrological predictions and management decisions. Model structure...... is never perfectly known, however, and incorrect assumptions can be a significant source of error when making model predictions. We describe a systematic approach for quantifying model structural uncertainty that is based on the integration of sparse borehole observations and large-scale airborne...

  13. Opposite effects of inhaled cadmium microparticles on mouse susceptibility to an airborne bacterial and an airborne viral infection

    Energy Technology Data Exchange (ETDEWEB)

    Bouley, G.; Chaumard, C.; Quero, A.M.; Girard, F.; Boudene, C.

    1982-04-01

    An experimental study on 489 mice is reported. The test animals were submitted to a single 15-mn exposure to atmosphere containing about 10 mg of cadmium microparticles (CdO) per m3 of air and the controls to an equivalent amount of aluminium microparticles (Al/sub 2/O/sub 3/). At the 48th hour after exposures, the test and control mice were submitted to a bacterial (Pasteurella multocida) or to a viral (Orthomyxovirus influenzae A) challenge, via the respiratory route. The exposure to cadmium significantly increased the death-rate of mice submitted to the bacterial challenge, but it significantly decreased the death-rate following the viral challenge.

  14. Quantification of morphology of bacterial colonies using laser scatter measurements and solid element optical modeling

    Science.gov (United States)

    Leavesley, Silas; Bayraktar, Bülent; Venkatapathi, Murugesan; Hirleman, E. Dan; Bhunia, Arun K.; Robinson, J. Paul; Hassler, Richard; Smith, Linda; Rajwa, Bartek

    2007-02-01

    Traditional biological and chemical methods for pathogen identification require complicated sample preparation for reliable results. Optical scattering technology has been used for identification of bacterial cells in suspension, but with only limited success. Our published reports have demonstrated that scattered light based identification of Listeria colonies growing on solid surfaces is feasible with proper pattern recognition tools. Recently we have extended this technique to classification of other bacterial genera including, Salmonella, Bacillus, and Vibrio. Our approach may be highly applicable to early detection and classification of pathogens in food-processing industry and in healthcare. The unique scattering patterns formed by colonies of different species are created through differences in colony microstructure (on the order of wavelength used), bulk optical properties, and the macroscopic morphology. While it is difficult to model the effect on scatter-signal patterns owing to the microstructural changes, the influence of bulk optical properties and overall shape of colonies can be modeled using geometrical optics. Our latest research shows that it is possible to model the scatter pattern of bacterial colonies using solid-element optical modeling software (TracePro), and theoretically assess changes in macro structure and bulk refractive indices. This study allows predicting the theoretical limits of resolution and sensitivity of our detection and classification methods. Moreover, quantification of changes in macro morphology and bulk refractive index provides an opportunity to study the response of colonies to various reagents and antibiotics.

  15. Quantification of airborne fossil and biomass carbonylic carbon by combined radiocarbon and liquid chromatography mass spectrometry

    Science.gov (United States)

    Larsen, B. R.; Tudos, A.; Slanina, J.; Van der Borg, K.; Kotzias, D.

    Airborne carbonyl compounds have been sampled at three European semi-remote to semi-urban test sites for radiocarbon ( 14C) analysis. The used methodology included collection on 2,4-dinitrophenylhydrazine coated silica gel cartridges, chromatographic isolation of the formed hydrazones, combustion into CO 2, reduction into graphite followed by accelerator mass spectrometry. In combination with this, liquid chromatography coupled to atmospheric pressure chemical ionisation mass spectrometry was used for chemical speciation of the collected carbonyls. At all sites the carbonyls were found to be of a mixed biogenic/anthropogenic origin. The determining factor for the proportion of fossil (anthropogenic) carbon in the samples was the vicinity of urban sources for carbonyls and their photochemical precursors. At meteorological conditions, which gave the test sites semi-rural/semi-remote characteristics the samples contained an average of 24% (range: 10-34%) of fossil carbonylic carbon. When air masses were transported from urban areas to the test-sites significantly higher proportions of fossil carbonylic carbon were determined with a maximum of 61%. Principal component analysis on this limited data set indicated that a low fossil proportion of carbonylic carbon is associated with high proportions of acetaldehyde, acetone, pentanone and acrolein. Until further radicarbon studies are carried out the conclusion remains that for the carbonyl compounds measured European background levels are of a predominant biogenic origin.

  16. Variations in airborne bacterial communities at high altitudes over the Noto Peninsula (Japan) in response to Asian dust events

    Science.gov (United States)

    Maki, Teruya; Hara, Kazutaka; Iwata, Ayumu; Lee, Kevin C.; Kawai, Kei; Kai, Kenji; Kobayashi, Fumihisa; Pointing, Stephen B.; Archer, Stephen; Hasegawa, Hiroshi; Iwasaka, Yasunobu

    2017-10-01

    Aerosol particles, including airborne microorganisms, are transported through the free troposphere from the Asian continental area to the downwind area in East Asia and can influence climate changes, ecosystem dynamics, and human health. However, the variations present in airborne bacterial communities in the free troposphere over downwind areas are poorly understood, and there are few studies that provide an in-depth examination of the effects of long-range transport of aerosols (natural and anthropogenic particles) on bacterial variations. In this study, the vertical distributions of airborne bacterial communities at high altitudes were investigated and the bacterial variations were compared between dust events and non-dust events.Aerosols were collected at three altitudes from ground level to the free troposphere (upper level: 3000 or 2500 m; middle level: 1200 or 500 m; and low level: 10 m) during Asian dust events and non-dust events over the Noto Peninsula, Japan, where westerly winds carry aerosols from the Asian continental areas. During Asian dust events, air masses at high altitudes were transported from the Asian continental area by westerly winds, and laser imaging detection and ranging (lidar) data indicated high concentrations of non-spherical particles, suggesting that dust-sand particles were transported from the central desert regions of Asia. The air samples collected during the dust events contained 10-100 times higher concentrations of microscopic fluorescent particles and optical particle counter (OPC) measured particles than in non-dust events. The air masses of non-dust events contained lower amounts of dust-sand particles. Additionally, some air samples showed relatively high levels of black carbon, which were likely transported from the Asian continental coasts. Moreover, during the dust events, microbial particles at altitudes of > 1200 m increased to the concentrations ranging from 1. 2 × 106 to 6. 6 × 106 particles m-3. In contrast

  17. Variations in airborne bacterial communities at high altitudes over the Noto Peninsula (Japan in response to Asian dust events

    Directory of Open Access Journals (Sweden)

    T. Maki

    2017-10-01

    Full Text Available Aerosol particles, including airborne microorganisms, are transported through the free troposphere from the Asian continental area to the downwind area in East Asia and can influence climate changes, ecosystem dynamics, and human health. However, the variations present in airborne bacterial communities in the free troposphere over downwind areas are poorly understood, and there are few studies that provide an in-depth examination of the effects of long-range transport of aerosols (natural and anthropogenic particles on bacterial variations. In this study, the vertical distributions of airborne bacterial communities at high altitudes were investigated and the bacterial variations were compared between dust events and non-dust events.Aerosols were collected at three altitudes from ground level to the free troposphere (upper level: 3000 or 2500 m; middle level: 1200 or 500 m; and low level: 10 m during Asian dust events and non-dust events over the Noto Peninsula, Japan, where westerly winds carry aerosols from the Asian continental areas. During Asian dust events, air masses at high altitudes were transported from the Asian continental area by westerly winds, and laser imaging detection and ranging (lidar data indicated high concentrations of non-spherical particles, suggesting that dust-sand particles were transported from the central desert regions of Asia. The air samples collected during the dust events contained 10–100 times higher concentrations of microscopic fluorescent particles and optical particle counter (OPC measured particles than in non-dust events. The air masses of non-dust events contained lower amounts of dust-sand particles. Additionally, some air samples showed relatively high levels of black carbon, which were likely transported from the Asian continental coasts. Moreover, during the dust events, microbial particles at altitudes of  >  1200 m increased to the concentrations ranging from 1. 2 × 106 to 6

  18. Optimization of quantitative polymerase chain reactions for detection and quantification of eight periodontal bacterial pathogens

    Directory of Open Access Journals (Sweden)

    Decat Ellen

    2012-12-01

    Full Text Available Abstract Background The aim of this study was to optimize quantitative (real-time polymerase chain reaction (qPCR assays for 8 major periodontal pathogens, i.e. Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum, Parvimonas micros, Porphyromonas gingivalis, Prevotella intermedia, Tanerella forsythia and Treponema denticola, and of the caries pathogen Streptococcus mutans. Results Eighteen different primer pairs were analyzed in silico regarding specificity (using BLAST analysis and the presence of secondary structures at primer binding sites (using mFOLD. The most specific and efficiently binding primer pairs, according to these analyses, were selected for qPCR-analysis to determine amplification efficiency, limit of quantification and intra-run reproducibility. For the selected primer pairs, one for each species, the specificity was confirmed by assessing amplification of DNA extracts from isolates of closely related species. For these primer pairs, the intercycler portability was evaluated on 3 different thermal cyclers (the Applied Biosystems 7300, the Bio-Rad iQ5 and the Roche Light Cycler 480. For all assays on the different cyclers, a good correlation of the standard series was obtained (i.e. r2 ≥ 0.98, but quantification limits varied among cyclers. The overall best quantification limit was obtained by using a 2 μl sample in a final volume of 10 μl on the Light Cycler 480. Conclusions In conclusion, the proposed assays allow to quantify the bacterial loads of S. mutans, 6 periodontal pathogenic species and the genus Fusobacterium.This can be of use in assessing periodontal risk, determination of the optimal periodontal therapy and evaluation of this treatment.

  19. Seasonal variability in airborne bacterial communities at a high elevation site and their relationship to other air studies and to potential sources

    Science.gov (United States)

    Bowers, R. M.; Mccubbin, I. B.; Hallar, A. G.; Fierer, N.

    2012-12-01

    Airborne bacteria are a large component of the near-surface atmospheric aerosol; however we know surprisingly little about their spatiotemporal dynamics and even less about their distributions at high-elevation. With this work, we describe seasonal shifts in bacterial abundances, total particle abundances, and bacterial community structure at a high-elevation research station located in Colorado, USA. In addition, we describe the unique composition of these high-elevation airborne bacterial communities as compared to the bacteria commonly observed throughout the lower elevation atmosphere as well as bacteria common to major sources such as leaf surfaces, soils, water bodies and various other surfaces. To address these knowledge gaps, we collected aerosol samples on the rooftop of Storm Peak Laboratory (3200 m ASL) over the course of 2-3 week periods during each of the four calendar seasons. Total bacterial abundances were assessed via flow cytometry, total particle abundances were calculated with an aerodynamic particle sizer, and bacterial communities were characterized using a high-throughput barcoded DNA sequencing approach. The airborne bacterial communities at Storm Peak Lab were then used in a meta-analysis comparing Storm Peak bacteria to other near-surface (lower elevation) bacterial communities and to the communities of likely source environments. Bacterial abundances varied by season, which was similar but not identical to the changes in total particle abundances across the same sampling period. Airborne bacterial community structure varied significantly by season, with the summer communities being the most distinct. Season specific bacterial groups were identified, suggesting that a large proportion of the airborne community may be derived from nearby sources. However following a multi-environment meta-analysis using several air and source derived bacterial community datasets, the high-elevation air communities were the most distinct as compared to the

  20. Mapping, Quantification and Analysis of Gravitative Processes Based on Repeat Airborne Lidar Datasets

    Science.gov (United States)

    Ebe, V.; Sailer, R.; Bollmann, E.; Mitterer, S.; Klug, C.; Stötter, J.

    2012-12-01

    In recent years the use of airborne laser scanning (ALS) data has gained increasingly in importance in geomorphology. Most research is based on the analysis of morphometric parameters derived from a single high-resolution digital elevation model (DEM). In contrast to the aforementioned mono-temporal analyses, in this study geomorphologic process areas are mapped, quantified and statistically evaluated by means of repeat ALS datasets. The study area is located in the Central Tyrolean Alps, Austria (Oetztal, Pitztal, Kaunertal and Nauderer Mountains) and covers an area of about 750 km^2. ALS point data of this area from 2006 and 2010 are used to calculate DEMs in various raster resolutions (1 m, 3 m, 5 m, 10 m). The mapping of the geomorphologic process areas is carried out on the basis of DEM differencing calculated from the 2006 and 2010 DEMs (dDEM). In these dDEMs, areas with a decrease in elevation (erosion) as well as areas with an increase in elevation (deposition) can be identified and mapped. The mapped process areas are thereafter classified into the gravitative process types rock fall, land slide and debris flow based on their morphometric characteristics. The analyses show that depending on the raster resolution a different number of processes can be identified. In the lowest resolution class (10 m) 62 distinct process areas could be mapped, whereas in the highest resolution class (1 m) 181 process areas could be identified. In the highest resolution a total of 78 process areas are mapped in the Oetztal area, of which 33 are classified as rock falls, 37 as land slides and 18 as debris flows. 23 areas were mapped in the Pitztal area (8 rock falls, 6 land slides and 18 debris flows), 55 in the Kaunertal area (11 rock falls, 9 land slides, 35 debris flows) and 16 in the Nauderer Mountains (4 rock falls, 2 land slides, 10 debris flows). All mapped process areas are within the elevation band from 2200 m to 3400 m. Almost all rock falls released above 3000 m in

  1. Dynamic solid phase microextraction for sampling of airborne sarin with gas chromatography-mass spectrometry for rapid field detection and quantification.

    Science.gov (United States)

    Hook, Gary L; Jackson Lepage, Carmela; Miller, Stephen I; Smith, Philip A

    2004-08-01

    A portable dynamic air sampler and solid phase microextraction were used to simultaneously detect, identify, and quantify airborne sarin with immediate analysis of samples using a field portable gas chromatography-mass spectrometry system. A mathematical model was used with knowledge of the mass of sarin trapped, linear air velocity past the exposed sampling fiber, and sample duration allowing calculation of concentration estimates. For organizations with suitable field portable instrumentation, these methods are potentially useful for rapid onsite detection and quantification of high concern analytes, either through direct environmental sampling or through sampling of air collected in bags.

  2. Protocol for Evaluating the Permissiveness of Bacterial Communities Toward Conjugal Plasmids by Quantification and Isolation of Transconjugants

    DEFF Research Database (Denmark)

    Klümper, Uli; Dechesne, Arnaud; Smets, Barth F.

    2014-01-01

    The transfer of conjugal plasmids is the main bacterial process of horizontal gene transfer to potentially distantly related bacteria. These extrachromosomal, circular DNA molecules host genes that code for their own replication and transfer to other organisms. Because additional accessory genes...... of a microbial community able to receive an introduced plasmid at both quantitative and phylogenetic levels. In this chapter, we describe a protocol for simultaneous quantification of plasmid transfer frequency to and high-throughput isolation of transconjugants from a mixed bacterial community after introducing...

  3. Vertical distribution of airborne bacterial communities in an Asian-dust downwind area, Noto Peninsula

    Science.gov (United States)

    Maki, Teruya; Hara, Kazutaka; Kobayashi, Fumihisa; Kurosaki, Yasunori; Kakikawa, Makiko; Matsuki, Atsushi; Chen, Bin; Shi, Guangyu; Hasegawa, Hiroshi; Iwasaka, Yasunobu

    2015-10-01

    Bacterial populations transported from ground environments to the atmosphere get dispersed throughout downwind areas and can influence ecosystem dynamics, human health, and climate change. However, the vertical bacterial distribution in the free troposphere was rarely investigated in detail. We collected aerosols at altitudes of 3000 m, 1000 m, and 10 m over the Noto Peninsula, Japan, where the westerly winds carry aerosols from continental and marine areas. During the sampling period on March 10, 2012, the air mass at 3000 m was transported from the Chinese desert region by the westerly winds, and a boundary layer was formed below 2000 m. Pyrosequencing targeting 16S rRNA genes (16S rDNA) revealed that the bacterial community at 3000 m was predominantly composed of terrestrial bacteria, such as Bacillus and Actinobacterium species. In contrast, those at 1000 m and 10 m included marine bacteria belonging to the classes Cyanobacteria and Alphaproteobacteria. The entire 16S rDNA sequences in the clone libraries were identical to those of the terrestrial and marine bacterial species, which originated from the Chinese desert region and the Sea of Japan, respectively. The origins of air masses and meteorological conditions contribute to vertical variations in the bacterial communities in downwind atmosphere.

  4. Quantification and risks associated with bacterial aerosols near domestic greywater-treatment systems

    Energy Technology Data Exchange (ETDEWEB)

    Benami, Maya; Busgang, Allison; Gillor, Osnat; Gross, Amit, E-mail: amgross@exchange.bgu.ac.il

    2016-08-15

    to provide more accurate quantification of small amounts of viable, aerosolized bacterial pathogens. - Highlights: • Greywater aerosols had higher bacterial counts compared to background amounts. • Low pathogen counts were detected on settle-plates from greywater aerosols. • Before enrichment no bacteria were found in greywater aerosols, using a BioSampler®. • After enrichment some pathogens were occasionally found in the greywater aerosols. • QMRA results show that greywater aerosols were below safety limits for S. aureus.

  5. Detection and quantification of bacterial spoilage in milk and pork meat using MALDI-TOF-MS and multivariate analysis.

    Science.gov (United States)

    Nicolaou, Nicoletta; Xu, Yun; Goodacre, Royston

    2012-07-17

    Microbiological safety is one of the cornerstones of quality control in the food industry. Identification and quantification of spoilage bacteria in pasteurized milk and meat in the food industry currently relies on accurate and sensitive yet time-consuming techniques which give retrospective values for microbial contamination. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS), a proven technique in the field of protein and peptide identification and quantification, may be a valuable alternative approach for the rapid assessment of microbial spoilage. In this work we therefore developed MALDI-TOF-MS as a novel analytical approach for the assessment of food that when combined with chemometrics allows for the detection and quantification of milk and pork meat spoilage bacteria. To develop this approach, natural spoilage of pasteurized milk and raw pork meat samples incubated at 15 °C and at room temperature, respectively, was conducted. Samples were collected for MALDI-TOF-MS analysis (which took 4 min per sample) at regular time intervals throughout the spoilage process, with concurrent calculation and documentation of reference total viable counts using traditional microbiological methods (these took 2 days). Multivariate statistical techniques such as principal component discriminant function analysis, canonical correlation analysis, partial least-squares (PLS) regression, and kernel PLS (KPLS) were used to analyze the data. The results from MALDI-TOF-MS combined with PLS or KPLS gave excellent bacterial quantification results for both milk and meat spoilage, and typical root mean squared errors for prediction in test spectra were between 0.53 and 0.79 log unit. Overall these novel findings strongly indicate that MALDI-TOF-MS when combined with chemometric approaches would be a useful adjunct for routine use in the milk and meat industry as a fast and accurate viable bacterial detection and quantification method.

  6. Airborne fungal and bacterial components in PM1 dust from biofuel plants.

    Science.gov (United States)

    Madsen, Anne Mette; Schlünssen, Vivi; Olsen, Tina; Sigsgaard, Torben; Avci, Hediye

    2009-10-01

    Fungi grown in pure cultures produce DNA- or RNA-containing particles smaller than spore size ( 3)-beta-D-glucans. In the 29 PM(1) samples, cultivable fungi were found in six samples and with a median concentration below detection level. Using microscopy, fungal spores were identified in 22 samples. The components NAGase and (1 --> 3)-beta-D-glucans, which are mainly associated with fungi, were present in all PM(1) samples. Thermophilic actinomycetes were present in 23 of the 29 PM(1) samples [average = 739 colony-forming units (CFU) m(-3)]. Cultivable and 'total bacteria' were found in average concentrations of, respectively, 249 CFU m(-3) and 1.8 x 10(5) m(-3). DNA- and RNA-containing particles of different lengths were counted by microscopy and revealed a high concentration of particles with a length of 0.5-1.5 microm and only few particles >1.5 microm. The number of cultivable fungi and beta-glucan in the total dust correlated significantly with the number of DNA/RNA-containing particles with lengths of between 1.0 and 1.5 microm, with DNA/RNA-containing particles >1.5 microm, and with other fungal components in PM(1) dust. Airborne beta-glucan and NAGase were found in PM(1) samples where no cultivable fungi were present, and beta-glucan and NAGase were found in higher concentrations per fungal spore in PM(1) dust than in total dust. This indicates that fungal particles smaller than fungal spore size are present in the air at the plants. Furthermore, many bacteria, including actinomycetes, were present in PM(1) dust. Only 0.2% of the bacteria in PM(1) dust were cultivable.

  7. Seasonal Variability of Airborne Particulate Matter and Bacterial Concentrations in Colorado Homes

    Directory of Open Access Journals (Sweden)

    Nicholas Clements

    2018-04-01

    Full Text Available Aerosol measurements were collected at fifteen homes over the course of one year in Colorado (USA to understand the temporal variability of indoor air particulate matter and bacterial concentrations and their relationship with home characteristics, inhabitant activities, and outdoor air particulate matter (PM. Indoor and outdoor PM2.5 concentrations averaged (±st. dev. 8.1 ± 8.1 μg/m3 and 6.8 ± 4.5 μg/m3, respectively. Indoor PM2.5 was statistically significantly higher during summer compared to spring and winter; outdoor PM2.5 was significantly higher for summer compared to spring and fall. The PM2.5 I/O ratio was 1.6 ± 2.4 averaged across all homes and seasons and was not statistically significantly different across the seasons. Average indoor PM10 was 15.4 ± 18.3 μg/m3 and was significantly higher during summer compared to all other seasons. Total suspended particulate bacterial biomass, as determined by qPCR, revealed very little seasonal differences across and within the homes. The qPCR I/O ratio was statistically different across seasons, with the highest I/O ratio in the spring and lowest in the summer. Using one-minute indoor PM10 data and activity logs, it was observed that elevated particulate concentrations commonly occurred when inhabitants were cooking and during periods with elevated outdoor concentrations.

  8. Detection and quantification of intracellular bacterial colonies by automated, high-throughput microscopy.

    Science.gov (United States)

    Ernstsen, Christina L; Login, Frédéric H; Jensen, Helene H; Nørregaard, Rikke; Møller-Jensen, Jakob; Nejsum, Lene N

    2017-08-01

    To target bacterial pathogens that invade and proliferate inside host cells, it is necessary to design intervention strategies directed against bacterial attachment, cellular invasion and intracellular proliferation. We present an automated microscopy-based, fast, high-throughput method for analyzing size and number of intracellular bacterial colonies in infected tissue culture cells. Cells are seeded in 48-well plates and infected with a GFP-expressing bacterial pathogen. Following gentamicin treatment to remove extracellular pathogens, cells are fixed and cell nuclei stained. This is followed by automated microscopy and subsequent semi-automated spot detection to determine the number of intracellular bacterial colonies, their size distribution, and the average number per host cell. Multiple 48-well plates can be processed sequentially and the procedure can be completed in one working day. As a model we quantified intracellular bacterial colonies formed by uropathogenic Escherichia coli (UPEC) during infection of human kidney cells (HKC-8). Urinary tract infections caused by UPEC are among the most common bacterial infectious diseases in humans. UPEC can colonize tissues of the urinary tract and is responsible for acute, chronic, and recurrent infections. In the bladder, UPEC can form intracellular quiescent reservoirs, thought to be responsible for recurrent infections. In the kidney, UPEC can colonize renal epithelial cells and pass to the blood stream, either via epithelial cell disruption or transcellular passage, to cause sepsis. Intracellular colonies are known to be clonal, originating from single invading UPEC. In our experimental setup, we found UPEC CFT073 intracellular bacterial colonies to be heterogeneous in size and present in nearly one third of the HKC-8 cells. This high-throughput experimental format substantially reduces experimental time and enables fast screening of the intracellular bacterial load and cellular distribution of multiple

  9. [Characterizing Beijing's Airborne Bacterial Communities in PM2.5 and PM1 Samples During Haze Pollution Episodes Using 16S rRNA Gene Analysis Method].

    Science.gov (United States)

    Wang, Bu-ying; Lang, Ji-dong; Zhang, Li-na; Fang, Jian-huo; Cao, Chen; Hao, Ji-ming; Zhu, Ting; Tian, Geng; Jiang, Jing-kun

    2015-08-01

    During 8th-14th Jan., 2013, severe particulate matter (PM) pollution episodes happened in Beijing. These air pollution events lead to high risks for public health. In addition to various PM chemical compositions, biological components in the air may also impose threaten. Little is known about airborne microbial community in such severe air pollution conditions. PM2.5 and PM10 samples were collected during that 7-day pollution period. The 16S rRNA gene V3 amplification and the MiSeq sequencing were performed for analyzing these samples. It is found that there is no significant difference at phylum level for PM2.5 bacterial communities during that 7-day pollution period both at phylum and at genus level. At genus level, Arthrobacter and Frankia are the major airborne microbes presented in Beijing winter.samples. At genus level, there are 39 common genera (combined by first 50 genera bacterial of the two analysis) between the 16S rRNA gene analysis and those are found by Metagenomic analysis on the same PM samples. Frankia and Paracoccus are relatively more abundant in 16S rRNA gene data, while Kocuria and Geodermatophilus are relatively more abundant in Meta-data. PM10 bacterial communities are similar to those of PM2.5 with some noticeable differences, i.e., at phylum level, more Firmicutes and less Actinobacteria present in PM10 samples than in PM2.5 samples, while at genus level, more Clostridium presents in PM10 samples. The findings in Beijing were compared with three 16S rRNA gene studies in other countries. Although the sampling locations and times are different from each other, compositions of bacterial community are similar for those sampled at the ground atmosphere. Airborne microbial communities near the ground surface are different from those sampled in the upper troposphere.

  10. Detection and quantification of intracellular bacterial colonies by automated, high-throughput microscopy

    DEFF Research Database (Denmark)

    Ernstsen, Christina L; Login, Frédéric H; Jensen, Helene H.

    2017-01-01

    cell disruption or transcellular passage, to cause sepsis. Intracellular colonies are known to be clonal, originating from single invading UPEC. In our experimental setup, we found UPEC CFT073 intracellular bacterial colonies to be heterogeneous in size and present in nearly one third of the HKC-8...... day. As a model we quantified intracellular bacterial colonies formed by uropathogenic Escherichia coli (UPEC) during infection of human kidney cells (HKC-8). Urinary tract infections caused by UPEC are among the most common bacterial infectious diseases in humans. UPEC can colonize tissues...

  11. Quantification of bacterial and archaeal symbionts in high and low microbial abundance sponges using real-time PCR

    KAUST Repository

    Bayer, Kristina

    2014-07-09

    In spite of considerable insights into the microbial diversity of marine sponges, quantitative information on microbial abundances and community composition remains scarce. Here, we established qPCR assays for the specific quantification of four bacterial phyla of representative sponge symbionts as well as the kingdoms Eubacteria and Archaea. We could show that the 16S rRNA gene numbers of Archaea, Chloroflexi, and the candidate phylum Poribacteria were 4-6 orders of magnitude higher in high microbial abundance (HMA) than in low microbial abundance (LMA) sponges and that actinobacterial 16S rRNA gene numbers were 1-2 orders higher in HMA over LMA sponges, while those for Cyanobacteria were stable between HMA and LMA sponges. Fluorescence in situ hybridization of Aplysina aerophoba tissue sections confirmed the numerical dominance of Chloroflexi, which was followed by Poribacteria. Archaeal and actinobacterial cells were detected in much lower numbers. By use of fluorescence-activated cell sorting as a primer- and probe-independent approach, the dominance of Chloroflexi, Proteobacteria, and Poribacteria in A. aerophoba was confirmed. Our study provides new quantitative insights into the microbiology of sponges and contributes to a better understanding of the HMA/LMA dichotomy. The authors quantified sponge symbionts in eight sponge species from three different locations by real time PCR targetting 16S rRNA genes. Additionally, FISH was performed and diversity and abundance of singularized microbial symbionts from Aplysina aerophoba was determined for a comprehensive quantification work. © 2014 Federation of European Microbiological Societies.

  12. Amplicon sequencing for the quantification of spoilage microbiota in complex foods including bacterial spores

    NARCIS (Netherlands)

    Boer, de P.; Caspers, M.; Sanders, J.W.; Kemperman, R.; Wijman, J.; Lommerse, G.; Roeselers, G.; Montijn, R.; Abee, T.; Kort, R.

    2015-01-01

    Background
    Spoilage of food products is frequently caused by bacterial spores and lactic acid bacteria. Identification of these organisms by classic cultivation methods is limited by their ability to form colonies on nutrient agar plates. In this study, we adapted and optimized 16S rRNA amplicon

  13. Comparison among the Quantification of Bacterial Pathogens by qPCR, dPCR, and Cultural Methods

    Directory of Open Access Journals (Sweden)

    Matteo Ricchi

    2017-06-01

    Full Text Available The demand for rapid methods for the quantification of pathogens is increasing. Among these methods, those based on nucleic acids amplification (quantitative PCRs are the most widespread worldwide. Together with the qPCR, a new approach named digital PCR (dPCR, has rapidly gained importance. The aim of our study was to compare the results obtained using two different dPCR systems and one qPCR in the quantification of three different bacterial pathogens: Listeria monocytogenes, Francisella tularensis, and Mycobacterium avium subsp. paratuberculosis. For this purpose, three pre-existing qPCRs were used, while the same primers and probes, as well as PCR conditions, were transferred to two different dPCR systems: the QX200 (Bio-Rad and the Quant Studio 3D (Applied Biosystems. The limits of detection and limits of quantification for all pathogens, and all PCR approaches applied, were determined using genomic pure DNAs. The quantification of unknown decimal suspensions of the three bacteria obtained by the three different PCR approaches was compared through the Linear Regression and Bland and Altman analyses. Our results suggest that, both dPCRs are able to quantify the same amount of bacteria, while the comparison among dPCRs and qPCRs, showed both over and under-estimation of the bacteria present in the unknown suspensions. Our results showed qPCR over-estimated the amount of M. avium subsp. paratuberculosis and F. tularensis cells. On the contrary, qPCR, compared to QX200 dPCR, under-estimated the amount of L. monocytogenes cells. However, the maximum difference among PCRs approaches was <0.5 Log10, while cultural methods underestimated the number of bacteria by one to two Log10 for Francisella tularensis and Mycobacterium avium subsp. paratuberculosis. On the other hand, cultural and PCRs methods quantified the same amount of bacteria for L. monocytogenes, suggesting for this last pathogen, PCRs approaches can be considered as a valid alternative

  14. Atmospheric characterization through fused mobile airborne and surface in situ surveys: methane emissions quantification from a producing oil field

    Directory of Open Access Journals (Sweden)

    I. Leifer

    2018-03-01

    Full Text Available Methane (CH4 inventory uncertainties are large, requiring robust emission derivation approaches. We report on a fused airborne–surface data collection approach to derive emissions from an active oil field near Bakersfield, central California. The approach characterizes the atmosphere from the surface to above the planetary boundary layer (PBL and combines downwind trace gas concentration anomaly (plume above background with normal winds to derive flux. This approach does not require a well-mixed PBL; allows explicit, data-based, uncertainty evaluation; and was applied to complex topography and wind flows. In situ airborne (collected by AJAX – the Alpha Jet Atmospheric eXperiment and mobile surface (collected by AMOG – the AutoMObile trace Gas – Surveyor data were collected on 19 August 2015 to assess source strength. Data included an AMOG and AJAX intercomparison transect profiling from the San Joaquin Valley (SJV floor into the Sierra Nevada (0.1–2.2 km altitude, validating a novel surface approach for atmospheric profiling by leveraging topography. The profile intercomparison found good agreement in multiple parameters for the overlapping altitude range from 500 to 1500 m for the upper 5 % of surface winds, which accounts for wind-impeding structures, i.e., terrain, trees, buildings, etc. Annualized emissions from the active oil fields were 31.3 ± 16 Gg methane and 2.4 ± 1.2 Tg carbon dioxide. Data showed the PBL was not well mixed at distances of 10–20 km downwind, highlighting the importance of the experimental design.

  15. RECONSTRUCTION, QUANTIFICATION, AND VISUALIZATION OF FOREST CANOPY BASED ON 3D TRIANGULATIONS OF AIRBORNE LASER SCANNING POINT DATA

    Directory of Open Access Journals (Sweden)

    J. Vauhkonen

    2015-03-01

    Full Text Available Reconstruction of three-dimensional (3D forest canopy is described and quantified using airborne laser scanning (ALS data with densities of 0.6–0.8 points m-2 and field measurements aggregated at resolutions of 400–900 m2. The reconstruction was based on computational geometry, topological connectivity, and numerical optimization. More precisely, triangulations and their filtrations, i.e. ordered sets of simplices belonging to the triangulations, based on the point data were analyzed. Triangulating the ALS point data corresponds to subdividing the underlying space of the points into weighted simplicial complexes with weights quantifying the (empty space delimited by the points. Reconstructing the canopy volume populated by biomass will thus likely require filtering to exclude that volume from canopy voids. The approaches applied for this purpose were (i to optimize the degree of filtration with respect to the field measurements, and (ii to predict this degree by means of analyzing the persistent homology of the obtained triangulations, which is applied for the first time for vegetation point clouds. When derived from optimized filtrations, the total tetrahedral volume had a high degree of determination (R2 with the stem volume considered, both alone (R2=0.65 and together with other predictors (R2=0.78. When derived by analyzing the topological persistence of the point data and without any field input, the R2 were lower, but the predictions still showed a correlation with the field-measured stem volumes. Finally, producing realistic visualizations of a forested landscape using the persistent homology approach is demonstrated.

  16. Airborne Laser Scanning Quantification of Disturbances from Hurricanes and Lightning Strikes to Mangrove Forests in Everglades National Park, USA

    Directory of Open Access Journals (Sweden)

    Kevin Whelan

    2008-04-01

    Full Text Available Airborne light detection and ranging (LIDAR measurements derived before and after Hurricanes Katrina and Wilma (2005 were used to quantify the impact of hurricanes and lightning strikes on the mangrove forest at two sites in Everglades National Park (ENP. Analysis of LIDAR measurements covering 61 and 68 ha areas of mangrove forest at the Shark River and Broad River sites showed that the proportion of high tree canopy detected by the LIDAR after the 2005 hurricane season decreased significantly due to defoliation and breakage of branches and trunks, while the proportion of low canopy and the ground increased drastically. Tall mangrove forests distant from tidal creeks suffered more damage than lower mangrove forests adjacent to the tidal creeks. The hurricanes created numerous canopy gaps, and the number of gaps per square kilometer increased from about 400~500 to 4000 after Katrina and Wilma. The total area of gaps in the forest increased from about 1~2% of the total forest area to 12%. The relative contribution of hurricanes to mangrove forest disturbance in ENP is at least 2 times more than that from lightning strikes. However, hurricanes and lightning strikes disturb the mangrove forest in a related way. Most seedlings in lightning gaps survived the hurricane impact due to the protection of trees surrounding the gaps, and therefore provide an important resource for forest recovery after the hurricane. This research demonstrated that LIDAR is an effective remote sensing tool to quantify the effects of disturbances such as hurricanes and lightning strikes in the mangrove forest.

  17. Elemental quantification of airborne particulate matter by instrumental neutron activation analysis and induced coupled plasma mass spectrometry analysis

    International Nuclear Information System (INIS)

    Hidayat, Achmad; Djojosubroto, Harjoto; Rukihati; Sutisna

    1999-01-01

    Airborne particulate were collected using Gent sampler for PM 10 and using high volume sampler for total suspended particulate (TSP). PM 10 sampling was carried out in Bandung during period of January to December 1997. Whereas TSP samples were collected at Serpong (rural area) and Jakarta (urban area) during period of May and July 1995. The concentration of the PM 10 in the air is independent to the level of the rainfall. The levels of the PM 10 and the PM 2.5 are lower than the maximum permissible levels set by the US Environmental Protection Agency in July 1997. The element detected using short lived radioactivity measurement in PM 10 and PM 2.5 were Al, Na, V, Mn, Br and Cl. Bromine concentration in both coarse and fine fractions was high, and the enrichment factor for bromine in these fraction was found between 2,000 - 10,000. The elemental concentrations of particulate matter obtained by ICP-MS was found that the Ag, Al, As, Ba, Cd, Co, Cr, Cs, Cu, Fe, In, K, Mg, Mn, Na, Ni, Pb, Rb, V and Zn in samples from Serpong area, were lower than those in samples taken from Jakarta area. The level of Pb concentrations in TSP samples from Serpong and Jakarta area were lower than Pb concentration proposed Indonesian standard of 2 μg/m 3 . The data obtained by INAA no significant different to those obtained by ICP-MS. Therefore comparative data can be obtained by these techniques. (author)

  18. Quantification of bioavailable chlortetracycline in pig feces using a bacterial whole-cell biosensor

    DEFF Research Database (Denmark)

    Hansen, L. H.; Aarestrup, Frank Møller; Sørensen, S. J.

    2002-01-01

    Bacterial whole-cell biosensors were used to measure the concentration of chlortetracycline (CTC) in the feces of pigs. In this study, the Escherichia coli biosensor used has a detection limit of 0.03 mg/kg CTC in pig feces. The tetracycline concentration was correlated with the appearance...... in the feces, to within the same order of magnitude as the total coliform count. The high level of tetracycline resistance was maintained in spite of the declining concentration of tetracycline. (C) 2002 Elsevier Science B.V. All rights reserved....

  19. Assessment and determinants of airborne bacterial and fungal concentrations in different indoor environments: Homes, child day-care centres, primary schools and elderly care centres

    Science.gov (United States)

    Madureira, Joana; Paciência, Inês; Rufo, João Cavaleiro; Pereira, Cristiana; Teixeira, João Paulo; de Oliveira Fernandes, Eduardo

    2015-05-01

    Until now the influence of risk factors resulting from exposure to biological agents in indoor air has been far less studied than outdoor pollution; therefore the uncertainty of health risks, and how to effectively prevent these, remains. This study aimed (i) to quantify airborne cultivable bacterial and fungal concentrations in four different types of indoor environment as well as to identify the recovered fungi; (ii) to assess the impact of outdoor bacterial and fungal concentrations on indoor air; (iii) to investigate the influence of carbon dioxide (CO2), temperature and relative humidity on bacterial and fungal concentrations; and (iv) to estimate bacterial and fungal dose rate for children (3-5 years old and 8-10 years old) in comparison with the elderly. Air samples were collected in 68 homes, 9 child day-care centres, 20 primary schools and 22 elderly care centres, in a total of 264 rooms with a microbiological air sampler and using tryptic soy agar and malt extract agar culture media for bacteria and fungi growth, respectively. For each building, one outdoor representative location were identified and simultaneously studied. The results showed that child day-care centres were the indoor microenvironment with the highest median bacterial and fungal concentrations (3870 CFU/m3 and 415 CFU/m3, respectively), whereas the lowest median concentrations were observed in elderly care centres (222 CFU/m3 and 180 CFU/m3, respectively). Indoor bacterial concentrations were significantly higher than outdoor concentrations (p occupancy and insufficient ventilation. Penicillium and Cladosporium were the most frequently occurring fungi. Children's had two times higher dose rate to biological pollutants when compared to adult individuals. Thus, due to children's susceptibility, special attention should be given to educational settings in order to guarantee their healthy future development.

  20. Quantification of antibiotic drug potency by a two-compartment radioassay of bacterial growth

    International Nuclear Information System (INIS)

    Boonkitticharoen, V.; Ehrhardt, J.C.; Kirchner, P.T.

    1990-01-01

    The two-compartment radioassay for microbial kinetics based on continuous measurement of the 14 CO 2 released by bacterial metabolism of 14C-labeled substrate offers a valuable approach to testing the potency of antimicrobial drugs. By using a previously validated radioassay with gram-positive and gram-negative bacteria, a group of protein synthesis inhibitors was evaluated for their effect on microbial growth kinetics. All tested drugs induced changes in both the slopes and intercepts of the growth curves. An exponential growth model was applied to quantify the drug effect on the processes of bacterial 14 CO 2 liberation and cell generation. The response was measured in terms of a generation rate constant. A linear dependence of the generation rate constant on the dose of spectinomycin was observed with Escherichia coli. Sigmoidal-shaped curves were found in the assays of chloramphenicol and tetracycline. The implications of dose-response curves are discussed on the basis of the receptor site concept for drug action. The assay sensitivities for chloramphenicol and tetracycline were similar to those obtained by the cell counting method, but the sensitivity of the radioassay was at least 10 times greater for spectinomycin

  1. High-Throughput Quantification of Bacterial-Cell Interactions Using Virtual Colony Counts

    Directory of Open Access Journals (Sweden)

    Stefanie Hoffmann

    2018-02-01

    Full Text Available The quantification of bacteria in cell culture infection models is of paramount importance for the characterization of host-pathogen interactions and pathogenicity factors involved. The standard to enumerate bacteria in these assays is plating of a dilution series on solid agar and counting of the resulting colony forming units (CFU. In contrast, the virtual colony count (VCC method is a high-throughput compatible alternative with minimized manual input. Based on the recording of quantitative growth kinetics, VCC relates the time to reach a given absorbance threshold to the initial cell count using a series of calibration curves. Here, we adapted the VCC method using the model organism Salmonella enterica sv. Typhimurium (S. Typhimurium in combination with established cell culture-based infection models. For HeLa infections, a direct side-by-side comparison showed a good correlation of VCC with CFU counting after plating. For MDCK cells and RAW macrophages we found that VCC reproduced the expected phenotypes of different S. Typhimurium mutants. Furthermore, we demonstrated the use of VCC to test the inhibition of Salmonella invasion by the probiotic E. coli strain Nissle 1917. Taken together, VCC provides a flexible, label-free, automation-compatible methodology to quantify bacteria in in vitro infection assays.

  2. Microfluidic quantification of multiple enteric and opportunistic bacterial pathogens in roof-harvested rainwater tank samples.

    Science.gov (United States)

    Ahmed, Warish; Zhang, Qian; Ishii, Satoshi; Hamilton, Kerry; Haas, Charles

    2018-01-30

    Potable and non-potable uses of roof-harvested rainwater (RHRW) are increasing due to water shortages. To protect human health risks, it is important to identify and quantify disease-causing pathogens in RHRW so that appropriate treatment options can be implemented. We used a microfluidic quantitative PCR (MFQPCR) system for the quantitative detection of a wide array of fecal indicator bacteria (FIB) and pathogens in RHRW tank samples along with culturable FIB and conventional qPCR analysis of selected pathogens. Among the nine pathogenic bacteria and their associated genes tested with the MFQPCR, 4.86 and 2.77% samples were positive for Legionella pneumophila and Shigella spp., respectively. The remaining seven pathogens were absent. MFQPCR and conventional qPCR results showed good agreement. Therefore, direct pathogen quantification by MFQPCR systems may be advantageous for circumstances where a thorough microbial analysis is required to assess the public health risks from multiple pathogens that occur simultaneously in the target water source.

  3. Quantification of yeast and bacterial gene transcripts in retail cheeses by reverse transcription-quantitative PCR.

    Science.gov (United States)

    Monnet, Christophe; Straub, Cécile; Castellote, Jessie; Onesime, Djamila; Bonnarme, Pascal; Irlinger, Françoise

    2013-01-01

    The cheese microbiota contributes to a large extent to the development of the typical color, flavor, and texture of the final product. Its composition is not well defined in most cases and varies from one cheese to another. The aim of the present study was to establish procedures for gene transcript quantification in cheeses by reverse transcription-quantitative PCR. Total RNA was extracted from five smear-ripened cheeses purchased on the retail market, using a method that does not involve prior separation of microbial cells. 16S rRNA and malate:quinone oxidoreductase gene transcripts of Corynebacterium casei, Brevibacterium aurantiacum, and Arthrobacter arilaitensis and 26S rRNA and beta tubulin gene transcripts of Geotrichum candidum and Debaryomyces hansenii could be detected and quantified in most of the samples. Three types of normalization were applied: against total RNA, against the amount of cheese, and against a reference gene. For the first two types of normalization, differences of reverse transcription efficiencies from one sample to another were taken into account by analysis of exogenous control mRNA. No good correlation was found between the abundances of target mRNA or rRNA transcripts and the viable cell concentration of the corresponding species. However, in most cases, no mRNA transcripts were detected for species that did not belong to the dominant species. The applications of gene expression measurement in cheeses containing an undefined microbiota, as well as issues concerning the strategy of normalization and the assessment of amplification specificity, are discussed.

  4. Identification of airborne bacterial and fungal species in the clinical microbiology laboratory of a university teaching hospital employing ribosomal DNA (rDNA) PCR and gene sequencing techniques.

    Science.gov (United States)

    Nagano, Yuriko; Walker, Jim; Loughrey, Anne; Millar, Cherie; Goldsmith, Colin; Rooney, Paul; Elborn, Stuart; Moore, John

    2009-06-01

    Universal or "broad-range" PCR-based ribosomal DNA (rDNA) was performed on a collection of 58 isolates (n = 30 bacteria + 28 fungi), originating from environmental air from several locations within a busy clinical microbiology laboratory, supporting a university teaching hospital. A total of 10 bacterial genera were identified including both Gram-positive and Gram-negative genera. Gram-positive organisms accounted for 27/30 (90%) of total bacterial species, consisting of seven genera and included (in descending order of frequency) Staphylococcus, Micrococcus, Corynebacterium, Paenibacillus, Arthrobacter, Janibacter and Rothia. Gram-negative organisms were less frequently isolated 3/30 (10%) and comprised three genera, including Moraxella, Psychrobacter and Haloanella. Eight fungal genera were identified among the 28 fungal organisms isolated, including (in descending order of frequency) Cladosporium, Penicillium, Aspergillus, Thanatephorus, Absidia, Eurotium, Paraphaeosphaeria and Tritirachium, with Cladosporium accounting for 10/28 (35.7%) of the total fungal isolates. In conclusion, this study identified the presence of 10 bacterial and eight fungal genera in the air within the laboratory sampled. Although this reflected diversity of the microorganisms present, none of these organisms have been described previously as having an inhalational route of laboratory-acquired infection. Therefore, we believe that the species of organisms identified and the concentration levels of these airborne contaminants determined, do not pose a significant health and safety threat for immunocompotent laboratory personnel and visitors.

  5. Quantification of Live Bacterial Sensing for Chemotaxis and Phagocytosis and of Macropinocytosis

    Directory of Open Access Journals (Sweden)

    Netra P. Meena

    2018-03-01

    Full Text Available Initial immunological defense mechanisms to pathogen invasion rely on innate pathways of chemotaxis and phagocytosis, original to ancient phagocytes. Although chemotaxis has been well-studied in mammalian and model systems using purified chemoattractants in defined conditions, directed movement toward live bacteria has been more difficult to assess. Dictyostelium discoideum is a professional phagocyte that chemotaxes toward bacteria during growth-phase in a process to locate nutrient sources. Using Dictyostelium as a model, we have developed a system that is able to quantify chemotaxis to very high sensitivity. Here, Dictyostelium can detect various chemoattractants at concentrations <1 nM. Given this exceedingly sensitive signal response, Dictyostelium will migrate directionally toward live gram positive and gram negative bacteria, in a highly quantifiable manner, and dependent upon bacterially-secreted chemoattractants. Additionally, we have developed a real-time, quantitative assay for phagocytosis of live gram positive and gram negative bacteria. To extend the analyses of endocytic functions, we further modified the system to quantify cellular uptake via macropinocytosis of smaller (<100 kDa molecules. These various approaches provide novel means to dissect potential for identification of novel chemoattractants and mechanistic factors that are essential for chemotaxis, phagocytosis, and/or macropinocytosis and for more detailed understanding in host-pathogen interactive defenses.

  6. Quantification of bacterial species of the vaginal microbiome in different groups of women, using nucleic acid amplification tests

    Directory of Open Access Journals (Sweden)

    Jespers Vicky

    2012-05-01

    Full Text Available Abstract Background The vaginal microbiome plays an important role in urogenital health. Quantitative real time Polymerase Chain Reaction (qPCR assays for the most prevalent vaginal Lactobacillus species and bacterial vaginosis species G. vaginalis and A. vaginae exist, but qPCR information regarding variation over time is still very limited. We set up qPCR assays for a selection of seven species and defined the temporal variation over three menstrual cycles in a healthy Caucasian population with a normal Nugent score. We also explored differences in qPCR data between these healthy women and an ‘at risk’ clinic population of Caucasian, African and Asian women with and without bacterial vaginosis (BV, as defined by the Nugent score. Results Temporal stability of the Lactobacillus species counts was high with L. crispatus counts of 108 copies/mL and L. vaginalis counts of 106 copies/mL. We identified 2 types of ‘normal flora’ and one ‘BV type flora’ with latent class analysis on the combined data of all women. The first group was particularly common in women with a normal Nugent score and was characterized by a high frequency of L. crispatus, L. iners, L. jensenii, and L. vaginalis and a correspondingly low frequency of L. gasseri and A. vaginae. The second group was characterized by the predominance of L. gasseri and L. vaginalis and was found most commonly in healthy Caucasian women. The third group was commonest in women with a high Nugent score but was also seen in a subset of African and Asian women with a low Nugent score and was characterized by the absence of Lactobacillus species (except for L. iners but the presence of G. vaginalis and A. vaginae. Conclusions We have shown that the quantification of specific bacteria by qPCR contributes to a better description of the non-BV vaginal microbiome, but we also demonstrated that differences in populations such as risk and ethnicity also have to be taken into account. We believe

  7. Bacterial communities in urban aerosols collected with wetted-wall cyclonic samplers and seasonal fluctuations of live and culturable airborne bacteria.

    Science.gov (United States)

    Ravva, Subbarao V; Hernlem, Bradley J; Sarreal, Chester Z; Mandrell, Robert E

    2012-02-01

    Airborne transmission of bacterial pathogens from point sources (e.g., ranches, dairy waste treatment facilities) to areas of food production (farms) has been suspected. Determining the incidence, transport and viability of extremely low levels of pathogens require collection of high volumes of air and characterization of live bacteria from aerosols. We monitored the numbers of culturable bacteria in urban aerosols on 21 separate days during a 9 month period using high volume cyclonic samplers at an elevation of 6 m above ground level. Culturable bacteria in aerosols fluctuated from 3 CFU to 6 million CFU/L of air per hour and correlated significantly with changes in seasonal temperatures, but not with humidity or wind speed. Concentrations of viable bacteria determined by fluorescence staining and flow cytometry correlated significantly with culturable bacteria. Members of the phylum Proteobacteria constituted 98% of the bacterial community, which was characterized using 16S rRNA gene sequencing using DNA from aerosols. Aquabacterium sp., previously characterized from aquatic environments, represented 63% of all clones and the second most common were Burkholderia sp; these are ubiquitous in nature and some are potential human pathogens. Whole genome amplification prior to sequencing resulted in a substantial decrease in species diversity compared to characterizing culturable bacteria sorted by flow cytometry based on scatter signals. Although 27 isolated colonies were characterized, we were able to culture 38% of bacteria characterized by sequencing. The whole genome amplification method amplified DNA preferentially from Phyllobacterium myrsinacearum, a minor member of the bacterial communities, whereas Variovorax paradoxus dominated the cultured organisms.

  8. Indoor-biofilter growth and exposure to airborne chemicals drive similar changes in plant root bacterial communities.

    Science.gov (United States)

    Russell, Jacob A; Hu, Yi; Chau, Linh; Pauliushchyk, Margarita; Anastopoulos, Ioannis; Anandan, Shivanthi; Waring, Michael S

    2014-08-01

    Due to the long durations spent inside by many humans, indoor air quality has become a growing concern. Biofiltration has emerged as a potential mechanism to clean indoor air of harmful volatile organic compounds (VOCs), which are typically found at concentrations higher indoors than outdoors. Root-associated microbes are thought to drive the functioning of plant-based biofilters, or biowalls, converting VOCs into biomass, energy, and carbon dioxide, but little is known about the root microbial communities of such artificially grown plants, how or whether they differ from those of plants grown in soil, and whether any changes in composition are driven by VOCs. In this study, we investigated how bacterial communities on biofilter plant roots change over time and in response to VOC exposure. Through 16S rRNA amplicon sequencing, we compared root bacterial communities from soil-grown plants with those from two biowalls, while also comparing communities from roots exposed to clean versus VOC-laden air in a laboratory biofiltration system. The results showed differences in bacterial communities between soil-grown and biowall-grown plants and between bacterial communities from plant roots exposed to clean air and those from VOC-exposed plant roots. Both biowall-grown and VOC-exposed roots harbored enriched levels of bacteria from the genus Hyphomicrobium. Given their known capacities to break down aromatic and halogenated compounds, we hypothesize that these bacteria are important VOC degraders. While different strains of Hyphomicrobium proliferated in the two studied biowalls and our lab experiment, strains were shared across plant species, suggesting that a wide range of ornamental houseplants harbor similar microbes of potential use in living biofilters. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  9. Real time monitoring of population dynamics in concurrent bacterial growth using SIFT-MS quantification of volatile metabolites

    Czech Academy of Sciences Publication Activity Database

    Sovová, Kristýna; Čepl, J.; Markoš, A.; Španěl, Patrik

    2013-01-01

    Roč. 138, č. 17 (2013), s. 4795-4801 ISSN 0003-2654 Grant - others:GA ČR(CZ) GA13-24275S Institutional support: RVO:61388955 Keywords : TUBE-MASS-SPECTROMETRY * PSEUDOMONAS -AERUGINOSA * AIRBORNE SIGNALS Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 3.906, year: 2013

  10. Infection of Tribolium castaneum with Bacillus thuringiensis: Quantification of Bacterial Replication within Cadavers, Transmission via Cannibalism, and Inhibition of Spore Germination

    Science.gov (United States)

    Milutinović, Barbara; Höfling, Christina; Futo, Momir; Scharsack, Jörn P.

    2015-01-01

    Reproduction within a host and transmission to the next host are crucial for the virulence and fitness of pathogens. Nevertheless, basic knowledge about such parameters is often missing from the literature, even for well-studied bacteria, such as Bacillus thuringiensis, an endospore-forming insect pathogen, which infects its hosts via the oral route. To characterize bacterial replication success, we made use of an experimental oral infection system for the red flour beetle Tribolium castaneum and developed a flow cytometric assay for the quantification of both spore ingestion by the individual beetle larvae and the resulting spore load after bacterial replication and resporulation within cadavers. On average, spore numbers increased 460-fold, showing that Bacillus thuringiensis grows and replicates successfully in insect cadavers. By inoculating cadaver-derived spores and spores from bacterial stock cultures into nutrient medium, we next investigated outgrowth characteristics of vegetative cells and found that cadaver-derived bacteria showed reduced growth compared to bacteria from the stock cultures. Interestingly, this reduced growth was a consequence of inhibited spore germination, probably originating from the host and resulting in reduced host mortality in subsequent infections by cadaver-derived spores. Nevertheless, we further showed that Bacillus thuringiensis transmission was possible via larval cannibalism when no other food was offered. These results contribute to our understanding of the ecology of Bacillus thuringiensis as an insect pathogen. PMID:26386058

  11. Infection of Tribolium castaneum with Bacillus thuringiensis: quantification of bacterial replication within cadavers, transmission via cannibalism, and inhibition of spore germination.

    Science.gov (United States)

    Milutinović, Barbara; Höfling, Christina; Futo, Momir; Scharsack, Jörn P; Kurtz, Joachim

    2015-12-01

    Reproduction within a host and transmission to the next host are crucial for the virulence and fitness of pathogens. Nevertheless, basic knowledge about such parameters is often missing from the literature, even for well-studied bacteria, such as Bacillus thuringiensis, an endospore-forming insect pathogen, which infects its hosts via the oral route. To characterize bacterial replication success, we made use of an experimental oral infection system for the red flour beetle Tribolium castaneum and developed a flow cytometric assay for the quantification of both spore ingestion by the individual beetle larvae and the resulting spore load after bacterial replication and resporulation within cadavers. On average, spore numbers increased 460-fold, showing that Bacillus thuringiensis grows and replicates successfully in insect cadavers. By inoculating cadaver-derived spores and spores from bacterial stock cultures into nutrient medium, we next investigated outgrowth characteristics of vegetative cells and found that cadaver-derived bacteria showed reduced growth compared to bacteria from the stock cultures. Interestingly, this reduced growth was a consequence of inhibited spore germination, probably originating from the host and resulting in reduced host mortality in subsequent infections by cadaver-derived spores. Nevertheless, we further showed that Bacillus thuringiensis transmission was possible via larval cannibalism when no other food was offered. These results contribute to our understanding of the ecology of Bacillus thuringiensis as an insect pathogen. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  12. Concentration of airborne Staphylococcus aureus (MRSA and MSSA), total bacteria, and endotoxins in pig farms.

    Science.gov (United States)

    Masclaux, Frederic G; Sakwinska, Olga; Charrière, Nicole; Semaani, Eulalia; Oppliger, Anne

    2013-06-01

    Pigs are very often colonized by Staphylococcus aureus and transmission of such pig-associated S. aureus to humans can cause serious medical, hygiene, and economic problems. The transmission route of zoonotic pathogens colonizing farm animals to humans is not well established and bioaerosols could play an important role. The aim of this study was to assess the potential occupational risk of working with S. aureus-colonized pigs in Switzerland. We estimated the airborne contamination by S. aureus in 37 pig farms (20 nursery and 17 fattening units; 25 in summer, 12 in winter). Quantification of total airborne bacterial DNA, airborne Staphylococcus sp. DNA, fungi, and airborne endotoxins was also performed. In this experiment, the presence of cultivable airborne methicillin-resistant S. aureus (MRSA) CC398 in a pig farm in Switzerland was reported for the first time. Airborne methicillin-sensitive S. aureus (MSSA) was found in ~30% of farms. The average airborne concentration of DNA copy number of total bacteria and Staphylococcus sp. measured by quantitative polymerase chain reaction was very high, respectively reaching values of 75 (± 28) × 10(7) and 35 (± 9.8) × 10(5) copy numbers m(-3) in summer and 96 (± 19) × 10(8) and 40 (± 12) × 10(6) copy numbers m(-3) in winter. Total mean airborne concentrations of endotoxins (1298 units of endotoxin m(-3)) and fungi (5707 colony-forming units m(-3)) exceeded the Swiss recommended values and were higher in winter than in summer. In conclusion, Swiss pig farmers will have to tackle a new emerging occupational risk, which could also have a strong impact on public health. The need to inform pig farmers about biological occupational risks is therefore crucial.

  13. Protocol for Evaluating the Permissiveness of Bacterial Communities Toward Conjugal Plasmids by Quantification and Isolation of Transconjugants

    DEFF Research Database (Denmark)

    Klümper, Uli; Dechesne, Arnaud; Smets, Barth F.

    2014-01-01

    The transfer of conjugal plasmids is the main bacterial process of horizontal gene transfer to potentially distantly related bacteria. These extrachromosomal, circular DNA molecules host genes that code for their own replication and transfer to other organisms. Because additional accessory genes...... may encode catabolic pathways, virulence factors, and antibiotic or metal resistances, it is of environmental, evolutionary, and medical relevance to track and monitor the fate of plasmids in mixed microbial community. When assessing the short-term and long-term implications of conjugal plasmid...

  14. A suite of recombinant luminescent bacterial strains for the quantification of bioavailable heavy metals and toxicity testing.

    Science.gov (United States)

    Ivask, Angela; Rõlova, Taisia; Kahru, Anne

    2009-05-08

    Recombinant whole-cell sensors have already proven useful in the assessment of the bioavailability of environmental pollutants like heavy metals and organic compounds. In this work 19 recombinant bacterial strains representing various Gram-positive (Staphylococcus aureus and Bacillus subtilis) and Gram-negative (Escherichia coli, Pseudomonas fluorescens) bacteria were constructed to express the luminescence encoding genes luxCDABE (from Photorhabdus luminescens) as a response to bioavailable heavy metals ("lights-on" metal sensors containing metal-response elements, 13 strains) or in a constitutive manner ("lights-off" constructs, 6 strains). The bioluminescence of all 13 "lights-on" metal sensor strains was expressed as a function of the sub-toxic metal concentrations enabling the quantitative determination of metals bioavailable for these strains. Five sensor strains, constructed for detecting copper and mercury, proved to be target metal specific, whereas eight other sensor strains were simultaneously induced by Cd2+, Hg2+, Zn2+and Pb2+. The lowest limits of determination of the "lights-on" sensor strains for the metals tested in this study were (microg l-1): 0.002 of CH3HgCl, 0.03 of HgCl2, 1.8 of CdCl2, 33 of Pb(NO3)2, 1626 of ZnSO4, 24 of CuSO4 and 340 of AgNO3. In general, the sensitivity of the "lights-on" sensor strains was mostly dependent on the metal-response element used while the selection of host bacterium played a relatively minor role. In contrast, toxicity of metals to the "lights-off" strains was only dependent on the bacterial host so that Gram-positive strains were remarkably more sensitive than Gram-negative ones. The constructed battery of 19 recombinant luminescent bacterial strains exhibits several novel aspects as it contains i) metal sensor strains with similar metal-response elements in different host bacteria; ii) metal sensor strains with metal-response elements in different copies and iii) a "lights-off" construct (control) for every

  15. Chlorophyll Fluorescence and Reflectance-Based Non-Invasive Quantification of Blast, Bacterial Blight and Drought Stresses in Rice

    Czech Academy of Sciences Publication Activity Database

    Šebela, David; Quiňones, C.; Cruz, C.; Ona, I.; Olejníčková, Julie; Jagadish, K. S. V.

    2018-01-01

    Roč. 59, č. 1 (2018), s. 30-43 ISSN 0032-0781 R&D Projects: GA MŠk(CZ) LO1415 EU Projects: European Commission(XE) 284443 - EPPN Institutional support: RVO:86652079 Keywords : marker-assisted selection * oryza-sativa l. * water- stress * magnaporthe-grisea * disease resistance * photosynthetic efficiency * spectral reflectance * carotenoid content * eucalyptus leaves * diurnal changes * Bacterial blight * Chlorophyll fluorescence * Drought stress * Reflectance * Rice bast Subject RIV: EF - Botanics OBOR OECD: Plant sciences, botany Impact factor: 4.760, year: 2016

  16. A suite of recombinant luminescent bacterial strains for the quantification of bioavailable heavy metals and toxicity testing

    Directory of Open Access Journals (Sweden)

    Kahru Anne

    2009-05-01

    Full Text Available Abstract Background Recombinant whole-cell sensors have already proven useful in the assessment of the bioavailability of environmental pollutants like heavy metals and organic compounds. In this work 19 recombinant bacterial strains representing various Gram-positive (Staphylococcus aureus and Bacillus subtilis and Gram-negative (Escherichia coli, Pseudomonas fluorescens bacteria were constructed to express the luminescence encoding genes luxCDABE (from Photorhabdus luminescens as a response to bioavailable heavy metals ("lights-on" metal sensors containing metal-response elements, 13 strains or in a constitutive manner ("lights-off" constructs, 6 strains. Results The bioluminescence of all 13 "lights-on" metal sensor strains was expressed as a function of the sub-toxic metal concentrations enabling the quantitative determination of metals bioavailable for these strains. Five sensor strains, constructed for detecting copper and mercury, proved to be target metal specific, whereas eight other sensor strains were simultaneously induced by Cd2+, Hg2+, Zn2+and Pb2+. The lowest limits of determination of the "lights-on" sensor strains for the metals tested in this study were (μg l-1: 0.002 of CH3HgCl, 0.03 of HgCl2, 1.8 of CdCl2, 33 of Pb(NO32, 1626 of ZnSO4, 24 of CuSO4 and 340 of AgNO3. In general, the sensitivity of the "lights-on" sensor strains was mostly dependent on the metal-response element used while the selection of host bacterium played a relatively minor role. In contrast, toxicity of metals to the "lights-off" strains was only dependent on the bacterial host so that Gram-positive strains were remarkably more sensitive than Gram-negative ones. Conclusion The constructed battery of 19 recombinant luminescent bacterial strains exhibits several novel aspects as it contains i metal sensor strains with similar metal-response elements in different host bacteria; ii metal sensor strains with metal-response elements in different copies and iii

  17. Bacterial quantification in teeth with apical periodontitis related to instrumentation and different intracanal medications: a randomized clinical trial.

    Science.gov (United States)

    Manzur, Aldo; González, Ana Maria; Pozos, Amaury; Silva-Herzog, Daniel; Friedman, Shimon

    2007-02-01

    The antibacterial efficacy of intracanal medication with calcium hydroxide [Ca(OH)2], 2% chlorhexidine gel (CHX), and a combination of both [Ca(OH)2/CHX] was assessed in teeth with chronic apical periodontitis. Thirty-three canals were instrumented, randomly divided into three groups, and medicated with either Ca(OH)2, CHX, or Ca(OH)2/CHX. Bacteriological samples obtained from the operative field and the root canals before (S1) and after instrumentation (S2) in the first treatment session, and after medication (S3) in the second session 1 week later, were assessed for bacterial growth, observed by turbidity and in agar plates, and viable colony-forming unit (CFU) counts. Bacterial growth and CFU counts decreased significantly from S1 to S2 (Mann-Whitney, p<0.05). Differences in growth and counts between S2 to S3 were not statistically significant for all three intracanal medication groups. It was concluded that the antibacterial efficacy of Ca(OH)2, CHX, and Ca(OH)2/CHX was comparable.

  18. HPLC-based quantification of bacterial housekeeping nucleotides and alarmone messengers ppGpp and pppGpp.

    Science.gov (United States)

    Varik, Vallo; Oliveira, Sofia Raquel Alves; Hauryliuk, Vasili; Tenson, Tanel

    2017-09-08

    Here we describe an HPLC-based method to quantify bacterial housekeeping nucleotides and the signaling messengers ppGpp and pppGpp. We have replicated and tested several previously reported HPLC-based approaches and assembled a method that can process 50 samples in three days, thus making kinetically resolved experiments feasible. The method combines cell harvesting by rapid filtration, followed by acid extraction, freeze-drying with chromatographic separation. We use a combination of C18 IPRP-HPLC (GMP unresolved and co-migrating with IMP; GDP and GTP; AMP, ADP and ATP; CTP; UTP) and SAX-HPLC in isocratic mode (ppGpp and pppGpp) with UV detection. The approach is applicable to bacteria without the requirement of metabolic labelling with 32P-labelled radioactive precursors. We applied our method to quantify nucleotide pools in Escherichia coli BW25113 K12-strain both throughout the growth curve and during acute stringent response induced by mupirocin. While ppGpp and pppGpp levels vary drastically (40- and ≥8-fold, respectively) these changes are decoupled from the quotients of the housekeeping pool and guanosine and adenosine housekeeping nucleotides: NTP/NDP/NMP ratio remains stable at 6/1/0.3 during both normal batch culture growth and upon acute amino acid starvation.

  19. A nanobody:GFP bacterial platform that enables functional enzyme display and easy quantification of display capacity.

    Science.gov (United States)

    Wendel, Sofie; Fischer, Emil C; Martínez, Virginia; Seppälä, Susanna; Nørholm, Morten H H

    2016-05-03

    Bacterial surface display is an attractive technique for the production of cell-anchored, functional proteins and engineering of whole-cell catalysts. Although various outer membrane proteins have been used for surface display, an easy and versatile high-throughput-compatible assay for evaluating and developing surface display systems is missing. Using a single domain antibody (also called nanobody) with high affinity for green fluorescent protein (GFP), we constructed a system that allows for fast, fluorescence-based detection of displayed proteins. The outer membrane hybrid protein LppOmpA and the autotransporter C-IgAP exposed the nanobody on the surface of Escherichia coli with very different efficiency. Both anchors were capable of functionally displaying the enzyme Chitinase A as a fusion with the nanobody, and this considerably increased expression levels compared to displaying the nanobody alone. We used flow cytometry to analyse display capability on single-cell versus population level and found that the signal peptide of the anchor has great effect on display efficiency. We have developed an inexpensive and easy read-out assay for surface display using nanobody:GFP interactions. The assay is compatible with the most common fluorescence detection methods, including multi-well plate whole-cell fluorescence detection, SDS-PAGE in-gel fluorescence, microscopy and flow cytometry. We anticipate that the platform will facilitate future in-depth studies on the mechanism of protein transport to the surface of living cells, as well as the optimisation of applications in industrial biotech.

  20. Multicenter Testing of the Rapid Quantification of Radical Oxygen Species in Cerebrospinal Fluid to Diagnose Bacterial Meningitis

    Science.gov (United States)

    Lukaszewicz, Anne-Claire; Faivre, Valérie; Bout, Hélène; Gayat, Etienne; Lagergren, Tina; Damoisel, Charles; Bresson, Damien; Paugam, Catherine; Mantz, Jean; Payen, Didier

    2015-01-01

    Purpose Meningitis is a serious concern after traumatic brain injury (TBI) or neurosurgery. This study tested the level of reactive oxygen species (ROS) in cerebrospinal fluid (CSF) to diagnose meningitis in febrile patients several days after trauma or surgery. Methods Febrile patients (temperature > 38°C) after TBI or neurosurgery were included prospectively. ROS were measured in CSF within 4 hours after sampling using luminescence in the basal state and after cell stimulation with phorbol 12-myristate 13-acetate (PMA). The study was conducted in a single-center cohort 1 (n = 54, training cohort) and then in a multicenter cohort 2 (n = 136, testing cohort) in the Intensive Care and Neurosurgery departments of two teaching hospitals. The performance of the ROS test was compared with classical CSF criteria, and a diagnostic decision for meningitis was made by two blinded experts. Results The production of ROS was higher in the CSF of meningitis patients than in non-infected CSF, both in the basal state and after PMA stimulation. In cohort 1, ROS production was associated with a diagnosis of meningitis with an AUC of 0.814 (95% confidence interval (CI) [0.684–0.820]) for steady-state and 0.818 (95% CI [0.655–0.821]) for PMA-activated conditions. The best threshold value obtained in cohort 1 was tested in cohort 2 and showed high negative predictive values and low negative likelihood ratios of 0.94 and 0.36 in the basal state, respectively, and 0.96 and 0.24 after PMA stimulation, respectively. Conclusion The ROS test in CSF appeared suitable for eliminating a diagnosis of bacterial meningitis. PMID:26011286

  1. Integrated micro-optofluidic platform for real-time detection of airborne microorganisms

    Science.gov (United States)

    Choi, Jeongan; Kang, Miran; Jung, Jae Hee

    2015-11-01

    We demonstrate an integrated micro-optofluidic platform for real-time, continuous detection and quantification of airborne microorganisms. Measurements of the fluorescence and light scattering from single particles in a microfluidic channel are used to determine the total particle number concentration and the microorganism number concentration in real-time. The system performance is examined by evaluating standard particle measurements with various sample flow rates and the ratios of fluorescent to non-fluorescent particles. To apply this method to real-time detection of airborne microorganisms, airborne Escherichia coli, Bacillus subtilis, and Staphylococcus epidermidis cells were introduced into the micro-optofluidic platform via bioaerosol generation, and a liquid-type particle collection setup was used. We demonstrate successful discrimination of SYTO82-dyed fluorescent bacterial cells from other residue particles in a continuous and real-time manner. In comparison with traditional microscopy cell counting and colony culture methods, this micro-optofluidic platform is not only more accurate in terms of the detection efficiency for airborne microorganisms but it also provides additional information on the total particle number concentration.

  2. Effect of temperature and relative humidity on the survival of airborne bacteria = Effect van temperatuur en relatieve luchtvochtig-heid op de overleving van bacteriën in de lucht

    NARCIS (Netherlands)

    Hoeksma, P.; Aarnink, A.J.A.; Ogink, N.W.M.

    2015-01-01

    It is generally agreed upon that pathogenic microorganisms emitted from livestock buildings in wet and dry aerosols may cause animal and human diseases by airborne transmission. The processes involved in the transmission of microorganisms via the airborne route are still not well revealed. Airborne

  3. Airborne microorganisms from waste containers.

    Science.gov (United States)

    Jedlicka, Sabrina S; Stravitz, David M; Lyman, Charles E

    2012-01-01

    In physician's offices and biomedical labs, biological waste is handled every day. This waste is disposed of in waste containers designed for holding red autoclave bags. The containers used in these environments are closed hands-free containers, often with a step pedal. While these containers protect the user from surface-borne microorganisms, the containers may allow airborne microorganisms to escape via the open/close mechanism because of the air current produced upon open/close cycles. In this study, the air current was shown to be sufficient to allow airborne escape of microorganisms held in the container, including Aspergillus niger. However, bacterial cultures, such as Escherichia coli and Lactococcus lactis did not escape. This may be due to the choice of bacterial cultures and the absence of solid waste, such as dust or other particulate matter in the waste containers, that such strains of bacteria could travel on during aerosolization. We compared these results to those obtained using a re-designed receptacle, which mimimizes air currents, and detected no escaping microorganisms. This study highlights one potential source of airborne contamination in labs, hospitals, and other environments that dispose of biological waste.

  4. Development and Validation of an HPLC-DAD Method for the Simultaneous Extraction and Quantification of Bisphenol-A, 4-Hydroxybenzoic Acid, 4-Hydroxyacetophenone and Hydroquinone in Bacterial Cultures of Lactococcus lactis

    Directory of Open Access Journals (Sweden)

    Angelos T. Rigopoulos

    2018-02-01

    Full Text Available Bisphenol-A, a synthetic organic compound with estrogen mimicking properties, may enter bloodstream through either dermal contact or ingestion. Probiotic bacterial uptake of bisphenol can play a major protective role against its adverse health effects. In this paper, a method for the quantification of BPA in bacterial cells of L. lactis and of BPA and its potential metabolites 4-hydroxybenzoic Acid, 4-hydroxyacetophenone and hydroquinone in the culture medium is described. Extraction of BPA from the cells was performed using methanol–H2O/TFA (0.08% (5:1 v/v followed by SPE. Culture medium was centrifuged and filtered through a 0.45 μm syringe filter. Analysis was conducted in a Nucleosil column, using a gradient of A (95:5 v/v H2O: ACN and B (5:95 v/v H2O: ACN, containing TFA, pH 2, with a flow rate of 0.5 mL/min. Calibration curves (0.5–600 μg/mL were constructed using 4-n-Octylphenol as internal standard (1 > R2 > 0.994. Limit of Detection (LOD and Limit of Quantification (LOQ values ranged between 0.23 to 4.99 μg/mL and 0.69 to 15.1 μg/mL respectively. A 24 h administration experiment revealed a decline in BPA concentration in the culture media up to 90.27% while the BPA photodegradation levels were low. Our results demonstrate that uptake and possible metabolism of BPA in L. lactis cells facilitates its removal.

  5. Pesticide side effects in an agricultural soil ecosystem as measured by amoA expression quantification and bacterial diversity changes

    DEFF Research Database (Denmark)

    Feld, Louise; Hjort Hjelmsø, Mathis; Schostag, Morten

    2015-01-01

    of specific microbial genes or as changes in diversity. To assess the impact of pesticides on gene expression, we focused on the amoA gene, which is involved in ammonia oxidation. We hypothesized that the amount of amoA transcript decreases upon pesticide application, and to test this hypothesis, we used...... reverse-transcription qPCR. We also hypothesized that bacterial diversity is affected by pesticides. This hypothesis was investigated via 454 sequencing and diversity analysis of the 16S ribosomal RNA and RNA genes, representing the active and total soil bacterial communities, respectively. We prepared...

  6. Real-time detection of airborne fluorescent bioparticles in Antarctica

    Science.gov (United States)

    Crawford, Ian; Gallagher, Martin W.; Bower, Keith N.; Choularton, Thomas W.; Flynn, Michael J.; Ruske, Simon; Listowski, Constantino; Brough, Neil; Lachlan-Cope, Thomas; Fleming, Zoë L.; Foot, Virginia E.; Stanley, Warren R.

    2017-12-01

    activity together with contributions from exposed ice margin bacterial colonies but also long-range transport from the southern coasts of Argentina and Chile. Dispersion modelling also demonstrated emissions from shipping lanes, and therefore marine anthropogenic sources cannot be ruled out. Average total concentrations of total fluorescent aerosols were found to be 1.9 ± 2.6 L-1 over a 3-week period crossing over from November into December, but peak concentrations during intermittent enhancement events could be up to several tens per litre. While this short pilot study is not intended to be generally representative of Antarctic aerosol, it demonstrates the usefulness of the UV-LIF measurement technique for quantification of airborne bioaerosol concentrations and to understand their dispersion. The potential importance for microbial colonisation of Antarctica is highlighted.

  7. Optical Airborne Tracker System

    Data.gov (United States)

    National Aeronautics and Space Administration — The Optical Airborne Tracker System (OATS) is an airborne dual-axis optical tracking system capable of pointing at any sky location or ground target.  The objectives...

  8. Two-colour fluorescence fluorimetric analysis for direct quantification of bacteria and its application in monitoring bacterial growth in cellulose degradation systems.

    Science.gov (United States)

    Duedu, Kwabena O; French, Christopher E

    2017-04-01

    Monitoring bacterial growth is an important technique required for many applications such as testing bacteria against compounds (e.g. drugs), evaluating bacterial composition in the environment (e.g. sewage and wastewater or food suspensions) and testing engineered bacteria for various functions (e.g. cellulose degradation). T?=1,^FigItem(1) ^ReloadFigure=Yesraditionally, rapid estimation of bacterial growth is performed using spectrophotometric measurement at 600nm (OD600) but this estimation does not differentiate live and dead cells or other debris. Colony counting enumerates live cells but the process is laborious and not suitable for large numbers of samples. Enumeration of live bacteria by flow cytometry is a more suitable rapid method with the use of dual staining with SYBR I Green nucleic acid gel stain and Propidium Iodide (SYBR-I/PI). Flow cytometry equipment and maintenance costs however are relatively high and this technique is unavailable in many laboratories that may require a rapid method for evaluating bacteria growth. We therefore sought to adapt and evaluate the SYBR-I/PI technique of enumerating live bacterial cells for a cheaper platform, a fluorimeter. The fluorimetry adapted SYBR-I/PI enumeration of bacteria in turbid growth media had direct correlations with OD600 (p>0.001). To enable comparison of fluorescence results across labs and instruments, a fluorescence intensity standard unit, the equivalent fluorescent DNA (EFD) was proposed, evaluated and found useful. The technique was further evaluated for its usefulness in enumerating bacteria in turbid media containing insoluble particles. Reproducible results were obtained which OD600 could not give. An alternative method based on the assessment of total protein using the Pierce Coomassie Plus (Bradford) Assay was also evaluated and compared. In all, the SYBR-I/PI method was found to be the quickest and most reliable. The protocol is potentially useful for high-throughput applications such as

  9. Challenges and Opportunities of Airborne Metagenomics

    KAUST Repository

    Behzad, H.

    2015-05-06

    Recent metagenomic studies of environments, such as marine and soil, have significantly enhanced our understanding of the diverse microbial communities living in these habitats and their essential roles in sustaining vast ecosystems. The increase in the number of publications related to soil and marine metagenomics is in sharp contrast to those of air, yet airborne microbes are thought to have significant impacts on many aspects of our lives from their potential roles in atmospheric events such as cloud formation, precipitation, and atmospheric chemistry to their major impact on human health. In this review, we will discuss the current progress in airborne metagenomics, with a special focus on exploring the challenges and opportunities of undertaking such studies. The main challenges of conducting metagenomic studies of airborne microbes are as follows: 1) Low density of microorganisms in the air, 2) efficient retrieval of microorganisms from the air, 3) variability in airborne microbial community composition, 4) the lack of standardized protocols and methodologies, and 5) DNA sequencing and bioinformatics-related challenges. Overcoming these challenges could provide the groundwork for comprehensive analysis of airborne microbes and their potential impact on the atmosphere, global climate, and our health. Metagenomic studies offer a unique opportunity to examine viral and bacterial diversity in the air and monitor their spread locally or across the globe, including threats from pathogenic microorganisms. Airborne metagenomic studies could also lead to discoveries of novel genes and metabolic pathways relevant to meteorological and industrial applications, environmental bioremediation, and biogeochemical cycles.

  10. A rapid kinetic chromogenic method for quantification of bacterial endotoxins in lyophilized reagents for labeling with 99mTc radiopharmaceuticals

    International Nuclear Information System (INIS)

    Fukumori, Neuza T.O.; Campos, Domingos G.; Silva, Laercio; Fernandes, Adriana V.; Mengatti, Jair; Silva, Constancia P.G.; Matsuda, Margareth M.N.

    2009-01-01

    A rapid quantitative kinetic chromogenic test in an automated Portable Test System (PTS) has been developed for determination of bacterial endotoxins in water, in-process and end-products using the Limulus amebocyte lysate (LAL). The aim of this work was to validate the method for lyophilized reagents for labeling with 99m Tc radiopharmaceuticals with no interfering factors. Experiments were performed in three consecutive batches of the lyophilized reagents Methylenediphosphonic Acid (MDP) and Pyrophosphate (PYRO) produced at IPEN-CNEN/ SP using the PTS from Endosafe, Inc. TM , Charleston, SC. The Maximum Valid Dilution (MVD) was calculated to establish the extent of dilution to avoid interfering test conditions (MVD=500). Better results were obtained above 1:20 dilution factor for MDP and 1:100 for PYRO. The parameters of coefficient correlation (R) -0.980, RPPC between 50 - 200% and coefficient variation (CV) of the samples less than 25% were satisfied and the endotoxin concentration was lower than the lowest concentration of the standard curve (0.05 EU mL -1 ), therefore less than the established limit in pharmacopoeias. The PTS is a rapid, simple and accurate technique using the quantitative kinetic chromogenic method for bacterial endotoxin determination. For this reason, it is very practical in the radiopharmaceutical area and it trends to be the method of choice for the pyrogen test. For MDP and PYRO, the validation was successfully performed. (author)

  11. A TaqMan-based real time PCR assay for specific detection and quantification of Xylella fastidiosa strains causing bacterial leaf scorch in oleander.

    Science.gov (United States)

    Guan, Wei; Shao, Jonathan; Singh, Raghuwinder; Davis, Robert E; Zhao, Tingchang; Huang, Qi

    2013-02-15

    A TaqMan-based real-time PCR assay was developed for specific detection of strains of X. fastidiosa causing oleander leaf scorch. The assay uses primers WG-OLS-F1 and WG-OLS-R1 and the fluorescent probe WG-OLS-P1, designed based on unique sequences found only in the genome of oleander strain Ann1. The assay is specific, allowing detection of only oleander-infecting strains, not other strains of X. fastidiosa nor other plant-associated bacteria tested. The assay is also sensitive, with a detection limit of 10.4fg DNA of X. fastidiosa per reaction in vitro and in planta. The assay can also be applied to detect low numbers of X. fastidiosa in insect samples, or further developed into a multiplex real-time PCR assay to simultaneously detect and distinguish diverse strains of X. fastidiosa that may occupy the same hosts or insect vectors. Specific and sensitive detection and quantification of oleander strains of X. fastidiosa should be useful for disease diagnosis, epidemiological studies, management of oleander leaf scorch disease, and resistance screening for oleander shrubs. Published by Elsevier B.V.

  12. CLPX-Airborne: Airborne GPS Bistatic Radar

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set consists of measurements of GPS signals reflected from the Earth's surface and collected on an airborne platform. A modified GPS Delay Mapping Receiver...

  13. Airborne geoid determination

    DEFF Research Database (Denmark)

    Forsberg, René; Olesen, Arne Vestergaard; Bastos, L.

    2000-01-01

    Airborne geoid mapping techniques may provide the opportunity to improve the geoid over vast areas of the Earth, such as polar areas, tropical jungles and mountainous areas, and provide an accurate "seam-less" geoid model across most coastal regions. Determination of the geoid by airborne methods......-suited for geoid determination, with high-frequency survey and downward continuation noise being offset by the low-pass gravity to geoid filtering operation. In the paper the basic principles of airborne geoid determination are outlined, and examples of results of recent airborne gravity and geoid surveys...

  14. Monitoring of airborne bacteria and aerosols in different wards of hospitals - Particle counting usefulness in investigation of airborne bacteria.

    Science.gov (United States)

    Mirhoseini, Seyed Hamed; Nikaeen, Mahnaz; Khanahmd, Hossein; Hatamzadeh, Maryam; Hassanzadeh, Akbar

    2015-01-01

    The presence of airborne bacteria in hospital environments is of great concern because of their potential role as a source of hospital-acquired infections (HAI). The aim of this study was the determination and comparison of the concentration of airborne bacteria in different wards of four educational hospitals, and evaluation of whether particle counting could be predictive of airborne bacterial concentration in different wards of a hospital. The study was performed in an operating theatre (OT), intensive care unit (ICU), surgery ward (SW) and internal medicine (IM) ward of four educational hospitals in Isfahan, Iran. A total of 80 samples were analyzed for the presence of airborne bacteria and particle levels. The average level of bacteria ranged from 75-1194 CFU/m (3) . Mean particle levels were higher than class 100,000 cleanrooms in all wards. A significant correlation was observed between the numbers of 1-5 µm particles and levels of airborne bacteria in operating theatres and ICUs. The results showed that factors which may influence the airborne bacterial level in hospital environments should be properly managed to minimize the risk of HAIs especially in operating theaters. Microbial air contamination of hospital settings should be performed by the monitoring of airborne bacteria, but particle counting could be considered as a good operative method for the continuous monitoring of air quality in operating theaters and ICUs where higher risks of infection are suspected.

  15. Airborne geoid determination

    DEFF Research Database (Denmark)

    Forsberg, René; Olesen, Arne Vestergaard; Bastos, L.

    2000-01-01

    Airborne geoid mapping techniques may provide the opportunity to improve the geoid over vast areas of the Earth, such as polar areas, tropical jungles and mountainous areas, and provide an accurate "seam-less" geoid model across most coastal regions. Determination of the geoid by airborne methods...

  16. HAI: A novel airborne multi-channel hygrometer for fast multi-phase H2O quantification: Performance of the HAI instrument during the first flights on the German HALO aircraft

    Science.gov (United States)

    Buchholz, B.; Ebert, V.; Kraemer, M.; Afchine, A.

    2014-12-01

    Common gas phase H2O measurements on fast airborne platforms e.g. using backward facing or "Rosemount"-inlets can lead to a high risk of ice and droplets contamination. In addition, currently no single hygrometer exists that allows a simultaneous, high-speed measurement of all phases (gas, liquid, ice) with the same detection principle. In the rare occasions multi-phase measurements are realized, gas-and condensed-phase observations rely on different methods, instruments and calibration strategies so that precision and accuracy levels are quite difficult to quantify. This is effectively avoided by the novel TDLAS instrument, HAI, Hygrometer for Atmospheric Investigation, which allows a simultaneous, high speed, multi-phase detection without any sensor calibration in a unique "2+2" channel concept. Hai combines two independent wavelength channels, at 1.4 µm and at 2.6 µm, for a wide dynamic range from 1 to 30 000 ppmv, with a simultaneous closed path (extractive) and open path detection. Thus, "Total", i.e. gas-phase plus condensed-phase water is measured by sampling via a forward facing inlet into "closed-path" extractive cells. A selective, sampling-free, high speed gas phase detection is realized via a dual-wavelength "open-path" cell placed outside of the aircraft fuselage. All channels can be sampled with 120 Hz (measurement cycle time Dt=1.6 ms) allowing an unprecedented spatial resolution of 30 cm at 900 km/h. The evaluation of the individual multi-channel raw-data is done post flight, without any channel interdependencies, in calibration-free mode, thus allowing fast, accurate and precise multi-phase water detection in flight. The performance could be shown in more than 200 net flights hours in three scientific flight campaigns (TACTS, ESMVal, ML-CIRRUS) on the new German HALO aircraft. In addition the level of the accuracy of the calibration free evaluation was evaluated at the German national primary water vapor standard.

  17. Challenges and opportunities of airborne metagenomics.

    Science.gov (United States)

    Behzad, Hayedeh; Gojobori, Takashi; Mineta, Katsuhiko

    2015-05-06

    Recent metagenomic studies of environments, such as marine and soil, have significantly enhanced our understanding of the diverse microbial communities living in these habitats and their essential roles in sustaining vast ecosystems. The increase in the number of publications related to soil and marine metagenomics is in sharp contrast to those of air, yet airborne microbes are thought to have significant impacts on many aspects of our lives from their potential roles in atmospheric events such as cloud formation, precipitation, and atmospheric chemistry to their major impact on human health. In this review, we will discuss the current progress in airborne metagenomics, with a special focus on exploring the challenges and opportunities of undertaking such studies. The main challenges of conducting metagenomic studies of airborne microbes are as follows: 1) Low density of microorganisms in the air, 2) efficient retrieval of microorganisms from the air, 3) variability in airborne microbial community composition, 4) the lack of standardized protocols and methodologies, and 5) DNA sequencing and bioinformatics-related challenges. Overcoming these challenges could provide the groundwork for comprehensive analysis of airborne microbes and their potential impact on the atmosphere, global climate, and our health. Metagenomic studies offer a unique opportunity to examine viral and bacterial diversity in the air and monitor their spread locally or across the globe, including threats from pathogenic microorganisms. Airborne metagenomic studies could also lead to discoveries of novel genes and metabolic pathways relevant to meteorological and industrial applications, environmental bioremediation, and biogeochemical cycles. © The Author(s) 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  18. Airborne Power Supply Unit

    Data.gov (United States)

    National Aeronautics and Space Administration — The Airborne Power Supply Unit (APSU) is a programmable DC/DC converter that can supply multiple constant voltage or constant current outputs in a small enclosure,...

  19. Airborne Test Bed Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Laboratory operates the main hangar on the Hanscom Air Force Base flight line. This very large building (~93,000sqft) accommodates the Laboratory's airborne test...

  20. Airborne Magnetic Trackline Database

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA National Centers for Environmental Information (formerly National Geophysical Data Center) receive airborne magnetic survey data from US and non-US...

  1. Waterberg coalfield airborne geophysics

    CSIR Research Space (South Africa)

    Fourie, S

    2009-07-01

    Full Text Available Airborne Geophysics Project Number: 1.5.5 Sub Committee: Geology and Geophysics Presenter: Dr. Stoffel Fourie Co-Workers: Dr. George Henry & Me. Leonie Marè Collaborators: Coaltech & CSIR Project Objectives Major Objectives: circle5 Initiate Semi...-Regional Exploration of the Waterberg Coalfield to the benefit of the Industry. circle5 Generate a good quality Airborne Geophysical Dataset. circle5 Generate a basic lineament and surface geology interpretation of the Ellisras Basin. circle5 Generate a basic...

  2. Superposition Quantification

    Science.gov (United States)

    Chang, Li-Na; Luo, Shun-Long; Sun, Yuan

    2017-11-01

    The principle of superposition is universal and lies at the heart of quantum theory. Although ever since the inception of quantum mechanics a century ago, superposition has occupied a central and pivotal place, rigorous and systematic studies of the quantification issue have attracted significant interests only in recent years, and many related problems remain to be investigated. In this work we introduce a figure of merit which quantifies superposition from an intuitive and direct perspective, investigate its fundamental properties, connect it to some coherence measures, illustrate it through several examples, and apply it to analyze wave-particle duality. Supported by Science Challenge Project under Grant No. TZ2016002, Laboratory of Computational Physics, Institute of Applied Physics and Computational Mathematics, Beijing, Key Laboratory of Random Complex Structures and Data Science, Chinese Academy of Sciences, Grant under No. 2008DP173182

  3. Bacterial Keratitis

    Science.gov (United States)

    ... Español Eye Health / Eye Health A-Z Bacterial Keratitis Sections What Is Bacterial Keratitis? Bacterial Keratitis Symptoms ... Lens Care Bacterial Keratitis Treatment What Is Bacterial Keratitis? Leer en Español: ¿Qué Es la Queratitis Bacteriana? ...

  4. Monitoring of airborne bacteria and aerosols in different wards of hospitals – Particle counting usefulness in investigation of airborne bacteria

    Directory of Open Access Journals (Sweden)

    Seyed Hamed Mirhoseini

    2015-12-01

    Full Text Available [b]Introduction and objective[/b]. The presence of airborne bacteria in hospital environments is of great concern because of their potential role as a source of hospital-acquired infections (HAI. The aim of this study was the determination and comparison of the concentration of airborne bacteria in different wards of four educational hospitals, and evaluation of whether particle counting could be predictive of airborne bacterial concentration in different wards of a hospital. [b]Materials and method.[/b] The study was performed in an operating theatre (OT, intensive care unit (ICU, surgery ward (SW and internal medicine (IM ward of four educational hospitals in Isfahan, Iran. A total of 80 samples were analyzed for the presence of airborne bacteria and particle levels. [b]Results.[/b] The average level of bacteria ranged from 75–1194 CFU/m [sup]3[/sup] . Mean particle levels were higher than class 100,000 cleanrooms in all wards. A significant correlation was observed between the numbers of 1–5 µm particles and levels of airborne bacteria in operating theatres and ICUs. The results showed that factors which may influence the airborne bacterial level in hospital environments should be properly managed to minimize the risk of HAIs especially in operating theaters. [b]Conclusions.[/b] Microbial air contamination of hospital settings should be performed by the monitoring of airborne bacteria, but particle counting could be considered as a good operative method for the continuous monitoring of air quality in operating theaters and ICUs where higher risks of infection are suspected.

  5. Mammalian airborne allergens

    NARCIS (Netherlands)

    Aalberse, Rob C.

    2014-01-01

    Historically, horse dandruff was a favorite allergen source material. Today, however, allergic symptoms due to airborne mammalian allergens are mostly a result of indoor exposure, be it at home, at work or even at school. The relevance of mammalian allergens in relation to the allergenic activity of

  6. Airborne Power Supply Study,

    Science.gov (United States)

    The airborne power supply study considers the conversion of 400 cycle aircraft power to regulated DC voltages. Topics include the review of present...power conversion techniques, monolithic IC and hybrid series voltage regulators, power supply problem areas, trade-off considerations and power system

  7. The airborne supercomputer

    Science.gov (United States)

    Rhea, John

    1990-05-01

    A new class of airborne supercomputer designated RH-32 is being developed at USAF research facilities, capable of performing the critical battle management function for any future antiballistic missile system that emerges from the SDI. This research is also aimed at applications for future tactical aircraft and retrofit into the supercomputers of the ATF. The computers are based on a system architecture known as multi-interlock pipe stages, developed by the DARPA. Fiber-optic data buses appear to be the only communications media that are likely to match the speed of the processors and they have the added advantage of being inherently radiation resistant. The RH-32 itself, being the product of a basic research effort, may never see operational use. However, the technologies that emerge from this major R&D program will set the standards for airborne computers well into the next century.

  8. Airborne wireless communication systems, airborne communication methods, and communication methods

    Science.gov (United States)

    Deaton, Juan D [Menan, ID; Schmitt, Michael J [Idaho Falls, ID; Jones, Warren F [Idaho Falls, ID

    2011-12-13

    An airborne wireless communication system includes circuitry configured to access information describing a configuration of a terrestrial wireless communication base station that has become disabled. The terrestrial base station is configured to implement wireless communication between wireless devices located within a geographical area and a network when the terrestrial base station is not disabled. The circuitry is further configured, based on the information, to configure the airborne station to have the configuration of the terrestrial base station. An airborne communication method includes answering a 911 call from a terrestrial cellular wireless phone using an airborne wireless communication system.

  9. Softness of the bacterial cell wall of Streptococcus mitis as probed by microelectrophoresis

    NARCIS (Netherlands)

    Rodriguez, VV; Busscher, HJ; Norde, W; van der Mei, HC

    Chemical and structural complexity of bacterial cell surfaces complicate accurate quantification of cell surfaces properties. The presence of fibrils, fimbriae or other surface appendages on bacterial cell surfaces largely influence those properties and would therefore play a major function in

  10. Softness of the bacterial cell wall of Streptococcus mitis as probed by micro-electrophoresis

    NARCIS (Netherlands)

    Vadillo-Rodriguez, V.; Busscher, H.J.; Norde, W.; Mei, van der H.C.

    2002-01-01

    Chemical and structural complexity of bacterial cell surfaces complicate accurate quantification of cell surfaces properties. The presence of fibrils, fimbriae or other surface appendages on bacterial cell surfaces largely influence those properties and would therefore play a major function in

  11. Studies on ultraviolet inactivation of air-borne microorganisms, 1

    International Nuclear Information System (INIS)

    Adachi, Shin-ichi; Doi, Hitoshi; Yamayoshi, Takao; Nunoura, Masako; Tatsumi, Noriyuki.

    1989-01-01

    UV(254nm) inactivation of air-borne bacteria in an air-controlling apparatus was studied. The appratus was composed of a chamber for vaporizing a bacterial suspension and an irradiation duct equipped with an UV lamp(GL-30). The bacterial which passed through the irradiation duct impinged on a petri dish by an air slit sampler. Selected bacteria for the experiment were Serratia marcescens, Escherichia coli, Sarcina lutea and Bacillus subtilis(spores). The apparatus was useful for the study of the susceptibility of air-borne bacteria to UV radiation. UV dose necessary to inhibit colony formation in 90% of individual bacteria in the controlled air was as low as 27 to 35% of the dose required for the agar plate method. (author)

  12. Airborne Laser Polarization Sensor

    Science.gov (United States)

    Kalshoven, James, Jr.; Dabney, Philip

    1991-01-01

    Instrument measures polarization characteristics of Earth at three wavelengths. Airborne Laser Polarization Sensor (ALPS) measures optical polarization characteristics of land surface. Designed to be flown at altitudes of approximately 300 m to minimize any polarizing or depolarizing effects of intervening atmosphere and to look along nadir to minimize any effects depending on look angle. Data from measurements used in conjunction with data from ground surveys and aircraft-mounted video recorders to refine mathematical models used in interpretation of higher-altitude polarimetric measurements of reflected sunlight.

  13. Bacterial meningitis

    NARCIS (Netherlands)

    Roos, Karen L.; van de Beek, Diederik

    2010-01-01

    Bacterial meningitis is a neurological emergency. Empiric antimicrobial and adjunctive therapy should be initiated as soon as a single set of blood cultures has been obtained. Clinical signs suggestive of bacterial meningitis include fever, headache, meningismus, vomiting, photophobia, and an

  14. Airborne monitoring system

    International Nuclear Information System (INIS)

    Kadmon, Y.; Gabovitch, A.; Tirosh, D.; Ellenbogen, M.; Mazor, T.; Barak, D.

    1997-01-01

    A complete system for tracking, mapping, and performing a composition analysis of a radioactive plume and contaminated area was developed at the NRCN. The system includes two major units : An airborne unit for monitoring and a ground station for analyzing. The airborne unit is mounted on a helicopter and includes file following. Four radiation sensor, two 2'' x 2'' Nal (Tl) sensors horizontally separated by lead shield for mapping and spectroscopy, and two Geiger Mueller (GM) tubes as part of the safety system. A multichannel analyzer card is used for spectroscopy. A navigation system, based on GPS and a barometric altitude meter, is used to locate the plume or ground data. The telemetry system, consisting of a transceiver and a modem, transfers all the data in real time to the ground station. An industrial PC (Field Works) runs a dedicated C++ Windows application to manage the acquired data. An independent microprocessor based backup system includes a recorder, display, and key pad. The ground station is based on an industrial PC, a telemetry system, a color printer and a modem to communicate with automatic meteorology stations in the relevant area. A special software controls the ground station. Measurement results are analyzed in the ground station to estimate plume parameters including motion, location, size, velocity, and perform risk assessment. (authors)

  15. Identification and Quantification of N-Acyl Homoserine Lactones Involved in Bacterial Communication by Small-Scale Synthesis of Internal Standards and Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry

    Science.gov (United States)

    Leipert, Jan; Treitz, Christian; Leippe, Matthias; Tholey, Andreas

    2017-12-01

    N-acyl homoserine lactones (AHL) are small signal molecules involved in the quorum sensing of many gram-negative bacteria, and play an important role in biofilm formation and pathogenesis. Present analytical methods for identification and quantification of AHL require time-consuming sample preparation steps and are hampered by the lack of appropriate standards. By aiming at a fast and straightforward method for AHL analytics, we investigated the applicability of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Suitable MALDI matrices, including crystalline and ionic liquid matrices, were tested and the fragmentation of different AHL in collision-induced dissociation MS/MS was studied, providing information about characteristic marker fragments ions. Employing small-scale synthesis protocols, we established a versatile and cost-efficient procedure for fast generation of isotope-labeled AHL standards, which can be used without extensive purification and yielded accurate standard curves. Quantitative analysis was possible in the low pico-molar range, with lower limits of quantification reaching from 1 to 5 pmol for different AHL. The developed methodology was successfully applied in a quantitative MALDI MS analysis of low-volume culture supernatants of Pseudomonas aeruginosa. [Figure not available: see fulltext.

  16. Bacterial membrane proteomics.

    Science.gov (United States)

    Poetsch, Ansgar; Wolters, Dirk

    2008-10-01

    About one quarter to one third of all bacterial genes encode proteins of the inner or outer bacterial membrane. These proteins perform essential physiological functions, such as the import or export of metabolites, the homeostasis of metal ions, the extrusion of toxic substances or antibiotics, and the generation or conversion of energy. The last years have witnessed completion of a plethora of whole-genome sequences of bacteria important for biotechnology or medicine, which is the foundation for proteome and other functional genome analyses. In this review, we discuss the challenges in membrane proteome analysis, starting from sample preparation and leading to MS-data analysis and quantification. The current state of available proteomics technologies as well as their advantages and disadvantages will be described with a focus on shotgun proteomics. Then, we will briefly introduce the most abundant proteins and protein families present in bacterial membranes before bacterial membrane proteomics studies of the last years will be presented. It will be shown how these works enlarged our knowledge about the physiological adaptations that take place in bacteria during fine chemical production, bioremediation, protein overexpression, and during infections. Furthermore, several examples from literature demonstrate the suitability of membrane proteomics for the identification of antigens and different pathogenic strains, as well as the elucidation of membrane protein structure and function.

  17. Scrubber capabilities to remove airborne microorganisms and other aerial pollutants from the exhaust air of animal houses

    NARCIS (Netherlands)

    Aarnink, A.J.A.; Landman, W.J.M.; Melse, R.W.; Zhao, Y.; Ploegaert, J.P.M.; Huynh, T.T.T.

    2011-01-01

    Two studies were conducted to assess the efficiency of air scrubbers to reduce airborne microorganisms in the exhaust air from animal houses. First, in a field study, the effects of a bio-scrubber and an acid scrubber on total bacterial counts were assessed. Higher bacterial counts were found in the

  18. Modeling for Airborne Contamination

    Energy Technology Data Exchange (ETDEWEB)

    F.R. Faillace; Y. Yuan

    2000-08-31

    The objective of Modeling for Airborne Contamination (referred to from now on as ''this report'') is to provide a documented methodology, along with supporting information, for estimating the release, transport, and assessment of dose to workers from airborne radioactive contaminants within the Monitored Geologic Repository (MGR) subsurface during the pre-closure period. Specifically, this report provides engineers and scientists with methodologies for estimating how concentrations of contaminants might be distributed in the air and on the drift surfaces if released from waste packages inside the repository. This report also provides dose conversion factors for inhalation, air submersion, and ground exposure pathways used to derive doses to potentially exposed subsurface workers. The scope of this report is limited to radiological contaminants (particulate, volatile and gaseous) resulting from waste package leaks (if any) and surface contamination and their transport processes. Neutron activation of air, dust in the air and the rock walls of the drift during the preclosure time is not considered within the scope of this report. Any neutrons causing such activation are not themselves considered to be ''contaminants'' released from the waste package. This report: (1) Documents mathematical models and model parameters for evaluating airborne contaminant transport within the MGR subsurface; and (2) Provides tables of dose conversion factors for inhalation, air submersion, and ground exposure pathways for important radionuclides. The dose conversion factors for air submersion and ground exposure pathways are further limited to drift diameters of 7.62 m and 5.5 m, corresponding to the main and emplacement drifts, respectively. If the final repository design significantly deviates from these drift dimensions, the results in this report may require revision. The dose conversion factors are further derived by using concrete of

  19. Transmission of Airborne Bacteria across Built Environments and Its Measurement Standards: A Review

    Directory of Open Access Journals (Sweden)

    So Fujiyoshi

    2017-11-01

    Full Text Available Human health is influenced by various factors including microorganisms present in built environments where people spend most of their lives (approximately 90%. It is therefore necessary to monitor and control indoor airborne microbes for occupational safety and public health. Most studies concerning airborne microorganisms have focused on fungi, with scant data available concerning bacteria. The present review considers papers published from 2010 to 2017 approximately and factors affecting properties of indoor airborne bacteria (communities and concentration with respect to temporal perspective and to multiscale interaction viewpoint. From a temporal perspective, bacterial concentrations in built environments change depending on numbers of human occupancy, while properties of bacterial communities tend to remain stable. Similarly, the bacteria found in social and community spaces such as offices, classrooms and hospitals are mainly associated with human occupancy. Other major sources of indoor airborne bacteria are (i outdoor environments, and (ii the building materials themselves. Indoor bacterial communities and concentrations are varied with varying interferences by outdoor environment. Airborne bacteria from the outdoor environment enter an indoor space through open doors and windows, while indoor bacteria are simultaneously released to the outer environment. Outdoor bacterial communities and their concentrations are also affected by geographical factors such as types of land use and their spatial distribution. The bacteria found in built environments therefore originate from any of the natural and man-made surroundings around humans. Therefore, to better understand the factors influencing bacterial concentrations and communities in built environments, we should study all the environments that humans contact as a single ecosystem. In this review, we propose the establishment of a standard procedure for assessing properties of indoor airborne

  20. Distribution and identification of culturable airborne microorganisms in a Swiss milk processing facility.

    Science.gov (United States)

    Brandl, Helmut; Fricker-Feer, Claudia; Ziegler, Dominik; Mandal, Jyotshna; Stephan, Roger; Lehner, Angelika

    2014-01-01

    Airborne communities (mainly bacteria) were sampled and characterized (concentration levels and diversity) at 1 outdoor and 6 indoor sites within a Swiss dairy production facility. Air samples were collected on 2 sampling dates in different seasons, one in February and one in July 2012 using impaction bioaerosol samplers. After cultivation, isolates were identified by mass spectrometry (matrix-assisted laser desorption/ionization-time-of-flight) and molecular (sequencing of 16S rRNA and rpoB genes) methods. In general, total airborne particle loads and total bacterial counts were higher in winter than in summer, but remained constant within each indoor sampling site at both sampling times (February and July). Bacterial numbers were generally very low (air) during the different steps of milk powder production. Elevated bacterial concentrations (with mean values of 391 ± 142 and 179 ± 33 cfu/m(3) of air during winter and summer sampling, respectively; n=15) occurred mainly in the "logistics area," where products in closed tins are packed in secondary packaging material and prepared for shipping. However, total bacterial counts at the outdoor site varied, with a 5- to 6-fold higher concentration observed in winter compared with summer. Twenty-five gram-positive and gram-negative genera were identified as part of the airborne microflora, with Bacillus and Staphylococcus being the most frequent genera identified. Overall, the culturable microflora community showed a composition typical and representative for the specific location. Bacterial counts were highly correlated with total airborne particles in the size range 1 to 5 µm, indicating that a simple surveillance system based upon counting of airborne particles could be implemented. The data generated in this study could be used to evaluate the effectiveness of the dairy plant's sanitation program and to identify potential sources of airborne contamination, resulting in increased food safety. Copyright © 2014

  1. Airborne Cloud Computing Environment (ACCE)

    Science.gov (United States)

    Hardman, Sean; Freeborn, Dana; Crichton, Dan; Law, Emily; Kay-Im, Liz

    2011-01-01

    Airborne Cloud Computing Environment (ACCE) is JPL's internal investment to improve the return on airborne missions. Improve development performance of the data system. Improve return on the captured science data. The investment is to develop a common science data system capability for airborne instruments that encompasses the end-to-end lifecycle covering planning, provisioning of data system capabilities, and support for scientific analysis in order to improve the quality, cost effectiveness, and capabilities to enable new scientific discovery and research in earth observation.

  2. CLPX Airborne: Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) Data

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set consists of apparent surface reflectance, subpixel snow-covered area and grain size inferred from data acquired by the Airborne Visible/Infrared...

  3. CLPX-Airborne: Airborne Synthetic Aperture Radar (AIRSAR) Imagery

    Data.gov (United States)

    National Aeronautics and Space Administration — Airborne Synthetic Aperture Radar (AIRSAR) is a side-looking imaging radar that is able to collect data irrespective of daylight or cloud cover. The AIRSAR...

  4. Modification of a pollen trap design to capture airborne conidia of Entomophaga maimaiga and detection of conidia by quantitative PCR

    Science.gov (United States)

    Tonya D. Bittner; Ann E. Hajek; Andrew M. Liebhold; Harold Thistle; Dan Cullen

    2017-01-01

    The goal of this study was to develop effective and practical field sampling methods for quantification of aerial deposition of airborne conidia of Entomophaga maimaiga over space and time. This important fungal pathogen is a major cause of larval death in invasive gypsy moth (Lymantria dispar) populations in the United States...

  5. Bacterial Proteasomes.

    Science.gov (United States)

    Jastrab, Jordan B; Darwin, K Heran

    2015-01-01

    Interest in bacterial proteasomes was sparked by the discovery that proteasomal degradation is required for the pathogenesis of Mycobacterium tuberculosis, one of the world's deadliest pathogens. Although bacterial proteasomes are structurally similar to their eukaryotic and archaeal homologs, there are key differences in their mechanisms of assembly, activation, and substrate targeting for degradation. In this article, we compare and contrast bacterial proteasomes with their archaeal and eukaryotic counterparts, and we discuss recent advances in our understanding of how bacterial proteasomes function to influence microbial physiology.

  6. Airborne Particulate Threat Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Patrick Treado; Oksana Klueva; Jeffrey Beckstead

    2008-12-31

    Aerosol threat detection requires the ability to discern between threat agents and ambient background particulate matter (PM) encountered in the environment. To date, Raman imaging technology has been demonstrated as an effective strategy for the assessment of threat agents in the presence of specific, complex backgrounds. Expanding our understanding of the composition of ambient particulate matter background will improve the overall performance of Raman Chemical Imaging (RCI) detection strategies for the autonomous detection of airborne chemical and biological hazards. Improving RCI detection performance is strategic due to its potential to become a widely exploited detection approach by several U.S. government agencies. To improve the understanding of the ambient PM background with subsequent improvement in Raman threat detection capability, ChemImage undertook the Airborne Particulate Threat Assessment (APTA) Project in 2005-2008 through a collaborative effort with the National Energy Technology Laboratory (NETL), under cooperative agreement number DE-FC26-05NT42594. During Phase 1 of the program, a novel PM classification based on molecular composition was developed based on a comprehensive review of the scientific literature. In addition, testing protocols were developed for ambient PM characterization. A signature database was developed based on a variety of microanalytical techniques, including scanning electron microscopy, FT-IR microspectroscopy, optical microscopy, fluorescence and Raman chemical imaging techniques. An automated particle integrated collector and detector (APICD) prototype was developed for automated collection, deposition and detection of biothreat agents in background PM. During Phase 2 of the program, ChemImage continued to refine the understanding of ambient background composition. Additionally, ChemImage enhanced the APICD to provide improved autonomy, sensitivity and specificity. Deliverables included a Final Report detailing our

  7. Bacterial adhesion

    NARCIS (Netherlands)

    Loosdrecht, van M.C.M.

    1988-01-01

    As mentioned in the introduction of this thesis bacterial adhesion has been studied from a variety of (mostly practice oriented) starting points. This has resulted in a range of widely divergent approaches. In order to elucidate general principles in bacterial adhesion phenomena, we felt it

  8. Characteristics of phylogenetic diversity in airborne bacterial populations in China

    Science.gov (United States)

    Chaudhry, Zahra; Santarpia, Joshua L.; Martins, J. V.

    2011-05-01

    Considering their potential implications for human health, agricultural productivity, and ecosystem stability, surprisingly little is known about the composition or dynamics of the atmosphere's biological aerosols. The few studies that have examined phylogenetic diversity in China focused on a single sampling period, whereas this study spans 3 months and includes over 300 samples. The 300+ samples were categorized by month and direction of their back-trajectory. DNA extraction was carried out on the pooled samples in a quantitative manner to allow for comparison between the amount of extracted material and the amount of initial total aerosol mass. Within an individual month, samples originating from similar land types and approximately equidistant to the sampling location exhibited similar diversity, whereas samples originating from much greater distances and from different land types included phyla unique to that location. Phyla from the same origin also varied from one month to the next. The biological diversity found from the Phylochips reinforces the hypothesis that air samples carry a biological record of their history.

  9. Karoo airborne geophysical survey

    International Nuclear Information System (INIS)

    Cole, D.J.; Stettler, E.H.

    1984-01-01

    Thirty four uranium anomalies were selected for ground follow-up from the analogue spectrometer records of Block 4 of the Karoo Airborne Geophysical Survey. The anomalies were plotted on 1:50 000 scale topographic maps and to 1:250 000 scale maps which are included in this report. The anomaly co-ordinates are tabulated together with the farms on which they occur. Results of the ground follow-up of the aerial anomalies are described. Twenty two anomalies are related to uranium mineralisation of which seventeen occur over baked mudstone adjacent to a dolerite intrusion. Five are located over fluvial channel sandstone of the Beaufort Group and subsurface mineralised sandstone may be present. The other twelve anomalies are spurious. Of the anomalies located over baked mudstone, fifteen emanate from ferruginous mudstone of the Whitehill Formation west of longitude 21 degrees 15 minutes. One of the two remaining anomalies over baked mudstone occurs over the Prince Albert Formation and the other anomaly is over baked mudstone and calcareous nodules of the Beaufort Group. The general low uranium values (less than 355 ppm eU3O8) render the occurrences uneconomic

  10. Optimization, validation, and application of a real-time PCR protocol for quantification of viable bacterial cells in municipal sewage sludge and biosolids using reporter genes and Escherichia coli.

    Science.gov (United States)

    van Frankenhuyzen, Jessica K; Trevors, Jack T; Flemming, Cecily A; Lee, Hung; Habash, Marc B

    2013-11-01

    Biosolids result from treatment of sewage sludge to meet jurisdictional standards, including pathogen reduction. Once government regulations are met, materials can be applied to agricultural lands. Culture-based methods are used to enumerate pathogen indicator microorganisms but may underestimate cell densities, which is partly due to bacteria existing in a viable but non-culturable physiological state. Viable indicators can also be quantified by realtime polymerase chain reaction (qPCR) used with propidium monoazide (PMA), a dye that inhibits amplification of DNA found extracellularly or in dead cells. The objectives of this study were to test an optimized PMA-qPCR method for viable pathogen detection in wastewater solids and to validate it by comparing results to data obtained by conventional plating. Reporter genes from genetically marked Pseudomonas sp. UG14Lr and Agrobacterium tumefaciens 542 cells were spiked into samples of primary sludge, and anaerobically digested and Lystek-treated biosolids as cell-free DNA, dead cells, viable cells, and mixtures of live and dead cells, followed by DNA extraction with and without PMA, and qPCR. The protocol was then used for Escherichia coli quantification in the three matrices, and results compared to plate counts. PMA-qPCR selectively detected viable cells, while inhibiting signals from cell-free DNA and DNA found in membrane-compromised cells. PMA-qPCR detected 0.5-1 log unit more viable E. coli cells in both primary solids and dewatered biosolids than plate counts. No viable E. coli was found in Lystek-treated biosolids. These data suggest PMA-qPCR may more accurately estimate pathogen cell numbers than traditional culture methods.

  11. Integrated micro-optofluidic platform for real-time detection of airborne microorganisms

    OpenAIRE

    Choi, Jeongan; Kang, Miran; Jung, Jae Hee

    2015-01-01

    We demonstrate an integrated micro-optofluidic platform for real-time, continuous detection and quantification of airborne microorganisms. Measurements of the fluorescence and light scattering from single particles in a microfluidic channel are used to determine the total particle number concentration and the microorganism number concentration in real-time. The system performance is examined by evaluating standard particle measurements with various sample flow rates and the ratios of fluoresc...

  12. Airborne particle monitoring with urban closed-circuit television camera networks and a chromatic technique

    International Nuclear Information System (INIS)

    Kolupula, Y R; Jones, G R; Deakin, A G; Spencer, J W; Aceves-Fernandez, M A

    2010-01-01

    An economic approach for the preliminary assessment of 2–10 µm sized (PM10) airborne particle levels in urban areas is described. It uses existing urban closed-circuit television (CCTV) surveillance camera networks in combination with particle accumulating units and chromatic quantification of polychromatic light scattered by the captured particles. Methods for accommodating extraneous light effects are discussed and test results obtained from real urban sites are presented to illustrate the potential of the approach

  13. Evaluation of principal cannabinoids in airborne particulates

    International Nuclear Information System (INIS)

    Balducci, C.; Nervegna, G.; Cecinato, A.

    2009-01-01

    The determination of delta(9)-tetrahydrocannabinol (Δ 9 -THC), cannabidiol (CND) and cannabinol (CNB), primary active components in cannabis preparation, was carried out on airborne particulates by applying a specific procedure consisting of soot extraction by ultrasonic bath, purification by solvent partitioning, derivatization with N-(t-butyldimethylsilyl)-N-methyl-trifluoroacetamide, and separation/detection through gas chromatography coupled with tandem mass spectrometry. The optimized procedure was found suitable for measuring the three psychotropic substances at concentrations ranging from ca. 0.001 to ca. 5.0 ng cm -3 of air, with recoveries always higher than 82%, accuracy >7.3% and precision >90%. Application of the procedure performed on field in Rome and Bari, Italy, demonstrated that all three compounds contaminate the air in Italian cities whereas in Algiers, Algeria, only cannabinol, the most stable in the atmosphere, exceeded the limit of quantification of the method. The relative percentages of the three cannabinoids in general reproduced those typical of the Cannabis sativa plant and were very different from those found in human blood, urine and sweat.

  14. Evaluation of principal cannabinoids in airborne particulates

    Energy Technology Data Exchange (ETDEWEB)

    Balducci, C., E-mail: balducci@iia.cnr.it [Italian National Research Council, Institute for Atmospheric Pollution (CNR-IIA), Monterotondo Stazione (Italy); Nervegna, G.; Cecinato, A. [Italian National Research Council, Institute for Atmospheric Pollution (CNR-IIA), Monterotondo Stazione (Italy)

    2009-05-08

    The determination of delta(9)-tetrahydrocannabinol ({Delta}{sup 9}-THC), cannabidiol (CND) and cannabinol (CNB), primary active components in cannabis preparation, was carried out on airborne particulates by applying a specific procedure consisting of soot extraction by ultrasonic bath, purification by solvent partitioning, derivatization with N-(t-butyldimethylsilyl)-N-methyl-trifluoroacetamide, and separation/detection through gas chromatography coupled with tandem mass spectrometry. The optimized procedure was found suitable for measuring the three psychotropic substances at concentrations ranging from ca. 0.001 to ca. 5.0 ng cm{sup -3} of air, with recoveries always higher than 82%, accuracy >7.3% and precision >90%. Application of the procedure performed on field in Rome and Bari, Italy, demonstrated that all three compounds contaminate the air in Italian cities whereas in Algiers, Algeria, only cannabinol, the most stable in the atmosphere, exceeded the limit of quantification of the method. The relative percentages of the three cannabinoids in general reproduced those typical of the Cannabis sativa plant and were very different from those found in human blood, urine and sweat.

  15. Bacterial Vaginosis

    Science.gov (United States)

    ... Archive STDs Home Page Bacterial Vaginosis (BV) Chlamydia Gonorrhea Genital Herpes Hepatitis HIV/AIDS & STDs Human Papillomavirus ( ... of getting other STDs, such as chlamydia and gonorrhea . These bacteria can sometimes cause pelvic inflammatory disease ( ...

  16. Haemophilus influenzae as an airborne contamination in child day care centers.

    Science.gov (United States)

    Lis, Danuta O; Górny, Rafał L

    2013-05-01

    The aim of this study was to assess the exposure of children to airborne Haemophilus influenzae in day care centers. Air samples were taken using an Andersen impactor in 32 rooms designed for children stay. The concentrations of airborne bacteria were calculated as colony forming units (CFU) (growing on trypticase soy agar) per cubic meter of air (CFU/m(3)). The compositions of bioaerosol were determined on blood trypticase soy agar and Haemophilus selective agar. Isolated strains were identified using API NH strips and apiweb software. The antibiotic resistance of H influenzae strains was determined by the disk diffusion method. Compared with the proposed criteria for microbiologic quality of indoor air, the rooms were characterized by the very high bacterial contamination of the air. The prevailing component of bacterial aerosol was gram-positive cocci. Airborne H influenzae strains were found in 25% of the investigated rooms and were mostly classified as biotype II (33%). It may be accepted that the exposure to airborne H influenzae is typical of child day care centers in contrast to indoor environments with older population. Child day care center contribute to the expansion of H influenzae in human population via air. Generally, airborne H influenzae isolates from the investigated child day care centers were susceptible to older antibiotics such as ampicillin and amoxicillin-clavulanic acid. Copyright © 2013 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Mosby, Inc. All rights reserved.

  17. Influence of membrane fatty acid composition and fluidity on airborne survival of Escherichia coli.

    Science.gov (United States)

    Ng, Tsz Wai; Chan, Wing Lam; Lai, Ka Man

    2018-04-01

    Finding ways to predict and control the survival of bacterial aerosols can contribute to the development of ways to alleviate a number of crucial microbiological problems. Significant damage in the membrane integrity of Escherichia coli during aerosolization and airborne suspension has been revealed which has prompted the question of how the membrane fatty acid composition and fluidity influence the survival of airborne bacteria. Two approaches of using isogenic mutants and different growth temperatures were selected to manipulate the membrane fatty acid composition of E. coli before challenging the bacteria with different relative humidity (RH) levels in an aerosol chamber. Among the mutants (fabR - , cfa. fadA - ), fabR - had the lowest membrane fluidity index (FI) and generally showed a higher survival than the parental strain. Surprisingly, its resistance to airborne stress was so strong that its viability was fully maintained even after airborne suspension at 40% RH, a harsh RH level to bacterial survival. Moreover, E. coli cultured at 20 °C with a higher FI than that at 30 and 37 °C generally had a lower survival after aerosolization and airborne suspension. Unlike FI, individual fatty acid and cyclopropane fatty acid composition did not relate to the bacterial survival. Lipid peroxidation of the membrane was undetected in all the bacteria. Membrane fluidity plays a stronger role in determining the bacteria survival during airborne suspension than during aerosolization. Certain relationships between FI and bacteria survival were identified, which could help predict the transmission of bacteria under different conditions.

  18. GLORIA: an airborne imaging FTS

    Science.gov (United States)

    Sha, Mahesh K.

    2017-11-01

    The Gimballed Limb Observer for Radiance Imaging of the Atmosphere (GLORIA) is an imaging Fourier Transform Spectrometer (FTS) which is capable of operating on various airborne platforms. The main scientific focus is on the dynamics and chemistry of the Upper Troposphere and Lower Stratosphere (UTLS) region.

  19. Airborne gamma-ray spectrometry

    DEFF Research Database (Denmark)

    Hovgaard, Jens

    A new method - Noise Adjusted Singular Value Decomposition, NASVD - for processing gamma-ray spectra has been developed as part of a Ph.D. project. By using this technique one is able to decompose a large set of data - for example from airborne gamma-ray surveys - into a few spectral components. ...

  20. BACTERIAL CONSORTIUM

    Directory of Open Access Journals (Sweden)

    Payel Sarkar

    2013-01-01

    Full Text Available Petroleum aromatic hydrocarbons like benzen e, toluene, ethyl benzene and xylene, together known as BTEX, has almost the same chemical structure. These aromatic hydrocarbons are released as pollutants in th e environment. This work was taken up to develop a solvent tolerant bacterial cons ortium that could degrade BTEX compounds as they all share a common chemical structure. We have isolated almost 60 different types of bacterial strains from different petroleum contaminated sites. Of these 60 bacterial strains almost 20 microorganisms were screene d on the basis of capability to tolerate high concentration of BTEX. Ten differe nt consortia were prepared and the compatibility of the bacterial strains within the consortia was checked by gram staining and BTEX tolerance level. Four successful mi crobial consortia were selected in which all the bacterial strains concomitantly grew in presence of high concentration of BTEX (10% of toluene, 10% of benzene 5% ethyl benzene and 1% xylene. Consortium #2 showed the highest growth rate in pr esence of BTEX. Degradation of BTEX by consortium #2 was monitored for 5 days by gradual decrease in the volume of the solvents. The maximum reduction observed wa s 85% in 5 days. Gas chromatography results also reveal that could completely degrade benzene and ethyl benzene within 48 hours. Almost 90% degradation of toluene and xylene in 48 hours was exhibited by consortium #2. It could also tolerate and degrade many industrial solvents such as chloroform, DMSO, acetonitrile having a wide range of log P values (0.03–3.1. Degradation of aromatic hydrocarbon like BTEX by a solvent tolerant bacterial consortium is greatly significant as it could degrade high concentration of pollutants compared to a bacterium and also reduces the time span of degradation.

  1. Rifaximin has minor effects on bacterial composition, inflammation and bacterial translocation in cirrhosis

    DEFF Research Database (Denmark)

    Kimer, Nina; Pedersen, Julie S.; Tavenier, Juliette

    2018-01-01

    .4), and MELD score 12 (±3.9). Patients received rifaximin 550 mg BD (n=36) or placebo BD (n=18). Blood and faecal (n=15) sampling were conducted at baseline and after four weeks. Bacterial DNA in blood was determined by real-time qPCR 16S rRNA gene quantification. Bacterial composition in faeces was analysed......: Four weeks of treatment with rifaximin had no impact on the inflammatory state and only minor effects on BT and intestinal bacterial composition in stable, decompensated cirrhosis (NCT01769040)....

  2. Bacterial Ecology

    DEFF Research Database (Denmark)

    Fenchel, Tom

    2011-01-01

    Bacterial ecology is concerned with the interactions between bacteria and their biological and nonbiological environments and with the role of bacteria in biogeochemical element cycling. Many fundamental properties of bacteria are consequences of their small size. Thus, they can efficiently exploit...

  3. Bacterial meningitis

    NARCIS (Netherlands)

    Heckenberg, Sebastiaan G. B.; Brouwer, Matthijs C.; van de Beek, Diederik

    2014-01-01

    Bacterial meningitis is a neurologic emergency. Vaccination against common pathogens has decreased the burden of disease. Early diagnosis and rapid initiation of empiric antimicrobial and adjunctive therapy are vital. Therapy should be initiated as soon as blood cultures have been obtained,

  4. Bacterial lipases

    NARCIS (Netherlands)

    Jaeger, Karl-Erich; Ransac, Stéphane; Dijkstra, Bauke W.; Colson, Charles; Heuvel, Margreet van; Misset, Onno

    Many different bacterial species produce lipases which hydrolyze esters of glycerol with preferably long-chain fatty acids. They act at the interface generated by a hydrophobic lipid substrate in a hydrophilic aqueous medium. A characteristic property of lipases is called interfacial activation,

  5. Bacterial Ecology

    DEFF Research Database (Denmark)

    Fenchel, Tom

    2011-01-01

    , the production and oxidation of methane, nitrate reduction and fixation of atmospheric nitrogen are exclusively carried out by different groups of bacteria. Some bacterial species – ‘extremophiles’ – thrive in extreme environments in which no eukaryotic organisms can survive with respect to temperature, salinity...

  6. Bacterial Vaginosis

    Science.gov (United States)

    ... that coats the walls of the vagina Vaginal discharge with an unpleasant or fishlike odor Vaginal pain or itching Burning during urination Doctors are unsure of the incubation period for bacterial vaginosis. How Is the Diagnosis Made? Your child’s pediatrician can make the diagnosis ...

  7. Bacterial stress

    Indian Academy of Sciences (India)

    First page Back Continue Last page Graphics. Bacterial stress. Physicochemical and chemical parameters: temperature, pressure, pH, salt concentration, oxygen, irradiation. Nutritional depravation: nutrient starvation, water shortage. Toxic compounds: Antibiotics, heavy metals, toxins, mutagens. Interactions with other cells: ...

  8. Ultraviolet germicidal irradiation inactivation of airborne fungal spores and bacteria in upper-room air and HVAC in-duct configurations

    Energy Technology Data Exchange (ETDEWEB)

    Kujundzic, E.; Hernandez, M. [Colorado Univ., Boulder, CO (United States). Dept. of Civil, Environmental and Architectural Engineering; Miller, S.L. [Colorado Univ., Boulder, CO (United States). Dept. of Mechanical Engineering

    2007-01-15

    This article presented an evaluation of the efficiency of ultraviolet germicidal irradiation (UVGI) for inactivating airborne fungal spores and bacterial vegetative cells under 3 configurations, namely intrinsic, upper-room air, and in-duct. Several experiments were conducted in a pilot-scale chamber fitted with 4 corner ultraviolet lamps that irradiated the entire chamber; a full-scale room fitted with a UVGI system that irradiated the top 30 cm of the room; and, the supply air duct of a heating ventilation and air-conditioning (HVAC) system. Fungal spores and vegetative cells of bacterium were aerosolized regularly such that their numbers and physiologic state were comparable both with and without the UVGI lamps operating. The article provided information on the materials and methods used including the experimental facilities (pilot-scale chamber, full-scale room, and in-duct UVGI system and ductwork) as well as the methods used for the three experimental studies. It also discussed the bioaerosol generation and sampling and quantification. These included culturing and direct microscopy. UV fluence rate was described. Last, the the results, discussion and conclusions from the studies were presented. It was shown that increasing the air stream velocity through the supply air duct reduces the residence time of bioaerosol being exposed to in-duct UVGI. 36 refs., 3 figs.

  9. Introduction to uncertainty quantification

    CERN Document Server

    Sullivan, T J

    2015-01-01

    Uncertainty quantification is a topic of increasing practical importance at the intersection of applied mathematics, statistics, computation, and numerous application areas in science and engineering. This text provides a framework in which the main objectives of the field of uncertainty quantification are defined, and an overview of the range of mathematical methods by which they can be achieved. Complete with exercises throughout, the book will equip readers with both theoretical understanding and practical experience of the key mathematical and algorithmic tools underlying the treatment of uncertainty in modern applied mathematics. Students and readers alike are encouraged to apply the mathematical methods discussed in this book to their own favourite problems to understand their strengths and weaknesses, also making the text suitable as a self-study. This text is designed as an introduction to uncertainty quantification for senior undergraduate and graduate students with a mathematical or statistical back...

  10. Bacterial Adhesion & Blocking Bacterial Adhesion

    DEFF Research Database (Denmark)

    Vejborg, Rebecca Munk

    2008-01-01

    reduce or delay bacterial biofilm formation of a range of urinary tract infectious E.coli and Klebsiella isolates. Several other proteinaceous coatings were also found to display anti-adhesive properties, possibly providing a measure for controlling the colonization of implant materials. Several other...... components. These substances may both mediate and stabilize the bacterial biofilm. Finally, several adhesive structures were examined, and a novel physiological biofilm phenotype in E.coli biofilms was characterized, namely cell chain formation. The autotransporter protein, antigen 43, was implicated...

  11. Airborne asbestos fibres monitoring in tunnel excavation.

    Science.gov (United States)

    Gaggero, Laura; Sanguineti, Elisa; Yus González, Adrián; Militello, Gaia Maria; Scuderi, Alberto; Parisi, Giovanni

    2017-07-01

    Tunnelling across ophiolitic formation with Naturally Occurring Asbestos (NOA) can release fibres into the environment, exposing workers, and the population, if fibres spread outside the tunnel, leading to increased risk of developing asbestos-related disease. Therefore, a careful plan of environmental monitoring is carried out during Terzo Valico tunnel excavation. In the present study, data of 1571 samples of airborne dust, collected between 2014 and 2016 inside the tunnels, and analyzed by SEM-EDS for quantification of workers exposure, are discussed. In particular, the engineering and monitoring management of 100 m tunnelling excavation across a serpentinite lens (Cravasco adit), intercalated within calcschists, is reported. At this chrysotile occurrence, 84% of 128 analyzed samples (from the zone closer to the front rock) were above 2 ff/l. However, thanks to safety measures implemented and tunnel compartmentation in zones, the asbestos fibre concentration did not exceed the Italian standard of occupational exposure (100 ff/l) and 100% of samples collected in the outdoor square were below 1 ff/l. During excavation under normal working conditions, asbestos concentrations were below 2 ff/l in 97.4% of the 668 analyzed samples. Our results showed that air monitoring can objectively confirm the presence of asbestos minerals at a rock front in relative short time and provide information about the nature of the lithology at the front. The present dataset, the engineering measures described and the operative conclusions are liable to support the improvement of legislation on workers exposure to asbestos referred to the tunnelling sector, lacking at present. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. The NASA Carbon Airborne Flux Experiment (CARAFE: instrumentation and methodology

    Directory of Open Access Journals (Sweden)

    G. M. Wolfe

    2018-03-01

    Full Text Available The exchange of trace gases between the Earth's surface and atmosphere strongly influences atmospheric composition. Airborne eddy covariance can quantify surface fluxes at local to regional scales (1–1000 km, potentially helping to bridge gaps between top-down and bottom-up flux estimates and offering novel insights into biophysical and biogeochemical processes. The NASA Carbon Airborne Flux Experiment (CARAFE utilizes the NASA C-23 Sherpa aircraft with a suite of commercial and custom instrumentation to acquire fluxes of carbon dioxide, methane, sensible heat, and latent heat at high spatial resolution. Key components of the CARAFE payload are described, including the meteorological, greenhouse gas, water vapor, and surface imaging systems. Continuous wavelet transforms deliver spatially resolved fluxes along aircraft flight tracks. Flux analysis methodology is discussed in depth, with special emphasis on quantification of uncertainties. Typical uncertainties in derived surface fluxes are 40–90 % for a nominal resolution of 2 km or 16–35 % when averaged over a full leg (typically 30–40 km. CARAFE has successfully flown two missions in the eastern US in 2016 and 2017, quantifying fluxes over forest, cropland, wetlands, and water. Preliminary results from these campaigns are presented to highlight the performance of this system.

  13. Bacterial lipases

    OpenAIRE

    Jaeger, Karl-Erich; Ransac, Stéphane; Dijkstra, Bauke W.; Colson, Charles; Heuvel, Margreet van; Misset, Onno

    1994-01-01

    Many different bacterial species produce lipases which hydrolyze esters of glycerol with preferably long-chain fatty acids. They act at the interface generated by a hydrophobic lipid substrate in a hydrophilic aqueous medium. A characteristic property of lipases is called interfacial activation, meaning a sharp increase in lipase activity observed when the substrate starts to form an emulsion, thereby presenting to the enzyme an interfacial area. As a consequence, the kinetics of a lipase rea...

  14. Disease quantification in dermatology

    DEFF Research Database (Denmark)

    Greve, Tanja Maria; Kamp, Søren; Jemec, Gregor B E

    2013-01-01

    Accurate documentation of disease severity is a prerequisite for clinical research and the practice of evidence-based medicine. The quantification of skin diseases such as psoriasis currently relies heavily on clinical scores. Although these clinical scoring methods are well established and very ...

  15. Monitoring and evaluation techniques for airborne contamination

    International Nuclear Information System (INIS)

    Xia Yihua

    1997-01-01

    Monitoring and evaluation of airborne contamination are of great importance for the purpose of protection of health and safety of workers in nuclear installations. Because airborne contamination is one of the key sources to cause exposure to individuals by inhalation and digestion, and to cause diffusion of contaminants in the environment. The main objectives of monitoring and evaluation of airborne contamination are: to detect promptly a loss of control of airborne material, to help identify those individuals and predict exposure levels, to assess the intake and dose commitment to the individuals, and to provide sufficient documentation of airborne radioactivity. From the viewpoint of radiation protection, the radioactive contaminants in air can be classified into the following types: airborne aerosol, gas and noble gas, and volatile gas. In this paper, the following items are described: sampling methods and techniques, measurement and evaluation, and particle size analysis. (G.K.)

  16. Monitoring and evaluation techniques for airborne contamination

    Energy Technology Data Exchange (ETDEWEB)

    Xia Yihua [China Inst. of Atomic Energy, Beijing (China)

    1997-06-01

    Monitoring and evaluation of airborne contamination are of great importance for the purpose of protection of health and safety of workers in nuclear installations. Because airborne contamination is one of the key sources to cause exposure to individuals by inhalation and digestion, and to cause diffusion of contaminants in the environment. The main objectives of monitoring and evaluation of airborne contamination are: to detect promptly a loss of control of airborne material, to help identify those individuals and predict exposure levels, to assess the intake and dose commitment to the individuals, and to provide sufficient documentation of airborne radioactivity. From the viewpoint of radiation protection, the radioactive contaminants in air can be classified into the following types: airborne aerosol, gas and noble gas, and volatile gas. In this paper, the following items are described: sampling methods and techniques, measurement and evaluation, and particle size analysis. (G.K.)

  17. The Origin And Spread Of Airborne Bacteria

    Science.gov (United States)

    Henderson-Begg, S. K.; Moffett, B. F.

    2009-12-01

    The presence of bacteria in clouds may affect their radiation and precipitation properties as some species are able to catalyse the freezing of water at high temperatures (-2C to -10C). Where cloud-borne bacteria originate and the distances they are able to travel in the air remains a mystery. In this study we have attempted to address these issues by comparing metagenomic DNA sequences from air samples with those from other environmental sources. Air samples were collected on 1 July 2009 from a hill top at Thursley Nature Reserve in Surrey, United Kingdom, a rural site, 31 miles from the nearest stretch of coastline, and on 6 July 2009 from the top of a six storey building in Stratford on the East end of London, 38 miles from the nearest coastal area. Samples were collected using the Karcher DS5500 vacuum into a liquid filled collection vessel at an air flow rate of 3.3 m3 min-1 over a 4 hour period. Samples were then concentrated and the bacterial content was investigated by PCR, cloning and sequencing of 16S rRNA genes. During the collection period on 1 July the Royston Weather Station in the South East of England recorded wind speed of 1.9 miles/hour in an Easterly direction, with no cloud cover, relative humidity of 74% and atmospheric pressure of 1021.6 mB. On 6 July wind speed was 9.8 miles/hour in a South Westerly direction, there was light cloud cover, relative humidity was 73.8% and atmospheric pressure was 1002.8 mB. Twenty cloned 16S PCR products from each air sample were sequenced. The species identification of each clone is shown in Table 1. The diversity of bacteria found at both sites was similar, with Stenotrophomona and Pedobacteria species dominating both samples. When the DNA sequences were blasted against the environmental samples database, all sequences were found to display greatest homology to metagenomic DNA from marine sources. This may suggest that the most numerous bacteria in air samples originate in the oceans. Taking account of the

  18. ZPR-9 airborne plutonium monitoring system

    International Nuclear Information System (INIS)

    Rusch, G.K.; McDowell, W.P.; Knapp, W.G.

    1975-01-01

    An airborne plutonium monitoring system which is installed in the ZPR-9 (Zero Power Reactor No. 9) facility at Argonne National Laboratory is described. The design and operational experience are discussed. This monitoring system utilizes particle size and density discrimination, alpha particle energy discrimination, and a background-subtraction techique operating in cascade to separate airborne-plutonium activity from other, naturally occurring, airborne activity. Relatively high sensitivity and reliability are achieved

  19. Electrospray Collection of Airborne Contaminants, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — In stark contrast to current stagnation-based methods for capturing airborne particulates and biological aerosols, our demonstrated, cost-effective electrospray...

  20. Electrospray Collection of Airborne Contaminants, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — In stark contrast to current stagnation-based methods for capturing airborne particulates and biological aerosols, our demonstrated, cost-effective electrospray...

  1. Bacterial mitosis

    DEFF Research Database (Denmark)

    Møller-Jensen, Jakob; Borch, Jonas; Dam, Mette

    2003-01-01

    Bacterial DNA segregation takes place in an active and ordered fashion. In the case of Escherichia coli plasmid R1, the partitioning system (par) separates paired plasmid copies and moves them to opposite cell poles. Here we address the mechanism by which the three components of the R1 par system...... movement is powered by insertional polymerization of ParM. Consistently, we find that segregating plasmids are positioned at the ends of extending ParM filaments. Thus, the process of R1 plasmid segregation in E. coli appears to be mechanistically analogous to the actin-based motility operating...

  2. Optimization of a real-time PCR assay to quantitate airborne fungi collected on a gelatin filter.

    Science.gov (United States)

    Yamamoto, Naomichi; Kimura, Minoru; Matsuki, Hideaki; Yanagisawa, Yukio

    2010-01-01

    The present study aimed to optimize a real-time PCR assay to quantitate airborne fungi collected on a gelatin filter. In particular, the study optimized conditions for the DNA extraction and real-time PCR amplification to accurately measure airborne fungal concentrations. First, time of fine bead homogenization to extract the DNA from fungal cells was optimized to maximize the DNA yield and prepare the DNA suitable for sensitive and precise quantification by a subsequent real-time PCR analysis. Second, a condition for the real-time PCR amplification was optimized to successfully amplify and quantitate the extracted fungal DNA. In particular, a dilution ratio of the DNA extracts to be introduced to PCR was optimized to achieve an appropriate balance between mitigating PCR inhibition and securing detection sensitivity. Since concentrations of airborne fungi generally observed in indoor and outdoor environments (i.e., 10(1)-10(4) CFU m(-3)) were found to be near the limit of quantification by the generally-used molecular-based detection technique in conjunction with use of gelatin filters, optimizations of these conditions were found to be crucial. Our preliminary result showed that a culture-based method underestimated concentrations of airborne environmental fungi by 1 to 2 orders of magnitude compared to those characterized by the real-time PCR assay. 2009 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  3. Fluorescent quantification of melanin

    OpenAIRE

    Fernandes, Bruno Pacheco; Matamá, Maria Teresa; Guimarães, Diana Isabel Pereira; Gomes, Andreia; Cavaco-Paulo, Artur

    2016-01-01

    Melanin quantification is reportedly performed by absorption spectroscopy, commonly at 405 nm. Here, we propose the implementation of fluorescence spectroscopy for melanin assessment. In a typical in vitro assay to assess melanin production in response to an external stimulus, absorption spectroscopy clearly overvalues melanin content. This method is also incapable of distinguishing non-melanotic/amelanotic control cells from those that are actually capable of performing melanogenesis. Theref...

  4. Chemical Microsensor Instrument for UAV Airborne Atmospheric Measurements Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Makel Engineering, Inc. (MEI) proposes to develop a miniaturized Airborne Chemical Microsensor Instrument (ACMI) suitable for real-time, airborne measurements of...

  5. Effect of isolate of ruminal fibrolytic bacterial culture supplementation on fibrolytic bacterial population and survivability of inoculated bacterial strain in lactating Murrah buffaloes

    Directory of Open Access Journals (Sweden)

    Brishketu Kumar

    2013-02-01

    Full Text Available Aim: The present study was conducted to evaluate the effect of bacterial culture supplementation on ruminal fibrolytic bacterial population as well as on survivability of inoculated bacterial strain in lactating Murrah buffaloes kept on high fibre diet. Materials and Methods: Fibrolytic bacterial strains were isolated from rumen liquor of fistulated Murrah buffaloes and live bacterial culture were supplemented orally in treatment group of lactating Murrah buffaloes fed on high fibre diet to see it's effect on ruminal fibrolytic bacterial population as well as to see the effect of survivability of the inoculated bacterial strain at three different time interval in comparison to control group. Results: It has been shown by real time quantification study that supplementation of bacterial culture orally increases the population of major fibre degrading bacteria i.e. Ruminococcus flavefaciens, Ruminococcus albus as well as Fibrobacter succinogenes whereas there was decrease in secondary fibre degrading bacterial population i.e. Butyrivibrio fibrisolvens over the different time periods. However, the inoculated strain of Ruminococcus flavefaciens survived significantly over the period of time, which was shown in stability of increased inoculated bacterial population. Conclusion: The isolates of fibrolytic bacterial strains are found to be useful in increasing the number of major ruminal fibre degrading bacteria in lactating buffaloes and may act as probiotic in large ruminants on fibre-based diets. [Vet World 2013; 6(1.000: 14-17

  6. Source terms for airborne effluents

    International Nuclear Information System (INIS)

    Blomeke, J.O.; Perona, J.J.

    1976-01-01

    The origin and nature of fuel cycle wastes are discussed with regard to high-level wastes, cladding, noble gases, iodine, tritium, 14 C, low-level and intermediate-level transuranic wastes, non-transuranic wastes, and ore tailings. The current practice for gaseous effluent treatment is described for light water reactors and high-temperature gas-cooled reactors. Other topics discussed are projections of nuclear power generation; projected accumulation of gaseous wastes; the impact of nuclear fuel cycle centers; and global buildup of airborne effluents

  7. Compositae dermatitis from airborne parthenolide

    DEFF Research Database (Denmark)

    Paulsen, E; Christensen, Lars Porskjær; Andersen, Klaus Ejner

    2007-01-01

    suspected of causing airborne contact allergy, and its most important allergen is the sesquiterpene lactone (SQL) parthenolide (PHL). OBJECTIVES: The aims of this study were to (i) assess the allergenicity of feverfew-derived monoterpenes and sesquiterpenes and their oxidized products in feverfew......, obtained by fractionation of ether extracts, dynamic headspace and high-volume air sampler (HIVAS) technique, respectively. RESULTS: Among 12 feverfew-allergic patients, eight had positive patch-test reactions to a HIVAS filter extract, while two tested positive to a headspace extract. Subsequent analysis...

  8. Geophex airborne unmanned survey system

    International Nuclear Information System (INIS)

    Won, I.J.; Taylor, D.W.A.

    1995-01-01

    The purpose of this effort is to design, construct, and evaluate a portable, remotely-piloted, airborne, geophysical survey system. This nonintrusive system will provide open-quotes stand-offclose quotes capability to conduct surveys and detect buried objects, structures, and conditions of interest at hazardous locations. This system permits two operators to rapidly conduct geophysical characterization of hazardous environmental sites. During a survey, the operators remain remote from, but within visual distance, of, the site. The sensor system never contacts the Earth, but can be positioned near the ground so that weak anomalies can be detected

  9. Real-time measurements of airborne biologic particles using fluorescent particle counter to evaluate microbial contamination: results of a comparative study in an operating theater.

    Science.gov (United States)

    Dai, Chunyang; Zhang, Yan; Ma, Xiaoling; Yin, Meiling; Zheng, Haiyang; Gu, Xuejun; Xie, Shaoqing; Jia, Hengmin; Zhang, Liang; Zhang, Weijun

    2015-01-01

    Airborne bacterial contamination poses a risk for surgical site infection, and routine surveillance of airborne bacteria is important. Traditional methods for detecting airborne bacteria are time consuming and strenuous. Measurement of biologic particle concentrations using a fluorescent particle counter is a novel method for evaluating air quality. The current study was to determine whether the number of biologic particles detected by the fluorescent particle counter can be used to indicate airborne bacterial counts in operating rooms. The study was performed in an operating theater at a university hospital in Hefei, China. The number of airborne biologic particles every minute was quantified using a fluorescent particle counter. Microbiologic air sampling was performed every 30 minutes using an Andersen air sampler (Pusong Electronic Instruments, Changzhou, China). Correlations between the 2 different methods were analyzed by Pearson correlation coefficients. A significant correlation was observed between biologic particle and bacterial counts (Pearson correlation coefficient = 0.76), and the counting results from 2 methods both increased substantially between operations, corresponding with human movements in the operating room. Fluorescent particle counters show potential as important tools for monitoring bacterial contamination in operating theatres. Copyright © 2015 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

  10. Kinetic quantification of plyometric exercise intensity.

    Science.gov (United States)

    Ebben, William P; Fauth, McKenzie L; Garceau, Luke R; Petushek, Erich J

    2011-12-01

    Ebben, WP, Fauth, ML, Garceau, LR, and Petushek, EJ. Kinetic quantification of plyometric exercise intensity. J Strength Cond Res 25(12): 3288-3298, 2011-Quantification of plyometric exercise intensity is necessary to understand the characteristics of these exercises and the proper progression of this mode of exercise. The purpose of this study was to assess the kinetic characteristics of a variety of plyometric exercises. This study also sought to assess gender differences in these variables. Twenty-six men and 23 women with previous experience in performing plyometric training served as subjects. The subjects performed a variety of plyometric exercises including line hops, 15.24-cm cone hops, squat jumps, tuck jumps, countermovement jumps (CMJs), loaded CMJs equal to 30% of 1 repetition maximum squat, depth jumps normalized to the subject's jump height (JH), and single leg jumps. All plyometric exercises were assessed with a force platform. Outcome variables associated with the takeoff, airborne, and landing phase of each plyometric exercise were evaluated. These variables included the peak vertical ground reaction force (GRF) during takeoff, the time to takeoff, flight time, JH, peak power, landing rate of force development, and peak vertical GRF during landing. A 2-way mixed analysis of variance with repeated measures for plyometric exercise type demonstrated main effects for exercise type and all outcome variables (p ≤ 0.05) and for the interaction between gender and peak vertical GRF during takeoff (p ≤ 0.05). Bonferroni-adjusted pairwise comparisons identified a number of differences between the plyometric exercises for the outcome variables assessed (p ≤ 0.05). These findings can be used to guide the progression of plyometric training by incorporating exercises of increasing intensity over the course of a program.

  11. Airborne Lidar Surface Topography (LIST) Simulator

    Science.gov (United States)

    Yu, Anthony W.; Krainak, Michael A.; Harding, David J.; Abshire, James B.; Sun, Xiaoli; Cavanaugh, John; Valett, Susan; Ramos-Izquierdo, Luis; Winkert, Tom; Plants, Michael; hide

    2011-01-01

    In this paper we will discuss our development effort of an airborne instrument as a pathfinder for the Lidar Surface Technology (LIST) mission. This paper will discuss the system approach, enabling technologies, instrument concept and performance of the Airborne LIST Simulator (A-LISTS).

  12. Resuscitation effects of catalase on airborne bacteria.

    OpenAIRE

    Marthi, B; Shaffer, B T; Lighthart, B; Ganio, L

    1991-01-01

    Catalase incorporation into enumeration media caused a significant increase (greater than 63%) in the colony-forming abilities of airborne bacteria. Incubation for 30 to 60 min of airborne bacteria in collection fluid containing catalase caused a greater than 95% increase in colony-forming ability. However, catalase did not have any effects on enumeration at high relative humidities (80 to 90%).

  13. Geronimo: Planning Considerations for Employing Airborne Forces

    Science.gov (United States)

    2017-05-25

    risk mitigation measure in crisis response scenarios, correlates to successful operations . In fact, operations undertaken without 100 or more days...22 4 Planning Time Allotted for Airborne Selected Airborne Operation ............................. 29 5 Summary Risk ...considerations. The doctrinal and service requirements provide a planner with a toolkit for mitigating risk prior to execution of an operation . First, a

  14. Airborne Oceanographic Lidar (AOL) (Global Carbon Cycle)

    Science.gov (United States)

    2003-01-01

    This bimonthly contractor progress report covers the operation, maintenance and data management of the Airborne Oceanographic Lidar and the Airborne Topographic Mapper. Monthly activities included: mission planning, sensor operation and calibration, data processing, data analysis, network development and maintenance and instrument maintenance engineering and fabrication.

  15. Digital airborne camera introduction and technology

    CERN Document Server

    Sandau, Rainer

    2014-01-01

    The last decade has seen great innovations on the airborne camera. This book is the first ever written on the topic and describes all components of a digital airborne camera ranging from the object to be imaged to the mass memory device.

  16. Realization of a scalable airborne radar

    NARCIS (Netherlands)

    Otten, M.P.G.; Vermeulen, B.C.B.; Liempt, L.J. van; Halsema, D. van; Jongh, R.V. de; Es, J. van

    2008-01-01

    Modern airborne ground surveillance radar systems are increasingly based on Active Electronically Scanned Array (AESA) antennas. Efficient use of array technology and the need for radar solutions for various airborne platforms, manned and unmanned, leads to the design of scalable radar systems. The

  17. Geophex Airborne Unmanned Survey System

    International Nuclear Information System (INIS)

    Won, I.L.; Keiswetter, D.

    1995-01-01

    Ground-based surveys place personnel at risk due to the proximity of buried unexploded ordnance (UXO) items or by exposure to radioactive materials and hazardous chemicals. The purpose of this effort is to design, construct, and evaluate a portable, remotely-piloted, airborne, geophysical survey system. This non-intrusive system will provide stand-off capability to conduct surveys and detect buried objects, structures, and conditions of interest at hazardous locations. During a survey, the operators remain remote from, but within visual distance of, the site. The sensor system never contacts the Earth, but can be positioned near the ground so that weak geophysical anomalies can be detected. The Geophex Airborne Unmanned Survey System (GAUSS) is designed to detect and locate small-scale anomalies at hazardous sites using magnetic and electromagnetic survey techniques. The system consists of a remotely-piloted, radio-controlled, model helicopter (RCH) with flight computer, light-weight geophysical sensors, an electronic positioning system, a data telemetry system, and a computer base-station. The report describes GAUSS and its test results

  18. Bacterial Biofilms in Jones Tubes.

    Science.gov (United States)

    Ahn, Eric S; Hauck, Matthew J; Kirk Harris, Jonathan; Robertson, Charles E; Dailey, Roger A

    To investigate the presence and microbiology of bacterial biofilms on Jones tubes (JTs) by direct visualization with scanning electron microscopy and polymerase chain reaction (PCR) of representative JTs, and to correlate these findings with inflammation and/or infection related to the JT. In this study, prospective case series were performed. JTs were recovered from consecutive patients presenting to clinic for routine cleaning or recurrent irritation/infection. Four tubes were processed for scanning electron microscopy alone to visualize evidence of biofilms. Two tubes underwent PCR alone for bacterial quantification. One tube was divided in half and sent for scanning electron microscopy and PCR. Symptoms related to the JTs were recorded at the time of recovery. Seven tubes were obtained. Five underwent SEM, and 3 out of 5 showed evidence of biofilms (60%). Two of the 3 biofilms demonstrated cocci and the third revealed rods. Three tubes underwent PCR. The predominant bacteria identified were Pseudomonadales (39%), Pseudomonas (16%), and Staphylococcus (14%). Three of the 7 patients (43%) reported irritation and discharge at presentation. Two symptomatic patients, whose tubes were imaged only, revealed biofilms. The third symptomatic patient's tube underwent PCR only, showing predominantly Staphylococcus (56%) and Haemophilus (36%) species. Two of the 4 asymptomatic patients also showed biofilms. All symptomatic patients improved rapidly after tube exchange and steroid antibiotic drops. Bacterial biofilms were variably present on JTs, and did not always correlate with patients' symptoms. Nevertheless, routine JT cleaning is recommended to treat and possibly prevent inflammation caused by biofilms.

  19. Workbook on reactor neutron activation analysis (NAA) of airborne particulate matter (APM)

    International Nuclear Information System (INIS)

    Tian Weizhi

    2000-01-01

    This publication presents general aspects of reactor neutron activation analysis (NAA) applied to measurement of elemental composition of airborne particulate matter. It presents an introduction to the NAA, its' basic principles and brief history of the method and discusses its' advantages and disadvantages. This publication also presents experimental procedures of NAA including sampling and sample preparation; preparation of calibration standard samples; reactor neutron irradiation; gamma-spectroscopy of the irradiated samples; quantification and presentation of analytical results. The publication pays attention to the quality assurance and quality control procedures including internal quality control, analysis of certified reference materials, and interlaboratory and multi-method comparison studies, control charts

  20. Infection Efficiency of Four Phytophthora infestans Clonal Lineages and DNA-Based Quantification of Sporangia.

    Directory of Open Access Journals (Sweden)

    Mamadou Lamine Fall

    Full Text Available The presence and abundance of pathogen inoculum is with host resistance and environmental conditions a key factor in epidemic development. Therefore, several spore-sampling devices have been proposed to monitor pathogen inoculum above fields. However, to make spore sampling more reliable as a management tool and to facilitate its adoption, information on infection efficiency and molecular tools for estimating airborne sporangia concentration are needed. Experiments were thus undertaken in a growth chamber to study the infection efficiency of four clonal lineages of P. infestans (US-8, US-11, US-23, and US-24 by measuring the airborne sporangia concentration and resulting disease intensity. The relationship between the airborne sporangia concentration and the number of lesions per leaf was exponential. For the same concentration, the sporangia of US-23 caused significantly more lesions than the sporangia of the other clonal lineages did. Under optimal conditions, an airborne sporangia concentration of 10 sporangia m-3 for US-23 was sufficient to cause one lesion per leaf, whereas for the other clonal lineages, it took 15 to 25 sporangia m-3 to reach the same disease intensity. However, in terms of diseased leaf area, there was no difference between clonal lineages US-8, US-23 and US-24. Also, a sensitive quantitative real-time polymerase chain reaction (qPCR tool was developed to quantify P. infestans airborne sporangia with detection sensitivity of one sporangium. The specificity of the qPCR assay was rigorously tested for airborne inoculum and was either similar to, or an improvement on, other published PCR assays. This assay allows rapid and reliable detection and quantification of P. infestans airborne sporangia and thereby, facilitates the implementation of spores-sampling network.

  1. Emission strength of airborne pathogens during toilet flushing.

    Science.gov (United States)

    Lai, A C K; Tan, T F; Li, W S; Ip, D K M

    2018-01-01

    The flushing of toilets generates contaminated aerosols, the transmission of which may cause the spread of disease, particularly in the immunocompromised or the elderly. This study investigated the emission strength of three types of airborne bacteria, namely Staphylococcus epidermidis, Escherichia coli, and Pseudomonas alcaligenes, during toilet flushing in a custom-built toilet under a controlled environment. Flushing was activated by a flushometer operated at two pressure levels, 400 kPa (high pressure [HP]) and 200 kPa (low pressure [LP]), and by a water cistern tank placed 95 cm (high tank [HT]) and 46 cm (low tank [LT]) above the toilet seat. The pathogens emitted by the first flush were calculated, with the correlations between airborne pathogen emissions and droplet concentration (HP, r=0.944, P<.001; LP, r=0.803, P<.001, HT, r=0.885, P<.05) and bacterial size (HP, r=-0.919, P<.001; LP, r=-0.936, P<.001; HT, r=-0.967, P<.05) in the different conditions then tested. The emission strength in the HP condition was statistically greater than that in the LP condition, whereas the cistern tank system produced less emissions than the flushometer system, and tank height was not found to be a sensitive parameter. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  2. Comparative performance of three sampling techniques to detect airborne [i]Salmonella[/i] species in poultry farms

    Directory of Open Access Journals (Sweden)

    Elisa Adell

    2014-03-01

    Full Text Available Sampling techniques to detect airborne [i]Salmonella[/i] species (spp. in two pilot scale broiler houses were compared. Broilers were inoculated at seven days of age with a marked strain of [i]Salmonella[/i] enteritidis. The rearing cycle lasted 42 days during the summer. Airborne [i]Salmonella[/i] spp. were sampled weekly using impaction, gravitational settling, and impingement techniques. Additionally, [i]Salmonella[/i] spp. were sampled on feeders, drinkers, walls, and in the litter. Environmental conditions (temperature, relative humidity, and airborne particulate matter (PM concentration were monitored during the rearing cycle. The presence of [i]Salmonella[/i] spp. was determined by culture-dependent and molecular methods. No cultivable [i]Salmonella[/i] spp. were recovered from the poultry houses’ surfaces, the litter, or the air before inoculation. After inoculation, cultivable [i]Salmonella[/i] spp. were recovered from the surfaces and in the litter. Airborne cultivable [i]Salmonella[/i] spp. Were detected using impaction and gravitational settling one or two weeks after the detection of [i]Salmonella[/i] spp. in the litter. No cultivable [i]Salmonella[/i] spp. were recovered using impingement based on culture-dependent techniques. At low airborne concentrations, the use of impingement for the quantification or detection of cultivable airborne Salmonella spp. is not recommended. In these cases, a combination of culture-dependent and culture-independent methods is recommended. These data are valuable to improve current measures to control the transmission of pathogens in livestock environments and for optimising the sampling and detection of airborne[i] Salmonella[/i] spp. in practical conditions.

  3. BACTERIAL PLASMIDS

    Directory of Open Access Journals (Sweden)

    Marina Dinic

    2007-12-01

    Full Text Available Plasmids, extrachromosomal DNA, were identified in bacteria pertaining to family of Enterobacteriacae for the very first time. After that, they were discovered in almost every single observed strain. The structure of plasmids is made of circular double chain DNA molecules which are replicated autonomously in a host cell. Their length may vary from few up to several hundred kilobase (kb. Among the bacteria, plasmids are mostly transferred horizontally by conjugation process. Plasmid replication process can be divided into three stages: initiation, elongation, and termination. The process involves DNA helicase I, DNA gyrase, DNA polymerase III, endonuclease, and ligase.Plasmids contain genes essential for plasmid function and their preservation in a host cell (the beginning and the control of replication. Some of them possess genes whichcontrol plasmid stability. There is a common opinion that plasmids are unnecessary fora growth of bacterial population and their vital functions; thus, in many cases they can be taken up or kicked out with no lethal effects to a plasmid host cell. However,there are numerous biological functions of bacteria related to plasmids. Plasmids identification and classification are based upon their genetic features which are presented permanently in all of them, and these are: abilities to preserve themselves in a host cell and to control a replication process. In this way, plasmids classification among incompatibility groups is performed. The method of replicon typing, which is based on genotype and not on phenotype characteristics, has the same results as in compatibility grouping.

  4. Airborne gamma ray spectrometer surveying

    International Nuclear Information System (INIS)

    1991-01-01

    The International Atomic Energy Agency (IAEA) in its role as collector and disseminator of information on nuclear techniques has long had an interest in gamma ray spectrometer methods and has published a number of Technical Reports on various aspects of the subject. At an Advisory Group Meeting held in Vienna in November 1986 to review appropriate activities the IAEA could take following the Chernobyl accident, it was recommended that preparation begin on a new Technical Report on airborne gamma ray spectrometer surveying, taking into account the use of the technique for environmental monitoring as well as for nuclear emergency response requirements. Shortly thereafter the IAEA became the lead organization in the Radioelement Geochemical Mapping section of the International Geological Correlation Programme/United Nations Educational, Scientific and Cultural Organization (UNESCO) Project on International Geochemical Mapping. These two factors led to the preparation of the present Technical Report. 18 figs, 4 tabs

  5. Airborne remote sensing of forest biomes

    Science.gov (United States)

    Sader, Steven A.

    1987-01-01

    Airborne sensor data of forest biomes obtained using an SAR, a laser profiler, an IR MSS, and a TM simulator are presented and examined. The SAR was utilized to investigate forest canopy structures in Mississippi and Costa Rica; the IR MSS measured forest canopy temperatures in Oregon and Puerto Rico; the TM simulator was employed in a tropical forest in Puerto Rico; and the laser profiler studied forest canopy characteristics in Costa Rica. The advantages and disadvantages of airborne systems are discussed. It is noted that the airborne sensors provide measurements applicable to forest monitoring programs.

  6. Accident sequence quantification with KIRAP

    International Nuclear Information System (INIS)

    Kim, Tae Un; Han, Sang Hoon; Kim, Kil You; Yang, Jun Eon; Jeong, Won Dae; Chang, Seung Cheol; Sung, Tae Yong; Kang, Dae Il; Park, Jin Hee; Lee, Yoon Hwan; Hwang, Mi Jeong.

    1997-01-01

    The tasks of probabilistic safety assessment(PSA) consists of the identification of initiating events, the construction of event tree for each initiating event, construction of fault trees for event tree logics, the analysis of reliability data and finally the accident sequence quantification. In the PSA, the accident sequence quantification is to calculate the core damage frequency, importance analysis and uncertainty analysis. Accident sequence quantification requires to understand the whole model of the PSA because it has to combine all event tree and fault tree models, and requires the excellent computer code because it takes long computation time. Advanced Research Group of Korea Atomic Energy Research Institute(KAERI) has developed PSA workstation KIRAP(Korea Integrated Reliability Analysis Code Package) for the PSA work. This report describes the procedures to perform accident sequence quantification, the method to use KIRAP's cut set generator, and method to perform the accident sequence quantification with KIRAP. (author). 6 refs

  7. Data for automated, high-throughput microscopy analysis of intracellular bacterial colonies using spot detection

    DEFF Research Database (Denmark)

    Ernstsen, Christina L; Login, Frédéric H; Jensen, Helene H

    2017-01-01

    Quantification of intracellular bacterial colonies is useful in strategies directed against bacterial attachment, subsequent cellular invasion and intracellular proliferation. An automated, high-throughput microscopy-method was established to quantify the number and size of intracellular bacterial...... of cell nuclei were automatically quantified using a spot detection-tool. The spot detection-output was exported to Excel, where data analysis was performed. In this article, micrographs and spot detection data are made available to facilitate implementation of the method....

  8. Comparison of three rapid and easy bacterial DNA extraction methods for use with quantitative real-time PCR

    NARCIS (Netherlands)

    van Tongeren, S. P.; Degener, J. E.; Harmsen, H. J. M.

    The development of fast and easy on-site molecular detection and quantification methods for hazardous microbes on solid surfaces is desirable for several applications where specialised laboratory facilities are absent. The quantification of bacterial contamination necessitates the assessment of the

  9. Airborne Multi-Gas Sensor, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Mesa Photonics has developed laser-based gas sensor technology compatible with UAV deployment. Our Airborne MUlti-Gas Sensor (AMUGS) technology is based upon...

  10. Airborne Radar Search for Diesel Submarines (ARSDS)

    National Research Council Canada - National Science Library

    Pilnick, Steven E; Landa, Jose

    2005-01-01

    .... In this research, a detection rate model is developed to analyze the effectiveness of an airborne radar search for a diesel submarine assumed to be intermittently operating with periscopes or masts...

  11. Airborne Radar Search for Diesel Submarines

    National Research Council Canada - National Science Library

    Pilnick, Steven E; Landa, Jose

    2005-01-01

    .... In this research, a detection rate model is developed to analyze the effectiveness of airborne radar search for a diesel submarine assumed to be intermittently operating with periscopes or masts...

  12. Airborne radioactive contamination following aerosol ventilation studies

    International Nuclear Information System (INIS)

    Mackie, A.; Hart, G.C.; Ibbett, D.A.; Whitehead, R.J.S.

    1994-01-01

    Lung aerosol ventilation studies may be accompanied by airborne contamination, with subsequent surface contamination. Airborne contamination has been measured prior to, during and following 59 consecutive 99 Tc m -diethylenetriamine pentaacetate (DTPA) aerosol studies using a personal air sampler. Airborne contamination ranging between 0 and 20 330 kBq m -3 has been measured. Airborne contamination increases with degree of patient breathing difficulty. The effective dose equivalent (EDE) to staff from ingested activity has been calculated to be 0.3 μSv per study. This figure is supported by data from gamma camera images of a contaminated staff member. However, surface contamination measurements reveal that 60% of studies exceed maximum permissible contamination limits for the hands; 16% of studies exceed limits for controlled area surfaces. (author)

  13. Airborne Laser (ABL): Issues for Congress

    National Research Council Canada - National Science Library

    Bolkcom, Christopher; Hildreth, Steven A

    2007-01-01

    Funding for the Airborne Laser (ABL) program began in FY1994, but the technologies supporting the ABL effort has evolved over 25 years of research and development concerning laser power concepts, pointing and tracking, and adaptive optics...

  14. SMEX03 Airborne GPS Bistatic Radar Data

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains measurements of Global Positioning System (GPS) signals reflected from the Earth’s surface and collected on an airborne platform. The...

  15. Airborne Multi-Gas Sensor, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Mesa Photonics proposes to develop an Airborne Multi-Gas Sensor (AMUGS) based upon two-tone, frequency modulation spectroscopy (TT-FMS). Mesa Photonics has developed...

  16. Miniaturized Airborne Imaging Central Server System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The innovation is a miniaturized airborne imaging central server system (MAICSS). MAICSS is designed as a high-performance-computer-based electronic backend that...

  17. Miniaturized Airborne Imaging Central Server System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The innovation is a miniaturized airborne imaging central server system (MAICSS). MAICSS is designed as a high-performance computer-based electronic backend that...

  18. Regenerable Lunar Airborne Dust Filter, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Effective methods are needed to control pervasive Lunar Dust within spacecraft and surface habitations. Once inside, airborne transmission is the primary mode of...

  19. Voxel inversion of airborne EM data

    DEFF Research Database (Denmark)

    Fiandaca, Gianluca G.; Auken, Esben; Christiansen, Anders Vest C A.V.C.

    2013-01-01

    of prior information. Inversion of geophysical data usually refers to a model space being linked to the actual observation points. For airborne surveys the spatial discretization of the model space reflects the flight lines. Often airborne surveys are carried out in areas where other ground-based...... geophysical data are available. The model space of geophysical inversions is usually referred to the positions of the measurements, and ground-based model positions do not generally coincide with the airborne model positions. Consequently, a model space based on the measuring points is not well suited...... for jointly inverting airborne and ground-based geophysical data. Furthermore, geological and groundwater models most often refer to a regular voxel grid not correlated to the geophysical model space, and incorporating the geophysical data into the geological/hydrological modelling grids is problematic. We...

  20. Distribution and diversity of airborne microflora under mangrove forest at sandspit area karachi, pakistan

    International Nuclear Information System (INIS)

    Nazim, K.; Khan, M.U.; Ali, Q.M.; Ahmed, M.; Shaukat, S.S.; Sherwani, S.K.

    2012-01-01

    Fungi and bacteria are heterotrophic decomposers that grow on organic matter and occupy various habitats in mangrove forests. This paper deals with the distribution and diversity of air-borne microbiota (fungi and bacteria) under a mangrove forest at Sandspit, Pakistan. A permanent stand was set up at Sandspit to observe the qualitative and quantitative variations throughout the year, using petri plate techniques. During the study, a total of 16 fungal species, viz., Aspergillus niger, A. fumigatus, A. sulphureus, A. terreus, A. wentii, A. flavus, Alternaria alternata, A. maritima, A. porri, Alternaria sp., Rhizopus varians, Mucormucedo, Penicillium sp., P. notatum, Dreshellera biseptata, Exosporiella fungorum, Cladosporium oxysporum and 14420 +- 267 bacterial colonies were recorded from the selected site. The study revealed that the fungi were the major component of airborne microflora in mangrove environment. It was observed that both fungal species and number of bacterial colonies were higher in summer than in winter. It is anticipated that the temperature and salinity of sea-water directly affect the diversity of fungi and bacteria in mangroves environment. The maximum diversity H' (1.906) was recorded in August whereas the minimum H' (1.053) was recorded in March. It is hoped that this research will add to our knowledge pertaining to the distribution and diversity of the airborne microbiota (bacteria and fungi) in mangrove ecosystem. (author)

  1. Variability of airborne bacteria in an urban Mediterranean area (Thessaloniki, Greece)

    Science.gov (United States)

    Genitsaris, Savvas; Stefanidou, Natassa; Katsiapi, Matina; Kormas, Konstantinos A.; Sommer, Ulrich; Moustaka-Gouni, Maria

    2017-05-01

    The abundance, biomass and the taxonomic composition of the total airborne bacterial communities in a coastal urban area of Northeastern Mediterranean Sea were examined. In total, 27 air samples were collected across three seasons from a sampling point of approximately 30 m altitude in the center of the city. The abundance and biomass were determined with the use of epifluorescent microscopy, while the taxonomic composition was characterized by next-generation sequencing methods. Overall, the highest values of bacterial abundance were recorded during summer, with values exceeding abundances recorded in other urban sites across Europe, reaching 41 × 104 cells m-3. Out of 6 core meteorological parameters, only air temperature was found to significantly affect the abundance and biomass of airborne bacteria. Concerning the taxonomic composition of the airborne bacterial community, the group of Proteobacteria was the most diverse, with 47% of the total number of OTUs belonging to them, followed by Firmicutes, Actinobacteria and Bacteroidetes. The most dominant OTU belonged to γ-Proteobacteria, and was closely affiliated to Pseudomonas sp., a taxon commonly found to actively participate in the formation of ice-nuclei in the atmosphere. Finally, 19 OTUs were shared between all seasons and were found to be among the most dominant overall. The majority of these OTUs were affiliated to genera from soil and wastewater origin, while several were affiliated to genera that include known or opportunistic pathogens. Yet, only rare OTUs were affiliated to taxa with possible marine origin (e.g. Synechococcus sp.). The results showed that the atmosphere of the study area harbors a diverse and abundant bacterial community.

  2. Airborne infections and modern building technology

    Energy Technology Data Exchange (ETDEWEB)

    LaForce, F.M.

    1986-01-01

    Over the last 30 yr an increased appreciation of the importance of airborne infection has evolved. The concept of droplet nuclei, infectious particles from 0.5 to 3 ..mu.. which stay suspended in air for long periods of time, has been accepted as an important determinant of infectivity. Important airborne pathogens in modern buildings include legionella pneumophila, Aspergillus sp., thermophilic actinomycetes, Mycobacterium tuberculosis, measles, varicella and rubella. Perhaps, the most important microbiologic threat to most buildings is L. pneumophila. This organism can multiply in water cooling systems and contaminate effluent air which can be drawn into a building and efficiently circulated throughout by existing ventilation systems. Hospitals are a special problem because of the concentration of immunosuppressed patients who are uniquely susceptible to airborne diseases such as aspergillosis, and the likelihood that patients ill from diseases that can be spread via the airborne route will be concentrated. Humidifiers are yet another problem and have been shown to be important in several outbreaks of allergic alveolitis and legionellosis. Control of airborne infections is largely an effort at identifying and controlling reservoirs of infection. This includes regular biocide treatment of cooling towers and evaporative condensers and identification and isolation of patients with diseases that may be spread via the airborne route.

  3. Crosscutting Airborne Remote Sensing Technologies for Oil and Gas and Earth Science Applications

    Science.gov (United States)

    Aubrey, A. D.; Frankenberg, C.; Green, R. O.; Eastwood, M. L.; Thompson, D. R.; Thorpe, A. K.

    2015-01-01

    Airborne imaging spectroscopy has evolved dramatically since the 1980s as a robust remote sensing technique used to generate 2-dimensional maps of surface properties over large spatial areas. Traditional applications for passive airborne imaging spectroscopy include interrogation of surface composition, such as mapping of vegetation diversity and surface geological composition. Two recent applications are particularly relevant to the needs of both the oil and gas as well as government sectors: quantification of surficial hydrocarbon thickness in aquatic environments and mapping atmospheric greenhouse gas components. These techniques provide valuable capabilities for petroleum seepage in addition to detection and quantification of fugitive emissions. New empirical data that provides insight into the source strength of anthropogenic methane will be reviewed, with particular emphasis on the evolving constraints enabled by new methane remote sensing techniques. Contemporary studies attribute high-strength point sources as significantly contributing to the national methane inventory and underscore the need for high performance remote sensing technologies that provide quantitative leak detection. Imaging sensors that map spatial distributions of methane anomalies provide effective techniques to detect, localize, and quantify fugitive leaks. Airborne remote sensing instruments provide the unique combination of high spatial resolution (<1 m) and large coverage required to directly attribute methane emissions to individual emission sources. This capability cannot currently be achieved using spaceborne sensors. In this study, results from recent NASA remote sensing field experiments focused on point-source leak detection, will be highlighted. This includes existing quantitative capabilities for oil and methane using state-of-the-art airborne remote sensing instruments. While these capabilities are of interest to NASA for assessment of environmental impact and global climate

  4. Quantification of Soil Properties with Hyperspectral Data: Selecting Spectral Variables with Different Methods to Improve Accuracies and Analyze Prediction Mechanisms

    Directory of Open Access Journals (Sweden)

    Michael Vohland

    2017-10-01

    Full Text Available We explored the potentials of both non-imaging laboratory and airborne imaging spectroscopy to assess arable soil quality indicators. We focused on microbial biomass-C (MBC and hot water-extractable C (HWEC, complemented by organic carbon (OC and nitrogen (N as well-studied spectrally active parameters. The aggregation of different spectral variable selection strategies was used to analyze benefits for reachable estimation accuracies and to explore spectral predictive mechanisms for MBC and HWEC. With selected variables, quantification accuracies improved markedly for MBC (laboratory: RPD = 2.32 instead of 1.33 with full spectra; airborne: 2.35 instead of 1.80 and OC (laboratory: RPD = 3.08 instead of 2.36; airborne: 2.20 instead of 1.94. Patterns of selected variables indicated similarities between HWEC and OC, but significant differences between all other soil variables. This agreed to our results of indirect approaches in which both (i wet-chemical data of OC and N and (ii spectra fitted to measured OC and N values were used to estimate MBC and HWEC. Compared to these approaches, we found marked benefits of laboratory and airborne data for a direct spectral quantification of MBC (but not for HWEC. This suggests specificity of spectra for MBC, usable for the determination of this important soil parameter.

  5. Assessment of airborne bacteria in selected occupational environments in Quezon City, Philippines.

    Science.gov (United States)

    Rendon, Rhoshela Vi C; Garcia, Bea Clarise B; Vital, Pierangeli G

    2017-05-04

    Exposure to bioaerosols has been associated with health deterioration among workers in several occupational environments. This highlights the need to study the microbiological quality of air of workplaces as no such study has been conducted yet in the Philippines. To detect and characterize the culturable mesophilic airborne bacteria in selected occupational environments we used passive sedimentation technique. It was observed that the number of colony-forming units was highest in junk shop, followed by the light railway transit station and last the office. By contrast, the bacterial composition was similar in all sites: Gram-positive cocci > Gram-positive bacilli > Gram-negative bacteria. Staphylococcus aureus and Bacillus spp. were also detected in all sites. These findings suggest that the presence of airborne bacteria may be a potential health hazard in urban occupational environments in the Philippines.

  6. Mapping permafrost with airborne electromagnetics

    Science.gov (United States)

    Minsley, B. J.; Ball, L. B.; Bloss, B. R.; Kass, A.; Pastick, N.; Smith, B. D.; Voss, C. I.; Walsh, D. O.; Walvoord, M. A.; Wylie, B. K.

    2014-12-01

    Permafrost is a key characteristic of cold region landscapes, yet detailed assessments of how the subsurface distribution of permafrost impacts the environment, hydrologic systems, and infrastructure are lacking. Data acquired from several airborne electromagnetic (AEM) surveys in Alaska provide significant new insight into the spatial extent of permafrost over larger areas (hundreds to thousands of square kilometers) than can be mapped using ground-based geophysical methods or through drilling. We compare several AEM datasets from different areas of interior Alaska, and explore the capacity of these data to infer geologic structure, permafrost extent, and related hydrologic processes. We also assess the impact of fires on permafrost by comparing data from different burn years within similar geological environments. Ultimately, interpretations rely on understanding the relationship between electrical resistivity measured by AEM surveys and the physical properties of interest such as geology, permafrost, and unfrozen water content in the subsurface. These relationships are often ambiguous and non-unique, so additional information is useful for reducing uncertainty. Shallow (upper ~1m) permafrost and soil characteristics identified from remotely sensed imagery and field observations help to constrain and aerially extend near-surface AEM interpretations, where correlations between the AEM and remote sensing data are identified using empirical multivariate analyses. Surface nuclear magnetic resonance (sNMR) measurements quantify the contribution of unfrozen water at depth to the AEM-derived electrical resistivity models at several locations within one survey area. AEM surveys fill a critical data gap in the subsurface characterization of permafrost environments and will be valuable in future mapping and monitoring programs in cold regions.

  7. Diagnosis of ventricular drainage-related bacterial meningitis by broad-range real-time polymerase chain reaction

    DEFF Research Database (Denmark)

    Deutch, Susanna; Dahlberg, Daniel; Hedegaard, Jesper

    2007-01-01

    OBJECTIVE: To compare a broad-range real-time polymerase chain reaction (PCR) diagnostic strategy with culture to evaluate additional effects on the etiological diagnosis and the quantification of the bacterial load during the course of ventricular drainage-related bacterial meningitis (VR-BM). M...

  8. Bioaerosol sampling for airborne bacteria in a small animal veterinary teaching hospital

    Directory of Open Access Journals (Sweden)

    Tisha A. M. Harper

    2013-08-01

    Full Text Available Background: Airborne microorganisms within the hospital environment can potentially cause infection in susceptible patients. The objectives of this study were to identify, quantify, and determine the nosocomial potential of common airborne microorganisms present within a small animal teaching hospital. Methods: Bioaerosol sampling was done initially in all 11 rooms and, subsequently, weekly samples were taken from selected rooms over a 9-week period. Samples were collected twice (morning and afternoon at each site on each sampling day. The rooms were divided into two groups: Group 1, in which morning sampling was post-cleaning and afternoon sampling was during activity, and Group 2, in which morning sampling was pre-cleaning and afternoon sampling was post-cleaning. The total aerobic bacterial plate counts per m3 and bacterial identification were done using standard microbiological methods. Results: A total of 14 bacterial genera were isolated with the most frequent being Micrococcus spp. followed by species of Corynebacterium, Bacillus, and Staphylococcus. There was a significant interaction between location and time for rooms in Group 1 (p=0.0028 but not in Group 2 (p>0.05. Microbial counts for rooms in Group 2 were significantly greater in the mornings than in the afternoon (p=0.0049. The microbial counts were also significantly different between some rooms (p=0.0333. Conclusion: The detection of significantly higher airborne microbial loads in different rooms at different times of the day suggests that the probability of acquiring nosocomial infections is higher at these times and locations.

  9. NAMMA SECOND GENERATION AIRBORNE PRECIPITATION RADAR (APR-2) V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The NAMMA Second Generation Airborne Precipitation Radar (APR-2) dataset was collected by using the Second Generation Airborne Precipitation Radar (APR-2), which is...

  10. Total Shallow-Water Survey Through Airborne Hydrography

    National Research Council Canada - National Science Library

    Wozencraft, Jennifer M; Lillycrop, W. J

    2002-01-01

    Eight years of SHOALS (Scanning Hydrographic Operational Airborne Lidar Survey) operations have proven that airborne bathymetric lidar is an ideal tool for rapidly measuring shallow water depths and nearshore land elevations...

  11. Appendix : airborne incidents : an econometric analysis of severity

    Science.gov (United States)

    2014-12-19

    This is the Appendix for Airborne Incidents: An Econometric Analysis of Severity Report. : Airborne loss of separation incidents occur when an aircraft breaches the defined separation limit (vertical and/or horizontal) with another aircraft or terrai...

  12. GRIP AIRBORNE SECOND GENERATION PRECIPITATION RADAR (APR-2) V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The GRIP Airborne Second Generation Precipitation Radar (APR-2) dataset was collected from the Second Generation Airborne Precipitation Radar (APR-2), which is a...

  13. An Airborne Capability for South Africa from a Special Operations ...

    African Journals Online (AJOL)

    term strategy, and airborne forces form an important component in its envisioned Contingency Brigade. This article examines the utility of contemporary airborne forces despite the decline in major parachute assaults. It also explains the ...

  14. CAMEX-4 ER-2 MODIS AIRBORNE SIMULATOR (MAS) V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The MODIS Airborne Simulator (MAS) is an airborne scanning spectrometer that acquires high spatial resolution imagery of cloud and surface features from its vantage...

  15. TCSP ER-2 MODIS AIRBORNE SIMULATOR (MAS) V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The TCSP ER-2 MODIS Airborne Simulator (MAS) dataset was collected by a MODIS Airborne Simulator (MAS), which is a multi-spectral line-scanner system that acquires...

  16. Hyperspectral airborne remote sensing of the Belgian coastal waters

    OpenAIRE

    Sterckx, S.; Debruyn, W.; Kempeneers, P.

    2005-01-01

    On the 16th of June 2003 a CASI (Compact Airborne Spectrographic Imager) hyperspectral airborne remote sensing campaign took place above the Southern North Sea, just offshore of Oostende. In coincidence with the airborne overpasses seaborne measurements of water leaving reflectance and water quality parameters were performed. In addition near-simultaneous satellite imagery are available. This paper deals with the analysis of the airborne data. The CASI data have been atmospherically corrected...

  17. Modification of a Pollen Trap Design To Capture Airborne Conidia of Entomophaga maimaiga and Detection of Conidia by Quantitative PCR.

    Science.gov (United States)

    Bittner, Tonya D; Hajek, Ann E; Liebhold, Andrew M; Thistle, Harold

    2017-09-01

    The goal of this study was to develop effective and practical field sampling methods for quantification of aerial deposition of airborne conidia of Entomophaga maimaiga over space and time. This important fungal pathogen is a major cause of larval death in invasive gypsy moth ( Lymantria dispar ) populations in the United States. Airborne conidia of this pathogen are relatively large (similar in size to pollen), with unusual characteristics, and require specialized methods for collection and quantification. Initially, dry sampling (settling of spores from the air onto a dry surface) was used to confirm the detectability of E. maimaiga at field sites with L. dispar deaths caused by E. maimaiga , using quantitative PCR (qPCR) methods. We then measured the signal degradation of conidial DNA on dry surfaces under field conditions, ultimately rejecting dry sampling as a reliable method due to rapid DNA degradation. We modified a chamber-style trap commonly used in palynology to capture settling spores in buffer. We tested this wet-trapping method in a large-scale (137-km) spore-trapping survey across gypsy moth outbreak regions in Pennsylvania undergoing epizootics, in the summer of 2016. Using 4-day collection periods during the period of late instar and pupal development, we detected variable amounts of target DNA settling from the air. The amounts declined over the season and with distance from the nearest defoliated area, indicating airborne spore dispersal from outbreak areas. IMPORTANCE We report on a method for trapping and quantifying airborne spores of Entomophaga maimaiga , an important fungal pathogen affecting gypsy moth ( Lymantria dispar ) populations. This method can be used to track dispersal of E. maimaiga from epizootic areas and ultimately to provide critical understanding of the spatial dynamics of gypsy moth-pathogen interactions. Copyright © 2017 American Society for Microbiology.

  18. NASA Airborne Astronomy Ambassadors (AAA)

    Science.gov (United States)

    Backman, D. E.; Harman, P. K.; Clark, C.

    2016-12-01

    NASA's Airborne Astronomy Ambassadors (AAA) is a three-part professional development (PD) program for high school physics and astronomy teachers. The AAA experience consists of: (1) blended-learning professional development composed of webinars, asynchronous content learning, and a series of hands-on workshops (2) a STEM immersion experience at NASA Armstrong Flight Research Center's B703 science research aircraft facility in Palmdale, California, and (3) ongoing participation in the AAA community of practice (CoP) connecting participants with astrophysics and planetary science Subject Matter Experts (SMEs). The SETI Institute (SI) is partnering with school districts in Santa Clara and Los Angeles Counties during the AAA program's "incubation" period, calendar years 2016 through 2018. AAAs will be selected by the school districts based on criteria developed during spring 2016 focus group meetings led by the program's external evaluator, WestEd.. Teachers with 3+ years teaching experience who are assigned to teach at least 2 sections in any combination of the high school courses Physics (non-AP), Physics of the Universe (California integrated model), Astronomy, or Earth & Space Sciences are eligible. Partner districts will select at least 48 eligible applicants with SI oversight. WestEd will randomly assign selected AAAs to group A or group B. Group A will complete PD in January - June of 2017 and then participate in SOFIA science flights during fall 2017 (SOFIA Cycle 5). Group B will act as a control during the 2017-18 school year. Group B will then complete PD in January - June of 2018 and participate in SOFIA science flights in fall 2018 (Cycle 6). Under the current plan, opportunities for additional districts to seek AAA partnerships with SI will be offered in 2018 or 2019. A nominal two-week AAA curriculum component will be developed by SI for classroom delivery that will be aligned with selected California Draft Science Framework Disciplinary Core Ideas

  19. 14 CFR 121.357 - Airborne weather radar equipment requirements.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Airborne weather radar equipment... § 121.357 Airborne weather radar equipment requirements. (a) No person may operate any transport... December 31, 1964, unless approved airborne weather radar equipment has been installed in the airplane. (b...

  20. 14 CFR 135.175 - Airborne weather radar equipment requirements.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Airborne weather radar equipment... Aircraft and Equipment § 135.175 Airborne weather radar equipment requirements. (a) No person may operate a... conditions that can be detected with airborne weather radar equipment, may reasonably be expected along the...

  1. 14 CFR 125.223 - Airborne weather radar equipment requirements.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Airborne weather radar equipment... Equipment Requirements § 125.223 Airborne weather radar equipment requirements. (a) No person may operate an airplane governed by this part in passenger-carrying operations unless approved airborne weather radar...

  2. 30 CFR 57.5001 - Exposure limits for airborne contaminants.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Exposure limits for airborne contaminants. 57... Underground § 57.5001 Exposure limits for airborne contaminants. Except as permitted by § 57.5005— (a) Except as provided in paragraph (b), the exposure to airborne contaminants shall not exceed, on the basis of...

  3. Automated image analysis for quantification of filamentous bacteria

    DEFF Research Database (Denmark)

    Fredborg, M.; Rosenvinge, F. S.; Spillum, E.

    2015-01-01

    Background: Antibiotics of the beta-lactam group are able to alter the shape of the bacterial cell wall, e.g. filamentation or a spheroplast formation. Early determination of antimicrobial susceptibility may be complicated by filamentation of bacteria as this can be falsely interpreted as growth...... displaying different resistant profiles and differences in filamentation kinetics were used to study a novel image analysis algorithm to quantify length of bacteria and bacterial filamentation. A total of 12 beta-lactam antibiotics or beta-lactam-beta-lactamase inhibitor combinations were analyzed...... in systems relying on colorimetry or turbidometry (such as Vitek-2, Phoenix, MicroScan WalkAway). The objective was to examine an automated image analysis algorithm for quantification of filamentous bacteria using the 3D digital microscopy imaging system, oCelloScope. Results: Three E. coli strains...

  4. Molecular quantification of lactic acid bacteria in fermented milk products using real-time quantitative PCR.

    Science.gov (United States)

    Furet, Jean-Pierre; Quénée, Pascal; Tailliez, Patrick

    2004-12-15

    Real-time quantitative PCR assays were developed for the absolute quantification of lactic acid bacteria (LAB) (Streptococcus thermophilus, Lactobacillus delbrueckii, L. casei, L. paracasei, L. rhamnosus, L. acidophilus and L. johnsonii) in fermented milk products. The results of molecular quantification and classic bacterial enumeration did not differ significantly with respect to S. thermophilus and the species of the L. casei group which were detected in the six commercial fermented products tested, thus showing that DNA extraction was efficient and that genomic DNA solutions were free of PCR inhibitors. For L. delbrueckii, the results of bacterial enumeration were generally lower by a factor 10 to 100 than those of PCR quantification, suggesting a loss of viability during storage of the dairy products at 1-8 degrees C for most of the strains in this species. Real-time quantitative assays enabled identification of the species of lactic acid bacterial strains initially present in commercial fermented milk products and their accurate quantification with a detection threshold of 10(3) cells per ml of product.

  5. Seasonal variability in bacterial and fungal diversity of the near-surface atmosphere.

    Science.gov (United States)

    Bowers, Robert M; Clements, Nicholas; Emerson, Joanne B; Wiedinmyer, Christine; Hannigan, Michael P; Fierer, Noah

    2013-01-01

    Bacteria and fungi are ubiquitous throughout the Earth's lower atmosphere where they often represent an important component of atmospheric aerosols with the potential to impact human health and atmospheric dynamics. However, the diversity, composition, and spatiotemporal dynamics of these airborne microbes remain poorly understood. We performed a comprehensive analysis of airborne microbes across two aerosol size fractions at urban and rural sites in the Colorado Front Range over a 14-month period. Coarse (PM10-2.5) and fine (PM2.5) particulate matter samples were collected at weekly intervals with both bacterial and fungal diversity assessed via high-throughput sequencing. The diversity and composition of the airborne communities varied across the sites, between the two size fractions, and over time. Bacteria were the dominant type of bioaerosol in the collected air samples, while fungi and plants (pollen) made up the remainder, with the relative abundances of fungi peaking during the spring and summer months. As bacteria made up the majority of bioaerosol particles, we analyzed the bacterial communities in greater detail using a bacterial-specific 16S rRNA gene sequencing approach. Overall, bacterial taxonomic richness and the relative abundances of specific bacterial taxa exhibited significant patterns of seasonality. Likewise, airborne bacterial communities varied significantly between sites and across aerosol size fractions. Source-tracking analyses indicate that soils and leaves represented important sources of bacteria to the near-surface atmosphere across all locations with cow fecal bacteria also representing an important source of bioaerosols at the more rural sites during early fall and early spring. Together, these data suggest that a complex set of environmental factors, including changes in atmospheric conditions and shifts in the relative importance of available microbial sources, act to control the composition of microbial bioaerosols in rural and

  6. CLPX Airborne: Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) Data, Version 1

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set consists of apparent surface reflectance, subpixel snow-covered area and grain size inferred from data acquired by the Airborne Visible/Infrared...

  7. Airborne Gravity: NGS' Airborne Gravity Data for AN01 (2009-2010)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Alaska collected in 2009-2010 over 2 surveys. This data set is part of the Gravity for the Re-definition of the American Vertical Datum...

  8. Prevention of bacterial adhesion

    DEFF Research Database (Denmark)

    Klemm, Per; Vejborg, Rebecca Munk; Hancock, Viktoria

    2010-01-01

    Management of bacterial infections is becoming increasingly difficult due to the emergence and increasing prevalence of bacterial pathogens that are resistant to available antibiotics. Conventional antibiotics generally kill bacteria by interfering with vital cellular functions, an approach...... that imposes selection pressure for resistant bacteria. New approaches are urgently needed. Targeting bacterial virulence functions directly is an attractive alternative. An obvious target is bacterial adhesion. Bacterial adhesion to surfaces is the first step in colonization, invasion, and biofilm formation....... As such, adhesion represents the Achilles heel of crucial pathogenic functions. It follows that interference with adhesion can reduce bacterial virulence. Here, we illustrate this important topic with examples of techniques being developed that can inhibit bacterial adhesion. Some of these will become...

  9. Human Indoor Exposure to Airborne Halogenated Flame Retardants: Influence of Airborne Particle Size

    OpenAIRE

    La Guardia, Mark J.; Schreder, Erika D.; Uding, Nancy; Hale, Robert C.

    2017-01-01

    Inhalation of halogenated flame-retardants (HFRs) released from consumer products is an important route of exposure. However, not all airborne HFRs are respirable, and thus interact with vascular membranes within the gas exchange (alveolar) region of the lung. HFRs associated with large (>4 ?m), inhalable airborne particulates are trapped on the mucosal lining of the respiratory tract and then are expelled or swallowed. The latter may contribute to internal exposure via desorption from partic...

  10. Airborne microorganisms and dust from livestock houses

    NARCIS (Netherlands)

    Zhao, Y.; Aarnink, A.J.A.; Jong, de M.C.M.; Groot Koerkamp, P.W.G.

    2011-01-01

    The objective of this study was to evaluate the efficiencies and suitability of samplers for airborne microorganisms and dust, which could be used in practical livestock houses. Two studies were performed: 1) Testing impaction and cyclone pre-separators for dust sampling in livestock houses; 2)

  11. Experimental airborne transmission of PRRS virus

    DEFF Research Database (Denmark)

    Kristensen, C.S.; Bøtner, Anette; Takai, H.

    2004-01-01

    A series of three experiments, differing primarily in airflow volume, were performed to evaluate the likelihood of airborne transmission of Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) from infected to non-infected pigs. Pigs were housed in two units (unit A and unit B) located 1 m...

  12. Geoid of Nepal from airborne gravity survey

    DEFF Research Database (Denmark)

    Forsberg, René; Olesen, Arne Vestergaard; Einarsson, Indriði

    2011-01-01

    An airborne gravity survey of Nepal was carried out December 2010 in a cooperation between DTU-Space, Nepal Survey Department, and NGA, USA. The entire country was flown with survey lines spaced 6 nm with a King Air aircraft, with a varying flight altitude from 4 to 10 km. The survey operations w...

  13. Topology optimized cloak for airborne sound

    DEFF Research Database (Denmark)

    Andkjær, Jacob Anders; Sigmund, Ole

    2013-01-01

    Directional acoustic cloaks that conceal an aluminum cylinder for airborne sound waves are presented in this paper. Subwavelength cylindrical aluminum inclusions in air constitute the cloak design to aid practical realizations. The positions and radii of the subwavelength cylinders are determined...

  14. Passive Sampling of Airborne Peroxyacetic Acid

    NARCIS (Netherlands)

    Henneken, H.; Assink, Laura; de Wit, Joyce; Vogel, M.; Karst, U.

    2006-01-01

    The first passive sampling device for the determination of airborne peroxyacetic acid (PAA) is presented. 2-([3-{2-[4-Amino-2-(methylsulfanyl)phenyl]-1-diazenyl}phenyl]sulfonyl)-1-ethanol (ADS) is used to impregnate glass fiber filters, and the reagent is oxidized by PAA to the corresponding

  15. Airborne gravity field Measurements - status and developments

    DEFF Research Database (Denmark)

    Olesen, Arne Vestergaard; Forsberg, René

    2016-01-01

    English Abstract:DTU-Space has since 1996 carried out large area airborne surveys over both polar, tropical and temperate regions, especially for geoid determination and global geopotential models. Recently we have started flying two gravimeters (LCR and Chekan-AM or inertial navigation systems) ...

  16. Airborne radioactive effluents: releases and processing

    International Nuclear Information System (INIS)

    Grissom, M.C.

    1982-10-01

    This bibliography contains 870 citations on airborne radioactive waste included in the Department of Energy's Energy Data Base from January 1981 through August 1982. These citations are to research reports, journal articles, books, patents, theses, and conference papers from worldwide sources. Five indexes, each preceded by a brief description, are provided: Corporate Author, Personal Author, Subject, Contract Number, and Report Number

  17. CALIOPE airborne CO{sub 2} DIAL (CACDI) system design

    Energy Technology Data Exchange (ETDEWEB)

    Mietz, D.; Archuleta, B.; Archuleta, J. [and others

    1997-09-01

    Los Alamos National Laboratory is currently developing an airborne CO{sub 2} Differential Absorption Lidar (DIAL) system based on second generation technology demonstrated last summer at NTS. The CALIOPE Airborne CO{sub 2} DIAL (CACDI) system requirements have been compiled based on the mission objectives and SONDIAL model trade studies. Subsystem designs have been developed based on flow down from these system requirements, as well as experience gained from second generation ground tests and N-ABLE (Non-proliferation AirBorne Lidar Experiments) airborne experiments. This paper presents the CACDI mission objectives, system requirements, the current subsystem design, and provides an overview of the airborne experimental plan.

  18. Monitoring airborne biotic contaminants in the indoor environment of pig and poultry confinement buildings.

    Science.gov (United States)

    Hong, Pei-Ying; Li, Xiangzhen; Yang, Xufei; Shinkai, Takumi; Zhang, Yuanhui; Wang, Xinlei; Mackie, Roderick I

    2012-06-01

    Given the growing concerns over human and animal health issues related to confined animal feeding operations, an in-depth examination is required to monitor for airborne bacteria and associated antibiotic resistance genes. Our 16S rRNA-based pyrosequencing revealed that the airborne microbial community skewed towards a higher abundance of Firmicutes (> 59.2%) and Bacteroidetes (4.2-31.4%) within the confinement buildings, while the office environment was predominated by Proteobacteria (55.2%). Furthermore, bioaerosols in the confinement buildings were sporadically associated with genera of potential pathogens, and these genera were more frequently observed in the bioaerosols of pig and layer hen confinement than the turkey confinement buildings and office environment. High abundances of tetracycline resistance genes (9.55 × 10(2) to 1.69 × 10(6) copies ng(-1) DNA) were also detected in the bioaerosols sampled from confinement buildings. Bacterial lineages present in the poultry bioaerosols clustered apart from those present in the pig bioaerosols and among the different phases of pig production, suggesting that different livestock as well as production phase were associated with a distinct airborne microbial community. By understanding the diversity of biotic contaminants associated with the different confinement buildings, this study facilitates the implementation of better management strategies to minimize potential health impacts on both livestock and humans working in this environment. © 2012 Society for Applied Microbiology and Blackwell Publishing Ltd.

  19. Specific amplification of bacterial DNA by optimized so-called universal bacterial primers in samples rich of plant DNA.

    Science.gov (United States)

    Dorn-In, Samart; Bassitta, Rupert; Schwaiger, Karin; Bauer, Johann; Hölzel, Christina S

    2015-06-01

    Universal primers targeting the bacterial 16S-rRNA-gene allow quantification of the total bacterial load in variable sample types by qPCR. However, many universal primer pairs also amplify DNA of plants or even of archaea and other eukaryotic cells. By using these primers, the total bacterial load might be misevaluated, whenever samples contain high amounts of non-target DNA. Thus, this study aimed to provide primer pairs which are suitable for quantification and identification of bacterial DNA in samples such as feed, spices and sample material from digesters. For 42 primers, mismatches to the sequence of chloroplasts and mitochondria of plants were evaluated. Six primer pairs were further analyzed with regard to the question whether they anneal to DNA of archaea, animal tissue and fungi. Subsequently they were tested with sample matrix such as plants, feed, feces, soil and environmental samples. To this purpose, the target DNA in the samples was quantified by qPCR. The PCR products of plant and feed samples were further processed for the Single Strand Conformation Polymorphism method followed by sequence analysis. The sequencing results revealed that primer pair 335F/769R amplified only bacterial DNA in samples such as plants and animal feed, in which the DNA of plants prevailed. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Airborne laser sensors and integrated systems

    Science.gov (United States)

    Sabatini, Roberto; Richardson, Mark A.; Gardi, Alessandro; Ramasamy, Subramanian

    2015-11-01

    The underlying principles and technologies enabling the design and operation of airborne laser sensors are introduced and a detailed review of state-of-the-art avionic systems for civil and military applications is presented. Airborne lasers including Light Detection and Ranging (LIDAR), Laser Range Finders (LRF), and Laser Weapon Systems (LWS) are extensively used today and new promising technologies are being explored. Most laser systems are active devices that operate in a manner very similar to microwave radars but at much higher frequencies (e.g., LIDAR and LRF). Other devices (e.g., laser target designators and beam-riders) are used to precisely direct Laser Guided Weapons (LGW) against ground targets. The integration of both functions is often encountered in modern military avionics navigation-attack systems. The beneficial effects of airborne lasers including the use of smaller components and remarkable angular resolution have resulted in a host of manned and unmanned aircraft applications. On the other hand, laser sensors performance are much more sensitive to the vagaries of the atmosphere and are thus generally restricted to shorter ranges than microwave systems. Hence it is of paramount importance to analyse the performance of laser sensors and systems in various weather and environmental conditions. Additionally, it is important to define airborne laser safety criteria, since several systems currently in service operate in the near infrared with considerable risk for the naked human eye. Therefore, appropriate methods for predicting and evaluating the performance of infrared laser sensors/systems are presented, taking into account laser safety issues. For aircraft experimental activities with laser systems, it is essential to define test requirements taking into account the specific conditions for operational employment of the systems in the intended scenarios and to verify the performance in realistic environments at the test ranges. To support the

  1. Eggshells as a source for occupational exposure to airborne bacteria in hatcheries.

    Science.gov (United States)

    Brauner, Paul; Klug, Kerstin; Jäckel, Udo

    2016-12-01

    Occupational exposure to high concentrations of airborne bacteria in poultry production is related to an increased risk of respiratory disorders. However, potential sources and formation of hatchery bioaerosols are rarely characterized. In this study, bacterial multiplication on fresh shell fragments from turkey hatching eggs under conditions present in a hatcher incubator was investigated. A 10 5 -fold amplification was observed both by colony count and total cell count gaining 4 × 10 7 cfu/cells per gram eggshell within 30 hr of incubation. Furthermore, the bacterial community present on eggshells was analyzed by generation of 16S rRNA gene clone libraries and identification of eight isolates. RFLP analysis revealed no shift in community composition during incubation and Enterococcus faecalis and Enterococcus gallinarum were found as the predominant species on turkey eggshells, both have been classified as risk group 2 microorganisms (German TRBA 466). Since Enterococcus spp. were found as predominant species on turkey eggshells, contribution of this genus to bioaerosol formation was demonstrated. During different work activities with poult and eggshell handling concentrations of airborne enterococci up to 1.3 × 10 4 cfu m -3 were detected. In contrast, no enterococci were identified at a day without poult or eggshell processing. In conclusion, turkey hatching eggs carry a viable specific microflora from breeder flocks to hatcheries. After hatching of turkey poults, hatcher incubators and eggshell fragments provide appropriate conditions for excessive bacterial growth. Thus, high bacterial loads on eggshell fragments are a source of potential harmful bioaersols caused by air flows, poult activity, and handling of equipment.

  2. Development of a standardized and safe airborne antibacterial assay, and its evaluation on antibacterial biomimetic model surfaces.

    Directory of Open Access Journals (Sweden)

    Ali Al-Ahmad

    Full Text Available Bacterial infection of biomaterials is a major concern in medicine, and different kinds of antimicrobial biomaterial have been developed to deal with this problem. To test the antimicrobial performance of these biomaterials, the airborne bacterial assay is used, which involves the formation of biohazardous bacterial aerosols. We here describe a new experimental set-up which allows safe handling of such pathogenic aerosols, and standardizes critical parameters of this otherwise intractable and strongly user-dependent assay. With this new method, reproducible, thorough antimicrobial data (number of colony forming units and live-dead-stain was obtained. Poly(oxonorbornene-based Synthetic Mimics of Antimicrobial Peptides (SMAMPs were used as antimicrobial test samples. The assay was able to differentiate even between subtle sample differences, such as different sample thicknesses. With this new set-up, the airborne bacterial assay was thus established as a useful, reliable, and realistic experimental method to simulate the contamination of biomaterials with bacteria, for example in an intraoperative setting.

  3. Silver nanoparticles toxicity against airborne strains of Staphylococcus spp.

    Science.gov (United States)

    Wolny-Koładka, Katarzyna A; Malina, Dagmara K

    2017-11-10

    The aim of this study was to explore the toxicity of silver nanoparticles (AgNPs) synthesized by chemical reduction method assessment with regard to airborne strains of Staphylococcus spp. The first step of the experiment was the preparation of silver nanoparticle suspension. The suspension was obtained by a fast and simple chemical method involving the reduction of silver ions through a reducing factor in the presence of the suitable stabilizer required to prevent the aggregation. In the second stage, varied instrumental techniques were used for the analysis and characterization of the obtained nanostructures. Third, the bacteria of the Staphylococcus genus were isolated from the air under stable conditions with 47 sports and recreational horses, relatively. Next, isolated strains were identified using biochemical and spectrophotometric methods. The final step was the evaluation of the Staphylococcus genus sensitivity to nanosilver using the disk diffusion test. It has been proven that prepared silver nanoparticles exhibit strong antibacterial properties. The minimum inhibitory concentration for tested isolates was 30 μg/mL. It has been found that the sensitivity of Staphylococcus spp. isolated from six identified species differs considerably. The size distribution of bacterial growth inhibition zones indicates that resistance to various nanosilver concentrations is an individual strain feature, and has no connection with belonging to a specific species.

  4. Technical note: concentration and composition of airborne aerobic bacteria inside an enclosed rabbit shed

    Directory of Open Access Journals (Sweden)

    S. Li

    2016-03-01

    Full Text Available Numerous studies have been conducted to analyse bacterial aerosols in animal houses, which is beneficial for the control of animal diseases. However, little information on aerosols in enclosed rabbit sheds was available. An FA-1 sampler was employed to collect air samples in an enclosed rabbit house in the Qingdao region of China. Concentration, composition, and aerodynamics of bacterial aerosols inside the enclosed rabbit shed were systematically analysed. The concentration of airborne bacteria inside the rabbit shed was 2.11-6.36×104 colony forming unit/m3 (CFU/m3. Seventeen species of bacteria belonging to eight genera were identified. Among these, there were 11 species belonging to 4 genera of gram-positive bacteria, and 6 species belonging to 4 genera of gram-negative bacteria. The dominant species of bacteria were, in descending order, Micrococcus luteus (49.4%, Staphylococcus epidermidis (25.5%, and Alcaligenes odorans (10.2%. A total of about 76.3% of airborne bacteria was distributed in stages C-F of the FA-1 sampler (that ranges from A to F, with aerodynamic radii <3.3 μm in diameter. These particulates could enter lower respiratory tracks and even alveoli, posing a potential threat to the health of both animals and breeders.

  5. Studying bacterial multispecies biofilms

    DEFF Research Database (Denmark)

    Røder, Henriette Lyng; Sørensen, Søren Johannes; Burmølle, Mette

    2016-01-01

    , but the identity and significance of interspecies bacterial interactions is neglected in these analyses. There is therefore an urgent need for bridging the gap between metagenomic analysis and in vitro models suitable for studies of bacterial interactions.Bacterial interactions and coadaptation are important......The high prevalence and significance of multispecies biofilms have now been demonstrated in various bacterial habitats with medical, industrial, and ecological relevance. It is highly evident that several species of bacteria coexist and interact in biofilms, which highlights the need for evaluating...

  6. Magnetic Approaches to Measuring and Mitigating Airborne Particulate Pollution

    Science.gov (United States)

    Maher, B.

    2014-12-01

    Human exposure to airborne particulate matter (PM) generates adverse human health impacts at all life stages from the embryonic to the terminal, including damage to respiratory and cardiovascular health, and neurodevelopment and cognitive function. Detailed understanding of the causal links between PM exposure and specific health impacts, and possible means to reduce PM exposure require knowledge of PM concentrations, compositions and sources at the fine-scale; i.e. beyond the current resolution of spatially-sparse conventional PM monitoring, non-unique elemental analyses, or poorly-validated PM modelling. Magnetically-ordered iron oxide minerals appear to be a ubiquitous component of urban PM. These minerals derive partly from the presence of iron impurities in fuels, which form, upon combustion, a non-volatile residue, often dominated by magnetite, within glassy, spherical condensates. Iron-rich, magnetic PM also arises from abrasion from vehicle components, including disk brakes, and road dust. The ubiquity and diversity of these magnetic PM phases, and the speed and sensitivity of magnetic analyses (down to trace concentrations), makes possible rapid, cost-effective magnetic characterization and quantification of PM, a field of study which has developed rapidly across the globe over the last 2 decades. Magnetic studies of actively-sampled PM, on filters, and passively-sampled PM, on tree leaves and other depositional surfaces, can be used to: monitor and map at high spatial resolution ambient PM concentrations; address the controversial issue of the efficacy of PM capture by vegetation; and add a new, discriminatory dimension to PM source apportionment.

  7. Reverse transcriptase real-time PCR for detection and quantification of viable Campylobacter jejuni directly from poultry faecal samples

    DEFF Research Database (Denmark)

    Bui, Thanh Xuan; Wolff, Anders; Madsen, Mogens

    2012-01-01

    Campylobacter spp. is the most common cause of bacterial diarrhoea in humans worldwide. Therefore, rapid and reliable methods fordetection and quantification of this pathogen are required. In this study, we have developed a reverse transcription quantitative real-time PCR(RT-qPCR) for detection a...

  8. Culture-independent identification and quantification of Gallibacterium anatis (G. anatis) by real-time quantitative PCR

    DEFF Research Database (Denmark)

    Wang, Chong; Robles, Francisco; Ramirez, Saul

    2016-01-01

    -time quantitative PCR (qPCR) method allowing species-specific identification and quantification of G. anatis. A G. anatis specific DNA sequence was identified in the gyrase subunit B gene (gyrB) and used to design a TaqMan probe and corresponding primers. The specificity of the assay was tested on 52 bacterial...

  9. First airborne transient em survey in antarctica

    DEFF Research Database (Denmark)

    Auken, Esben; Mikucki, J. J.; Sørensen, Kurt Ingvard K.I.

    2012-01-01

    A first airborne transient electromagnetic survey was flown in Antarctica in December 2011 with the SkyTEM system. This transient airborne EM system has been optimized in Denmark for almost ten years and was specially designed for ground water mapping. The SkyTEM tool is ideal for mapping...... conductive targets, and the transient AEM method provides a better understanding of the saline ground water system for microbiology, paleoclimate studies, or geothermal potential. In this study we present preliminary results from our field survey which resulted in more than 1000 km of flight lines...... are presented here, the Taylor Valley demonstrating the promising capabilities of the geophysical method to map permafrost and the saline ground water systems....

  10. Designing transmitting CMUT cells for airborne applications.

    Science.gov (United States)

    Unlügedik, Aslı; Taşdelen, A; Atalar, Abdullah; Köymen, Hayrettin

    2014-11-01

    We report a new mode of airborne operation for capacitive micromachined ultrasonic transducers (CMUT), in which the plate motion spans the entire gap without collapsing and the transducer is driven by a sinusoidal voltage without a dc bias. We present equivalent-circuit-based design fundamentals for an airborne CMUT cell and verify the design targets using fabricated CMUTs. The performance limits for silicon plates are derived. We experimentally obtain 78.9 dB//20 μPa@1 m source level at 73.7 kHz, with a CMUT cell of radius 2.05 mm driven by 71 V sinusoidal drive voltage at half the frequency. The measured quality factor is 120. We also study and discuss the interaction of the nonlinear transduction force and the nonlinearity of the plate compliance.

  11. Analyzing Options for Airborne Emergency Wireless Communications

    Energy Technology Data Exchange (ETDEWEB)

    Michael Schmitt; Juan Deaton; Curt Papke; Shane Cherry

    2008-03-01

    In the event of large-scale natural or manmade catastrophic events, access to reliable and enduring commercial communication systems is critical. Hurricane Katrina provided a recent example of the need to ensure communications during a national emergency. To ensure that communication demands are met during these critical times, Idaho National Laboratory (INL) under the guidance of United States Strategic Command has studied infrastructure issues, concerns, and vulnerabilities associated with an airborne wireless communications capability. Such a capability could provide emergency wireless communications until public/commercial nodes can be systematically restored. This report focuses on the airborne cellular restoration concept; analyzing basic infrastructure requirements; identifying related infrastructure issues, concerns, and vulnerabilities and offers recommended solutions.

  12. Airborne geophysics in Australia: the government contribution

    International Nuclear Information System (INIS)

    Denham, D.

    1997-01-01

    Airborne geophysical data sets provide important cost-effective information for resource exploration and land management. Improved techniques, developed recently, now enable high-resolution aeromagnetic and gamma-ray surveys to be used extensively by the resource industries to improve the cost effectiveness of exploration and by governments to encourage resource development and sustainable management of natural resources. Although airborne geophysical techniques have been used extensively and are now used almost routinely by mineral explorers, it is only in the last few years that governments have been involved as major players in the acquisition of data. The exploration industry pioneered the imaging of high-resolution airborne geophysical data sets in the early 1980s and, at the same time, the Northern Territory Government started a modest program of flying the Northern Territory, at 500 m flight-line spacing, to attract mineral exploration. After the start of the National Geoscience Mapping Accord in 1990, the then BMR and its State/Territory counterparts used the new high-resolution data as an essential ingredient to underpin mapping programs. These new data sets proved so valuable that, starting in 1992/93, the annual expenditure by the Commonwealth and States/Northern Territory increased from roughly $2 million per year to a massive $10 million per year. These investments by governments, although unlikely to be permanently sustainable, have been made to encourage and expand exploration activity by providing new high-quality data sets in industry at very low cost. There are now approximately 11 million line-km of airborne geophysical data available in databases held by the Commonwealth, States and Northern Territory. The results so far have seen a significant increase in exploration activity in States that have embarked on this course (e.g. South Australia and Victoria), and the information provided from these surveys is proving crucial to understanding the

  13. The Caltech airborne submillimeter SIS receiver

    Science.gov (United States)

    Zmuidzinas, Jonas; Carlstrom, J.; Miller, D.; Ugras, N. G.

    1995-01-01

    We have constructed a sensitive submillimeter receiver for the NASA Kuiper Airborne Observatory (KAO) which at present operates in the 500-750 GHz band. The DSB receiver noise temperature is about 5 h nu/k(sub B) over the 500-700 GHz range. This receiver has been used to detect H2O(18)O, HCl, and CH in interstellar molecular clouds, and also to search for C(+) emission from the highly redshifted galaxy (z = 2.3) IRAS 10214.

  14. Holographic Airborne Rotating Lidar Instrument Experiment (HARLIE)

    Science.gov (United States)

    Schwemmer, Geary K.

    1998-01-01

    Scanning holographic lidar receivers are currently in use in two operational lidar systems, PHASERS (Prototype Holographic Atmospheric Scanner for Environmental Remote Sensing) and now HARLIE (Holographic Airborne Rotating Lidar Instrument Experiment). These systems are based on volume phase holograms made in dichromated gelatin (DCG) sandwiched between 2 layers of high quality float glass. They have demonstrated the practical application of this technology to compact scanning lidar systems at 532 and 1064 nm wavelengths, the ability to withstand moderately high laser power and energy loading, sufficient optical quality for most direct detection systems, overall efficiencies rivaling conventional receivers, and the stability to last several years under typical lidar system environments. Their size and weight are approximately half of similar performing scanning systems using reflective optics. The cost of holographic systems will eventually be lower than the reflective optical systems depending on their degree of commercialization. There are a number of applications that require or can greatly benefit from a scanning capability. Several of these are airborne systems, which either use focal plane scanning, as in the Laser Vegetation Imaging System or use primary aperture scanning, as in the Airborne Oceanographic Lidar or the Large Aperture Scanning Airborne Lidar. The latter class requires a large clear aperture opening or window in the aircraft. This type of system can greatly benefit from the use of scanning transmission holograms of the HARLIE type because the clear aperture required is only about 25% larger than the collecting aperture as opposed to 200-300% larger for scan angles of 45 degrees off nadir.

  15. Airborne Tactical Free-Electron Laser

    Energy Technology Data Exchange (ETDEWEB)

    Whitney, Roy; Neil, George

    2007-02-01

    The goal of 100 kilowatts (kW) of directed energy from an airborne tactical platform has proved challenging due to the size and weight of most of the options that have been considered. However, recent advances in Free-Electron Lasers appear to offer a solution along with significant tactical advantages: a nearly unlimited magazine, time structures for periods from milliseconds to hours, radar like functionality, and the choice of the wavelength of light that best meets mission requirements. For an Airborne Tactical Free-Electron Laser (ATFEL) on a platforms such as a Lockheed C-130J-30 and airships, the two most challenging requirements, weight and size, can be met by generating the light at a higher harmonic, aggressively managing magnet weights, managing cryogenic heat loads using recent SRF R&D results, and using FEL super compact design concepts that greatly reduce the number of components. The initial R&D roadmap for achieving an ATFEL is provided in this paper. Performing this R&D is expected to further reduce the weight, size and power requirements for the FELs the Navy is currently developing for shipboard applications, as well as providing performance enhancements for the strategic airborne MW class FELs. The 100 kW ATFEL with its tactical advantages may prove sufficiently attractive for early advancement in the queue of deployed FELs.

  16. Airborne laser altimeter measurements of landscape topography

    International Nuclear Information System (INIS)

    Ritchie, J.C.

    1995-01-01

    Measurements of topography can provide a wealth of information on landscape properties for managing hydrologic and geologic systems and conserving natural and agricultural resources. This article discusses the application of an airborne laser altimeter to measure topography and other landscape surface properties. The airborne laser altimeter makes 4000 measurements per second with a vertical recording resolution of 5 cm. Data are collected digitally with a personal computer. A video camera, borehole sighted with the laser, records an image for locating flight lines. GPS data are used to locate flight line positions on the landscape. Laser data were used to measure vegetation canopy topography, height, cover, and distribution and to measure microtopography of the land surface and gullies with depths of 15–20 cm. Macrotopography of landscape profiles for segments up to 4 km were in agreement with available topographic maps but provided more detail. Larger gullies with and without vegetation, and stream channel cross sections and their associated floodplains have also been measured and reported in other publications. Landscape segments for any length could be measured for either micro- or macrotopography. Airborne laser altimeter measurements of landscape profiles can provide detailed information on landscape properties or specific needs that will allow better decisions on the design and location of structures (i.e., roads, pipe, and power lines) and for improving the management and conservation of natural and agricultural landscapes. (author)

  17. Coral Pigments: Quantification Using HPLC and Detection by Remote Sensing

    Science.gov (United States)

    Cottone, Mary C.

    1995-01-01

    Widespread coral bleaching (loss of pigments of symbiotic dinoflagellates), and the corresponding decline in coral reef health worldwide, mandates the monitoring of coral pigmentation. Samples of the corals Porites compressa and P. lobata were collected from a healthy reef at Puako, Hawaii, and chlorophyll (chl) a, peridinin, and Beta-carotene (Beta-car) were quantified using reverse-phase high performance liquid chromatography (HPLC). Detailed procedures are presented for the extraction of the coral pigments in 90% acetone, and the separation, identification, and quantification of the major zooxanthellar pigments using spectrophotometry and a modification of the HPLC system described by Mantoura and Llewellyn (1983). Beta-apo-8-carotenal was found to be inadequate as in internal standard, due to coelution with chl b and/or chl a allomer in the sample extracts. Improvements are suggested, which may result in better resolution of the major pigments and greater accuracy in quantification. Average concentrations of peridinin, chl a, and Beta-car in corals on the reef were 5.01, 8.59, and 0.29, micro-grams/cm(exp 2), respectively. Average concentrations of peridinin and Beta-car did not differ significantly between the two coral species sampled; however, the mean chl a concentration in P. compressa specimens (7.81 ,micro-grams/cm(exp 2) was significantly lower than that in P. lobata specimens (9.96 11g/cm2). Chl a concentrations determined spectrophotometrically were significantly higher than those generated through HPLC, suggesting that spectrophotometry overestimates chl a concentrations. The average ratio of chl a-to-peridinin concentrations was 1.90, with a large (53%) coefficient of variation and a significant difference between the two species sampled. Additional data are needed before conclusions can be drawn regarding average pigment concentrations in healthy corals and the consistency of the chl a/peridinin ratio. The HPLC pigment concentration values

  18. Geological Mapping of Sabah, Malaysia, Using Airborne Gravity Survey

    DEFF Research Database (Denmark)

    Fauzi Nordin, Ahmad; Jamil, Hassan; Noor Isa, Mohd

    2016-01-01

    Airborne gravimetry is an effective tool for mapping local gravity fields using a combination of airborne sensors, aircraft and positioning systems. It is suitable for gravity surveys over difficult terrains and areas mixed with land and ocean. This paper describes the geological mapping of Sabah...... using airborne gravity surveys. Airborne gravity data over land areas of Sabah has been combined with the marine airborne gravity data to provide a seamless land-to-sea gravity field coverage in order to produce the geological mapping. Free-air and Bouguer anomaly maps (density 2.67 g/cm3) have been...... gravity data were 5-6 km. The airborne gravity survey database for landand marine areas has been compiled using ArcGIS geodatabase format in order to produce the update geological map of Sabah....

  19. Assessment of Probiotic Viability during Cheddar Cheese Manufacture and Ripening Using Propidium Monoazide-PCR Quantification

    OpenAIRE

    Desfossés-Foucault, Émilie; Dussault-Lepage, Véronique; Le Boucher, Clémentine; Savard, Patricia; LaPointe, Gisèle; Roy, Denis

    2012-01-01

    The use of a suitable food carrier such as cheese could significantly enhance probiotic viability during storage. The main goal of this study was to assess viability of commercial probiotic strains during Cheddar cheesemaking and ripening (four to six months) by comparing the efficiency of microbiological and molecular approaches. Molecular methods such as quantitative PCR (qPCR) allow bacterial quantification, and DNA-blocking molecules such as propidium monoazide (PMA) select only the livin...

  20. Efficacy Assessment of Lemon Peel Aromatherpy Againts Airborne Bacteria Experimental Study in ICU Room of Sultan Agung Islamic Hospital Semarang

    Directory of Open Access Journals (Sweden)

    Merin Awu Sari

    2012-06-01

    Design and Method: This experimental study used post test only control groups design. The number of airborne bacteria colonies obtained from ICU room of Sultan Agung Islamic Hospital Semarang treated with lemon peel aromatherapy at the concentration of 100 % and the control group (-.The data were analyzed for normality using Shapiro Wilk followed by independent T-test Result: independent inT-test Independent showed a significant differences in the number of bacterial colonies between the treated groups receiving 100% concentration of lemon peel aromatherapy and control group (- (p < 0.045. Conclusion: Aromatherapy extracts of lemon peel has effect on reducing the number of airborne bacteria in the ICU of Sultan Agung Islamic Hospital Semarang (Sains Medika, 4(1:71-77.

  1. Airborne or Fomite Transmission for Norovirus? A Case Study Revisited

    OpenAIRE

    Xiao, Shenglan; Tang, Julian W.; Li, Yuguo

    2017-01-01

    Norovirus infection, a highly prevalent condition associated with a high rate of morbidity, comprises a significant health issue. Although norovirus transmission mainly occurs via the fecal-oral and vomit-oral routes, airborne transmission has been proposed in recent decades. This paper re-examines a previously described norovirus outbreak in a hotel restaurant wherein airborne transmission was originally inferred. Specifically, the original evidence that suggested airborne transmission was r...

  2. High-Performance Airborne Optical Carbon Dioxide Analyzer, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Environmental species measurement on airborne atmospheric research craft is a demanding application for optical sensing techniques. Yet optical techniques offer many...

  3. High-Performance Airborne Optical Carbon Dioxide Analyzer, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Environmental species measurement on airborne atmospheric research craft is a demanding application for optical sensing techniques. Yet optical techniques offer many...

  4. Airborne infectious disease and the suppression of pulmonary bioaerosols.

    Science.gov (United States)

    Fiegel, Jennifer; Clarke, Robert; Edwards, David A

    2006-01-01

    The current understanding of airborne pathogen spread in relation to the new methods of suppressing exhaled bioaerosols using safe surface-active materials, such as isotonic saline, is reviewed here. We discuss the physics of bioaerosol generation in the lungs, what is currently known about the relationship between expired bioaerosols and airborne infectious disease and current methods of airborne infectious disease containment. We conclude by reviewing recent experiments that suggest the delivery of isotonic saline can significantly diminish exhaled aerosol--generated from airway lining fluid in the course of natural breathing. We also discuss these implications in relation to airborne infectious disease control.

  5. Towards airborne nanoparticle mass spectrometry with nanomechanical string resonators

    DEFF Research Database (Denmark)

    Schmid, Silvan; Kurek, Maksymilian; Boisen, Anja

    2013-01-01

    airborne nanoparticle sensors. Recently, nanomechanical mass spectrometry was established. One of the biggest challenges of nanomechanical sensors is the low efficiency of diffusion-based sampling. We developed an inertial-based sampling method that enables the efficient sampling of airborne nanoparticles...... mode. Mass spectrometry of airborne nanoparticles requires the simultaneous operation in the first and second mode, which can be implemented in the transduction scheme of the resonator. The presented results lay the cornerstone for the realization of a portable airborne nanoparticle mass spectrometer....

  6. [Spontaneous bacterial peritonitis].

    Science.gov (United States)

    Strauss, Edna; Caly, Wanda Regina

    2003-01-01

    Spontaneous bacterial peritonitis occurs in 30% of patients with ascites due to cirrhosis leading to high morbidity and mortality rates. The pathogenesis of spontaneous bacterial peritonitis is related to altered host defenses observed in end-stage liver disease, overgrowth of microorganisms, and bacterial translocation from the intestinal lumen to mesenteric lymph nodes. Clinical manifestations vary from severe to slight or absent, demanding analysis of the ascitic fluid. The diagnosis is confirmed by a number of neutrophils over 250/mm3 associated or not to bacterial growth in culture of an ascites sample. Enterobacteriae prevail and Escherichia coli has been the most frequent bacterium reported. Mortality rates decreased markedly in the last two decades due to early diagnosis and prompt antibiotic treatment. Third generation intravenous cephalosporins are effective in 70% to 95% of the cases. Recurrence of spontaneous bacterial peritonitis is common and can be prevented by the continuous use of oral norfloxacin. The development of bacterial resistance demands the search for new options in the prophylaxis of spontaneous bacterial peritonitis; probiotics are a promising new approach, but deserve further evaluation. Short-term antibiotic prophylaxis is recommended for patients with cirrhosis and ascites shortly after an acute episode of gastrointestinal bleeding.

  7. Development of a Novel Method for Temporal Analysis of Airborne Microbial Communities

    Science.gov (United States)

    Spring, A.; Domingue, K. D.; Mooney, M. M.; Kerber, T. V.; Lemmer, K. M.; Docherty, K. M.

    2017-12-01

    Microorganisms are ubiquitous in the atmosphere, which serves as an important vector for microbial dispersal to all terrestrial habitats. Very little is known about the mechanisms that control microbial dispersal, because sampling of airborne microbial communities beyond 2 m above the ground is limited. The goal of this study was to construct and test an airborne microbial sampling system to collect sufficient DNA for conducting next generation sequencing and microbial community analyses. The system we designed employs helium-filled helikites as a mechanism for launching samplers to various altitudes. The samplers use a passive collection dish system, weigh under 6 lbs and are operated by remote control from the ground. We conducted several troubleshooting experiments to test sampler functionality. We extracted DNA from sterile collection dish surfaces and examined communities using amplicons of the V4 region of 16S rRNA in bacteria using Illumina Mi-Seq. The results of these experiments demonstrate that the samplers we designed 1) remain decontaminated when closed and collect sufficient microbial biomass for DNA-based analyses when open for 6 hours; 2) are optimally decontaminated with 15 minutes of UV exposure; 3) require 8 collection dish surfaces to collect sufficient biomass. We also determined that DNA extraction conducted within 24 hours of collection has less of an impact on community composition than extraction after frozen storage. Using this sampling system, we collected samples from multiple altitudes in December 2016 and May 2017 at 3 sites in Kalamazoo and Pellston, Michigan. In Kalamazoo, areas sampled were primarily developed or agricultural, while in Pellston they were primarily forested. We observed significant differences between airborne bacterial communities collected at each location and time point. Additionally, bacterial communities did not differ with altitude, suggesting that terrestrial land use has an important influence on the upward

  8. Interfering with bacterial gossip

    DEFF Research Database (Denmark)

    Bjarnsholt, Thomas; Tolker-Nielsen, Tim; Givskov, Michael

    2011-01-01

    defense. Antibiotics exhibit a rather limited effect on biofilms. Furthermore, antibiotics have an ‘inherent obsolescence’ because they select for development of resistance. Bacterial infections with origin in bacterial biofilms have become a serious threat in developed countries. Pseudomonas aeruginosa...... that appropriately target bacteria in their relevant habitat with the aim of mitigating their destructive impact on patients. In this review we describe molecular mechanisms involved in “bacterial gossip” (more scientifically referred to as quorum sensing (QS) and c-di-GMP signaling), virulence, biofilm formation......, resistance and QS inhibition as future antimicrobial targets, in particular those that would work to minimize selection pressures for the development of resistant bacteria....

  9. Quantification of virtue in late Medieval Europe.

    Science.gov (United States)

    Kemp, Simon

    2018-02-01

    Fourteenth century Europe saw a growing interest in quantification. This interest has been well studied by historians of physical sciences, but medieval scholars were also interested in the quantification of psychological qualities. In general, the quantification issues addressed by medieval scholars were theoretical, even (by our standards) mathematical, rather than those of practical measurement. There was recognition that the seriousness of a sin and the penance laid down for it should be proportionate. A number of late medieval scholars were interested in the quantification of caritas, a Latin word that is translatable as charity or loving benevolence. The scholastic interest linked to the practical issue of how caritas might become habitual through the repeated performance of virtuous acts. Gregory of Rimini's treatment of caritas in his commentary on Peter Lombard's Sentences illustrates how one medieval scholar related the quantification of virtue to the quantification of physical qualities such as temperature and luminescence. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  10. Quantification of filamentation by uropathogenic Escherichia coli during experimental bladder cell infection by using semi-automated image analysis

    DEFF Research Database (Denmark)

    Klein, Kasper; Palarasah, Yaseelan; Kolmos, Hans Jørn

    2015-01-01

    of bacterial pathogens and study the advantages of bacterial morphological plasticity, methods are needed to accurately quantify changes in bacterial cell shape. In this study, we present a method for quantification of bacterial filamentation based on automatic detection and measurement of bacterial units......Several rod-shaped pathogens including Escherichia coli, Salmonella spp. and Klebsiella pneumonia are capable of adopting highly filamentous cell shapes under certain circumstances. This phenomenon occurs as a result of continued cell elongation during growth without the usual septation into single...... rod-shaped cells. Evidence has emerged over the past decade suggesting that this morphological transformation is controlled and reversible and provides selective advantages under certain growth conditions, such as during infection in humans. In order to identify the factors which induce filamentation...

  11. Detection of airborne allergen (Pla a 1 in relation to Platanus pollen in Córdoba, South Spain

    Directory of Open Access Journals (Sweden)

    Purificación Alcázar

    2015-02-01

    Full Text Available Córdoba is one of the Spanish cities with the highest records of plane tree pollen grains in the air. Clinical studies have identified[i] Platanus[/i] as a major cause of pollinosis. This fact provokes an important public health problem during early spring when these trees bloom. The objective of the study is to evaluate the correlation between airborne pollen counts and Pla a 1 aeroallergen concentrations in Córdoba, to elucidate if airborne pollen can be an accurate measure that helps to explain the prevalence of allergenic symptoms. Pollen sampling was performed during 2011–2012 using a Hirst-type sampler. Daily average concentration of pollen grains (pollen grains/m 3 was obtained following the methodology proposed by the Spanish Aerobiology Network. A multi-vial cyclone was used for the aeroallergen quantification. Allergenic particles were measured by ELISA using specific antibodies Pla a 1. The trend of[i] Platanus[/i] pollen was characterized by a marked seasonality, reaching high concentrations in a short period of time. Airborne pollen and aeroallergen follow similar trends. The overlapping profile between both variables during both years shows that pollen and Pla a 1 are significantly correlated. The highest significant correlation coefficients were obtained during 2011 and for the post peak. Although some studies have found notable divergence between pollen and allergen concentrations in the air, in the case of [i]Platanus[/i] in Córdoba, similar aerobiological dynamics between pollen and Pla a 1 have been found. Allergenic activity was found only during the plane tree pollen season, showing a close relationship with daily pollen concentrations. The obtained pollen potency was similar for both years of study. The results suggest that the allergenic response in sensitive patients to plane tree pollen coincide with the presence and magnitude of airborne pollen.

  12. Bacterial surface adaptation

    Science.gov (United States)

    Utada, Andrew

    2014-03-01

    Biofilms are structured multi-cellular communities that are fundamental to the biology and ecology of bacteria. Parasitic bacterial biofilms can cause lethal infections and biofouling, but commensal bacterial biofilms, such as those found in the gut, can break down otherwise indigestible plant polysaccharides and allow us to enjoy vegetables. The first step in biofilm formation, adaptation to life on a surface, requires a working knowledge of low Reynolds number fluid physics, and the coordination of biochemical signaling, polysaccharide production, and molecular motility motors. These crucial early stages of biofilm formation are at present poorly understood. By adapting methods from soft matter physics, we dissect bacterial social behavior at the single cell level for several prototypical bacterial species, including Pseudomonas aeruginosa and Vibrio cholerae.

  13. Bacterial Meningitis in Infants

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2004-04-01

    Full Text Available A retrospective study of 80 infantile patients (ages 30-365 days; 47 male, 33 female with culture-proven bacterial meningitis seen over a 16 year period (1986-2001 is reported from Taiwan.

  14. Factitious Bacterial Meningitis Revisited

    Science.gov (United States)

    Peterson, E.; Thrupp, L.; Uchiyama, N.; Hawkins, B.; Wolvin, B.; Greene, G.

    1982-01-01

    Nonviable gram-negative bacilli were seen in smears of cerebrospinal fluid from eight infants in whom bacterial meningitis was ruled out. Tubes from commercial kits were the source of the factitious organisms. PMID:7153328

  15. Vimentin in Bacterial Infections

    DEFF Research Database (Denmark)

    Mak, Tim N; Brüggemann, Holger

    2016-01-01

    filaments (IFs). IFs have not only roles in maintaining the structural integrity of the cell, but they are also involved in many cellular processes including cell adhesion, immune signaling, and autophagy, processes that are important in the context of bacterial infections. Here, we summarize the knowledge...... about the role of IFs in bacterial infections, focusing on the type III IF protein vimentin. Recent studies have revealed the involvement of vimentin in host cell defenses, acting as ligand for several pattern recognition receptors of the innate immune system. Two main aspects of bacteria......-vimentin interactions are presented in this review: the role of vimentin in pathogen-binding on the cell surface and subsequent bacterial invasion and the interaction of cytosolic vimentin and intracellular pathogens with regards to innate immune signaling. Mechanistic insight is presented involving distinct bacterial...

  16. Airborne LIDAR Data Processing and Analysis Tools

    Science.gov (United States)

    Zhang, K.

    2007-12-01

    Airborne LIDAR technology allows accurate and inexpensive measurements of topography, vegetation canopy heights, and buildings over large areas. In order to provide researchers high quality data, NSF has created the National Center for Airborne Laser Mapping (NCALM) to collect, archive, and distribute the LIDAR data. However, the LIDAR systems collect voluminous irregularly-spaced, three-dimensional point measurements of ground and non-ground objects scanned by the laser beneath the aircraft. To advance the use of the technology and data, NCALM is developing public domain algorithms for ground and non-ground measurement classification and tools for data retrieval and transformation. We present the main functions of the ALDPAT (Airborne LIDAR Data Processing and Analysis Tools) developed by NCALM. While Geographic Information Systems (GIS) provide a useful platform for storing, analyzing, and visualizing most spatial data, the shear volume of raw LIDAR data makes most commercial GIS packages impractical. Instead, we have developed a suite of applications in ALDPAT which combine self developed C++ programs with the APIs of commercial remote sensing and GIS software. Tasks performed by these applications include: 1) transforming data into specified horizontal coordinate systems and vertical datums; 2) merging and sorting data into manageable sized tiles, typically 4 square kilometers in dimension; 3) filtering point data to separate measurements for the ground from those for non-ground objects; 4) interpolating the irregularly spaced elevations onto a regularly spaced grid to allow raster based analysis; and 5) converting the gridded data into standard GIS import formats. The ALDPAT 1.0 is available through http://lidar.ihrc.fiu.edu/.

  17. Even Shallower Exploration with Airborne Electromagnetics

    Science.gov (United States)

    Auken, E.; Christiansen, A. V.; Kirkegaard, C.; Nyboe, N. S.; Sørensen, K.

    2015-12-01

    Airborne electromagnetics (EM) is in many ways undergoing the same type rapid technological development as seen in the telecommunication industry. These developments are driven by a steadily increasing demand for exploration of minerals, groundwater and geotechnical targets. The latter two areas demand shallow and accurate resolution of the near surface geology in terms of both resistivity and spatial delineation of the sedimentary layers. Airborne EM systems measure the grounds electromagnetic response when subject to either a continuous discrete sinusoidal transmitter signal (frequency domain) or by measuring the decay of currents induced in the ground by rapid transmission of transient pulses (time domain). In the last decade almost all new developments of both instrument hardware and data processing techniques has focused around time domain systems. Here we present a concept for measuring the time domain response even before the transient transmitter current has been turned off. Our approach relies on a combination of new instrument hardware and novel modeling algorithms. The newly developed hardware allows for measuring the instruments complete transfer function which is convolved with the synthetic earth response in the inversion algorithm. The effect is that earth response data measured while the transmitter current is turned off can be included in the inversion, significantly increasing the amount of available information. We demonstrate the technique using both synthetic and field data. The synthetic examples provide insight on the physics during the turn off process and the field examples document the robustness of the method. Geological near surface structures can now be resolved to a degree that is unprecedented to the best of our knowledge, making airborne EM even more attractive and cost-effective for exploration of water and minerals that are crucial for the function of our societies.

  18. Precision Rectification of Airborne SAR Image

    DEFF Research Database (Denmark)

    Dall, Jørgen; Liao, M.; Zhang, Zhe

    1997-01-01

    A simple and direct procedure for the rectification of a certain class of airborne SAR data is presented. The relief displacements of SAR data are effectively removed by means of a digital elevation model and the image is transformed to the ground coordinate system. SAR data from the Danish EMISAR......([7]) is used. The EMISAR produces data with a geometrical resolution of 2.0 meters. The corrected image is tested against photogrammetric control measurements and an accuracy better than 0.5 pixel corresponding to 0.75 meters is obtained. The results indicate promising possibilities...... for the application of SAR data in the difficult process of map revision and updating....

  19. Highly Protable Airborne Multispectral Imaging System

    Science.gov (United States)

    Lehnemann, Robert; Mcnamee, Todd

    2001-01-01

    A portable instrumentation system is described that includes and airborne and a ground-based subsytem. It can acquire multispectral image data over swaths of terrain ranging in width from about 1.5 to 1 km. The system was developed especially for use in coastal environments and is well suited for performing remote sensing and general environmental monitoring. It includes a small,munpilotaed, remotely controlled airplance that carries a forward-looking camera for navigation, three downward-looking monochrome video cameras for imaging terrain in three spectral bands, a video transmitter, and a Global Positioning System (GPS) reciever.

  20. Improvements in the detection of airborne plutonium

    International Nuclear Information System (INIS)

    Ryden, D.J.

    1981-02-01

    It is shown how it is possible to compensate individually for each of the background components on the filter paper used to collect samples. Experimentally it has been shown that the resulting compensated background count-rate averages zero with a standard deviation very close to the fundamental limit set by random statistical variations. Considerable improvements in the sensitivity of detecting airborne plutonium have been achieved. Two new plutonium-in-air monitors which use the compensation schemes described in this report are now available. Both have operated successfully in high concentrations of radon daughters. (author)

  1. 1. Airborne 2. Hangár

    OpenAIRE

    Johnson, Christy

    2008-01-01

    Hangár, Bakelit Multi Art Center 7th L1 Dance Festival, Budapest, Hungary Installation, 2008 AIRBORNE (projection-sound-monitor installation) was sited in the Hangár, B.A.C. as part of the 7th L1 Dance Festival in Budapest, Hungary (March 2008). This work continues Johnson's interest in and use of 'found' material (16mm wind tunnel footage), and performative methods (sound recording of Channel 9 on United Airlines). This immersive work explores the turbulence of suspension and sets ...

  2. Airborne radioactive emission control technology. Volume III

    International Nuclear Information System (INIS)

    Skoski, L.; Berlin, R.; Corby, D.; Clancy, J.; Hoopes, G.

    1980-03-01

    This report reviews the current and future control technology for airborne emissions from a wide variety of industries/facilities, including uranium mining and milling, other nuclear fuel cycle facilities, other NRC-licensed and DOE facilities, fossil fuel facilities, selected metal and non-metal extraction industries, and others. Where specific radioactivity control technology is lacking, a description of any existing control technology is given. Future control technology is assessed in terms of improvements to equipment performance and process alterations. A catalogue of investigated research on advanced control technologies is presented

  3. Airborne radioactive emission control technology. Volume II

    International Nuclear Information System (INIS)

    Skoski, L.; Berlin, R.; Corby, D.; Clancy, J.; Hoopes, G.

    1980-03-01

    This report reviews the current and future control technology for airborne emissions from a wide variety of industries/facilities, including uranium mining and milling, other nuclear fuel cycle facilities, other NRC-licensed and DOE facilities, fossil fuel facilities, selected metal and non-metal extraction industries, and others. Where specific radioactivity control technology is lacking, a description of any existing control technology is given. Future control technology is assessed in terms of improvements to equipment performance and process alterations. A catalogue of investigated research on advanced control technologies is presented

  4. Airborne radioactive emission control technology. Volume I

    International Nuclear Information System (INIS)

    Skoski, L.; Berlin, R.; Corby, D.; Clancy, J.; Hoopes, G.

    1980-03-01

    This report reviews the current and future control technology for airborne emissions from a wide variety of industries/facilities, includimg uranium mining and milling, other nuclear fuel cycle facilities, other NRC-licensed and DOE facilities, fossil fuel facilities, selected metal and non-metal extraction industries, and others. Where specific radioactivity control technology is lacking a description of any existing control technology is given. Future control technology is assessed in terms of improvements to equipment performance and process alterations. A catalogue of investigated research on advanced control technologies is presented

  5. Reducing windshear risk through airborne systems technology

    Science.gov (United States)

    Bowles, Roland L.

    1990-01-01

    A preliminary set of performance criteria for predictive windshear detection and warning systems is defined. Candidate airborne remote sensor technologies based on microwave Doppler radar, Doppler lidar, and IR radiometric techniques are examined from the viewpoint of overall system requirements, and the performance of each sensor is evaluated for representative microburst environments and ground clutter conditions. Preliminary simulation results indicate that all three sensors have potential for detecting windshear, and provide adequate warning time to permit flight crews to avoid the affected area or escape from the encounter.

  6. Savannah River Plant airborne emissions and controls

    International Nuclear Information System (INIS)

    Dukes, E.K.; Benjamin, R.W.

    1982-12-01

    The Savannah River Plant (SRP) was established to produce special nuclear materials, principally plutonium and tritium, for national defense needs. Major operating facilities include three nuclear reactors, two chemical separations plants, a fuel and target fabrication plant, and a heavy-water rework plant. An extensive environmental surveillance program has been maintained continuously since 1951 (before SRP startup) to determine the concentrations of radionuclides in a 1200-square-mile area centered on the plant, and the radiation exposure of the population resulting from SRP operations. This report provides data on SRP emissions, controls systems, and airborne radioactive releases. The report includes descriptions of current measurement technology. 10 references, 14 figures, 9 tables

  7. Treatment of gaseous and airborne radioactive waste

    International Nuclear Information System (INIS)

    Leichsenring, C.H.

    1982-01-01

    Gaseous and airborne radionuclides in the fuel cycle are retained in vessel off-gas filter systems and in the dissolver off-gas cleaning system. Those systems have to meet the regulatory requirements for both normal and accident conditions. From the solutions liquid aerosols are formed during liquid transfer (air lifts, steam jets) or by air sparging or by evaporation processes. During dissolution the volatile radionuclides i.e. 85 Kr, 129 I and 14 C are liberated and enter into the dissolver off-gas cleaning system. Flow sheets of different cleaning systems and their stage of development are described. (orig./RW)

  8. [Diagnosis of bacterial vaginosis].

    Science.gov (United States)

    Djukić, Slobodanka; Ćirković, Ivana; Arsić, Biljana; Garalejić, Eliana

    2013-01-01

    Bacterial vaginosis is a common, complex clinical syndrome characterized by alterations in the normal vaginal flora. When symptomatic, it is associated with a malodorous vaginal discharge and on occasion vaginal burning or itching. Under normal conditions, lactobacilli constitute 95% of the bacteria in the vagina. Bacterial vaginosis is associated with severe reduction or absence of the normal H2O2-producing lactobacilli and overgrowth of anaerobic bacteria and Gardnerella vaginalis, Atopobium vaginae, Mycoplasma hominis and Mobiluncus species. Most types of infectious disease are diagnosed by culture, by isolating an antigen or RNA/DNA from the microbe, or by serodiagnosis to determine the presence of antibodies to the microbe. Therefore, demonstration of the presence of an infectious agent is often a necessary criterion for the diagnosis of the disease. This is not the case for bacterial vaginosis, since the ultimate cause of the disease is not yet known. There are a variety of methods for the diagnosis of bacterial vaginosis but no method can at present be regarded as the best. Diagnosing bacterial vaginosis has long been based on the clinical criteria of Amsel, whereby three of four defined criteria must be satisfied. Nugent's scoring system has been further developed and includes validation of the categories of observable bacteria structures. Up-to-date molecular tests are introduced, and better understanding of vaginal microbiome, a clear definition for bacterial vaginosis, and short-term and long-term fluctuations in vaginal microflora will help to better define molecular tests within the broader clinical context.

  9. Development of a chemically defined medium for studying foodborne bacterial-fungal interactions

    DEFF Research Database (Denmark)

    Aunsbjerg, Stina Dissing; Honoré, Anders Hans; Vogensen, Finn Kvist

    2015-01-01

    There is a growing interest for using natural preservatives in the food and dairy industries including the application of bacterial cultures to inhibit fungal spoilage. Several antifungal metabolites from bacteria have been identified, but their relative importance has been difficult to establish....... In dynamic systems such as fermented milk products, the complexity of the food matrix affects detection, identification and quantification of antifungal metabolites, and thereby the understanding of the bacterial-fungal interactions. To ease the identification and quantification of bacterial metabolites (as...... judged by ultra-performance liquid chromatography/mass spectrometry) a chemically defined interaction medium (CDIM) was developed. The medium supported growth of antifungal cultures such as Lactobacillus paracasei and Propionibacterium freudenreichii, as well as spoilage moulds and yeasts isolated from...

  10. Concentration of bioaerosols in composting plants using different quantification methods.

    Science.gov (United States)

    van Kampen, Vera; Sander, Ingrid; Liebers, Verena; Deckert, Anja; Neumann, Heinz-Dieter; Buxtrup, Martin; Willer, Eckart; Felten, Christian; Jäckel, Udo; Klug, Kerstin; Brüning, Thomas; Raulf, Monika; Bünger, Jürgen

    2014-07-01

    Bioaerosols (organic dusts) containing viable and non-viable microorganisms and their metabolic products can lead to adverse health effects in exposed workers. Standard quantification methods of airborne microorganisms are mainly based on cultivation, which often underestimates the microbial burden. The aim of the study was to determine the microbial load in German composting plants with different, mainly cultivation-independent, methods. Second purpose was to evaluate which working areas are associated with higher or lower bioaerosol concentrations. A total of 124 inhalable dust samples were collected at different workplaces in 31 composting plants. Besides the determination of inhalable dust, particles, and total cell numbers, antigen quantification for moulds (Aspergillus fumigatus, Aspergillus versicolor, Penicillium chrysogenum, and Cladosporium spp.) and mites was performed. Concentrations of β-glucans as well as endotoxin and pyrogenic activities were also measured. The number of colony forming units (cfu) was determined by cultivation of moulds and actinomycetes in 36 additional dust samples. With the exception of particle numbers, concentrations of all determined parameters showed significant correlations (P parameters were measured highest in dusty working areas like next to the shredder and during processing with the exception of Cladosporium antigens that were found in the highest concentrations in the delivery area. The lowest concentrations of dust, particles, antigens, and pyrogenic activity were determined in wheel loader cabins (WLCs), which were equipped with an air filtration system. It was possible to assess the microbial load of air in composting plants with different quantification methods. Since allergic and toxic reactions may be also caused by nonliving microorganisms, cultivation-independent methods may provide additional information about bioaerosol composition. In general, air filtration reduced the bioaerosol exposure shown in WLCs

  11. SOFIA's Airborne Astronomy Ambassadors: An External Evaluation of Cycle 1

    Science.gov (United States)

    Phillips, Michelle

    2015-01-01

    The Stratospheric Observatory for Infrared Astronomy (SOFIA) represents a partnership between NASA and the German Aerospace Center (DLR). The observatory itself is a Boeing 747 SP that has been modified to serve as the world's largest airborne research observatory. The SOFIA Airborne Astronomy Ambassadors (AAA) program is a component of SOFIA's…

  12. Moving Target Indication for Multi-channel Airborne Radar Systems

    NARCIS (Netherlands)

    Lidicky, L.

    2010-01-01

    Moving target indication (MTI) using radar is of great interest in civil and military applications. Its uses include airborne or space-borne surveillance of ground moving vehicles (cars, trains) or ships at sea, for instance. Airborne (space-borne) radar offers several advantages when compared to

  13. Air-borne radiation from bone conduction transducers.

    Science.gov (United States)

    Lightfoot, G R

    1979-05-01

    The relative magnitudes of air-borne radiation and mechanical vibration from three types of bone conduction transducer have been measured. The study suggests that the presence of excess air-borne radiation can lead to the observation of a false air-bone gap in audiometry. Some methods of overcoming this effect are considered.

  14. Adaptive Restoration of Airborne Daedalus AADS1268 ATM Thermal Data

    International Nuclear Information System (INIS)

    D. Yuan; E. Doak; P. Guss; A. Will

    2002-01-01

    To incorporate the georegistration and restoration processes into airborne data processing in support of U.S. Department of Energy's nuclear emergency response task, we developed an adaptive restoration filter for airborne Daedalus AADS1268 ATM thermal data based on the Wiener filtering theory. Preliminary assessment shows that this filter enhances the detectability of small weak thermal anomalies in AADS1268 thermal images

  15. UAVSAR: An Airborne Window on Earth Surface Deformation

    Science.gov (United States)

    Hensley, Scott

    2011-01-01

    This study demonstrates that UAVSAR's precision autopilot and electronic steering have allowed for the reliable collection of airborne repeat pass radar interferometric data for deformation mapping. Deformation maps from temporal scales ranging from hours to months over a variety of signals of geophysical interest illustrate the utility of UAVSAR airborne repeat pass interferometry to these studies.

  16. 30 CFR 56.5001 - Exposure limits for airborne contaminants.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Exposure limits for airborne contaminants. 56... Quality and Physical Agents Air Quality § 56.5001 Exposure limits for airborne contaminants. Except as... contaminants shall not exceed, on the basis of a time weighted average, the threshold limit values adopted by...

  17. Measuring airborne microorganisms and dust from livestock houses

    NARCIS (Netherlands)

    Yang Zhao, Yang

    2011-01-01

    Airborne transmission has been suspected to be responsible for epidemics of highly infectious disease in livestock production. In such transmission, the pathogenic microorganisms may associate with dust particles. However, the extent to which airborne transmission plays a role in the

  18. OPTIMIZING THE PAKS METHOD FOR MEASURING AIRBORNE ACROLEIN

    Science.gov (United States)

    Airborne acrolein is produced from the combustion of fuel and tobacco and is of concern due to its potential for respiratory tract irritation and other adverse health effects. DNPH active-sampling is a method widely used for sampling airborne aldehydes and ketones (carbonyls); ...

  19. Airborne Asbestos Exposures from Warm Air Heating Systems in Schools.

    Science.gov (United States)

    Burdett, Garry J; Dewberry, Kirsty; Staff, James

    2016-01-01

    concentration and the statistically relevant limits of quantification (LOQ), which are routinely applied. The PCM fibre concentrations were all below the LOQ but analytical TEM showed that few of the fibres counted in the background samples were asbestos. The background TEM asbestos concentrations for the individual samples analysed from all three schools were at or below the AS, with a pooled average below the LOQ (schools, there was no significant increase in the airborne amosite concentration in the classrooms during simulated disturbance conditions. At the third school, four of the five classrooms sampled gave measurable concentrations of amosite by TEM during simulated disturbance conditions. The highest concentration of amosite fibres countable by PCM was 0.0043 f ml(-1) with a pooled average of 0.0019 f ml(-1). The air sampling strategy was effective and worked well and the results provide further important evidence to inform the sampling and management of asbestos in schools. © The Author 2015. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.

  20. Atomic force microscopy studies of bioprocess engineering surfaces - imaging, interactions and mechanical properties mediating bacterial adhesion.

    Science.gov (United States)

    James, Sean A; Hilal, Nidal; Wright, Chris J

    2017-07-01

    The detrimental effect of bacterial biofilms on process engineering surfaces is well documented. Thus, interest in the early stages of bacterial biofilm formation; in particular bacterial adhesion and the production of anti-fouling coatings has grown exponentially as a field. During this time, Atomic force microscopy (AFM) has emerged as a critical tool for the evaluation of bacterial adhesion. Due to its versatility AFM offers not only insight into the topographical landscape and mechanical properties of the engineering surfaces, but elucidates, through direct quantification the topographical and biomechnical properties of the foulants The aim of this review is to collate the current research on bacterial adhesion, both theoretical and practical, and outline how AFM as a technique is uniquely equipped to provide further insight into the nanoscale world at the bioprocess engineering surface. Copyright © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. airborne data analysis/monitor system

    Science.gov (United States)

    Stephison, D. B.

    1981-01-01

    An Airborne Data Analysis/Monitor System (ADAMS), a ROLM 1666 computer based system installed onboard test airplanes used during experimental testing is evaluated. In addition to the 1666 computer, the ADAMS hardware includes a DDC System 90 fixed head disk and a Miltape DD400 floppy disk. Boeing designed a DMA interface to the data acquisition system and an intelligent terminal to reduce system overhead and simplify operator commands. The ADAMS software includes RMX/RTOS and both ROLM FORTRAN and assembly language are used. The ADAMS provides real time displays that enable onboard test engineers to make rapid decisions about test conduct thus reducing the cost and time required to certify new model airplanes, and improved the quality of data derived from the test, leading to more rapid development of improvements resulting in quieter, safer, and more efficient airplanes. The availability of airborne data processing removes most of the weather and geographical restrictions imposed by telemetered flight test data systems. A data base is maintained to describe the airplane, the data acquisition system, the type of testing, and the conditions under which the test is performed.

  2. Airborne fungi in an intensive care unit

    Directory of Open Access Journals (Sweden)

    C. L. Gonçalves

    2017-07-01

    Full Text Available Abstract The presence of airborne fungi in Intensive Care Unit (ICUs is associated with increased nosocomial infections. The aim of this study was the isolation and identification of airborne fungi presented in an ICU from the University Hospital of Pelotas – RS, with the attempt to know the place’s environmental microbiota. 40 Petri plates with Sabouraud Dextrose Agar were exposed to an environment of an ICU, where samples were collected in strategic places during morning and afternoon periods for ten days. Seven fungi genera were identified: Penicillium spp. (15.18%, genus with the higher frequency, followed by Aspergillus spp., Cladosporium spp., Fusarium spp., Paecelomyces spp., Curvularia spp., Alternaria spp., Zygomycetes and sterile mycelium. The most predominant fungi genus were Aspergillus spp. (13.92% in the morning and Cladosporium spp. (13.92% in the afternoon. Due to their involvement in different diseases, the identified fungi genera can be classified as potential pathogens of inpatients. These results reinforce the need of monitoring the environmental microorganisms with high frequency and efficiently in health institutions.

  3. Airborne Methane Measurements using Optical Parametric Amplifiers

    Science.gov (United States)

    Riris, H.; Numata, K.; Li, S.; Wu, S.; Ramanathan, A.; Dawsey, M.; Abshire, J. B.; Kawa, S. R.; Mao, J.

    2012-12-01

    We report on airborne methane measurements with an active sensing instrument using widely tunable, seeded optical parametric generation (OPG). Methane is a strong greenhouse gas on Earth and it is also a potential biogenic marker on Mars and other planetary bodies. Methane in the Earth's atmosphere survives for a shorter time than CO2 but its impact on climate change can be larger than CO2. Carbon and methane emissions from land are expected to increase as permafrost melts exposing millennial-age carbon stocks to respiration (aerobic-CO2 and anaerobic-CH4) and fires. Methane emissions from clathrates in the Arctic Ocean and on land are also likely to respond to climate warming. However, there is considerable uncertainty in present Arctic flux levels, as well as how fluxes will change with the changing environment and more measurements are needed. In this paper we report on an airborne demonstration of atmospheric methane column optical depth measurements at 1.65 μm using widely tunable, seeded optical parametric amplifier (OPA) and a photon counting detector. Our results show good agreement between the experimentally derived optical depth measurements and theoretical calculations and follow the expected changes for aircraft altitudes from 3 to 11 km. The technique has also been used to measure carbon dioxide and monoxide, water vapor, and other trace gases in the near and mid-infrared spectral regions on the ground.

  4. Changes to airborne pollen counts across Europe.

    Directory of Open Access Journals (Sweden)

    Chiara Ziello

    Full Text Available A progressive global increase in the burden of allergic diseases has affected the industrialized world over the last half century and has been reported in the literature. The clinical evidence reveals a general increase in both incidence and prevalence of respiratory diseases, such as allergic rhinitis (common hay fever and asthma. Such phenomena may be related not only to air pollution and changes in lifestyle, but also to an actual increase in airborne quantities of allergenic pollen. Experimental enhancements of carbon dioxide (CO[Formula: see text] have demonstrated changes in pollen amount and allergenicity, but this has rarely been shown in the wider environment. The present analysis of a continental-scale pollen data set reveals an increasing trend in the yearly amount of airborne pollen for many taxa in Europe, which is more pronounced in urban than semi-rural/rural areas. Climate change may contribute to these changes, however increased temperatures do not appear to be a major influencing factor. Instead, we suggest the anthropogenic rise of atmospheric CO[Formula: see text] levels may be influential.

  5. Precise Point Positioning in the Airborne Mode

    Science.gov (United States)

    El-Mowafy, Ahmed

    2011-01-01

    The Global Positioning System (GPS) is widely used for positioning in the airborne mode such as in navigation as a supplementary system and for geo-referencing of cameras in mapping and surveillance by aircrafts and Unmanned Aerial Vehicles (UAV). The Precise Point Positioning (PPP) approach is an attractive positioning approach based on processing of un-differenced observations from a single GPS receiver. It employs precise satellite orbits and satellite clock corrections. These data can be obtained via the internet from several sources, e.g. the International GNSS Service (IGS). The data can also broadcast from satellites, such as via the LEX signal of the new Japanese satellite system QZSS. The PPP can achieve positioning precision and accuracy at the sub-decimetre level. In this paper, the functional and stochastic mathematical modelling used in PPP is discussed. Results of applying the PPP method in an airborne test using a small fixed-wing aircraft are presented. To evaluate the performance of the PPP approach, a reference trajectory was established by differential positioning of the same GPS observations with data from a ground reference station. The coordinate results from the two approaches, PPP and differential positioning, were compared and statistically evaluated. For the test at hand, positioning accuracy at the cm-to-decimetre was achieved for latitude and longitude coordinates and doubles that value for height estimation.

  6. Handling Trajectory Uncertainties for Airborne Conflict Management

    Science.gov (United States)

    Barhydt, Richard; Doble, Nathan A.; Karr, David; Palmer, Michael T.

    2005-01-01

    Airborne conflict management is an enabling capability for NASA's Distributed Air-Ground Traffic Management (DAG-TM) concept. DAGTM has the goal of significantly increasing capacity within the National Airspace System, while maintaining or improving safety. Under DAG-TM, autonomous aircraft maintain separation from each other and from managed aircraft unequipped for autonomous flight. NASA Langley Research Center has developed the Autonomous Operations Planner (AOP), an onboard decision support system that provides airborne conflict management (ACM) and strategic flight planning support for autonomous aircraft pilots. The AOP performs conflict detection, prevention, and resolution from nearby traffic aircraft and area hazards. Traffic trajectory information is assumed to be provided by Automatic Dependent Surveillance Broadcast (ADS-B). Reliable trajectory prediction is a key capability for providing effective ACM functions. Trajectory uncertainties due to environmental effects, differences in aircraft systems and performance, and unknown intent information lead to prediction errors that can adversely affect AOP performance. To accommodate these uncertainties, the AOP has been enhanced to create cross-track, vertical, and along-track buffers along the predicted trajectories of both ownship and traffic aircraft. These buffers will be structured based on prediction errors noted from previous simulations such as a recent Joint Experiment between NASA Ames and Langley Research Centers and from other outside studies. Currently defined ADS-B parameters related to navigation capability, trajectory type, and path conformance will be used to support the algorithms that generate the buffers.

  7. Bacterial Cell Mechanics.

    Science.gov (United States)

    Auer, George K; Weibel, Douglas B

    2017-07-25

    Cellular mechanical properties play an integral role in bacterial survival and adaptation. Historically, the bacterial cell wall and, in particular, the layer of polymeric material called the peptidoglycan were the elements to which cell mechanics could be primarily attributed. Disrupting the biochemical machinery that assembles the peptidoglycan (e.g., using the β-lactam family of antibiotics) alters the structure of this material, leads to mechanical defects, and results in cell lysis. Decades after the discovery of peptidoglycan-synthesizing enzymes, the mechanisms that underlie their positioning and regulation are still not entirely understood. In addition, recent evidence suggests a diverse group of other biochemical elements influence bacterial cell mechanics, may be regulated by new cellular mechanisms, and may be triggered in different environmental contexts to enable cell adaptation and survival. This review summarizes the contributions that different biomolecular components of the cell wall (e.g., lipopolysaccharides, wall and lipoteichoic acids, lipid bilayers, peptidoglycan, and proteins) make to Gram-negative and Gram-positive bacterial cell mechanics. We discuss the contribution of individual proteins and macromolecular complexes in cell mechanics and the tools that make it possible to quantitatively decipher the biochemical machinery that contributes to bacterial cell mechanics. Advances in this area may provide insight into new biology and influence the development of antibacterial chemotherapies.

  8. Comparison of five DNA quantification methods

    DEFF Research Database (Denmark)

    Nielsen, Karsten; Mogensen, Helle Smidt; Hedman, Johannes

    2008-01-01

    Six commercial preparations of human genomic DNA were quantified using five quantification methods: UV spectrometry, SYBR-Green dye staining, slot blot hybridization with the probe D17Z1, Quantifiler Human DNA Quantification kit and RB1 rt-PCR. All methods measured higher DNA concentrations than...... Quantification kit in two experiments. The measured DNA concentrations with Quantifiler were 125 and 160% higher than expected based on the manufacturers' information. When the Quantifiler human DNA standard (Raji cell line) was replaced by the commercial human DNA preparation G147A (Promega) to generate the DNA...... standard curve in the Quantifiler Human DNA Quantification kit, the DNA quantification results of the human DNA preparations were 31% higher than expected based on the manufacturers' information. The results indicate a calibration problem with the Quantifiler human DNA standard for its use...

  9. [State-of-the-art status on airborne antibiotic resistant bacteria and antibiotic resistance genes].

    Science.gov (United States)

    Li, J; Yao, M S

    2018-04-06

    The world is facing more deaths due to increasing antibiotic-resistant bacterial infections and the shortage of new highly effective antibiotics, however the air media as its important transmission route has not been adequately studied. Based on the latest literature acquired in this work, we have discussed the state-of-the-art research progress of the concentration, distribution and spread of antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) in different environmental air media, and also analyzed some future prevention and control measures. The large use of antibiotics in the medical settings and animal husbandry places has resulted in higher abundances of ARB and ARGs in the relevant and surrounding atmosphere than in urban and general indoor air environments. ARGs can be spread by adhering to airborne particles, and researchers have also found that air media contain more abundant ARGs than other environmental media such as soil, water and sediment. It was suggested in this review that strengthening the monitoring, study on spreading factors and biological toxicity, and also research and development on pathogen accurate diagnosis and new green antibiotic are expected to help effectively monitor, prevent and control of the impacts of airborne resistant bacteria and resistance genes on both human and ecologies.

  10. A Method for Quantification of Epithelium Colonization Capacity by Pathogenic Bacteria

    Directory of Open Access Journals (Sweden)

    Rune M. Pedersen

    2018-02-01

    Full Text Available Most bacterial infections initiate at the mucosal epithelium lining the gastrointestinal, respiratory, and urogenital tracts. At these sites, bacterial pathogens must adhere and increase in numbers to effectively breach the outer barrier and invade the host. If the bacterium succeeds in reaching the bloodstream, effective dissemination again requires that bacteria in the blood, reestablish contact to distant endothelium sites and form secondary site foci. The infectious potential of bacteria is therefore closely linked to their ability to adhere to, colonize, and invade epithelial and endothelial surfaces. Measurement of bacterial adhesion to epithelial cells is therefore standard procedure in studies of bacterial virulence. Traditionally, such measurements have been conducted with microtiter plate cell cultures to which bacteria are added, followed by washing procedures and final quantification of retained bacteria by agar plating. This approach is fast and straightforward, but yields only a rough estimate of the adhesive properties of the bacteria upon contact, and little information on the ability of the bacterium to colonize these surfaces under relevant physiological conditions. Here, we present a method in which epithelia/endothelia are simulated by flow chamber-grown human cell layers, and infection is induced by seeding of pathogenic bacteria on these surfaces under conditions that simulate the physiological microenvironment. Quantification of bacterial adhesion and colonization of the cell layers is then performed by in situ time-lapse fluorescence microscopy and automatic detection of bacterial surface coverage. The method is demonstrated in three different infection models, simulating Staphylococcus aureus endothelial infection and Escherichia coli intestinal- and uroepithelial infection. The approach yields valuable information on the fitness of the bacterium to successfully adhere to and colonize epithelial surfaces and can be used

  11. Bacterial meningitis in children

    International Nuclear Information System (INIS)

    Marji, S.

    2007-01-01

    To demonstrate the epidemiology, clinical manifestations and bacteriological profile of bacterial meningitis in children beyond the neonatal period in our hospital. This was a retrospective descriptive study conducted at Prince Rashid Hospital in Irbid, Jordan. The medical records of 50 children with the diagnosis of bacterial meningitis during 4 years period, were reviewed. The main cause of infection was streptococcus pneumoniae, followed by Haemophilus influenza and Niesseria meningitides. Mortality was higher in infants and meningococcal infection, while complications were more encountered in cases of streptococcus pneumoniae. Cerebrospinal fluid culture was positive in 11 cases and Latex agglutination test in 39. There is a significant reduction of the numbers of bacterial meningitis caused by Haemophilus influenza type B species. (author)

  12. Interfering with bacterial gossip

    DEFF Research Database (Denmark)

    Bjarnsholt, Thomas; Tolker-Nielsen, Tim; Givskov, Michael

    2011-01-01

    Biofilm resilience poses major challenges to the development of novel antimicrobial agents. Biofilm bacteria can be considered small groups of “Special Forces” capable of infiltrating the host and destroying important components of the cellular defense system with the aim of crippling the host...... defense. Antibiotics exhibit a rather limited effect on biofilms. Furthermore, antibiotics have an ‘inherent obsolescence’ because they select for development of resistance. Bacterial infections with origin in bacterial biofilms have become a serious threat in developed countries. Pseudomonas aeruginosa...... that appropriately target bacteria in their relevant habitat with the aim of mitigating their destructive impact on patients. In this review we describe molecular mechanisms involved in “bacterial gossip” (more scientifically referred to as quorum sensing (QS) and c-di-GMP signaling), virulence, biofilm formation...

  13. Diagnosis of bacterial vaginosis

    Directory of Open Access Journals (Sweden)

    Đukić Slobodanka

    2013-01-01

    Full Text Available Bacterial vaginosis is a common, complex clinical syndrome characterized by alterations in the normal vaginal flora. When symptomatic, it is associated with a malodorous vaginal discharge and on occasion vaginal burning or itching. Under normal conditions, lactobacilli constitute 95% of the bacteria in the vagina. Bacterial vaginosis is associated with severe reduction or absence of the normal H2O2­producing lactobacilli and overgrowth of anaerobic bacteria and Gardnerella vaginalis, Atopobium vaginae, Mycoplasma hominis and Mobiluncus species. Most types of infectious disease are diagnosed by culture, by isolating an antigen or RNA/DNA from the microbe, or by serodiagnosis to determine the presence of antibodies to the microbe. Therefore, demonstration of the presence of an infectious agent is often a necessary criterion for the diagnosis of the disease. This is not the case for bacterial vaginosis, since the ultimate cause of the disease is not yet known. There are a variety of methods for the diagnosis of bacterial vaginosis but no method can at present be regarded as the best. Diagnosing bacterial vaginosis has long been based on the clinical criteria of Amsel, whereby three of four defined criteria must be satisfied. Nugent’s scoring system has been further developed and includes validation of the categories of observable bacteria structures. Up­to­date molecular tests are introduced, and better understanding of vaginal microbiome, a clear definition for bacterial vaginosis, and short­term and long­term fluctuations in vaginal microflora will help to better define molecular tests within the broader clinical context.

  14. Alternative analysis of airborne laser data collected within conventional multi-parameter airborne geophysical surveys

    Science.gov (United States)

    Ahl, Andreas; Supper, R.; Motschka, K.; Schattauer, I.

    2010-05-01

    For the interpretation of airborne gamma-ray spectrometry as well as airborne electromagnetics it is of great importance to determine the distance between the geophysical sensor and the ground surface. Since radar altimeters do not penetrate vegetation, laser altimeters became popular in airborne geophysics over the past years. Currently the airborne geophysical platform of the Geological Survey of Austria (GBA) is equipped with a Riegl LD90-3800VHS-FLP high resolution laser altimeter, measuring the distances according to the first and the last reflected pulse. The goal of the presented study was to explore the possibilities of deriving additional information about the survey area from the laser data and to determine the accuracy of such results. On one hand the difference between the arrival time of the first and the last reflected pulse can be used to determine the height of the vegetation. This parameter is for example important for the correction of damping effects on airborne gamma-ray measurements caused by vegetation. Moreover especially for groundwater studies at catchment scale, this parameter can also be applied to support the spatial assessment of evapotranspiration. In combination with the altitude above geoid, determined by a GPS receiver, a rough digital elevation model of the survey area can be derived from the laser altimetry. Based on a data set from a survey area in the northern part of Austria, close to the border with the Czech Republic, the reliability of such a digital elevation model and the calculated vegetation height was tested. In this study a mean deviation of -1.4m, with a standard deviation of ±3.4m, between the digital elevation model from Upper Austria (25m spatial resolution) and the determined elevation model was determined. We also found an obvious correlation between the calculated vegetation heights greater 15m and the mapped forest published by the ‘Department of Forest Inventory' of the ‘Federal Forest Office' of Austria

  15. Adult bacterial meningitis

    DEFF Research Database (Denmark)

    Meyer, C N; Samuelsson, I S; Galle, M

    2004-01-01

    Episodes of adult bacterial meningitis (ABM) at a Danish hospital in 1991-2000 were identified from the databases of the Department of Clinical Microbiology, and compared with data from the Danish National Patient Register and the Danish National Notification System. Reduced penicillin susceptibi......Episodes of adult bacterial meningitis (ABM) at a Danish hospital in 1991-2000 were identified from the databases of the Department of Clinical Microbiology, and compared with data from the Danish National Patient Register and the Danish National Notification System. Reduced penicillin...

  16. Bacterial blight of cotton

    Directory of Open Access Journals (Sweden)

    Aïda JALLOUL

    2015-04-01

    Full Text Available Bacterial blight of cotton (Gossypium ssp., caused by Xanthomonas citri pathovar malvacearum, is a severe disease occurring in all cotton-growing areas. The interactions between host plants and the bacteria are based on the gene-for-gene concept, representing a complex resistance gene/avr gene system. In light of the recent data, this review focuses on the understanding of these interactions with emphasis on (1 the genetic basis for plant resistance and bacterial virulence, (2 physiological mechanisms involved in the hypersensitive response to the pathogen, including hormonal signaling, the oxylipin pathway, synthesis of antimicrobial molecules and alteration of host cell structures, and (3 control of the disease.

  17. Bacterial meningitis in infants.

    Science.gov (United States)

    Ku, Lawrence C; Boggess, Kim A; Cohen-Wolkowiez, Michael

    2015-03-01

    Neonatal bacterial meningitis is uncommon but devastating. Morbidity among survivors remains high. The types and distribution of pathogens are related to gestational age, postnatal age, and geographic region. Confirming the diagnosis is difficult. Clinical signs are often subtle, lumbar punctures are frequently deferred, and cerebrospinal fluid (CSF) cultures can be compromised by prior antibiotic exposure. Infants with bacterial meningitis can have negative blood cultures and normal CSF parameters. Promising tests such as the polymerase chain reaction require further study. Prompt treatment with antibiotics is essential. Clinical trials investigating a vaccine for preventing neonatal Group B Streptococcus infections are ongoing. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. Study of airborne science experiment management concepts for application to space shuttle, volume 2

    Science.gov (United States)

    Mulholland, D. R.; Reller, J. O., Jr.; Neel, C. B.; Haughney, L. C.

    1973-01-01

    Airborne research management and shuttle sortie planning at the Ames Research Center are reported. Topics discussed include: basic criteria and procedures for the formulation and approval of airborne missions; ASO management structure and procedures; experiment design, development, and testing aircraft characteristics and experiment interfaces; information handling for airborne science missions; mission documentation requirements; and airborne science methods and shuttle sortie planning.

  19. Water microbiology. Bacterial pathogens and water.

    Science.gov (United States)

    Cabral, João P S

    2010-10-01

    Water is essential to life, but many people do not have access to clean and safe drinking water and many die of waterborne bacterial infections. In this review a general characterization of the most important bacterial diseases transmitted through water-cholera, typhoid fever and bacillary dysentery-is presented, focusing on the biology and ecology of the causal agents and on the diseases' characteristics and their life cycles in the environment. The importance of pathogenic Escherichia coli strains and emerging pathogens in drinking water-transmitted diseases is also briefly discussed. Microbiological water analysis is mainly based on the concept of fecal indicator bacteria. The main bacteria present in human and animal feces (focusing on their behavior in their hosts and in the environment) and the most important fecal indicator bacteria are presented and discussed (focusing on the advantages and limitations of their use as markers). Important sources of bacterial fecal pollution of environmental waters are also briefly indicated. In the last topic it is discussed which indicators of fecal pollution should be used in current drinking water microbiological analysis. It was concluded that safe drinking water for all is one of the major challenges of the 21st century and that microbiological control of drinking water should be the norm everywhere. Routine basic microbiological analysis of drinking water should be carried out by assaying the presence of Escherichia coli by culture methods. Whenever financial resources are available, fecal coliform determinations should be complemented with the quantification of enterococci. More studies are needed in order to check if ammonia is reliable for a preliminary screening for emergency fecal pollution outbreaks. Financial resources should be devoted to a better understanding of the ecology and behavior of human and animal fecal bacteria in environmental waters.

  20. Water Microbiology. Bacterial Pathogens and Water

    Directory of Open Access Journals (Sweden)

    João P. S. Cabral

    2010-10-01

    Full Text Available Water is essential to life, but many people do not have access to clean and safe drinking water and many die of waterborne bacterial infections. In this review a general characterization of the most important bacterial diseases transmitted through water—cholera, typhoid fever and bacillary dysentery—is presented, focusing on the biology and ecology of the causal agents and on the diseases’ characteristics and their life cycles in the environment. The importance of pathogenic Escherichia coli strains and emerging pathogens in drinking water-transmitted diseases is also briefly discussed. Microbiological water analysis is mainly based on the concept of fecal indicator bacteria. The main bacteria present in human and animal feces (focusing on their behavior in their hosts and in the environment and the most important fecal indicator bacteria are presented and discussed (focusing on the advantages and limitations of their use as markers. Important sources of bacterial fecal pollution of environmental waters are also briefly indicated. In the last topic it is discussed which indicators of fecal pollution should be used in current drinking water microbiological analysis. It was concluded that safe drinking water for all is one of the major challenges of the 21st century and that microbiological control of drinking water should be the norm everywhere. Routine basic microbiological analysis of drinking water should be carried out by assaying the presence of Escherichia coli by culture methods. Whenever financial resources are available, fecal coliform determinations should be complemented with the quantification of enterococci. More studies are needed in order to check if ammonia is reliable for a preliminary screening for emergency fecal pollution outbreaks. Financial resources should be devoted to a better understanding of the ecology and behavior of human and animal fecal bacteria in environmental waters.

  1. NASA Airborne Science Program: NASA Stratospheric Platforms

    Science.gov (United States)

    Curry, Robert E.

    2010-01-01

    The National Aeronautics and Space Administration conducts a wide variety of remote sensing projects using several unique aircraft platforms. These vehicles have been selected and modified to provide capabilities that are particularly important for geophysical research, in particular, routine access to very high altitudes, long range, long endurance, precise trajectory control, and the payload capacity to operate multiple, diverse instruments concurrently. While the NASA program has been in operation for over 30 years, new aircraft and technological advances that will expand the capabilities for airborne observation are continually being assessed and implemented. This presentation will review the current state of NASA's science platforms, recent improvements and new missions concepts as well as provide a survey of emerging technologies unmanned aerial vehicles for long duration observations (Global Hawk and Predator). Applications of information technology that allow more efficient use of flight time and the ability to rapidly reconfigure systems for different mission objectives are addressed.

  2. SOFIA'S Challenge: Scheduling Airborne Astronomy Observations

    Science.gov (United States)

    Frank, Jeremy

    2005-01-01

    The Stratospheric Observatory for Infrared Astronomy (SOFIA) is NASA's next generation airborne astronomical observatory, and will commence operations in 2005. The facility consists of a 747-SP modified to accommodate a 2.5 meter telescope. SOFIA is expected to fly an average of 140 science flights per year over its 20 year lifetime. Depending on the nature of the instrument used during flight, 5-15 observations per flight are expected. The SOFIA telescope is mounted aft of the wings on the port side of the aircraft and is articulated through a range of 20deg to 60deg of elevation. The telescope has minimal lateral flexibility; thus, the aircraft must turn constantly to maintain the telescope's focus on an object during observations. A significant problem in future SOFIA operations is that of scheduling flights in support of observations. Investigators are expected to propose small numbers of observations, and many observations must be grouped together to make up single flights. Flight planning for the previous generation airborne observatory, the Kuiper Airborne Observatory (KAO), was done by hand; planners had to choose takeoff time, observations to perform, and decide on setup-actions (called "dead-legs") to position the aircraft prior to observing. This task frequently required between 6-8 hours to plan one flight The scope of the flight planning problem for supporting GI observations with the anticipated flight rate for SOFIA makes the manual approach for flight planning daunting. In response, we have designed an Automated Flight Planner (AFP) that accepts as input a set of requested observations, designated flight days, weather predictions and fuel limitations, and searches automatically for high-quality flight plans that satisfy all relevant aircraft and astronomer specified constraints. The AFP can generate one candidate flight plan in 5-10 minutes, of computation time, a feat beyond the capabilities of human flight planners. The rate at which the AFP can

  3. Composite mapping experiences in airborne gamma spectrometry

    International Nuclear Information System (INIS)

    Bucher, B.

    2014-01-01

    During an international intercomparison exercise of airborne gamma spectrometry held in Switzerland 2007 teams from Germany, France and Switzerland were proving their capabilities. One of the tasks was the composite mapping of an area around Basel. Each team was mainly covering the part of its own country at its own flying procedures. They delivered the evaluated data in a data format agreed in advance. The quantities to be delivered were also defined in advance. Nevertheless, during the process to put the data together a few questions raised: Which dose rate was meant? Had the dose rate to be delivered with or without cosmic contribution? Activity per dry or wet mass? Which coordinate system was used? Finally, the data could be put together in one map. For working procedures in case of an emergency, quantities of interest and exchange data format have to be defined in advance. But the procedures have also to be proved regularly. (author)

  4. Airborne Oceanographic Lidar (AOL) flight mission participation

    Science.gov (United States)

    Hoge, F. E.

    From February 1986 to the present, the AOL participated in six interagency flight missions. (1) Shelf Edge Exchange Processes (SEEP II) (Department of Energy). The SEEP experiments are designed to assess the assimilative capacity of the Continental Shelf to absorb the energy by-products introduced into the near-shore ocean environment from coastal communities and marine activities such as energy production plants and offshore oil operations. (2) BIOWATT II (Office of Naval Research). The major objective of this study was to provide a better understanding of the relationships between ocean physics, biology, bioluminescence, and optics in oligotrophic portions of the Atlantic Ocean. (3) Fall Experiment (FLEX) (Department of Energy). The FLEX studies were designed to determine the fate of low salinity water in the coastal boundary zone that is advected south towards the Florida coast during autumn. (4) Greenland Sea and Icelandic Marine Biological Experiments (NASA). The investigations were designed to evaluate the distribution of surface layer chlorophyll in the Greeland Sea and in the coastal waters in the vicinity of Iceland. (5) Submerged Oceanic Scattering Layer Experiment (Naval Ocean Systems Center). This flight experiment demonstrated for the first time the feasibility of detecting and metrically measuring the depth to submerged layers of particulate matter in the shelf break region and in the inner coastal zone. (6) Microbial Exchanges and Coupling in Coastal Atlantic Systems (National Science Foundation). This investigation was designed to study the transportation and fate of particulates in coastal waters and in particular the Chesapeake Bay/coastal Atlantic Ocean. Shortly after the conduct of the flight experiments, airborne laser-induced chlorophyll a and phycoerythrin fluorescence data, as well as sea surface temperature and airborne expendable bathythermograph water column temperature profiles are supplied to cooperating institutions.

  5. Data simulation of an airborne lidar system

    Science.gov (United States)

    Kim, Seongjoon; Min, Seonghong; Kim, Geunhan; Lee, Impyeong; Jun, Chulmin

    2009-05-01

    An airborne LIDAR (LIght Detection And Ranging) system can rapidly generate 3D points by densely sampling the terrain surfaces using laser pulses. The LIDAR points can be efficiently utilized for automatic reconstruction of 3D models of the objects on the terrain and the terrain itself. The data simulation of such a LIDAR system is significantly useful not only to design an optimal sensor for a specific application but also to assess data processing algorithms with various kinds of test data. In this study, we thus attempted to develop data simulation software of an airborne LIDAR system generally consisting of a GPS, an IMU and a laser scanner. We focused particularly on the geometric modeling of the sensors and the object modeling of the targets and background. Hence the data simulation software has been developed using these models. For the geometric modeling, we derived the sensor equation by modeling not only the geometric relationships between the three modules, such as a GPS, an IMU and a laser scanner but also the systematic errors associated with them. Moreover, for rapid and effective simulation, we designed the data model for both targets and background. We constructed the model data by converting the VRML formatted data into the designed model and stored these data in a 3D spatial database that can offer more effective 3D spatial indexing and query processing. Finally, we developed a program that generates simulated data along with the system parameters of a sensor, a terrain model and its trajectories over the model given.

  6. A Study of Reflected Sonic Booms Using Airborne Measurements

    Science.gov (United States)

    Kantor, Samuel R.; Cliatt, Larry J.

    2017-01-01

    In support of ongoing efforts to bring commercial supersonic flight to the public, the Sonic Booms in Atmospheric Turbulence (SonicBAT) flight test conducted at NASA Armstrong Flight Research Center. During this test, airborne sonic boom measurements were made using an instrumented TG-14 motor glider, called the Airborne Acoustic Measurement Platform (AAMP).During the flight program, the AAMP was consistently able to measure the sonic boom wave that was reflected off of the ground, in addition to the incident wave, resulting in the creation of a completely unique data set of airborne sonic boom reflection measurements.

  7. Photothermal Infrared Spectroscopy of Airborne Samples with Mechanical String Resonators

    DEFF Research Database (Denmark)

    Yamada, Shoko; Schmid, Silvan; Larsen, Tom

    2013-01-01

    -scale airborne samples. Airborne sample material is directly collected on the microstring with an efficient nondiffusion limited sampling method based on inertial impaction. Resonance frequency shifts, proportional to the absorbed heat in the microstring, are recorded as monochromatic IR light is scanned over...... the mid-infrared range. As a proof-of-concept, we sample and analyze polyvinylpyrrolidone (PVP) and the IR spectrum measured by photothermal spectroscopy matches the reference IR spectrum measured by an FTIR spectrometer. We further identify the organic surface coating of airborne TiO2 nanoparticles...

  8. NASA Langley Airborne High Spectral Resolution Lidar Instrument Description

    Science.gov (United States)

    Harper, David B.; Cook, Anthony; Hostetler, Chris; Hair, John W.; Mack, Terry L.

    2006-01-01

    NASA Langley Research Center (LaRC) recently developed the LaRC Airborne High Spectral Resolution Lidar (HSRL) to make measurements of aerosol and cloud distribution and optical properties. The Airborne HSRL has undergone as series of test flights and was successfully deployed on the Megacity Initiative: Local and Global Research Observations (MILAGRO) field mission in March 2006 (see Hair et al. in these proceedings). This paper provides an overview of the design of the Airborne HSRL and descriptions of some key subsystems unique to this instrument.

  9. Estimation of Needed Isolation Capacity for an Airborne Influenza Pandemic.

    Science.gov (United States)

    Subhash, Shobha S; Baracco, Gio; Miller, Shelly L; Eagan, Aaron; Radonovich, Lewis J

    2016-01-01

    We estimated the number of isolation beds needed to care for a surge in patients during an airborne-transmissible influenza pandemic. Based on US health system data, the amount of available airborne isolation beds needed for ill patients will be exceeded early in the course of a moderate or severe influenza pandemic, requiring medical facilities to find ways to further expand isolation bed capacity. Rather than building large numbers of permanent airborne infection isolation rooms to increase surge capacity, an investment that would come at great financial cost, it may be more prudent to prepare for wide-scale creation of just-in-time temporary negative-pressure wards.

  10. Assessment of airborne bacteria and noroviruses in air emission from a new highly-advanced hospital wastewater treatment plant.

    Science.gov (United States)

    Uhrbrand, K; Schultz, A C; Koivisto, A J; Nielsen, U; Madsen, A M

    2017-04-01

    Exposure to bioaerosols can pose a health risk to workers at wastewater treatment plants (WWTPs) and to habitants of their surroundings. The main objective of this study was to examine the presence of harmful microorganisms in the air emission from a new type of hospital WWTP employing advanced wastewater treatment technologies. Air particle measurements and sampling of inhalable bacteria, endotoxin and noroviruses (NoVs) were performed indoor at the WWTP and outside at the WWTP ventilation air exhaust, downwind of the air exhaust, and upwind of the WWTP. No significant differences were seen in particle and endotoxin concentrations between locations. Bacterial concentrations were comparable or significantly lower in the exhaust air than inside the WWTP and in the upwind reference. Bacterial isolates were identified using matrix-assisted laser desorption-ionization time-of-flight mass spectrometry. In total, 35 different bacterial genera and 64 bacterial species were identified in the air samples. Significantly higher genus and species richness was found with an Andersen Cascade Impactor compared with filter-based sampling. No pathogenic bacteria were found in the exhaust air. Streptomyces was the only bacterium found in the air both inside the WWTP and at the air emission, but not in the upwind reference. NoV genomes were detected in the air inside the WWTP and at the air exhaust, albeit in low concentrations. As only traces of NoV genomes could be detected in the exhaust air they are unlikely to pose a health risk to surroundings. Hence, we assess the risk of airborne exposure to pathogenic bacteria and NoVs from the WWTP air emission to surroundings to be negligible. However, as a slightly higher NoV concentration was detected inside the WWTP, we cannot exclude the possibility that exposure to airborne NoVs can pose a health risk to susceptible to workers inside the WWTP, although the risk may be low. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. The Bacterial Growth Curve.

    Science.gov (United States)

    Paulton, Richard J. L.

    1991-01-01

    A procedure that allows students to view an entire bacterial growth curve during a two- to three-hour student laboratory period is described. Observations of the lag phase, logarithmic phase, maximum stationary phase, and phase of decline are possible. A nonpathogenic, marine bacterium is used in the investigation. (KR)

  12. Bacterial fingerprints across Europe

    NARCIS (Netherlands)

    Glasner, Corinna

    2014-01-01

    Bacterial pathogens, such as Staphylococcus aureus and carbapenemase-producing Enterobacteriaceae (CPE), impose major threats to human health worldwide. Both have a ‘Jekyll & Hyde’ character, since they can be present as human commensals, but can also become harmful invasive pathogens especially

  13. [Bacterial biofilms and infection].

    Science.gov (United States)

    Lasa, I; Del Pozo, J L; Penadés, J R; Leiva, J

    2005-01-01

    In developed countries we tend to think of heart disease and the numerous forms of cancer as the main causes of mortality, but on a global scale infectious diseases come close, or may even be ahead: 14.9 million deaths in 2002 compared to cardiovascular diseases (16.9 million deaths) and cancer (7.1 million deaths) (WHO report 2004). The infectious agents responsible for human mortality have evolved as medical techniques and hygienic measures have changed. Modern-day acute infectious diseases caused by specialized bacterial pathogens such as diphtheria, tetanus, cholera, plague, which represented the main causes of death at the beginning of XX century, have been effectively controlled with antibiotics and vaccines. In their place, more than half of the infectious diseases that affect mildly immunocompromised patients involve bacterial species that are commensal with the human body; these can produce chronic infections, are resistant to antimicrobial agents and there is no effective vaccine against them. Examples of these infections are the otitis media, native valve endocarditis, chronic urinary infections, bacterial prostatitis, osteomyelitis and all the infections related to medical devices. Direct analysis of the surface of medical devices or of tissues that have been foci of chronic infections shows the presence of large numbers of bacteria surrounded by an exopolysaccharide matrix, which has been named the "biofilm". Inside the biofilm, bacteria grow protected from the action of the antibodies, phagocytic cells and antimicrobial treatments. In this article, we describe the role of bacterial biofilms in human persistent infections.

  14. EDITORIAL SPONTANEOUS BACTERIAL PERITONITIS ...

    African Journals Online (AJOL)

    hi-tech

    Spontaneous bacterial peritonitis (SBP) frequent]y occurs in patients with liver cirrhosis and ascites. It is defined as an infection of previously sterile ascitic fluid without any demonstrable intrabdominal source of infection. It is now internationally agreed that a polymorphonuclear (PMN) cell count in the ascitic fluid of over 250 ...

  15. Seizures Complicating Bacterial Meningitis

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2004-09-01

    Full Text Available The clinical data of 116 patients, 1 month to <5 years of age, admitted for bacterial meningitis, and grouped according to those with and without seizures during hospitalization, were compared in a study at Buddhist Dalin Tzu Chi General Hospital, Chang Gung Memorial Hospital and other centers in Taiwan.

  16. Diagnosis of bacterial infection

    African Journals Online (AJOL)

    rapid and easy-to-use test for bacterial infections. Clearly, this is a very ... detect antigens or specific antibodies, e.g. group A streptococcal antigen testing can be employed to reduce antibiotic use. Culture-based tests are often ... White blood cell count 12 000 cells/mm³; or the presence of >10% ...

  17. Bacterial Meningitis Outcome

    OpenAIRE

    J Gordon Millichap

    1995-01-01

    The neurologic, psychological, and educational outcomes of bacterial meningitis in 130 children evaluated at a mean age of 8 years, and 6 years after their meningitis, are reported from the Department of Paediatrics and Clinical Epidemiology and Biostatistics Unit, University of Melbourne, and the Royal Children’s Hospital, Victoria, Australia.

  18. Advancing agricultural greenhouse gas quantification*

    Science.gov (United States)

    Olander, Lydia; Wollenberg, Eva; Tubiello, Francesco; Herold, Martin

    2013-03-01

    1. Introduction Better information on greenhouse gas (GHG) emissions and mitigation potential in the agricultural sector is necessary to manage these emissions and identify responses that are consistent with the food security and economic development priorities of countries. Critical activity data (what crops or livestock are managed in what way) are poor or lacking for many agricultural systems, especially in developing countries. In addition, the currently available methods for quantifying emissions and mitigation are often too expensive or complex or not sufficiently user friendly for widespread use. The purpose of this focus issue is to capture the state of the art in quantifying greenhouse gases from agricultural systems, with the goal of better understanding our current capabilities and near-term potential for improvement, with particular attention to quantification issues relevant to smallholders in developing countries. This work is timely in light of international discussions and negotiations around how agriculture should be included in efforts to reduce and adapt to climate change impacts, and considering that significant climate financing to developing countries in post-2012 agreements may be linked to their increased ability to identify and report GHG emissions (Murphy et al 2010, CCAFS 2011, FAO 2011). 2. Agriculture and climate change mitigation The main agricultural GHGs—methane and nitrous oxide—account for 10%-12% of anthropogenic emissions globally (Smith et al 2008), or around 50% and 60% of total anthropogenic methane and nitrous oxide emissions, respectively, in 2005. Net carbon dioxide fluxes between agricultural land and the atmosphere linked to food production are relatively small, although significant carbon emissions are associated with degradation of organic soils for plantations in tropical regions (Smith et al 2007, FAO 2012). Population growth and shifts in dietary patterns toward more meat and dairy consumption will lead to

  19. Airborne gamma ray measurements conducted during an international trial in Finland

    Energy Technology Data Exchange (ETDEWEB)

    Sanderson, D.C.W.; Allyson, J.D.; McConville, P.; Murphy, S.; Smith, J. [Scottish Univ. Research and Reactor Centre, Glasgow, Scotland (United Kingdom)

    1997-12-31

    The Scottish Universities Research and Reactor Centre (SURRC) contributed to the Resume 95 exercise by developing the calibration site at Vesivehmaa, and by participating in the airborne gamma spectrometry (AGS) part of the study. This paper summarises the airborne survey results from the SURRC team. The AGS tasks included fallout mapping of a 6x3 km area in central Finland with nominal 150 m line spacing, and a time constrained search for an undisclosed number of hidden radioactive sources. Measurements at the calibration site were also taken to provide a basis for traceable cross comparison between each teams` quantification procedures at a single, well characterised, location. A full set of calibrated maps of Chernobyl deposition and natural radionuclides, together with overlays corresponding to topography, roads, rivers and lakes were finished during the survey and displayed at the end of the exercise. The main survey area (Area II) was found to have a mean {sup 137}Cs deposition of 64.4{+-}24.4 kBq m{sup -2}, based on the calibration appropriate to the Vesivehmaa site. The major point sources in Area III were discovered, although the collimated {sup 137}Cs and {sup 60}Co sources were not. Retrospective analysis has shown that sources Cs3 and Cs4 were not significantly above local environmental levels in our data set; whereas the low activity {sup 60}Co source Co3 was detected. This confirms the improved sensitivity of AGS source searches to nuclides which are not already present as environmental contaminants. The collimated {sup 192}Ir was found both using scattered radiation and from full energy lines detected with a Ge detector. The {sup 99m}Tc was located using a ratio of low energy integrals from the NaI spectra. (EG). 28 refs.

  20. Airborne gamma ray measurements conducted during an international trial in Finland

    International Nuclear Information System (INIS)

    Sanderson, D.C.W.; Allyson, J.D.; McConville, P.; Murphy, S.; Smith, J.

    1997-01-01

    The Scottish Universities Research and Reactor Centre (SURRC) contributed to the Resume 95 exercise by developing the calibration site at Vesivehmaa, and by participating in the airborne gamma spectrometry (AGS) part of the study. This paper summarises the airborne survey results from the SURRC team. The AGS tasks included fallout mapping of a 6x3 km area in central Finland with nominal 150 m line spacing, and a time constrained search for an undisclosed number of hidden radioactive sources. Measurements at the calibration site were also taken to provide a basis for traceable cross comparison between each teams' quantification procedures at a single, well characterised, location. A full set of calibrated maps of Chernobyl deposition and natural radionuclides, together with overlays corresponding to topography, roads, rivers and lakes were finished during the survey and displayed at the end of the exercise. The main survey area (Area II) was found to have a mean 137 Cs deposition of 64.4±24.4 kBq m -2 , based on the calibration appropriate to the Vesivehmaa site. The major point sources in Area III were discovered, although the collimated 137 Cs and 60 Co sources were not. Retrospective analysis has shown that sources Cs3 and Cs4 were not significantly above local environmental levels in our data set; whereas the low activity 60 Co source Co3 was detected. This confirms the improved sensitivity of AGS source searches to nuclides which are not already present as environmental contaminants. The collimated 192 Ir was found both using scattered radiation and from full energy lines detected with a Ge detector. The 99m Tc was located using a ratio of low energy integrals from the NaI spectra. (EG)

  1. Corticosteroids for Bacterial Keratitis

    Science.gov (United States)

    Srinivasan, Muthiah; Mascarenhas, Jeena; Rajaraman, Revathi; Ravindran, Meenakshi; Lalitha, Prajna; Glidden, David V.; Ray, Kathryn J.; Hong, Kevin C.; Oldenburg, Catherine E.; Lee, Salena M.; Zegans, Michael E.; McLeod, Stephen D.; Lietman, Thomas M.; Acharya, Nisha R.

    2013-01-01

    Objective To determine whether there is a benefit in clinical outcomes with the use of topical corticosteroids as adjunctive therapy in the treatment of bacterial corneal ulcers. Methods Randomized, placebo-controlled, double-masked, multicenter clinical trial comparing prednisolone sodium phosphate, 1.0%, to placebo as adjunctive therapy for the treatment of bacterial corneal ulcers. Eligible patients had a culture-positive bacterial corneal ulcer and received topical moxifloxacin for at least 48 hours before randomization. Main Outcome Measures The primary outcome was best spectacle-corrected visual acuity (BSCVA) at 3 months from enrollment. Secondary outcomes included infiltrate/scar size, reepithelialization, and corneal perforation. Results Between September 1, 2006, and February 22, 2010, 1769 patients were screened for the trial and 500 patients were enrolled. No significant difference was observed in the 3-month BSCVA (−0.009 logarithm of the minimum angle of resolution [logMAR]; 95% CI, −0.085 to 0.068; P = .82), infiltrate/scar size (P = .40), time to reepithelialization (P = .44), or corneal perforation (P > .99). A significant effect of corticosteroids was observed in subgroups of baseline BSCVA (P = .03) and ulcer location (P = .04). At 3 months, patients with vision of counting fingers or worse at baseline had 0.17 logMAR better visual acuity with corticosteroids (95% CI, −0.31 to −0.02; P = .03) compared with placebo, and patients with ulcers that were completely central at baseline had 0.20 logMAR better visual acuity with corticosteroids (−0.37 to −0.04; P = .02). Conclusions We found no overall difference in 3-month BSCVA and no safety concerns with adjunctive corticosteroid therapy for bacterial corneal ulcers. Application to Clinical Practice Adjunctive topical corticosteroid use does not improve 3-month vision in patients with bacterial corneal ulcers. PMID:21987582

  2. Scaling wood volume estimates from inventory plots to landscapes with airborne LiDAR in temperate deciduous forest

    Directory of Open Access Journals (Sweden)

    Shaun R. Levick

    2016-05-01

    Full Text Available Abstract Background Monitoring and managing carbon stocks in forested ecosystems requires accurate and repeatable quantification of the spatial distribution of wood volume at landscape to regional scales. Grid-based forest inventory networks have provided valuable records of forest structure and dynamics at individual plot scales, but in isolation they may not represent the carbon dynamics of heterogeneous landscapes encompassing diverse land-management strategies and site conditions. Airborne LiDAR has greatly enhanced forest structural characterisation and, in conjunction with field-based inventories, it provides avenues for monitoring carbon over broader spatial scales. Here we aim to enhance the integration of airborne LiDAR surveying with field-based inventories by exploring the effect of inventory plot size and number on the relationship between field-estimated and LiDAR-predicted wood volume in deciduous broad-leafed forest in central Germany. Results Estimation of wood volume from airborne LiDAR was most robust (R2 = 0.92, RMSE = 50.57 m3 ha−1 ~14.13 Mg C ha−1 when trained and tested with 1 ha experimental plot data (n = 50. Predictions based on a more extensive (n = 1100 plot network with considerably smaller (0.05 ha plots were inferior (R2 = 0.68, RMSE = 101.01 ~28.09 Mg C ha−1. Differences between the 1 and 0.05 ha volume models from LiDAR were negligible however at the scale of individual land-management units. Sample size permutation tests showed that increasing the number of inventory plots above 350 for the 0.05 ha plots returned no improvement in R2 and RMSE variability of the LiDAR-predicted wood volume model. Conclusions Our results from this study confirm the utility of LiDAR for estimating wood volume in deciduous broad-leafed forest, but highlight the challenges associated with field plot size and number in establishing robust relationships between airborne LiDAR and field derived wood volume. We

  3. Simultaneous determination of gene expression and bacterial identity in single cells in defined mixtures of pure cultures

    DEFF Research Database (Denmark)

    Poulsen, Lars K.; Dalton, Helen M.; Angels, Mark

    1997-01-01

    A protocol was developed to achieve the simultaneous determination of gene expression and bacterial identity at the level of single cells: a chromogenic beta-galactosidase activity assay was combined with in situ hybridization of Fluorescently labelled oligonucleotide probes to rRNA. The method...... allows monitoring of gene expression and quantification of beta-galactosidase activity in single cells....

  4. Airborne Gravity: NGS' Gravity Data for CS06 (2012 & 2013)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Texas collected in 2012 & 2013 over 2 surveys. This data set is part of the Gravity for the Re-definition of the American Vertical...

  5. Airborne Gravity: NGS' Gravity Data for EN01 (2011)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for New York, Canada, and Lake Ontario collected in 2011 over 1 survey. This data set is part of the Gravity for the Re-definition of the...

  6. Airborne Gravity: NGS' Gravity Data for CN02 (2013 & 2014)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Nebraska collected in 2013 & 2014 over 3 surveys. This data set is part of the Gravity for the Re-definition of the American Vertical...

  7. Airborne Gravity: NGS' Gravity Data for ES01 (2013)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Florida, the Bahamas, and the Atlantic Ocean collected in 2013 over 1 survey. This data set is part of the Gravity for the Re-definition of...

  8. Airborne Gravity: NGS' Gravity Data for CN03 (2014)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Nebraska collected in 2014 over one survey. This data set is part of the Gravity for the Re-definition of the American Vertical Datum...

  9. CAMEX-3 AIRBORNE VERTICAL ATMOSPHERE PROFILING SYSTEM (AVAPS) V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The CAMEX-3 DC-8 Airborne Vertical Atmosphere Profiling System (AVAPS) uses dropwinsonde and Global Positioning System (GPS) receivers to measure the atmospheric...

  10. CLPX Airborne Gamma Snow and Soil Moisture Surveys

    Data.gov (United States)

    National Aeronautics and Space Administration — Airborne gamma surveys were conducted over each of the three Cold Land Processes Field Experiment (CLPX) Meso-cell Study Areas (MSAs) in northern Colorado, USA,...

  11. Dispersion model for airborne radioactive particulates inside a process building

    International Nuclear Information System (INIS)

    Perkins, W.C.; Stoddard, D.H.

    1984-02-01

    An empirical model, predicting the spread of airborne radioactive particles after they are released inside a building, has been developed. The basis for this model is a composite of data for dispersion of airborne activity recorded during 12 case incidents. These incidents occurred at the Savannah River Plant (SRP) during approximately 90 plant-years of experience with the chemical and metallurgical processing of purified neptunium and plutonium. The model illustrates that the multiple-air-zone concept, used in the designs of many nuclear facilities, can be an efficient safety feature to limit the spread of airborne activity from a release. This study also provides some insight into an apparently anomalous behavior of airborne particulates, namely, their migration against the prevailing flow of ventilation air. 2 references, 12 figures, 4 tables

  12. GRIP AIRBORNE SECOND GENERATION PRECIPITATION RADAR (APR-2) V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The Second Generation Airborne Precipitation Radar (APR-2) is a dual-frequency (13 GHz and 35 GHz), Doppler, dual-polarization radar system. It has a downward...

  13. SMEX02 Airborne Synthetic Aperture Radar (AIRSAR) Data, Iowa

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains radar backscatter measurments taken over the Soil Moisture Experiments 2002 (SMEX02) Walnut Creek Watershed area in Iowa, USA. The Airborne...

  14. Advances and perspectives in bathymetry by airborne lidar

    Science.gov (United States)

    Zhou, Guoqing; Wang, Chenxi; Li, Mingyan; Wang, Yuefeng; Ye, Siqi; Han, Caiyun

    2015-12-01

    In this paper, the history of the airborne lidar and the development stages of the technology are reviewed. The basic principle of airborne lidar and the method of processing point-cloud data were discussed. At present, single point laser scanning method is widely used in bathymetric survey. Although the method has high ranging accuracy, the data processing and hardware system is too much complicated and expensive. For this reason, this paper present a kind of improved dual-frequency method for bathymetric and sea surface survey, in this method 176 units of 1064nm wavelength laser has been used by push-broom scanning and due to the airborne power limits still use 532nm wavelength single point for bathymetric survey by zigzag scanning. We establish a spatial coordinates for obtaining the WGS-84 of point cloud by using airborne POS system.

  15. SAFARI 2000 MODIS Airborne Simulator (MAS) Browse Images

    Data.gov (United States)

    National Aeronautics and Space Administration — The MODIS Airborne Simulator (MAS) collected imagery for the SAFARI 2000 field campaign. Currently available data consist of browse imagery and flight track...

  16. Airborne Cloud Radar (ACR) Reflectivity, Wakasa Bay, Japan

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set includes 94 GHz co- and cross-polarized radar reflectivity. The Airborne Cloud Radar (ACR) sensor was mounted to a NASA P-3 aircraft flown over the Sea...

  17. Experimental relations between airborne and ground measured wheat canopy temperatures

    Science.gov (United States)

    Millard, J. P.; Reginato, R. J.; Idso, S. B.; Jackson, R. D.; Goettelman, R. C.; Leroy, M. J.

    1980-01-01

    Experiments using ground-based measurements of canopy temperatures have shown that plant temperatures are good indicators of plant water stress, and thus are useful for assessing water requirements and predicting yields. An intensive 23-day airborne- and ground-measurement program was conducted in Phoenix, Arizona in 1977 to compare airborne-acquired wheat canopy temperatures with simultaneous ground measurements. For canopies that covered at least 85 percent of the soil surface, airborne measurements differed from ground measurements of plant temperature by less than 2 C. Regardless of the amount of plant cover, the airborne measurements were virtually identical to ground-nadir measurements, and thus represent a combination of plant temperature and solid background temperature.

  18. A metagenomic framework for the study of airborne microbial communities.

    Directory of Open Access Journals (Sweden)

    Shibu Yooseph

    Full Text Available Understanding the microbial content of the air has important scientific, health, and economic implications. While studies have primarily characterized the taxonomic content of air samples by sequencing the 16S or 18S ribosomal RNA gene, direct analysis of the genomic content of airborne microorganisms has not been possible due to the extremely low density of biological material in airborne environments. We developed sampling and amplification methods to enable adequate DNA recovery to allow metagenomic profiling of air samples collected from indoor and outdoor environments. Air samples were collected from a large urban building, a medical center, a house, and a pier. Analyses of metagenomic data generated from these samples reveal airborne communities with a high degree of diversity and different genera abundance profiles. The identities of many of the taxonomic groups and protein families also allows for the identification of the likely sources of the sampled airborne bacteria.

  19. CLPX Airborne Gamma Snow and Soil Moisture Surveys, Version 1

    Data.gov (United States)

    National Aeronautics and Space Administration — Airborne gamma surveys were conducted over each of the three Cold Land Processes Field Experiment (CLPX) Meso-cell Study Areas (MSAs) in northern Colorado, USA,...

  20. Reconfigurable Weather Radar for Airborne Applications, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Intelligent Automation, Inc (IAI) and its university partner, University of Oklahoma (OU), Norman, propose a forward-looking airborne environment sensor based on...

  1. APR-2 Dual-frequency Airborne Radar Observations, Wakasa Bay

    Data.gov (United States)

    National Aeronautics and Space Administration — In January and February 2003, the Airborne Second Generation Precipitation Radar (APR-2) collected data in the Wakasa Bay AMSR-E validation campaign over the sea of...

  2. SMEX02 Airborne GPS Bistatic Radar Data, Iowa

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains measurements of Global Positioning System (GPS) signals reflected from the Earth’s surface and collected on an airborne platform. The...

  3. Airborne Gravity: NGS' Gravity Data for AN03 (2010)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Alaska collected in 2010 and 2012 over 2 surveys. This data set is part of the Gravity for the Re-definition of the American Vertical Datum...

  4. Airborne Gravity: NGS' Gravity Data for PN01 (2014)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for California and Oregon collected in 2011 over 1 survey. This data set is part of the Gravity for the Re-definition of the American Vertical...

  5. Airborne Gravity: NGS' Gravity Data for AN08 (2016)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Alaska collected in 2016 over one survey. This data set is part of the Gravity for the Re-definition of the American Vertical Datum...

  6. Airborne Geophysical/Geological Mineral Inventory CIP Program

    National Research Council Canada - National Science Library

    1999-01-01

    The Airborne-Geophysical/Geological Mineral Inventory project is a special multi-year investment to expand the knowledge base of Alaska's mineral resources and catalyze private-sector mineral development...

  7. Airborne Wide Area Imager for Wildfire Mapping and Detection Project

    Data.gov (United States)

    National Aeronautics and Space Administration — An advanced airborne imaging system for fire detection/mapping is proposed. The goal of the project is to improve control and management of wildfires in order to...

  8. Airborne Gravity: NGS' Gravity Data for TS01 (2014)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Puerto Rico and the Virgin Islands collected in 2009 over 1 survey. This data set is part of the Gravity for the Re-definition of the...

  9. Airborne Gravity: NGS' Gravity Data for EN04 (2013)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Michigan and Lake Huron collected in 2012 over 1 survey. This data set is part of the Gravity for the Re-definition of the American...

  10. Airborne Gravity: NGS' Gravity Data for EN10 (2013)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for New York, Pennsylvania, New Jersey, Connecticut and the Atlantic Ocean collected in 2013 over 1 survey. This data set is part of the...

  11. Airborne Gravity: NGS' Gravity Data for EN09 (2016)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Airborne gravity data for Massachusetts, Connecticut, Rhode Island, New Hampshire, New York, and the Atlantic Ocean collected in 2012 over 1 survey. This data set is...

  12. Miniaturized Airborne Imaging Central Server System, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The innovation is a miniaturized airborne imaging central server system (MAICSS). MAICSS is designed as a high-performance-computer-based electronic backend that...

  13. Miniaturized Airborne Imaging Central Server System, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — The innovation is a miniaturized airborne imaging central server system (MAICSS). MAICSS is designed as a high-performance computer-based electronic backend that...

  14. CAMEX-3 AIRBORNE VERTICAL ATMOSPHERE PROFILING SYSTEM (AVAPS) V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The CAMEX-3 DC-8 Airborne Vertical Atmosphere Profiling System (AVAPS) uses dropwindsonde and Global Positioning System (GPS) receivers to measure the atmospheric...

  15. Thermal Mapping Airborne Simulator for Small Satellite Sensor, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — A high performance, inexpensive, airborne simulator that will serve as the prototype for a small satellite based imaging system capable of mapping thermal anomalies...

  16. TCSP ER-2 MODIS AIRBORNE SIMULATOR (MAS) V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The MODIS Airborne Simulator (MAS) is a multi-spectral line-scanner system that acquires image data in 50 spectral bands over wavelengths ranging from 0.46 to 14.3...

  17. A Metagenomic Framework for the Study of Airborne Microbial Communities

    OpenAIRE

    Yooseph, Shibu; Andrews-Pfannkoch, Cynthia; Tenney, Aaron; McQuaid, Jeff; Williamson, Shannon; Thiagarajan, Mathangi; Brami, Daniel; Zeigler-Allen, Lisa; Hoffman, Jeff; Goll, Johannes B.; Fadrosh, Douglas; Glass, John; Adams, Mark D.; Friedman, Robert; Venter, J. Craig

    2013-01-01

    Understanding the microbial content of the air has important scientific, health, and economic implications. While studies have primarily characterized the taxonomic content of air samples by sequencing the 16S or 18S ribosomal RNA gene, direct analysis of the genomic content of airborne microorganisms has not been possible due to the extremely low density of biological material in airborne environments. We developed sampling and amplification methods to enable adequate DNA recovery to allow m...

  18. Using High-Resolution Hyperspectral and Thermal Airborne Imagery to Assess Physiological Condition in the Context of Wheat Phenotyping

    Directory of Open Access Journals (Sweden)

    Victoria Gonzalez-Dugo

    2015-10-01

    Full Text Available There is a growing need for developing high-throughput tools for crop phenotyping that would increase the rate of genetic improvement. In most cases, the indicators used for this purpose are related with canopy structure (often acquired with RGB cameras and multispectral sensors allowing the calculation of NDVI, but using approaches related with the crop physiology are rare. High-resolution hyperspectral remote sensing imagery provides optical indices related to physiological condition through the quantification of photosynthetic pigment and chlorophyll fluorescence emission. This study demonstrates the use of narrow-band indicators of stress as a potential tool for phenotyping under rainfed conditions using two airborne datasets acquired over a wheat experiment with 150 plots comprising two species and 50 varieties (bread and durum wheat. The flights were performed at the early stem elongation stage and during the milking stage. Physiological measurements made at the time of flights demonstrated that the second flight was made during the terminal stress, known to largely determine final yield under rainfed conditions. The hyperspectral imagery enabled the extraction of thermal, radiance, and reflectance spectra from 260 spectral bands from each plot for the calculation of indices related to photosynthetic pigment absorption in the visible and red-edge regions, the quantification of chlorophyll fluorescence emission, as well as structural indices related to canopy structure. Under the conditions of this study, the structural indices (i.e., NDVI did not show a good performance at predicting yield, probably because of the large effects of terminal water stress. Thermal indices, indices related to chlorophyll fluorescence (calculated using the FLD method, and carotenoids pigment indices (PRI and CAR demonstrated to be better suited for screening complex traits such as crop yield. The study concludes that the indicators derived from high

  19. Uncertainty Quantification in Aerodynamics Simulations, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The objective of the proposed work (Phases I and II) is to develop uncertainty quantification methodologies and software suitable for use in CFD simulations of...

  20. Uncertainty quantification theory, implementation, and applications

    CERN Document Server

    Smith, Ralph C

    2014-01-01

    The field of uncertainty quantification is evolving rapidly because of increasing emphasis on models that require quantified uncertainties for large-scale applications, novel algorithm development, and new computational architectures that facilitate implementation of these algorithms. Uncertainty Quantification: Theory, Implementation, and Applications provides readers with the basic concepts, theory, and algorithms necessary to quantify input and response uncertainties for simulation models arising in a broad range of disciplines. The book begins with a detailed discussion of applications where uncertainty quantification is critical for both scientific understanding and policy. It then covers concepts from probability and statistics, parameter selection techniques, frequentist and Bayesian model calibration, propagation of uncertainties, quantification of model discrepancy, surrogate model construction, and local and global sensitivity analysis. The author maintains a complementary web page where readers ca...

  1. Direct qPCR quantification using the Quantifiler(®) Trio DNA quantification kit.

    Science.gov (United States)

    Liu, Jason Yingjie

    2014-11-01

    The effectiveness of a direct quantification assay is essential to the adoption of the combined direct quantification/direct STR workflow. In this paper, the feasibility of using the Quantifiler(®) Trio DNA quantification kit for the direct quantification of forensic casework samples was investigated. Both low-level touch DNA samples and blood samples were collected on PE swabs and quantified directly. The increased sensitivity of the Quantifiler(®) Trio kit enabled the detection of less than 10pg of DNA in unprocessed touch samples and also minimizes the stochastic effect experienced by different targets in the same sample. The DNA quantity information obtained from a direct quantification assay using the Quantifiler(®) Trio kit can also be used to accurately estimate the optimal input DNA quantity for a direct STR amplification reaction. The correlation between the direct quantification results (Quantifiler(®) Trio kit) and the direct STR results (GlobalFiler™ PCR amplification kit(*)) for low-level touch DNA samples indicates that direct quantification using the Quantifiler(®) Trio DNA quantification kit is more reliable than the Quantifiler(®) Duo DNA quantification kit for predicting the STR results of unprocessed touch DNA samples containing less than 10pg of DNA. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  2. Radiometric detection of bacterial metabolism

    International Nuclear Information System (INIS)

    Camargo, E.E.; Wagner Junior, H.N.

    1979-01-01

    The measurement of 14 CO 2 produced by the bacterial oxidation of labelled compounds is discussed as a means of evaluating the bacterial metabolism. The following items are discussed:automated radiometric detection, types of graphs, clinical applications of the radiometric system and influential factors. Complementary studies on bacterial assimilation of substances are presented. (M.A.) [pt

  3. Oil spill characterization thanks to optical airborne imagery during the NOFO campaign 2015

    Science.gov (United States)

    Viallefont-Robinet, F.; Ceamanos, X.; Angelliaume, S.; Miegebielle, V.

    2017-10-01

    One of the objectives of the NAOMI (New Advanced Observation Method Integration) research project, fruit of a partnership between Total and ONERA, is to work on the detection, the quantification and the characterization of offshore hydrocarbon at the sea surface using airborne remote sensing. In this framework, work has been done to characterize the spectral signature of hydrocarbons in lab in order to build a database of oil spectral signatures. The main objective of this database is to provide spectral libraries for data processing algorithms to be applied to airborne VNIRSWIR hyperspectral images. A campaign run by the NOFO institute (Norwegian Clean Seas Association for Operating Companies) took place in 2015 to test anti-pollution equipment. During this campaign, several hydrocarbon products, including an oil emulsion, were released into the sea, off the Norwegian coast. The NOFO team allowed the NAOMI project to acquire data over the resulting oil slicks using the SETHI system, which is an airborne remote sensing imaging system developed by ONERA. SETHI integrates a new generation of optoelectronic and radar payloads and can operate over a wide range of frequency bands. SETHI is a pod-based system operating onboard a Falcon 20 Dassault aircraft, which is owned by AvDEF. For these experiments, imaging sensors were constituted by 2 synthetic aperture radar (SAR), working at X and L bands in a full polarimetric mode (HH, HV, VH, VV) and 2 HySpex hyperspectral cameras working in the VNIR (0,4 to 1 μm) and SWIR (1 to 2,5 μm) spectral ranges. A sample of the oil emulsion that was used during the campaign was sent to our laboratory for analysis. Measurements of its transmission and of its reflectance in the VNIR and SWIR spectral domains have been performed at ONERA with a Perkin Elmer spectroradiometer and a spectrogoniometer. Several samples of the oil emulsion were prepared in order to measure spectral variations according to oil thickness, illumination angle

  4. [Relationships between air conditioning, airborne microorganisms and health].

    Science.gov (United States)

    Parat, S; Perdrix, A; Baconnier, P

    1999-01-01

    Concurrently with the increase of air-conditioning, potentially severe or frequent new diseases have emerged, giving rise to social and economical consequences. The first part of this work is a state of the art review of the relationships between air-conditioning, airborne microorganisms and health, through a technical, metrological and medical approach. The second part presents four studies performed in this field. Two of them deal with the relationship between airborne microorganisms and technical features of air-conditioning. Measurements performed on actual sites demonstrated the benefit of using high efficiency filters and low risk components in air-conditioning systems. The third study was aimed to look for a relationship between airborne microorganisms and sick building syndrome symptoms. Statistical analyses of individual data revealed significant associations between airborne bacteria or fungi and symptoms. These results may be the first step in determining a dose-response relationship, in order to define threshold limit values in this field. In the fourth study, the contribution of particle counting in assessing exposure to airborne microorganisms was explored by monitoring simultaneous variations of microbial and particle concentrations. The results showed that associating particle counting may allow to detect microbial variations instantaneously, and therefore improve the assessment of exposure to airborne microorganisms.

  5. Miniaturized Airborne Imaging Central Server System

    Science.gov (United States)

    Sun, Xiuhong

    2011-01-01

    In recent years, some remote-sensing applications require advanced airborne multi-sensor systems to provide high performance reflective and emissive spectral imaging measurement rapidly over large areas. The key or unique problem of characteristics is associated with a black box back-end system that operates a suite of cutting-edge imaging sensors to collect simultaneously the high throughput reflective and emissive spectral imaging data with precision georeference. This back-end system needs to be portable, easy-to-use, and reliable with advanced onboard processing. The innovation of the black box backend is a miniaturized airborne imaging central server system (MAICSS). MAICSS integrates a complex embedded system of systems with dedicated power and signal electronic circuits inside to serve a suite of configurable cutting-edge electro- optical (EO), long-wave infrared (LWIR), and medium-wave infrared (MWIR) cameras, a hyperspectral imaging scanner, and a GPS and inertial measurement unit (IMU) for atmospheric and surface remote sensing. Its compatible sensor packages include NASA s 1,024 1,024 pixel LWIR quantum well infrared photodetector (QWIP) imager; a 60.5 megapixel BuckEye EO camera; and a fast (e.g. 200+ scanlines/s) and wide swath-width (e.g., 1,920+ pixels) CCD/InGaAs imager-based visible/near infrared reflectance (VNIR) and shortwave infrared (SWIR) imaging spectrometer. MAICSS records continuous precision georeferenced and time-tagged multisensor throughputs to mass storage devices at a high aggregate rate, typically 60 MB/s for its LWIR/EO payload. MAICSS is a complete stand-alone imaging server instrument with an easy-to-use software package for either autonomous data collection or interactive airborne operation. Advanced multisensor data acquisition and onboard processing software features have been implemented for MAICSS. With the onboard processing for real time image development, correction, histogram-equalization, compression, georeference, and

  6. Inverse problems and uncertainty quantification

    KAUST Repository

    Litvinenko, Alexander

    2013-12-18

    In a Bayesian setting, inverse problems and uncertainty quantification (UQ)— the propagation of uncertainty through a computational (forward) model—are strongly connected. In the form of conditional expectation the Bayesian update becomes computationally attractive. This is especially the case as together with a functional or spectral approach for the forward UQ there is no need for time- consuming and slowly convergent Monte Carlo sampling. The developed sampling- free non-linear Bayesian update is derived from the variational problem associated with conditional expectation. This formulation in general calls for further discretisa- tion to make the computation possible, and we choose a polynomial approximation. After giving details on the actual computation in the framework of functional or spectral approximations, we demonstrate the workings of the algorithm on a number of examples of increasing complexity. At last, we compare the linear and quadratic Bayesian update on the small but taxing example of the chaotic Lorenz 84 model, where we experiment with the influence of different observation or measurement operators on the update.

  7. Stochastic approach for radionuclides quantification

    Science.gov (United States)

    Clement, A.; Saurel, N.; Perrin, G.

    2018-01-01

    Gamma spectrometry is a passive non-destructive assay used to quantify radionuclides present in more or less complex objects. Basic methods using empirical calibration with a standard in order to quantify the activity of nuclear materials by determining the calibration coefficient are useless on non-reproducible, complex and single nuclear objects such as waste packages. Package specifications as composition or geometry change from one package to another and involve a high variability of objects. Current quantification process uses numerical modelling of the measured scene with few available data such as geometry or composition. These data are density, material, screen, geometric shape, matrix composition, matrix and source distribution. Some of them are strongly dependent on package data knowledge and operator backgrounds. The French Commissariat à l'Energie Atomique (CEA) is developing a new methodology to quantify nuclear materials in waste packages and waste drums without operator adjustment and internal package configuration knowledge. This method suggests combining a global stochastic approach which uses, among others, surrogate models available to simulate the gamma attenuation behaviour, a Bayesian approach which considers conditional probability densities of problem inputs, and Markov Chains Monte Carlo algorithms (MCMC) which solve inverse problems, with gamma ray emission radionuclide spectrum, and outside dimensions of interest objects. The methodology is testing to quantify actinide activity in different kind of matrix, composition, and configuration of sources standard in terms of actinide masses, locations and distributions. Activity uncertainties are taken into account by this adjustment methodology.

  8. Inverse Problems and Uncertainty Quantification

    KAUST Repository

    Litvinenko, Alexander

    2014-01-06

    In a Bayesian setting, inverse problems and uncertainty quantification (UQ) - the propagation of uncertainty through a computational (forward) modelare strongly connected. In the form of conditional expectation the Bayesian update becomes computationally attractive. This is especially the case as together with a functional or spectral approach for the forward UQ there is no need for time- consuming and slowly convergent Monte Carlo sampling. The developed sampling- free non-linear Bayesian update is derived from the variational problem associated with conditional expectation. This formulation in general calls for further discretisa- tion to make the computation possible, and we choose a polynomial approximation. After giving details on the actual computation in the framework of functional or spectral approximations, we demonstrate the workings of the algorithm on a number of examples of increasing complexity. At last, we compare the linear and quadratic Bayesian update on the small but taxing example of the chaotic Lorenz 84 model, where we experiment with the influence of different observation or measurement operators on the update.

  9. Uncertainty Quantification in Numerical Aerodynamics

    KAUST Repository

    Litvinenko, Alexander

    2017-05-16

    We consider uncertainty quantification problem in aerodynamic simulations. We identify input uncertainties, classify them, suggest an appropriate statistical model and, finally, estimate propagation of these uncertainties into the solution (pressure, velocity and density fields as well as the lift and drag coefficients). The deterministic problem under consideration is a compressible transonic Reynolds-averaged Navier-Strokes flow around an airfoil with random/uncertain data. Input uncertainties include: uncertain angle of attack, the Mach number, random perturbations in the airfoil geometry, mesh, shock location, turbulence model and parameters of this turbulence model. This problem requires efficient numerical/statistical methods since it is computationally expensive, especially for the uncertainties caused by random geometry variations which involve a large number of variables. In numerical section we compares five methods, including quasi-Monte Carlo quadrature, polynomial chaos with coefficients determined by sparse quadrature and gradient-enhanced version of Kriging, radial basis functions and point collocation polynomial chaos, in their efficiency in estimating statistics of aerodynamic performance upon random perturbation to the airfoil geometry [D.Liu et al \\'17]. For modeling we used the TAU code, developed in DLR, Germany.

  10. Bacterial Cell Wall Components

    Science.gov (United States)

    Ginsberg, Cynthia; Brown, Stephanie; Walker, Suzanne

    Bacterial cell-surface polysaccharides cells are surrounded by a variety of cell-surface structures that allow them to thrive in extreme environments. Components of the cell envelope and extracellular matrix are responsible for providing the cells with structural support, mediating intercellular communication, allowing the cells to move or to adhere to surfaces, protecting the cells from attack by antibiotics or the immune system, and facilitating the uptake of nutrients. Some of the most important cell wall components are polysaccharide structures. This review discusses the occurrence, structure, function, and biosynthesis of the most prevalent bacterial cell surface polysaccharides: peptidoglycan, lipopolysaccharide, arabinogalactan, and lipoarabinomannan, and capsular and extracellular polysaccharides. The roles of these polysaccharides in medicine, both as drug targets and as therapeutic agents, are also described.

  11. Upscaling surface energy fluxes over the North Slope of Alaska using airborne eddy-covariance measurements and environmental response functions

    Science.gov (United States)

    Serafimovich, Andrei; Metzger, Stefan; Hartmann, Jörg; Kohnert, Katrin; Zona, Donatella; Sachs, Torsten

    2018-03-01

    The objective of this study was to upscale airborne flux measurements of sensible heat and latent heat and to develop high resolution flux maps. In order to support the evaluation of coupled atmospheric/land-surface models we investigated spatial patterns of energy fluxes in relation to land-surface properties. We used airborne eddy-covariance measurements acquired by the POLAR 5 research aircraft in June-July 2012 to analyze surface fluxes. Footprint-weighted surface properties were then related to 21 529 sensible heat flux observations and 25 608 latent heat flux observations using both remote sensing and modelled data. A boosted regression tree technique was used to estimate environmental response functions between spatially and temporally resolved flux observations and corresponding biophysical and meteorological drivers. In order to improve the spatial coverage and spatial representativeness of energy fluxes we used relationships extracted across heterogeneous Arctic landscapes to infer high-resolution surface energy flux maps, thus directly upscaling the observational data. These maps of projected sensible heat and latent heat fluxes were used to assess energy partitioning in northern ecosystems and to determine the dominant energy exchange processes in permafrost areas. This allowed us to estimate energy fluxes for specific types of land cover, taking into account meteorological conditions. Airborne and modelled fluxes were then compared with measurements from an eddy-covariance tower near Atqasuk. Our results are an important contribution for the advanced, scale-dependent quantification of surface energy fluxes and provide new insights into the processes affecting these fluxes for the main vegetation types in high-latitude permafrost areas.

  12. Airborne lidar-based estimates of tropical forest structure in complex terrain: opportunities and trade-offs for REDD+

    Science.gov (United States)

    Leitold, Veronika; Keller, Michael; Morton, Douglas C; Cook, Bruce D; Shimabukuro, Yosio E

    2015-12-01

    Carbon stocks and fluxes in tropical forests remain large sources of uncertainty in the global carbon budget. Airborne lidar remote sensing is a powerful tool for estimating aboveground biomass, provided that lidar measurements penetrate dense forest vegetation to generate accurate estimates of surface topography and canopy heights. Tropical forest areas with complex topography present a challenge for lidar remote sensing. We compared digital terrain models (DTM) derived from airborne lidar data from a mountainous region of the Atlantic Forest in Brazil to 35 ground control points measured with survey grade GNSS receivers. The terrain model generated from full-density (~20 returns m -2 ) data was highly accurate (mean signed error of 0.19 ± 0.97 m), while those derived from reduced-density datasets (8 m -2 , 4 m -2 , 2 m -2 and 1 m -2 ) were increasingly less accurate. Canopy heights calculated from reduced-density lidar data declined as data density decreased due to the inability to accurately model the terrain surface. For lidar return densities below 4 m -2 , the bias in height estimates translated into errors of 80-125 Mg ha -1 in predicted aboveground biomass. Given the growing emphasis on the use of airborne lidar for forest management, carbon monitoring, and conservation efforts, the results of this study highlight the importance of careful survey planning and consistent sampling for accurate quantification of aboveground biomass stocks and dynamics. Approaches that rely primarily on canopy height to estimate aboveground biomass are sensitive to DTM errors from variability in lidar sampling density.

  13. Lung involvement quantification in chest radiographs

    International Nuclear Information System (INIS)

    Giacomini, Guilherme; Alvarez, Matheus; Oliveira, Marcela de; Miranda, Jose Ricardo A.; Pina, Diana R.; Pereira, Paulo C.M.; Ribeiro, Sergio M.

    2014-01-01

    Tuberculosis (TB) caused by Mycobacterium tuberculosis, is an infectious disease which remains a global health problem. The chest radiography is the commonly method employed to assess the TB's evolution. The methods for quantification of abnormalities of chest are usually performed on CT scans (CT). This quantification is important to assess the TB evolution and treatment and comparing different treatments. However, precise quantification is not feasible for the amount of CT scans required. The purpose of this work is to develop a methodology for quantification of lung damage caused by TB through chest radiographs. It was developed an algorithm for computational processing of exams in Matlab, which creates a lungs' 3D representation, with compromised dilated regions inside. The quantification of lung lesions was also made for the same patients through CT scans. The measurements from the two methods were compared and resulting in strong correlation. Applying statistical Bland and Altman, all samples were within the limits of agreement, with a confidence interval of 95%. The results showed an average variation of around 13% between the two quantification methods. The results suggest the effectiveness and applicability of the method developed, providing better risk-benefit to the patient and cost-benefit ratio for the institution. (author)

  14. Bacterial meningitis in Nottingham.

    OpenAIRE

    Ispahani, P.

    1983-01-01

    Records of 171 cases of bacterial meningitis admitted to Nottingham hospitals from January 1974 to June 1980 were reviewed. The distribution of organisms producing meningitis and the factors influencing mortality in different age groups were assessed. Neisseria meningitidis, Haemophilus influenzae and Streptococcus pneumoniae accounted for 69% of all proven cases. The overall mortality was 26% being lowest in patients with meningococcal meningitis (0%) and highest in those with pneumococcal m...

  15. HIGH RESOLUTION AIRBORNE SHALLOW WATER MAPPING

    Directory of Open Access Journals (Sweden)

    F. Steinbacher

    2012-07-01

    Full Text Available In order to meet the requirements of the European Water Framework Directive (EU-WFD, authorities face the problem of repeatedly performing area-wide surveying of all kinds of inland waters. Especially for mid-sized or small rivers this is a considerable challenge imposing insurmountable logistical efforts and costs. It is therefore investigated if large-scale surveying of a river system on an operational basis is feasible by employing airborne hydrographic laser scanning. In cooperation with the Bavarian Water Authority (WWA Weilheim a pilot project was initiated by the Unit of Hydraulic Engineering at the University of Innsbruck and RIEGL Laser Measurement Systems exploiting the possibilities of a new LIDAR measurement system with high spatial resolution and high measurement rate to capture about 70 km of riverbed and foreland for the river Loisach in Bavaria/Germany and the estuary and parts of the shoreline (about 40km in length of lake Ammersee. The entire area surveyed was referenced to classic terrestrial cross-section surveys with the aim to derive products for the monitoring and managing needs of the inland water bodies forced by the EU-WFD. The survey was performed in July 2011 by helicopter and airplane and took 3 days in total. In addition, high resolution areal images were taken to provide an optical reference, offering a wide range of possibilities on further research, monitoring, and managing responsibilities. The operating altitude was about 500 m to maintain eye-safety, even for the aided eye, the airspeed was about 55 kts for the helicopter and 75 kts for the aircraft. The helicopter was used in the alpine regions while the fixed wing aircraft was used in the plains and the urban area, using appropriate scan rates to receive evenly distributed point clouds. The resulting point density ranged from 10 to 25 points per square meter. By carefully selecting days with optimum water quality, satisfactory penetration down to the river

  16. Assessment of probiotic viability during Cheddar cheese manufacture and ripening using propidium monoazide-PCR quantification

    Directory of Open Access Journals (Sweden)

    Emilie eDesfossés-Foucault

    2012-10-01

    Full Text Available The use of a suitable food carrier such as cheese could significantly enhance probiotic viability during storage. The main goal of this study was to assess viability of commercial probiotic strains during Cheddar cheesemaking and ripening (four to six months by comparing the efficiency of microbiological and molecular approaches. Molecular methods such as quantitative PCR (qPCR allow bacterial quantification, and DNA-blocking molecules such as propidium monoazide (PMA select only the living cells’ DNA. Cheese samples were manufactured with a lactococci starter and with one of three probiotic strains (Bifidobacterium animalis subsp. lactis BB-12, Lactobacillus rhamnosus RO011 or Lactobacillus helveticus RO052 or a mixed culture containing B. animalis subsp. lactis BB-12 and L. helveticus RO052 (MC1, both lactobacilli strains (MC2 or all three strains (MC3. DNA extractions were then carried out on PMA-treated and non-treated cell pellets in order to assess PMA treatment efficiency, followed by quantification using the 16S rRNA gene, the elongation factor Tu gene (tuf or the transaldolase gene (tal. Results with intact/dead ratios of bacteria showed that PMA-treated cheese samples had a significantly lower bacterial count than non-treated DNA samples (P<0.005, confirming that PMA did eliminate dead bacteria from PCR quantification. For both quantification methods, the addition of probiotic strains seemed to accelerate the loss of lactococci viability in comparison to control cheese samples, especially when L. helveticus RO052 was added. Viability of all three probiotic strains was also significantly reduced in mixed culture cheese samples (P<0.0001, B. animalis subsp. lactis BB-12 being the most sensitive to the presence of other strains. However, all probiotic strains did retain their viability (log nine cfu/g of cheese throughout ripening. This study was successful in monitoring living probiotic species in Cheddar cheese samples through PMA-qPCR.

  17. Neglected bacterial zoonoses.

    Science.gov (United States)

    Chikeka, I; Dumler, J S

    2015-05-01

    Bacterial zoonoses comprise a group of diseases in humans or animals acquired by direct contact with or by oral consumption of contaminated animal materials, or via arthropod vectors. Among neglected infections, bacterial zoonoses are among the most neglected given emerging data on incidence and prevalence as causes of acute febrile illness, even in areas where recognized neglected tropical diseases occur frequently. Although many other bacterial infections could also be considered in this neglected category, five distinct infections stand out because they are globally distributed, are acute febrile diseases, have high rates of morbidity and case fatality, and are reported as commonly as malaria, typhoid or dengue virus infections in carefully designed studies in which broad-spectrum diagnoses are actively sought. This review will focus attention on leptospirosis, relapsing fever borreliosis and rickettsioses, including scrub typhus, murine typhus and spotted fever group rickettsiosis. Of greatest interest is the lack of distinguishing clinical features among these infections when in humans, which confounds diagnosis where laboratory confirmation is lacking, and in regions where clinical diagnosis is often attributed to one of several perceived more common threats. As diseases such as malaria come under improved control, the real impact of these common and under-recognized infections will become evident, as will the requirement for the strategies and allocation of resources for their control. Copyright © 2015 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

  18. Bacterial growth kinetics

    International Nuclear Information System (INIS)

    Boonkitticharoen, V.; Ehrhardt, J.C.; Kirchner, P.T.

    1989-01-01

    Quantitative measurement of bacterial growth may be made using a radioassay technique. This method measures, by scintillation counting, the 14 CO 2 derived from the bacterial metabolism of a 14 C-labeled substrate. Mathematical growth models may serve as reliable tools for estimation of the generation rate constant (or slope of the growth curve) and provide a basis for evaluating assay performance. Two models, i.e., exponential and logistic, are proposed. Both models yielded an accurate fit to the data from radioactive measurement of bacterial growth. The exponential model yielded high precision values of the generation rate constant, with an average relative standard deviation of 1.2%. Under most conditions the assay demonstrated no changes in the slopes of growth curves when the number of bacteria per inoculation was changed. However, the radiometric assay by scintillation method had a growth-inhibiting effect on a few strains of bacteria. The source of this problem was thought to be hypersensitivity to trace amounts of toluene remaining on the detector

  19. Reverse transcriptase real-time PCR for detection and quantification of viable Campylobacter jejuni directly from poultry faecal samples.

    Science.gov (United States)

    Bui, Xuan Thanh; Wolff, Anders; Madsen, Mogens; Bang, Dang Duong

    2012-01-01

    Campylobacter spp. is the most common cause of bacterial diarrhoea in humans worldwide. Therefore, rapid and reliable methods for detection and quantification of this pathogen are required. In this study, we have developed a reverse transcription quantitative real-time PCR (RT-qPCR) for detection and quantification of viable Campylobacter jejuni directly from chicken faecal samples. The results of this method and a DNA-based quantitative real-time PCR (qPCR) method were compared with those of a bacterial culture method. Using bacterial culture and RT-qPCR methods, viable C. jejuni cells could be detected for up to 5 days in both the C. jejuni spiked and the naturally contaminated faecal samples. We found that no RT-qPCR signals were obtained when viable C. jejuni cells could not be counted by the culture method. In contrast, using a DNA-based qPCR method, dead or non-viable Campylobacter cells were detected, and all tested samples were positive, even after 20 days of storage. The developed method for detection and quantification of viable C. jejuni cells directly from chicken faecal samples can be used for further research on the survival of Campylobacter in the environment. Copyright © 2011 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  20. Airborne particulate matter (PM) filter analysis and modeling by total reflection X-ray fluorescence (TXRF) and X-ray standing wave (XSW).

    Science.gov (United States)

    Borgese, L; Salmistraro, M; Gianoncelli, A; Zacco, A; Lucchini, R; Zimmerman, N; Pisani, L; Siviero, G; Depero, L E; Bontempi, E

    2012-01-30

    This work is presented as an improvement of a recently introduced method for airborne particulate matter (PM) filter analysis [1]. X-ray standing wave (XSW) and total reflection X-ray fluorescence (TXRF) were performed with a new dedicated laboratory instrumentation. The main advantage of performing both XSW and TXRF, is the possibility to distinguish the nature of the sample: if it is a small droplet dry residue, a thin film like or a bulk sample. Another advantage is related to the possibility to select the angle of total reflection to make TXRF measurements. Finally, the possibility to switch the X-ray source allows to measure with more accuracy lighter and heavier elements (with a change in X-ray anode, for example from Mo to Cu). The aim of the present study is to lay the theoretical foundation of the new proposed method for airborne PM filters quantitative analysis improving the accuracy and efficiency of quantification by means of an external standard. The theoretical model presented and discussed demonstrated that airborne PM filters can be considered as thin layers. A set of reference samples is prepared in laboratory and used to obtain a calibration curve. Our results demonstrate that the proposed method for quantitative analysis of air PM filters is affordable and reliable without the necessity to digest filters to obtain quantitative chemical analysis, and that the use of XSW improve the accuracy of TXRF analysis. Copyright © 2011 Elsevier B.V. All rights reserved.

  1. Does airborne nickel exposure induce nickel sensitization?

    Science.gov (United States)

    Mann, Eugen; Ranft, Ulrich; Eberwein, Georg; Gladtke, Dieter; Sugiri, Dorothee; Behrendt, Heidrun; Ring, Johannes; Schäfer, Torsten; Begerow, Jutta; Wittsiepe, Jürgen; Krämer, Ursula; Wilhelm, Michael

    2010-06-01

    Nickel is one of the most prevalent causes of contact allergy in the general population. This study focuses on human exposure to airborne nickel and its potential to induce allergic sensitization. The study group consisted of 309 children at school-starter age living in the West of Germany in the vicinity of two industrial sources and in a rural town without nearby point sources of nickel. An exposure assessment of nickel in ambient air was available for children in the Ruhr district using routinely monitored ambient air quality data and dispersion modelling. Internal nickel exposure was assessed by nickel concentrations in morning urine samples of the children. The observed nickel sensitization prevalence rates varied between 12.6% and 30.7%. Statistically significant associations were showed between exposure to nickel in ambient air and urinary nickel concentration as well as between urinary nickel concentration and nickel sensitization. Furthermore, an elevated prevalence of nickel sensitization was associated with exposure to increased nickel concentrations in ambient air. The observed associations support the assumption that inhaled nickel in ambient air might be a risk factor for nickel sensitization; further studies in larger collectives are necessary.

  2. Airborne silica levels in an urban area

    Energy Technology Data Exchange (ETDEWEB)

    De Berardis, B. [Dipartimento di Tecnologie e Salute, Istituto Superiore di Sanita, Viale Regina Elena, 299, 00161 Rome (Italy)]. E-mail: barbara.deberardis@iss.it; Incocciati, E. [CONTARP Consulenza Tecnica Accertamento Rischi e Prevenzione, INAIL Direzione Generale, 00143 Rome (Italy); Massera, S. [CONTARP Consulenza Tecnica Accertamento Rischi e Prevenzione, INAIL Direzione Generale, 00143 Rome (Italy); Gargaro, G. [CONTARP Consulenza Tecnica Accertamento Rischi e Prevenzione, INAIL Direzione Generale, 00143 Rome (Italy); Paoletti, L. [Dipartimento di Tecnologie e Salute, Istituto Superiore di Sanita, Viale Regina Elena, 299, 00161 Rome (Italy)

    2007-09-01

    In order to evaluate the exposure levels of the general population we studied the concentrations of silica particles in the inhalable particulate fraction (PM10) in different meteorological-climate periods in an urban area of Rome. In order to determine the concentration and the granulometric spectrum of silica particles, PM10 sampled by a cascade impactor was analysed by X-ray diffractometry (XRD) and by scanning electron microscopy equipped with a thin-window system for X-ray microanalysis (SEM/EDX). Over the period September 2004-October 2005 the abundance of silica particles as evaluated by SEM/EDX ranged from 1.6 to 10.4% of the total PM10 particulate, with a weight concentration of free crystalline silica, evaluated by XRD, in the range 0.25-2.87 {mu}g/m{sup 3}. The mean diameter of silica particles ranged from 0.3 to 10.5 {mu}m, with more than 87% of particles having a diameter of less than 2.5 {mu}m. The correlations between SEM/EDX and XRD data seem to suggest that the airborne silica particles in the urban location studied were mainly in the form crystalline silica. A strong relationship was found between the meteorological-climate conditions and the concentration level of free crystalline silica. This result suggests that the Southern winds from the Sahara desert carry an important amount of silica particles into Mediterranean Europe.

  3. Robust automatic camera pointing for airborne surveillance

    Science.gov (United States)

    Dwyer, David; Wren, Lee; Thornton, John; Bonsor, Nigel

    2002-08-01

    Airborne electro-optic surveillance from a moving platform currently requires regular interaction from a trained operator. Even simple tasks such as fixating on a static point on the ground can demand constant adjustment of the camera orientation to compensate for platform motion. In order to free up operator time for other tasks such as navigation and communication with ground assets, an automatic gaze control system is needed. This paper describes such a system, based purely on tracking points within the video image. A number of scene points are automatically selected and their inter-frame motion tracked. The scene motion is then estimated using a model of a planar projective transform. For reliable and accurate camera pointing, the modeling of the scene motion must be robust to common problems such as scene point obscuration, objects moving independently within the scene and image noise. This paper details a COTS based system for automatic camera fixation and describes ways of preventing objects moving in the scene or poor motion estimates from corrupting the scene motion model.

  4. Diversity and seasonal dynamics of airborne archaea

    Science.gov (United States)

    Fröhlich-Nowoisky, J.; Ruzene Nespoli, C.; Pickersgill, D. A.; Galand, P. E.; Müller-Germann, I.; Nunes, T.; Gomes Cardoso, J.; Almeida, S. M.; Pio, C.; Andreae, M. O.; Conrad, R.; Pöschl, U.; Després, V. R.

    2014-11-01

    Archaea are widespread and abundant in many terrestrial and aquatic environments, and are thus outside extreme environments, accounting for up to ~10% of the prokaryotes. Compared to bacteria and other microorganisms, however, very little is known about the abundance, diversity, and dispersal of archaea in the atmosphere. By means of DNA analysis and Sanger sequencing targeting the 16S rRNA (435 sequences) and amoA genes in samples of air particulate matter collected over 1 year at a continental sampling site in Germany, we obtained first insights into the seasonal dynamics of airborne archaea. The detected archaea were identified as Thaumarchaeota or Euryarchaeota, with soil Thaumarchaeota (group I.1b) being present in all samples. The normalized species richness of Thaumarchaeota correlated positively with relative humidity and negatively with temperature. This together with an increase in bare agricultural soil surfaces may explain the diversity peaks observed in fall and winter. The detected Euryarchaeota were mainly predicted methanogens with a low relative frequency of occurrence. A slight increase in their frequency during spring may be linked to fertilization processes in the surrounding agricultural fields. Comparison with samples from the Cape Verde islands (72 sequences) and from other coastal and continental sites indicates that the proportions of Euryarchaeota are enhanced in coastal air, which is consistent with their suggested abundance in marine surface waters. We conclude that air transport may play an important role in the dispersal of archaea, including assumed ammonia-oxidizing Thaumarchaeota and methanogens.

  5. A 3D airborne ultrasound scanner

    Science.gov (United States)

    Capineri, L.; Masotti, L.; Rocchi, S.

    1998-06-01

    This work investigates the feasibility of an ultrasound scanner designed to reconstruct three-dimensional profiles of objects in air. There are many industrial applications in which it is important to obtain quickly and accurately the digital reconstruction of solid objects with contactless methods. The final aim of this project was the profile reconstruction of shoe lasts in order to eliminate the mechanical tracers from the reproduction process of shoe prototypes. The feasibility of an ultrasonic scanner was investigated in laboratory conditions on wooden test objects with axial symmetry. A bistatic system based on five airborne polyvinylidenedifluoride (PVDF) transducers was mechanically moved to emulate a cylindrical array transducer that can host objects of maximum width and height 20 cm and 40 cm respectively. The object reconstruction was based on a simplified version of the synthetic aperture focusing technique (SAFT): the time of flight (TOF) of the first in time echo for each receiving transducer was taken into account, a coarse spatial sampling of the ultrasonic field reflected on the array transducer was delivered and the reconstruction algorithm was based on the ellipsoidal backprojection. Measurements on a wooden cone section provided submillimetre accuracy in a controlled environment.

  6. RADIOMETRIC CALIBRATION OF AIRBORNE LASER SCANNING DATA

    Directory of Open Access Journals (Sweden)

    Pilarska Magdalena

    2016-12-01

    Full Text Available Airborne laser scanning (ALS is widely used passive remote sensing technique. The radiometric calibration of ALS data is presented in this article. This process is a necessary element in data processing since it eliminates the influence of the external factors on the obtained values of radiometric features such as range and incidence angle. The datasets were captured with three different laser scanners; since each of these operates at a different wavelength (532, 106 4 and 1550 nm this makes the experiment more interesting. Radiometric calibration is a complex process, and a short theoretical background is therefore provided at the beginning of the article. The applied calibration procedure relies on areas with known reflectivity . The calibration region s should exhibit s table radiometric properties, therefore asphalt is used to calibrate each dataset and calculate a calibration constant for each flight block (wavelength independently . Following this, the results of radiometric calibration , reflectance and backscattering coefficient, are presented and discussed in detail. Finally, the obtained reflectance values are compared with spectral characteristics. It could be shown that the reflectance values which result from radiometric calibration are similar to values presented on spectral characteristics.

  7. Airborne effluent control at uranium mills

    International Nuclear Information System (INIS)

    Sears, M.B.

    1976-01-01

    The Oak Ridge National Laboratory has made an engineering cost--environmental benefit study of radioactive waste treatment systems for decreasing the amount of radioactive materials released from uranium ore processing mills. This paper summarizes the results of the study which pertain to the control and/or abatement of airborne radioactive materials from the mill processes. The tailings area is not included. Present practices in the uranium milling industry, with particular emphasis on effluent control and waste management, have been surveyed. A questionnaire was distributed to each active mill in the United States. Replies were received from about 75 percent of the mill operators. Visits were made to six operating uranium mills that were selected because they represented the different processes in use today and the newest, most modern in mill designs. Discussions were held with members of the Region IV Office of NRC and the Grand Junction Office of ERDA. Nuclear Science Abstracts, as well as other sources, were searched for literature pertinent to uranium mill processes, effluent control, and waste management

  8. Airborne radiometric: Data evaluation and calibration

    International Nuclear Information System (INIS)

    Wendt, I.; Sengpiel, K.P.; Lenz, H.

    1984-01-01

    The airborne geophysical system of the BGR (German Geological Survey) consists of a helicopter equipped with an electromagnetic system with two transmittors and two receivers, a proton resonance magnetometer and a 16 L NaJ-crystal with four channel recording. All these data together with navigation data and flight altitude above ground are recorded each second on a nine track magnetic tape for further data evaluation. Different corrections have to be applied to the rough data such as: smoothing by means of a digital filter to reduce statistical noise, altitude correction, Compton-correction, and drift correction (cross-profile evaluation). Then the corrected measuring data are combined with the navigation data in order to be able to produce iso-line maps. The final results are presented as: line plots for U, Th, and K (and EM-data and magnetometer data); actual flight line plots; iso-line maps for U, Th, and K; iso-line maps for conductivity; depth of conducting layer; and magnetometry maps. The procedures of correction and evaluation of the above mentioned data as well as the calibration of the NaJ-detector in terms of ppm U, Th, and %K are dicussed in the paper. (author)

  9. Composite mapping experiences in airborne gamma spectrometry.

    Science.gov (United States)

    Bucher, B

    2014-08-01

    During an international intercomparison exercise of airborne gamma spectrometry held in Switzerland 2007 teams from Germany, France and Switzerland were proving their capabilities. One of the tasks was the composite mapping of an area around Basel. Each team was mainly covering the part of its own country at its own flying procedures. They delivered the evaluated data in a data format agreed in advance. The quantities to be delivered were also defined in advance. Nevertheless, during the process to put the data together a few questions raised: Which dose rate was meant? Had the dose rate to be delivered with or without cosmic contribution? Activity per dry or wet mass? Which coordinate system was used? Finally, the data could be put together in one map. For working procedures in case of an emergency, quantities of interest and exchange data format have to be defined in advance. But the procedures have also to be proved regularly. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  10. Flow cytometric bacterial cell counts challenge conventional heterotrophic plate counts for routine microbiological drinking water monitoring.

    Science.gov (United States)

    Van Nevel, S; Koetzsch, S; Proctor, C R; Besmer, M D; Prest, E I; Vrouwenvelder, J S; Knezev, A; Boon, N; Hammes, F

    2017-04-15

    Drinking water utilities and researchers continue to rely on the century-old heterotrophic plate counts (HPC) method for routine assessment of general microbiological water quality. Bacterial cell counting with flow cytometry (FCM) is one of a number of alternative methods that challenge this status quo and provide an opportunity for improved water quality monitoring. After more than a decade of application in drinking water research, FCM methodology is optimised and established for routine application, supported by a considerable amount of data from multiple full-scale studies. Bacterial cell concentrations obtained by FCM enable quantification of the entire bacterial community instead of the minute fraction of cultivable bacteria detected with HPC (typically water samples per day, depending on the laboratory and selected staining procedure(s). Moreover, many studies have shown FCM total (TCC) and intact (ICC) cell concentrations to be reliable and robust process variables, responsive to changes in the bacterial abundance and relevant for characterising and monitoring drinking water treatment and distribution systems. The purpose of this critical review is to initiate a constructive discussion on whether FCM could replace HPC in routine water quality monitoring. We argue that FCM provides a faster, more descriptive and more representative quantification of bacterial abundance in drinking water. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Concentration and Viability of Airborne Bacteria Over the Kuroshio Extension Region in the Northwestern Pacific Ocean: Data From Three Cruises

    Science.gov (United States)

    Hu, Wei; Murata, Kotaro; Fukuyama, Shinichiro; Kawai, Yoshimi; Oka, Eitarou; Uematsu, Mitsuo; Zhang, Daizhou

    2017-12-01

    Airborne bacteria have been shown to act as condensation and ice nuclei in mixed-phase clouds and are consequently hypothesized to have significant effects on atmospheric processes and even the global climate. However, few data are available regarding their concentration and variation in the air over the open ocean. Aerosol samples were collected during three cruises in the early summers of 2013, 2014, and 2016 over the Kuroshio Extension region of the northwest Pacific Ocean. The concentrations of viable and nonviable bacterial cells in the marine surface air were quantified using epifluorescence enumeration with the LIVE/DEAD BacLight stain. The concentrations of total bacteria varied between 1.0 × 104 and 2.5 × 105 cells m-3 and averaged 5.2 × 104, 1.0 × 105, and 7.5 × 104 cells m-3 in the three respective cruises. The viabilities, i.e., the ratios of the concentration of viable bacterial cells to that of total bacterial cells, ranged from 80% to 100% (average 93%), and the respective means were 93%, 89%, and 96% in the cruises. The total bacterial concentration had a close correlation with the wind speed near the sea surface, and the bacterial viability correlated negatively with the air temperature, sea surface temperature, and concentration of coarse particles (size > 1 μm). The deposition and sea spray fluxes of bacteria were roughly estimated as hundreds of cells m-2 s-1 on average. The limited data on bacterial concentration and viability from the three cruises indicate the rapid air-sea exchange of bacteria over the Kuroshio Extension region of the northwest Pacific Ocean.

  12. Effects of nitric oxide and nitrogen dioxide on bacterial growth

    Science.gov (United States)

    Mancinelli, R. L.; Mckay, C. P.

    1983-01-01

    While it is generally thought that the bactericidal effects of NO and NO2 derive from their reaction with water to form nitrous and nitric acids (Shank et al., 1962), this appears to be true only at high concentrations. The data presented here suggest that at low NO and NO2 concentrations, acids are not present in high enough concentrations to act as toxic agents. Reference is made to a study by Grant et al. (1979), which found that exposing acid forest soil to 1 ppm of NO2 did not cause the soil pH to drop. The results presented here show that at low concentrations of NO and NO2, the NO is bacteriostatic for some organisms and not for others, whereas NO2 may protect some bacteria from the inhibitory effects of NO. Since it has been shown that bacteria can divide while airborne (Dimmick et al., 1979), the present results suggest that NO at the low concentrations found in the atmosphere can select for resistant bacteria in the air and affect the viable airborne bacterial population.

  13. Uncertainty quantification for environmental models

    Science.gov (United States)

    Hill, Mary C.; Lu, Dan; Kavetski, Dmitri; Clark, Martyn P.; Ye, Ming

    2012-01-01

    Environmental models are used to evaluate the fate of fertilizers in agricultural settings (including soil denitrification), the degradation of hydrocarbons at spill sites, and water supply for people and ecosystems in small to large basins and cities—to mention but a few applications of these models. They also play a role in understanding and diagnosing potential environmental impacts of global climate change. The models are typically mildly to extremely nonlinear. The persistent demand for enhanced dynamics and resolution to improve model realism [17] means that lengthy individual model execution times will remain common, notwithstanding continued enhancements in computer power. In addition, high-dimensional parameter spaces are often defined, which increases the number of model runs required to quantify uncertainty [2]. Some environmental modeling projects have access to extensive funding and computational resources; many do not. The many recent studies of uncertainty quantification in environmental model predictions have focused on uncertainties related to data error and sparsity of data, expert judgment expressed mathematically through prior information, poorly known parameter values, and model structure (see, for example, [1,7,9,10,13,18]). Approaches for quantifying uncertainty include frequentist (potentially with prior information [7,9]), Bayesian [13,18,19], and likelihood-based. A few of the numerous methods, including some sensitivity and inverse methods with consequences for understanding and quantifying uncertainty, are as follows: Bayesian hierarchical modeling and Bayesian model averaging; single-objective optimization with error-based weighting [7] and multi-objective optimization [3]; methods based on local derivatives [2,7,10]; screening methods like OAT (one at a time) and the method of Morris [14]; FAST (Fourier amplitude sensitivity testing) [14]; the Sobol' method [14]; randomized maximum likelihood [10]; Markov chain Monte Carlo (MCMC) [10

  14. A flow cytometric technique for quantification and differentiation of bacteria in bulk tank milk

    DEFF Research Database (Denmark)

    Holm, C.; Mathiasen, T.; Jespersen, Lene

    2004-01-01

    AIMS: The present study describes a flow cytometric technique for quantification and differentiation of bacteria in bulk tank milk according to the main cause of elevated counts. METHODS AND RESULTS: A total of 75 Danish bulk tank milk samples exceeding the grading level of 3.0 x 10(4) CFU ml(-1...... parameters were as follows: staining with Oregon Green conjugated wheat germ agglutinin that binds to the cell wall of bacteria, staining with hexidium iodide that binds to all bacterial DNA, the flow cytometric forward scatter and the flow cytometric side scatter. Three regions in the flow cytometric plot...

  15. Open Source Software Reuse in the Airborne Cloud Computing Environment

    Science.gov (United States)

    Khudikyan, S. E.; Hart, A. F.; Hardman, S.; Freeborn, D.; Davoodi, F.; Resneck, G.; Mattmann, C. A.; Crichton, D. J.

    2012-12-01

    Earth science airborne missions play an important role in helping humans understand our climate. A challenge for airborne campaigns in contrast to larger NASA missions is that their relatively modest budgets do not permit the ground-up development of data management tools. These smaller missions generally consist of scientists whose primary focus is on the algorithmic and scientific aspects of the mission, which often leaves data management software and systems to be addressed as an afterthought. The Airborne Cloud Computing Environment (ACCE), developed by the Jet Propulsion Laboratory (JPL) to support Earth Science Airborne Program, is a reusable, multi-mission data system environment for NASA airborne missions. ACCE provides missions with a cloud-enabled platform for managing their data. The platform consists of a comprehensive set of robust data management capabilities that cover everything from data ingestion and archiving, to algorithmic processing, and to data delivery. Missions interact with this system programmatically as well as via browser-based user interfaces. The core components of ACCE are largely based on Apache Object Oriented Data Technology (OODT), an open source information integration framework at the Apache Software Foundation (ASF). Apache OODT is designed around a component-based architecture that allows for selective combination of components to create highly configurable data management systems. The diverse and growing community that currently contributes to Apache OODT fosters on-going growth and maturation of the software. ACCE's key objective is to reduce cost and risks associated with developing data management systems for airborne missions. Software reuse plays a prominent role in mitigating these problems. By providing a reusable platform based on open source software, ACCE enables airborne missions to allocate more resources to their scientific goals, thereby opening the doors to increased scientific discovery.

  16. NMR study of the 1-13C glucose colon bacterial metabolism

    International Nuclear Information System (INIS)

    Briet, F.; Flourie, B.; Pochart, P.; Rambaud, J.C.; Desjeux, J.F.; Dallery, L.; Grivet, J.P.

    1994-01-01

    The aim of the study is to examine in-vitro and by nuclear magnetic resonance the biological pathways for the fermentation of the 1- 13 C labelled glucose (99 atoms percent) by human colon bacteria. The preparation of the bacterial suspension and the glucose degradation kinetics are presented; the NMR analysis sensitivity and quantification features are discussed and results are presented. 2 figs., 1 ref

  17. Analysis of Bacterial Vaginosis-Related Amines in Vaginal Fluid by Gas Chromatography and Mass Spectrometry

    OpenAIRE

    Wolrath, Helen; Forsum, Urban; Larsson, P. G.; Borén, Hans

    2001-01-01

    The presence of various amines in vaginal fluid from women with malodorous vaginal discharge has been reported before. The investigations have used several techniques to identify the amines. However, an optimized quantification, together with a sensitive analysis method in connection with a diagnostic procedure for vaginal discharge, including the syndrome of bacterial vaginosis, as defined by the accepted “gold standard,” has not been done before. We now report a sensitive gas chromatographi...

  18. Elementary analysis of airborne dust (preliminary findings of the AFR Coordinated Airborne Dust Programme (LVPr))

    International Nuclear Information System (INIS)

    1983-03-01

    In March 1981 the systematic measuring of 15 elements of airborne dust was started in the Coordinated Airborne Dust Program (LVPr) by the Association for the Promotion of Radionuclide Technology (AFR). The sampling was done under comparable conditions at five selected places within the Federal Republic of Germany by using especially developed large-filter High Volume Samplers. The aim of this research is to establish the foundation for further investigations on the effects of the current given element concentrations on human life. When the results of the first half-year (summer period) were in hand, these element concentrations, which had been analysed using different methods, were presented to a group of experts, also with the experience gained with the analytical methods, in order to critically assess procedure and philosophy of this study. This evaluation was done on the occasion of a colloquium on Jun 29th, 1982 at the Karlsruhe Nuclear Research Centre. The presented AFR-Report contains the papers and the discussions of this meeting as well as the average element data with respect to the sampling time between 15th and 40th week of the year 1981. The discussion contributions presented here correspond to the essential statements that have been given and recorded. A total classification of all data relating to the whole sampling time of the LVPr will be given in AFR-Report No. 007. (orig.) [de

  19. Bacterial and fungal aerosols in the work environment of cleaners

    Directory of Open Access Journals (Sweden)

    Małgorzata Gołofit-Szymczak

    2015-12-01

    Full Text Available Background: Cleaning services are carried out in almost all sectors and branches of industry. Due to the above, cleaners are exposed to various harmful biological agents, depending on the tasks performed and the commercial sector involved. The aim of this study was to assess the exposure of cleaning workers to biological agents based on quantitative and qualitative characteristics of airborne microflora. Material and methods: A six-stage Andersen sampler was used to collect bioaerosols during the cleaning activities in different workplaces, including schools, offices, car services, healthy services and shops. Standard Petri dishes filled with blood trypticase soy agar and malt extract agar were used for bacterial and fungal sampling, respectively. Results: The bioaerosol concentration values obtained during testing of selected workposts of cleaners were lower than the Polish recommended threshold limit values for microorganisms concentrations in public service. The most prevalent bacterial species in studied places were Gram-positive cocci (mainly of genera Micrococcus, Staphylococcus and endospore-forming Gram-positive rods (mainly of genera Bacillus. Among the most common fungal species were those from genera Penicillium and Aspergillus. The size distribution analysis revealed that bioaerosols present in the air of workposts at shops, schools and car services may be responsible for nose and eye mucosa irritation and allergic reactions in the form of asthma or allergic inflammation in the cleaning workers. Conclusions: The study shows that occupational activities of cleaning workers are associated with exposure to airborne biological agents classified into risk groups, 1. and 2., according to their level of infection risk, posing respiratory hazard. Med Pr 2015;66(6:779–791

  20. Beryllium solubility in occupational airborne particles: Sequential extraction procedure and workplace application.

    Science.gov (United States)

    Rousset, Davy; Durand, Thibaut

    2016-01-01

    Modification of an existing sequential extraction procedure for inorganic beryllium species in the particulate matter of emissions and in working areas is described. The speciation protocol was adapted to carry out beryllium extraction in closed-face cassette sampler to take wall deposits into account. This four-step sequential extraction procedure aims to separate beryllium salts, metal, and oxides from airborne particles for individual quantification. Characterization of the beryllium species according to their solubility in air samples may provide information relative to toxicity, which is potentially related to the different beryllium chemical forms. Beryllium salts (BeF(2), BeSO(4)), metallic beryllium (Bemet), and beryllium oxide (BeO) were first individually tested, and then tested in mixtures. Cassettes were spiked with these species and recovery rates were calculated. Quantitative analyses with matched matrix were performed using inductively coupled plasma mass spectrometry (ICP-MS). Method Detection Limits (MDLs) were calculated for the four matrices used in the different extraction steps. In all cases, the MDL was below 4.2 ng/sample. This method is appropriate for assessing occupational exposure to beryllium as the lowest recommended threshold limit values are 0.01 µg.m(-3) in France([) (1) (]) and 0.05 µg.m(-3) in the USA.([ 2 ]) The protocol was then tested on samples from French factories where occupational beryllium exposure was suspected. Beryllium solubility was variable between factories and among the same workplace between different tasks.

  1. Elliptic Cylinder Airborne Sampling and Geostatistical Mass Balance Approach for Quantifying Local Greenhouse Gas Emissions.

    Science.gov (United States)

    Tadić, Jovan M; Michalak, Anna M; Iraci, Laura; Ilić, Velibor; Biraud, Sébastien C; Feldman, Daniel R; Bui, Thaopaul; Johnson, Matthew S; Loewenstein, Max; Jeong, Seongeun; Fischer, Marc L; Yates, Emma L; Ryoo, Ju-Mee

    2017-09-05

    In this study, we explore observational, experimental, methodological, and practical aspects of the flux quantification of greenhouse gases from local point sources by using in situ airborne observations, and suggest a series of conceptual changes to improve flux estimates. We address the major sources of uncertainty reported in previous studies by modifying (1) the shape of the typical flight path, (2) the modeling of covariance and anisotropy, and (3) the type of interpolation tools used. We show that a cylindrical flight profile offers considerable advantages compared to traditional profiles collected as curtains, although this new approach brings with it the need for a more comprehensive subsequent analysis. The proposed flight pattern design does not require prior knowledge of wind direction and allows for the derivation of an ad hoc empirical correction factor to partially alleviate errors resulting from interpolation and measurement inaccuracies. The modified approach is applied to a use-case for quantifying CH 4 emission from an oil field south of San Ardo, CA, and compared to a bottom-up CH 4 emission estimate.

  2. Forest understory trees can be segmented accurately within sufficiently dense airborne laser scanning point clouds.

    Science.gov (United States)

    Hamraz, Hamid; Contreras, Marco A; Zhang, Jun

    2017-07-28

    Airborne laser scanning (LiDAR) point clouds over large forested areas can be processed to segment individual trees and subsequently extract tree-level information. Existing segmentation procedures typically detect more than 90% of overstory trees, yet they barely detect 60% of understory trees because of the occlusion effect of higher canopy layers. Although understory trees provide limited financial value, they are an essential component of ecosystem functioning by offering habitat for numerous wildlife species and influencing stand development. Here we model the occlusion effect in terms of point density. We estimate the fractions of points representing different canopy layers (one overstory and multiple understory) and also pinpoint the required density for reasonable tree segmentation (where accuracy plateaus). We show that at a density of ~170 pt/m² understory trees can likely be segmented as accurately as overstory trees. Given the advancements of LiDAR sensor technology, point clouds will affordably reach this required density. Using modern computational approaches for big data, the denser point clouds can efficiently be processed to ultimately allow accurate remote quantification of forest resources. The methodology can also be adopted for other similar remote sensing or advanced imaging applications such as geological subsurface modelling or biomedical tissue analysis.

  3. Taking Stock of Circumboreal Forest Carbon With Ground Measurements, Airborne and Spaceborne LiDAR

    Science.gov (United States)

    Neigh, Christopher S. R.; Nelson, Ross F.; Ranson, K. Jon; Margolis, Hank A.; Montesano, Paul M.; Sun, Guoqing; Kharuk, Viacheslav; Naesset, Erik; Wulder, Michael A.; Andersen, Hans-Erik

    2013-01-01

    The boreal forest accounts for one-third of global forests, but remains largely inaccessible to ground-based measurements and monitoring. It contains large quantities of carbon in its vegetation and soils, and research suggests that it will be subject to increasingly severe climate-driven disturbance. We employ a suite of ground-, airborne- and space-based measurement techniques to derive the first satellite LiDAR-based estimates of aboveground carbon for the entire circumboreal forest biome. Incorporating these inventory techniques with uncertainty analysis, we estimate total aboveground carbon of 38 +/- 3.1 Pg. This boreal forest carbon is mostly concentrated from 50 to 55degN in eastern Canada and from 55 to 60degN in eastern Eurasia. Both of these regions are expected to warm >3 C by 2100, and monitoring the effects of warming on these stocks is important to understanding its future carbon balance. Our maps establish a baseline for future quantification of circumboreal carbon and the described technique should provide a robust method for future monitoring of the spatial and temporal changes of the aboveground carbon content.

  4. Mutagenicity and clastogenicity of native airborne particulate matter samples collected under industrial, urban or rural influence.

    Science.gov (United States)

    Lepers, C; Dergham, M; Armand, L; Billet, S; Verdin, A; Andre, V; Pottier, D; Courcot, D; Shirali, P; Sichel, F

    2014-08-01

    Airborne particulate matter has recently been classified by the IARC as carcinogenic to humans (group 1). However, the link between PM chemical composition and its carcinogenicity is still unclear. The aim of the present study was to evaluate and to compare genotoxic potencies of 6 native PM samples collected in spring-summer or autumn-winter, either in industrial, urban or rural area. We evaluated their mutagenicity through Ames test on YG1041, TA98, and TA102 tester strains, and their clastogenicity on human bronchial epithelial BEAS-2B cells using comet assay, γ-H2AX quantification, and micronucleus assay. Ames test results showed a strong positive response, presumably associated with nitro-aromatics content. In addition, at least 2 positive responses were observed out of the 3 genotoxicity assays for each of the 6 samples, demonstrating their clastogenicity. Our data suggest that PM samples collected in autumn-winter season are more genotoxic than those collected in spring-summer, potentially because of higher concentrations of adsorbed organic compounds. Taken together, our results showed the mutagenicity and clastogenicity of native PM₂.₅ samples from different origins, and bring additional elements to explain the newly recognized carcinogenicity of outdoor air pollution. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Radiology of bacterial pneumonia

    Energy Technology Data Exchange (ETDEWEB)

    Vilar, Jose E-mail: vilar_jlu@gva.es; Domingo, Maria Luisa; Soto, Cristina; Cogollos, Jonathan

    2004-08-01

    Bacterial pneumonia is commonly encountered in clinical practice. Radiology plays a prominent role in the evaluation of pneumonia. Chest radiography is the most commonly used imaging tool in pneumonias due to its availability and excellent cost benefit ratio. CT should be used in unresolved cases or when complications of pneumonia are suspected. The main applications of radiology in pneumonia are oriented to detection, characterisation and follow-up, especially regarding complications. The classical classification of pneumonias into lobar and bronchial pneumonia has been abandoned for a more clinical classification. Thus, bacterial pneumonias are typified into three main groups: Community acquired pneumonia (CAD), Aspiration pneumonia and Nosocomial pneumonia (NP).The usual pattern of CAD is that of the previously called lobar pneumonia; an air-space consolidation limited to one lobe or segment. Nevertheless, the radiographic patterns of CAD may be variable and are often related to the causative agent. Aspiration pneumonia generally involves the lower lobes with bilateral multicentric opacities. Nosocomial Pneumonia (NP) occurs in hospitalised patients. The importance of NP is related to its high mortality and, thus, the need to obtain a prompt diagnosis. The role of imaging in NP is limited but decisive. The most valuable information is when the chest radiographs are negative and rule out pneumonia. The radiographic patterns of NP are very variable, most commonly showing diffuse multifocal involvement and pleural effusion. Imaging plays also an important role in the detection and evaluation of complications of bacterial pneumonias. In many of these cases, especially in hospitalised patients, chest CT must be obtained in order to better depict these associate findings.

  6. Radiology of bacterial pneumonia

    International Nuclear Information System (INIS)

    Vilar, Jose; Domingo, Maria Luisa; Soto, Cristina; Cogollos, Jonathan

    2004-01-01

    Bacterial pneumonia is commonly encountered in clinical practice. Radiology plays a prominent role in the evaluation of pneumonia. Chest radiography is the most commonly used imaging tool in pneumonias due to its availability and excellent cost benefit ratio. CT should be used in unresolved cases or when complications of pneumonia are suspected. The main applications of radiology in pneumonia are oriented to detection, characterisation and follow-up, especially regarding complications. The classical classification of pneumonias into lobar and bronchial pneumonia has been abandoned for a more clinical classification. Thus, bacterial pneumonias are typified into three main groups: Community acquired pneumonia (CAD), Aspiration pneumonia and Nosocomial pneumonia (NP).The usual pattern of CAD is that of the previously called lobar pneumonia; an air-space consolidation limited to one lobe or segment. Nevertheless, the radiographic patterns of CAD may be variable and are often related to the causative agent. Aspiration pneumonia generally involves the lower lobes with bilateral multicentric opacities. Nosocomial Pneumonia (NP) occurs in hospitalised patients. The importance of NP is related to its high mortality and, thus, the need to obtain a prompt diagnosis. The role of imaging in NP is limited but decisive. The most valuable information is when the chest radiographs are negative and rule out pneumonia. The radiographic patterns of NP are very variable, most commonly showing diffuse multifocal involvement and pleural effusion. Imaging plays also an important role in the detection and evaluation of complications of bacterial pneumonias. In many of these cases, especially in hospitalised patients, chest CT must be obtained in order to better depict these associate findings

  7. Bacterial Degradation of Pesticides

    DEFF Research Database (Denmark)

    Knudsen, Berith Elkær

    This PhD project was carried out as part of the Microbial Remediation of Contaminated Soil and Water Resources (MIRESOWA) project, funded by the Danish Council for Strategic Research (grant number 2104-08-0012). The environment is contaminated with various xenobiotic compounds e.g. pesticides......D student, to construct fungal-bacterial consortia in order to potentially stimulate pesticide degradation thereby increasing the chance of successful bioaugmentation. The results of the project are reported in three article manuscripts, included in this thesis. In manuscript I, the mineralization of 2...

  8. Bacterial mitotic machineries

    DEFF Research Database (Denmark)

    Gerdes, Kenn; Møller-Jensen, Jakob; Ebersbach, Gitte

    2004-01-01

    Here, we review recent progress that yields fundamental new insight into the molecular mechanisms behind plasmid and chromosome segregation in prokaryotic cells. In particular, we describe how prokaryotic actin homologs form mitotic machineries that segregate DNA before cell division. Thus, the Par......M protein of plasmid R1 forms F actin-like filaments that separate and move plasmid DNA from mid-cell to the cell poles. Evidence from three different laboratories indicate that the morphogenetic MreB protein may be involved in segregation of the bacterial chromosome....

  9. Changes in bacterial meningitis.

    OpenAIRE

    Carter, P E; Barclay, S M; Galloway, W H; Cole, G F

    1990-01-01

    In 1964, one of us (WHG) undertook a retrospective study of bacterial meningitis in childhood in the north east of Scotland during the period 1946-61. We have recently carried out a similar review of cases occurring during 1971-86, to compare the incidence, mortality, and bacteriological patterns. During the earlier period 285 cases occurred, a total incidence of 16.9/100,000 children per year. In the later period 274 children were affected, an annual incidence of 17.8/100,000. The overall mo...

  10. Bioaerosol emissions and detection of airborne antibiotic resistance genes from a wastewater treatment plant

    Science.gov (United States)

    Li, Jing; Zhou, Liantong; Zhang, Xiangyu; Xu, Caijia; Dong, Liming; Yao, Maosheng

    2016-01-01

    Air samples from twelve sampling sites (including seven intra-plant sites, one upwind site and four downwind sites) from a wastewater treatment plant (WWTP) in Beijing were collected using a Reuter Centrifugal Sampler High Flow (RCS); and their microbial fractions were studied using culturing and high throughput gene sequence. In addition, the viable (fluorescent) bioaerosol concentrations for 7 intra-plant sites were also monitored for 30 min each using an ultraviolet aerodynamic particle sizer (UV-APS). Both air and water samples collected from the plant were investigated for possible bacterial antibiotic resistance genes and integrons using polymerase chain reaction (PCR) coupled with gel electrophoresis. The results showed that the air near sludge thickening basin was detected to have the highest level of culturable bacterial aerosols (up to 1697 CFU/m3) and fungal aerosols (up to 930 CFU/m3). For most sampling sites, fluorescent peaks were observed at around 3-4 μm, except the office building with a peak at 1.5 μm, with a number concentration level up to 1233-6533 Particles/m3. About 300 unique bacterial species, including human opportunistic pathogens, such as Comamonas Testosteroni and Moraxella Osloensis, were detected from the air samples collected over the biological reaction basin. In addition, we have detected the sul2 gene resistant to cotrimoxazole (also known as septra, bactrim and TMP-SMX) and class 1 integrase gene from the air samples collected from the screen room and the biological reaction basin. Overall, the screen room, sludge thickening basin and biological reaction basin imposed significant microbial exposure risks, including those from airborne antibiotic resistance genes.

  11. Recent advances in the detection and quantification of microbial contamination in fuel systems

    Energy Technology Data Exchange (ETDEWEB)

    Passman, Frederick J. [Biodeterioration Control Associates, Inc., Princeton, NJ (United States); Maradukhel, Gulerana; Merks, Michael [LuminUltra Technologies Ltd., Fredericton, NB (Canada)

    2013-06-01

    Quantification of adenosine triphosphate (ATP) in fuels and fuel-associated waters was first presented at the 6th International Fuels Colloquium in 2007. At the time, two issues limited the overall usefulness of A TP as a test parameter: inability to detect dormant microbes and inability to differentiate between bacteria and fungi. Recent research has addressed both of these issues. This paper presents protocols for detecting dormant microbes - identified as microbes that are not metabolically active in the sampled fluid, but which can become active under appropriate conditions - and for differentiating fungi from bacteria. The newly developed protocols achieve > 90% detection of bacterial endospores in fuels and fuel-associated water. They also provide > 90% differentiation between bacterial and fungal contaminants in these fluids. (orig.)

  12. Airborne Sea of Dust over China

    Science.gov (United States)

    2002-01-01

    TDust covered northern China in the last week of March during some of the worst dust storms to hit the region in a decade. The dust obscuring China's Inner Mongolian and Shanxi Provinces on March 24, 2002, is compared with a relatively clear day (October 31, 2001) in these images from the Multi-angle Imaging SpectroRadiometer's vertical-viewing (nadir) camera aboard NASA's Terra satellite. Each image represents an area of about 380 by 630 kilometers (236 by 391 miles). In the image from late March, shown on the right, wave patterns in the yellowish cloud liken the storm to an airborne ocean of dust. The veil of particulates obscures features on the surface north of the Yellow River (visible in the lower left). The area shown lies near the edge of the Gobi desert, a few hundred kilometers, or miles, west of Beijing. Dust originates from the desert and travels east across northern China toward the Pacific Ocean. For especially severe storms, fine particles can travel as far as North America. The Multi-angle Imaging SpectroRadiometer, built and managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., is one of five Earth-observing instruments aboard the Terra satellite, launched in December 1999. The instrument acquires images of Earth at nine angles simultaneously, using nine separate cameras pointed forward, downward and backward along its flight path. The change in reflection at different view angles affords the means to distinguish different types of atmospheric particles, cloud forms and land surface covers. Image courtesy NASA/GSFC/LaRC/JPL, MISR Team

  13. Forest Delineation Based on Airborne LIDAR Data

    Directory of Open Access Journals (Sweden)

    Norbert Pfeifer

    2012-03-01

    Full Text Available The delineation of forested areas is a critical task, because the resulting maps are a fundamental input for a broad field of applications and users. Different national and international forest definitions are available for manual or automatic delineation, but unfortunately most definitions lack precise geometrical descriptions for the different criteria. A mandatory criterion in forest definitions is the criterion of crown coverage (CC, which defines the proportion of the forest floor covered by the vertical projection of the tree crowns. For loosely stocked areas, this criterion is especially critical, because the size and shape of the reference area for calculating CC is not clearly defined in most definitions. Thus current forest delineations differ and tend to be non-comparable because of different settings for checking the criterion of CC in the delineation process. This paper evaluates a new approach for the automatic delineation of forested areas, based on airborne laser scanning (ALS data with a clearly defined method for calculating CC. The new approach, the ‘tree triples’ method, is based on defining CC as a relation between the sum of the crown areas of three neighboring trees and the area of their convex hull. The approach is applied and analyzed for two study areas in Tyrol, Austria. The selected areas show a loosely stocked forest at the upper timberline and a fragmented forest on the hillside. The fully automatic method presented for delineating forested areas from ALS data shows promising results with an overall accuracy of 96%, and provides a beneficial tool for operational applications.

  14. Airborne DOAS in South Africa: escaping flatland

    Science.gov (United States)

    Broccardo, S. P.; Heue, K.; Piketh, S.; Platt, U.

    2010-12-01

    The satellite instruments SCIAMACHY, OMI and GOME-2 show high average tropospheric NO2 vertical column densities over the South African Highveld, a region with a high density of coal-fired power stations and other heavy industries. A pushbroom-imaging DOAS spectrometer was flown over the Highveld and surrounding areas in order to further investigate this feature of the satellite record. The wavelength range of the instrument includes differential absorption structures of gases relevant to air quality such as NO2 and SO2. The high spatial resolution of the instrument allows individual sources to be distinguished, while the mobility of the airborne platform allows larger-scale measurements to be made. Emissions fluxes for individual facilities are calculated. An NO flux for the city of Johannesburg is derived from the nadir DOAS column measurements. Similarly, a flux for the entire Highveld region is derived and compared to a satellite-derived flux. The Highveld provides an excellent outdoor laboratory for development of trace-gas remote sensing instrumentation. The greater Johannesburg conurbation and nearby industrial point sources are surrounded by rural areas for several hundred kilometers on all sides. Flat topography and a stable atmosphere in winter lead to plumes with high trace-gas concentrations that are easy to measure and distinguish from the background. A lightweight scanning multi-axis spectrometer is being built to measure industrial plumes from an ultra-light aircraft. Using a tomographic inversion, this instrument will give a vertical cross-section of the plume, allowing validation of dispersion models and direct comparison with in-situ measurements. Using a suitable flight path, a three dimensional representation of the plume can be built up.

  15. Recent advances in airborne radiometric technology

    International Nuclear Information System (INIS)

    Jobst, J.E.

    1985-01-01

    Since its inception, the DOE Remote Sensing Laboratory has made dramatic innovations in airborne radiometric technology. In the past few years there have been at least four major changes in operational philosophy. (1) The helicopter is now the prime radiation survey vehicle. Surveys are conducted at low speed and low altitude, with lines spaced only a few hundred feet apart. Radiation anomalies and subtle changes in background can be readily identified. (2) Much greater emphasis is now placed on accurate, detailed analysis and interpretation of radiation data. Dramatic improvements in survey hardware and software provide much more data of considerably better quality. (3) Recent Laboratory research has been concentrated on error-free, positive identification of point radiation sources. In the past, the extent and magnitude of dispersed sources were the major concerns. (4) Integrated remote sensing has been strongly emphasized at the Laboratory in recent years. This involves the simultaneous use of radiation detectors, aerial cameras, and the multispectral scanner imagery. The synergistic effects of such data correlation are of significantly greater value in analyzing the terrestrial environment. Many of the changes in operational philosophy are directly traceable to new or dramatically improved hardware and software employed at the Laboratory. Six items have been instrumental in the above technological advances: (1) the UHF Transponder System and its predecessor, the Microwave Ranging System; (2) Model IC of the REDAR data acquisition system; (3) the development of the search algorithm; (4) continued improvements in the REDACA data analysis system; (5) deployment of polyscin sodium iodide radiation detectors; and (6) development of the Graphic Overview System

  16. Modelling airborne dispersion for disaster management

    Science.gov (United States)

    Musliman, I. A.; Yohnny, L.

    2017-05-01

    Industrial disasters, like any other disasters, can happen anytime, anywhere and in any form. Airborne industrial disaster is a kind of catastrophic event involving the release of particles such as chemicals and industrial wastes into environment in gaseous form, for instance gas leakages. Unlike solid and liquid materials, gases are often colourless and odourless, the particles are too tiny to be visible to the naked eyes; hence it is difficult to identify the presence of the gases and to tell the dispersion and location of the substance. This study is to develop an application prototype to perform simulation modelling on the gas particles to determine the dispersion of the gas particles and to identify the coverage of the affected area. The prototype adopted Lagrangian Particle Dispersion (LPD) model to calculate the position of the gas particles under the influence of wind and turbulent velocity components, which are the induced wind due to the rotation of the Earth, and Convex Hull algorithm to identify the convex points of the gas cloud to form the polygon of the coverage area. The application performs intersection and overlay analysis over a set of landuse data at Pasir Gudang, Johor industrial and residential area. Results from the analysis would be useful to tell the percentage and extent of the affected area, and are useful for the disaster management to evacuate people from the affected area. The developed application can significantly increase efficiency of emergency handling during a crisis. For example, by using a simulation model, the emergency handling can predict what is going to happen next, so people can be well informed and preparations works can be done earlier and better. Subsequently, this application helps a lot in the decision making process.

  17. Modelling airborne dispersion for disaster management

    International Nuclear Information System (INIS)

    Musliman, I A; Yohnny, L

    2017-01-01

    Industrial disasters, like any other disasters, can happen anytime, anywhere and in any form. Airborne industrial disaster is a kind of catastrophic event involving the release of particles such as chemicals and industrial wastes into environment in gaseous form, for instance gas leakages. Unlike solid and liquid materials, gases are often colourless and odourless, the particles are too tiny to be visible to the naked eyes; hence it is difficult to identify the presence of the gases and to tell the dispersion and location of the substance. This study is to develop an application prototype to perform simulation modelling on the gas particles to determine the dispersion of the gas particles and to identify the coverage of the affected area. The prototype adopted Lagrangian Particle Dispersion (LPD) model to calculate the position of the gas particles under the influence of wind and turbulent velocity components, which are the induced wind due to the rotation of the Earth, and Convex Hull algorithm to identify the convex points of the gas cloud to form the polygon of the coverage area. The application performs intersection and overlay analysis over a set of landuse data at Pasir Gudang, Johor industrial and residential area. Results from the analysis would be useful to tell the percentage and extent of the affected area, and are useful for the disaster management to evacuate people from the affected area. The developed application can significantly increase efficiency of emergency handling during a crisis. For example, by using a simulation model, the emergency handling can predict what is going to happen next, so people can be well informed and preparations works can be done earlier and better. Subsequently, this application helps a lot in the decision making process. (paper)

  18. Current technology in sampling for airborne radionuclides

    International Nuclear Information System (INIS)

    Schulte, H.F.

    1976-01-01

    Sampling for airborne radionuclides is an important part of assessing the occupational environment and that of the public or out-plant environment. Both of these are important to the operation of any nuclear facility. Most such facilities do not emit radionuclides continuously to any extent and hence both the occupational and environmental sampling system is designed to detect deviations from normal conditions or untoward events. Work with materials of a low degree of radioactivity or with nonradioactive materials may involve operations which are not enclosed and significant contaminating material may always exist in the air. In this case, the sampling is directed toward measuring this ambient level and assessing its continued impact on the worker and on the environment. Publication No. 12 of the International Commission on Radiological Protection specifies the types of operations where sampling is necessary for worker protection and the American National Standards Institute publication N 13.1-1969 is a guide to the methods used. Increasingly, this field is covered by various regulations which specify when sampling must be done and, in some cases, how it shall be done. These include requirements of the Occupational Safety and Health Administration, the Nuclear Regulatory Commission, and the Environmental Protection Agency. Needless to say, where these have specified methods they must be followed although in most cases exact procedures are not detailed as requirements. Within the plant, needs for sampling are often suggested by surface monitoring results and by bioassay, and outside by analysis of plants, soils, and material from fallout trays. 15 references

  19. Optical Properties of Airborne Soil Organic Particles

    Energy Technology Data Exchange (ETDEWEB)

    Veghte, Daniel P. [William; China, Swarup [William; Weis, Johannes [Chemical; Department; Kovarik, Libor [William; Gilles, Mary K. [Chemical; Laskin, Alexander [Department

    2017-09-27

    Recently, airborne soil organic particles (ASOP) were reported as a type of solid organic particles emitted after water droplets impacted wet soils. Chemical constituents of ASOP are macromolecules such as polysaccharides, tannins, and lignin (derived from degradation of plants and biological organisms). Optical properties of ASOP were inferred from the quantitative analysis of the electron energy-loss spectra acquired over individual particles in the transmission electron microscope. The optical constants of ASOP are further compared with those measured for laboratory generated particles composed of Suwanee River Fulvic Acid (SRFA) reference material, which was used as a laboratory surrogate of ASOP. The particle chemical compositions were analyzed using energy dispersive x-ray spectroscopy, electron energy-loss spectroscopy, and synchrotron-based scanning transmission x-ray microscopy with near edge x-ray absorption fine structure spectroscopy. ASOP and SRFA exhibit similar carbon composition, but SRFA has minor contributions of S and Na. When ASOP are heated to 350 °C their absorption increases as a result of their pyrolysis and partial volatilization of semi-volatile organic constituents. The retrieved refractive index (RI) at 532 nm of SRFA particles, ASOP, and heated ASOP were 1.22-62 0.07i, 1.29-0.07i, and 1.90-0.38i, respectively. Compared to RISRFA, RIASOP has a higher real part but similar imaginary part. These measurements of ASOP optical constants suggest that they have properties characteristic of atmospheric brown carbon and therefore their potential effects on the radiative forcing of climate need to be assessed in atmospheric models.

  20. An integrated compact airborne multispectral imaging system using embedded computer

    Science.gov (United States)

    Zhang, Yuedong; Wang, Li; Zhang, Xuguo

    2015-08-01

    An integrated compact airborne multispectral imaging system using embedded computer based control system was developed for small aircraft multispectral imaging application. The multispectral imaging system integrates CMOS camera, filter wheel with eight filters, two-axis stabilized platform, miniature POS (position and orientation system) and embedded computer. The embedded computer has excellent universality and expansibility, and has advantages in volume and weight for airborne platform, so it can meet the requirements of control system of the integrated airborne multispectral imaging system. The embedded computer controls the camera parameters setting, filter wheel and stabilized platform working, image and POS data acquisition, and stores the image and data. The airborne multispectral imaging system can connect peripheral device use the ports of the embedded computer, so the system operation and the stored image data management are easy. This airborne multispectral imaging system has advantages of small volume, multi-function, and good expansibility. The imaging experiment results show that this system has potential for multispectral remote sensing in applications such as resource investigation and environmental monitoring.

  1. Airborne soil particulates as vehicles for Salmonella contamination of tomatoes.

    Science.gov (United States)

    Kumar, Govindaraj Dev; Williams, Robert C; Al Qublan, Hamzeh M; Sriranganathan, Nammalwar; Boyer, Renee R; Eifert, Joseph D

    2017-02-21

    The presence of dust is ubiquitous in the produce growing environment and its deposition on edible crops could occur. The potential of wind-distributed soil particulate to serve as a vehicle for S. Newport transfer to tomato blossoms and consequently, to fruits, was explored. Blossoms were challenged with previously autoclaved soil containing S. Newport (9.39log CFU/g) by brushing and airborne transfer. One hundred percent of blossoms brushed with S. Newport-contaminated soil tested positive for presence of the pathogen one week after contact (PCompressed air was used to simulate wind currents and direct soil particulates towards blossoms. Airborne soil particulates resulted in contamination of 29% of the blossoms with S. Newport one week after contact. Biophotonic imaging of blossoms post-contact with bioluminescent S. Newport-contaminated airborne soil particulates revealed transfer of the pathogen on petal, stamen and pedicel structures. Both fruits and calyxes that developed from blossoms contaminated with airborne soil particulates were positive for presence of S. Newport in both fruit (66.6%) and calyx (77.7%). Presence of S. Newport in surface-sterilized fruit and calyx tissue tested indicated internalization of the pathogen. These results show that airborne soil particulates could serve as a vehicle for Salmonella. Hence, Salmonella contaminated dust and soil particulate dispersion could contribute to pathogen contamination of fruit, indicating an omnipresent yet relatively unexplored contamination route. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Modelling the risk of airborne infectious disease using exhaled air.

    Science.gov (United States)

    Issarow, Chacha M; Mulder, Nicola; Wood, Robin

    2015-05-07

    In this paper we develop and demonstrate a flexible mathematical model that predicts the risk of airborne infectious diseases, such as tuberculosis under steady state and non-steady state conditions by monitoring exhaled air by infectors in a confined space. In the development of this model, we used the rebreathed air accumulation rate concept to directly determine the average volume fraction of exhaled air in a given space. From a biological point of view, exhaled air by infectors contains airborne infectious particles that cause airborne infectious diseases such as tuberculosis in confined spaces. Since not all infectious particles can reach the target infection site, we took into account that the infectious particles that commence the infection are determined by respiratory deposition fraction, which is the probability of each infectious particle reaching the target infection site of the respiratory tracts and causing infection. Furthermore, we compute the quantity of carbon dioxide as a marker of exhaled air, which can be inhaled in the room with high likelihood of causing airborne infectious disease given the presence of infectors. We demonstrated mathematically and schematically the correlation between TB transmission probability and airborne infectious particle generation rate, ventilation rate, average volume fraction of exhaled air, TB prevalence and duration of exposure to infectors in a confined space. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  3. Detection Range of Airborne Magnetometers in Magnetic Anomaly Detection

    Directory of Open Access Journals (Sweden)

    Chengjing Li

    2015-11-01

    Full Text Available Airborne magnetometers are utilized for the small-range search, precise positioning, and identification of the ferromagnetic properties of underwater targets. As an important performance parameter of sensors, the detection range of airborne magnetometers is commonly set as a fixed value in references regardless of the influences of environment noise, target magnetic properties, and platform features in a classical model to detect airborne magnetic anomalies. As a consequence, deviation in detection ability analysis is observed. In this study, a novel detection range model is proposed on the basis of classic detection range models of airborne magnetometers. In this model, probability distribution is applied, and the magnetic properties of targets and the environment noise properties of a moving submarine are considered. The detection range model is also constructed by considering the distribution of the moving submarine during detection. A cell-averaging greatest-of-constant false alarm rate test method is also used to calculate the detection range of the model at a desired false alarm rate. The detection range model is then used to establish typical submarine search probabilistic models. Results show that the model can be used to evaluate not only the effects of ambient magnetic noise but also the moving and geomagnetic features of the target and airborne detection platform. The model can also be utilized to display the actual operating range of sensor systems.

  4. Dispersion model for airborne particulates inside a building

    International Nuclear Information System (INIS)

    Perkins, W.C.; Stoddard, D.H.

    1985-01-01

    An empirical model has been developed for the spread of airborne radioactive particles after they are released inside a building. The model has been useful in performing safety analyses of actinide materials facilities at the Savannah River Plant (SRP). These facilities employ the multiple-air-zone concept; that is, ventilation air flows from rooms or areas of least radioactive material hazard, through zones of increasing hazard, to a treatment system. A composite of the data for dispersion of airborne activity during 12 actual case incidents at SRP forms the basis for this model. These incidents occurred during approximately 90 plant-years of experience at SRP with the chemical and metallurgical processing of purified neptunium and plutonium after their recovery from irradiated uranium. The model gives ratios of the airborne activity concentrations in rooms and corridors near the site of the release. The multiple-air-zone concept has been applied to many designs of nuclear facilities as a safety feature to limit the spread of airborne activity from a release. The model illustrates the limitations of this concept: it predicts an apparently anomalous behavior of airborne particulates; namely, a small migration against the flow of the ventilation air

  5. Glass characterization to assess the airborne sound isolation

    International Nuclear Information System (INIS)

    Alba Fernandez, J.; Rey Tormos, R. del; Ramis Soriano, J.; Berto Carbo, L.

    2012-01-01

    The main contribution of this paper is the formulation of an alternative to experimental determination of loss factor and, consequently, to improve the predictions of airborne sound insulation for any type of monolithic or laminated glass. In addition, a review of the standards related to measurement of mechanical parameters of glass is carried out, with particular interest in laminated glass Indeed, one of the problems that arise in the current context of building acoustics is to meet the requirements of facades airborne sound insulation of existing Building Technical Code (BTC). It is known that the blind and the hollow part of the facade should be distinguished. The weakest part regarding to airborne sound insulation is the empty one (consisting of glass, woodwork and other elements). Choosing an adequate woodwork makes the glass surface become the limiting factor. The Constructive Elements Catalog (CEC) of the BTC, the UNE-EN 12758:2011 standard, as well as some, increasingly, data vendors provide information about airborne sound insulation for monolithic glass, laminated glass and double glazing. In the case of laminated glass, these data are limited only to those with a single intermediate layer, and also nonacoustic. Can therefore be said that there is a gap of knowledge in this regard. To obtain reliable predictions of airborne sound insulation of multilayer partitions, such as laminated glass, mechanical characteristics must be known, being loss factor one of the most important. (Author) 7 refs.

  6. The use of nuclear and related techniques for the studies of possible health impact of airborne particulate matter in a metal industry

    International Nuclear Information System (INIS)

    Djojosubroto, Harjoto; Supriatna, Dadang; Kumolowati, Endang; Widjajakusuma, Benjamin

    2000-01-01

    Various processes in an industry may produce gases and fine airborne particulate matters. Elements and hazardous chemicals in the fine particulate matters may enter the human body through inhalation and direct contact with the skin. Excessive inhalation and contact with the fine airborne particulate matter may lead to intoxication due to excessive intake of the hazardous chemicals and toxic elements. The elements will be accumulated in human organs, such as liver, kidneys and brain, manifest in clinical syndromes such as hypertension, renal failure and neurological symptoms and signs. The absorbed elements are excreted through the urinary tract as urine. They also can be excreted through hair and nails. Elevated blood and urinary aluminum levels have been observed after occupational exposure to various aluminum compounds. This phenomenon indicates the absorption through inhalation, as there are no data indicating significant dermal absorption for aluminum. Absorption of chromium compounds in the workplace occurs mainly through inhalation. The absorption is dependent on the valence and solubility of the particular chromium species. Some elements such as trivalent chromium ions are readily cleared from the blood, but hexavalent chromium ions are retained much longer in the blood. The aluminum compounds vary greatly in their toxic and carcinogenic effects. Although the trivalent chromium is readily excreted, continuous intake may cause the blood chromium level to be higher than normal. These elements may either have an deleterious effect on, or be considered essential for human health. In this study, the levels and health effects of airborne particulate matter in the workplace are assessed by elemental quantification of blood, hair and nail of workers in a metal industry and in airborne particulate samples that are collected at the workplace. The present report represents progress of activities following the first Research Co-ordination Meeting 1997 in Vienna

  7. Rapid in Vitro Quantification of S. aureus Biofilms on Vascular Graft Surfaces

    Directory of Open Access Journals (Sweden)

    Monika Herten

    2017-12-01

    Full Text Available Objectives: Increasing resistance of microorganisms and particularly tolerance of bacterial biofilms against antibiotics require the need for alternative antimicrobial substances. S. aureus is the most frequent pathogen causing vascular graft infections. In order to evaluate the antimicrobial efficacy, quantification of the bacterial biofilms is necessary. Aim of the present study was the validation of an in vitro model for quantification of bacterial biofilm on vascular graft surfaces using three different assays.Methods: Standardized discs of vascular graft material (Dacron or PTFE or polystyrene (PS as control surface with 0.25 cm2 surface area were inoculated with 10−3 diluted overnight culture of three biofilm-producing S. aureus isolates (BEB-029, BEB-295, SH1000 in 96-well PS culture plates. After incubation for 4 and 18 h, the biofilm was determined by three different methods: (a mitochondrial ATP concentration as measure of bacterial viability (ATP, (b crystal violet staining (Cry, and (c vital cell count by calculation of colony-forming units (CFU. The experiments were performed three times. Quadruplicates were used for each isolate, time point, and method. In parallel, bacterial biofilms were documented via scanning electron microscopy.Results: All three methods could quantify biofilms on the PS control. Time needed was 0:40, 13:10, and 14:30 h for ATP, Cry, and CFU, respectively. The Cry assay could not be used for vascular graft surfaces due to high unspecific background staining. However, ATP assay and CFU count showed comparable results on vascular graft material and control. The correlations between ATP and CFU assay differed according to the surface and incubation time and were significant only after 4 h on Dacron (BEB-029, p = 0.013 and on PS (BEB-029, p < 0.001. Between ATP and Cry assay on PS, a significant correlation could be detected after 4 h (BEB-295, p = 0.027 and after 18 h (all three strains, p < 0.026. The

  8. Resistance of Aerosolized Bacterial Viruses to Four Germicidal Products.

    Directory of Open Access Journals (Sweden)

    Nathalie Turgeon

    Full Text Available Viral diseases can spread through a variety of routes including aerosols. Yet, limited data are available on the efficacy of aerosolized chemicals to reduce viral loads in the air. Bacteriophages (phages are often used as surrogates for hazardous viruses in aerosol studies because they are inexpensive, easy to handle, and safe for laboratory workers. Moreover, several of these bacterial viruses display physical characteristics similar to pathogenic human and animal viruses, like morphological size, type of nucleic acids, capsid morphology, and the presence of an envelope. In this study, the efficacy of four chemicals was evaluated on four airborne phages at two different relative humidity levels. Non-tailed bacteriophages MS2 (single-stranded RNA, ϕ6 (double-stranded RNA, enveloped, PR772 (double-stranded DNA, and ϕX174 (single-stranded DNA were first aerosolized in a 55L rotative environmental chamber at 19°C with 25% and 50% relative humidity. Then, hydrogen peroxide, Eugenol (phenylpropene used in commercial perfumes and flavorings, Mist® (automobile disinfectant containing Triethylene glycol, and Pledge® (multisurface disinfectant containing Isopropanol, n-Alkyl Dimethyl Benzyl Amonium Chlorides, and n-Alkyl Dimethyl Ethylbenzyl Ammonium Chloride were nebulized with the phages using a separate nebulizer. Aerosols were maintained in suspension during 10 minutes, 1 hour, and 2 hours. Viral aerosols were sampled using an SKC BioSampler and samples were analyzed using qPCR and plaque assays. The resistance levels of the four phages varied depending on the relative humidity (RH and germicidal products tested. Phage MS2 was the most stable airborne virus under the environmental conditions tested while phage PR772 was the least stable. Pledge® and Eugenol reduced the infectivity of all airborne phages tested. At 25% RH, Pledge® and Eugenol were more effective at reducing infectivity of RNA phages ϕ6 and MS2. At 50% RH, Pledge® was the most

  9. Animal Models of Bacterial Keratitis

    Science.gov (United States)

    Marquart, Mary E.

    2011-01-01

    Bacterial keratitis is a disease of the cornea characterized by pain, redness, inflammation, and opacity. Common causes of this disease are Pseudomonas aeruginosa and Staphylococcus aureus. Animal models of keratitis have been used to elucidate both the bacterial factors and the host inflammatory response involved in the disease. Reviewed herein are animal models of bacterial keratitis and some of the key findings in the last several decades. PMID:21274270

  10. Airborne Signals from a Wounded Leaf Facilitate Viral Spreading and Induce Antibacterial Resistance in Neighboring Plants

    Science.gov (United States)

    Dorokhov, Yuri L.; Komarova, Tatiana V.; Petrunia, Igor V.; Frolova, Olga Y.; Pozdyshev, Denis V.; Gleba, Yuri Y.

    2012-01-01

    Many plants release airborne volatile compounds in response to wounding due to pathogenic assault. These compounds serve as plant defenses and are involved in plant signaling. Here, we study the effects of pectin methylesterase (PME)-generated methanol release from wounded plants (“emitters”) on the defensive reactions of neighboring “receiver” plants. Plant leaf wounding resulted in the synthesis of PME and a spike in methanol released into the air. Gaseous methanol or vapors from wounded PME-transgenic plants induced resistance to the bacterial pathogen Ralstonia solanacearum in the leaves of non-wounded neighboring “receiver” plants. In experiments with different volatile organic compounds, gaseous methanol was the only airborne factor that could induce antibacterial resistance in neighboring plants. In an effort to understand the mechanisms by which methanol stimulates the antibacterial resistance of “receiver” plants, we constructed forward and reverse suppression subtractive hybridization cDNA libraries from Nicotiana benthamiana plants exposed to methanol. We identified multiple methanol-inducible genes (MIGs), most of which are involved in defense or cell-to-cell trafficking. We then isolated the most affected genes for further analysis: β-1,3-glucanase (BG), a previously unidentified gene (MIG-21), and non-cell-autonomous pathway protein (NCAPP). Experiments with Tobacco mosaic virus (TMV) and a vector encoding two tandem copies of green fluorescent protein as a tracer of cell-to-cell movement showed the increased gating capacity of plasmodesmata in the presence of BG, MIG-21, and NCAPP. The increased gating capacity is accompanied by enhanced TMV reproduction in the “receivers”. Overall, our data indicate that methanol emitted by a wounded plant acts as a signal that enhances antibacterial resistance and facilitates viral spread in neighboring plants. PMID:22496658

  11. Assessment of composition and origin of airborne bacteria in the free troposphere over Japan

    Science.gov (United States)

    Maki, Teruya; Kakikawa, Makiko; Kobayashi, Fumihisa; Yamada, Maromu; Matsuki, Atsushi; Hasegawa, Hiroshi; Iwasaka, Yasunobu

    2013-08-01

    Long-range transport of airborne microorganisms through the free troposphere significantly impacts biological ecosystems, human life, and atmospheric processes in downwind areas. However, microbial communities in the free troposphere have rarely been investigated because the direct collection of microbial cells at high altitudes requires sophisticated sampling techniques. In this study, tropospheric air sampling was performed using a balloon and an aircraft at 800 m and 3000 m, respectively, over the Noto Peninsula in Japan (37.5°N, 137.4°E) where free tropospheric winds carry aerosols from continental areas. The air samples were collected during four different sampling periods when air masses came from desert regions of Asian continent (west samples) and from Siberia of Russia North Asia (north samples). The west samples contained higher levels of aerosols, and bacteria from the west samples grew in culture media containing up to 15% NaCl. In contrast, bacteria from the north samples could not be cultured in the same media. All isolates obtained from the NaCl-amended cultures were similar to Bacillus subtilis and classified as Firmicutes. A 16S rDNA clone library prepared from the west samples was mainly composed of one phylotype of Firmicutes that corresponded to the cultured B. subtilis sequence. A clone library prepared from the north samples consisted primarily of two phyla, i.e., Actinobacteria and Proteobacteria, which are known to dominantly inhabit low-temperature environments of North Asia. Our results suggest that airborne bacterial communities at high altitudes include several species that vary by the direction and interaction of free tropospheric winds.

  12. Human Indoor Exposure to Airborne Halogenated Flame Retardants: Influence of Airborne Particle Size.

    Science.gov (United States)

    La Guardia, Mark J; Schreder, Erika D; Uding, Nancy; Hale, Robert C

    2017-05-09

    Inhalation of halogenated flame-retardants (HFRs) released from consumer products is an important route of exposure. However, not all airborne HFRs are respirable, and thus interact with vascular membranes within the gas exchange (alveolar) region of the lung. HFRs associated with large (>4 µm), inhalable airborne particulates are trapped on the mucosal lining of the respiratory tract and then are expelled or swallowed. The latter may contribute to internal exposure via desorption from particles in the digestive tract. Exposures may also be underestimated if personal activities that re-suspend particles into the breathing zone are not taken into account. Here, samples were collected using personal air samplers, clipped to the participants' shirt collars (n = 18). We observed that the larger, inhalable air particulates carried the bulk (>92%) of HFRs. HFRs detected included those removed from commerce (i.e., polybrominated diphenyl ethers (Penta-BDEs: BDE-47, -85, -100, -99, and -153)), their replacements; e.g., 2-ethylhexyl 2,3,4,5-tetrabromobenzoate (TBB or EH-TBB); bis(2-ethylhexyl) 3,4,5,6-tetrabromophthalate (TBPH or BEH-TEBP) and long-produced chlorinated organophosphate-FRs (ClOPFRs): tris(2-chloroethyl)phosphate (TCEP), tris(1-chloro-2-propyl)phosphate (TCPP or TCIPP), and tris(1,3-dichloro-2-propyl)phosphate (TDCPP or TDCIPP). Our findings suggest estimates relying on a single exposure route, i.e., alveolar gas exchange, may not accurately estimate HFR internal dosage, as they ignore contributions from larger inhalable particulates that enter the digestive tract. Consideration of the fate and bioavailability of these larger particulates resulted in higher dosage estimates for HFRs with log K oa 12 (i.e., TBB and TBPH) compared to the alveolar route exposure alone. Of those HFRs examined, the most significant effect was the lower estimate by 41% for TBPH. The bulk of TBPH uptake from inhaled particles was estimated to be through the digestive tract, with

  13. DETECTION AND IDENTIFICATION OF TOXIC AIR POLLUTANTS USING AIRBORNE LWIR HYPERSPECTRAL IMAGING

    Science.gov (United States)

    Airborne longwave infrared LWIR) hyperspectral imagery was utilized to detect and identify gaseous chemical release plumes at sites in sourthern Texzas. The Airborne Hysperspectral Imager (AHI), developed by the University of Hawaii was flown over a petrochemical facility and a ...

  14. Characterization of airborne uranium from test firing of XM774 ammunition

    International Nuclear Information System (INIS)

    Glissmeyer, J.A.; Mishima, J.

    1979-11-01

    Pacific Northwest Laboratory conducted experiments at Aberdeen Proving Grounds, Maryland, to characterize the airborne depleted uranium (DU) resulting from the test firings of 105-mm, APFSDS-T XM774 ammunition. The goal was to obtain data pertinent to evaluations of human inhalation exposure to the airborne DU. Data was desired concerning the following: (1) size distribution of airborne DU; (2) quantity of airborne DU; (3) dispersion of airborne DU from the target vicinity; (4) amount of DU deposited on the ground; (5) solubility of airborne DU compounds in lung fluid; and (6) oxide forms of airborne and fallout DU. The experiments involved extensive air sampling for total airborne DU particulates and respirable DU particles both above the targets and at distances downwind. Fallout and fragments were collected around the target area. High-speed movies of the smoke generated from the impact of the penetrators were taken to estimate the cloud volumes. Results of the experiments are presented

  15. Airborne incidents : an econometric analysis of severity, December 31, 2014 : technical summary

    Science.gov (United States)

    2014-12-31

    This is a technical summary of the Airborne Incidents: An Econometric Analysis of Severity main report. : Airborne loss of separation incidents occur when an aircraft breaches the defined separation limit (vertical and/or horizontal) with anoth...

  16. Advances in the testing and evaluation of airborne radar through realtime simulation of synthetic clutter

    CSIR Research Space (South Africa)

    Strydom, JJ

    2011-11-01

    Full Text Available Clutter Simulation ? CSIR 2011 Slide 20 From: G. Morris and L. Harkness, Airborne Pulsed Doppler Radar Synthetic Clutter Simulation Recorded Data Airborne Range Doppler map ? CSIR 2011 Slide 21 Data from: Synthetic Clutter Simulation Building...

  17. CAMEX-4 CONICALLY-SCANNING TWO-LOOK AIRBORNE RADIOMETER (C-STAR) V1a

    Data.gov (United States)

    National Aeronautics and Space Administration — The CAMEX-4 Conically-Scanning Two-Look Airborne Radiometer (C-STAR) dataset was collected by the Conically-Scanning Two-look Airborne Radiometer (C-STAR), which was...

  18. Aerosol-Fluorescence Spectrum Analyzer: Real-Time Measurement of Emission Spectra of Airborne Biological Particles

    National Research Council Canada - National Science Library

    Hill, Steven

    1997-01-01

    ...) made from various biological materials (e.g., Bacillus subtilis spores, B. anthrasis spores, riboflavin, and tree leaves). The AFS may be useful in detecting and characterizing airborne bacteria and other airborne particles of biological origin.

  19. Optimization of the ion chromatographic quantification of airborne fluoride, acetate and formate in the Metropolitan Museum of Art, New York.

    Science.gov (United States)

    Kontozova-Deutsch, Velichka; Deutsch, Felix; Bencs, László; Krata, Agnieszka; Van Grieken, René; De Wael, Karolien

    2011-10-30

    Ion chromatographic (IC) methods have been compared in order to achieve an optimal separation of fluoride, acetate and formate under various elution conditions on two formerly introduced analytical columns (i and ii) and a novel one (iii): (i) an IonPac AS14 (250 mm × 4 mm I.D.), (ii) Allsep A-2 (150 mm × 4.6mm I.D.), and (iii) an IC SI-50 4E (250 mm (length) × 4mm (internal diameter - I.D.)). The IC conditions for the separation of the anions concerned were optimized on the IC SI-50 4E column. A near baseline separation of these anions was attained on the IonPac AS14, whereas the peaks of fluoride and acetate could not be resolved on the Allsep A-2. A baseline separation for the three anions was achieved on the IC SI-50 4E column, when applying an eluent mixture of 3.2 mmol/L Na(2)CO(3) and 1.0 mmol/L NaHCO(3) with a flow rate of 1.0 mL/min. The highest precision of 1.7, 3.0 and 2.8% and the best limits of detection (LODs) of 0.014, 0.22 and 0.17 mg/L for fluoride, acetate and formate, respectively, were obtained with the IC SI-50 4E column. Hence, this column was applied for the determination of the acetic and formic acid contents of air samples taken by means of passive gaseous sampling at the Metropolitan Museum of Art in New York, USA. Atmospheric concentrations of acetic and formic acid up to 1050 and 450 μg/m(3), respectively, were found in non-aerated showcases of the museum. In galleries and outdoors, rather low levels of acetic and formic acid were detected with average concentrations of 50 and 10 μg/m(3), respectively. The LOD data of acetate and formate on the IC SI-50 4E column correspond to around 0.5 μg/m(3) for both acetic and formic acid in air samples. Copyright © 2011 Elsevier B.V. All rights reserved.

  20. Mapping methane sources and emissions over California from direct airborne flux and VOC source tracer measurements

    Science.gov (United States)

    Guha, A.; Misztal, P. K.; Peischl, J.; Karl, T.; Jonsson, H. H.; Woods, R. K.; Ryerson, T. B.; Goldstein, A. H.

    2013-12-01

    Quantifying the contributions of methane (CH4) emissions from anthropogenic sources in the Central Valley of California is important for validation of the statewide greenhouse gas (GHG) inventory and subsequent AB32 law implementation. The state GHG inventory is largely based on activity data and emission factor based estimates. The 'bottom-up' emission factors for CH4 have large uncertainties and there is a lack of adequate 'top-down' measurements to characterize emission rates. Emissions from non-CO2 GHG sources display spatial heterogeneity and temporal variability, and are thus, often, poorly characterized. The Central Valley of California is an agricultural and industry intensive region with large concentration of dairies and livestock operations, active oil and gas fields and refining operations, as well as rice cultivation all of which are known CH4 sources. In order to gain a better perspective of the spatial distribution of major CH4 sources in California, airborne measurements were conducted aboard a Twin Otter aircraft for the CABERNET (California Airborne BVOC Emissions Research in Natural Ecosystems Transects) campaign, where the driving research goal was to understand the spatial distribution of biogenic VOC emissions. The campaign took place in June 2011 and encompassed over forty hours of low-altitude and mixed layer airborne CH4 and CO2 measurements alongside coincident VOC measurements. Transects during eight unique flights covered much of the Central Valley and its eastern edge, the Sacramento-San Joaquin delta and the coastal range. We report direct quantification of CH4 fluxes using real-time airborne Eddy Covariance measurements. CH4 and CO2 were measured at 1-Hz data rate using an instrument based on Cavity Ring Down Spectroscopy (CRDS) along with specific VOCs (like isoprene, methanol, acetone etc.) measured at 10-Hz using Proton Transfer Reaction Mass Spectrometer - Eddy Covariance (PTRMS-EC) flux system. Spatially resolved eddy covariance

  1. [Identification of airborne pollen and airborne particles with pollen allergen (Cry j 1, Dac g) by aeroallergen immunoblotting technique].

    Science.gov (United States)

    Takahashi, Yuichi; Nagoya, Takao; Ohta, Nobuo

    2002-08-01

    After collection of airborne particles with a seven-day recording volumetric spore trap (Burkard model) using optically clear, pressure sensitive acrylic adhesive tapes, a dry PVDF membrane was pressed down firmly onto the adhesive tape, antigen-antibody reaction was performed in full contact with the tapes and PVDF membrane. Dark purple spots from airborne pollen allergens were examined under a light microscope to evaluate the form of pollens and particles wit h the antigenicity. It is clarified that identification of the form of pollens with the antigencity is possible not only pollens with the antigenicity but a pollen has already lost its shape, and it is also clarified that some airborne particular matters have the pollen antigencity. Airborne samples were collected during the Cryptomeria japonica or grass pollen season. Samples collected during the C. japonica pollen season were treated with anti-Cry j 1 monoclonal antibody, and those during the grass pollen season with anti-Dac g rabbit IgG. Samples collected during the C. japonica and the grass pollen peak season were treated with antibodies from sera of pollinosis patients. Spots originated not only from relevant pollen grains but also from parts of airborne particular matter have the pollen antigenicity and some spots could not observed for any kind of particles.

  2. Polar gravity fields from GOCE and airborne gravity

    DEFF Research Database (Denmark)

    Forsberg, René; Olesen, Arne Vestergaard; Yidiz, Hasan

    2011-01-01

    Airborne gravity, together with high-quality surface data and ocean satellite altimetric gravity, may supplement GOCE to make consistent, accurate high resolution global gravity field models. In the polar regions, the special challenge of the GOCE polar gap make the error characteristics...... of combination models especially sensitive to the correct merging of satellite and surface data. We outline comparisons of GOCE to recent airborne gravity surveys in both the Arctic and the Antarctic. The comparison is done to new 8-month GOCE solutions, as well as to a collocation prediction from GOCE gradients...... in Antarctica. It is shown how the enhanced gravity field solutions improve the determination of ocean dynamic topography in both the Arctic and in across the Drake Passage. For the interior of Antarctica, major airborne gravity programs are currently being carried out, and there is an urgent need...

  3. Airborne signals of communication in sagebrush: a pharmacological approach.

    Science.gov (United States)

    Shiojiri, Kaori; Ishizaki, Satomi; Ozawa, Rika; Karban, Richard

    2015-01-01

    When plants receive volatiles from a damaged plant, the receivers become more resistant to herbivory. This phenomenon has been reported in many plant species and called plant-plant communication. Lab experiments have suggested that several compounds may be functioning as airborne signals. The objective of this study is to identify potential airborne signals used in communication between sagebrush (Artemisia tridentata) individuals in the field. We collected volatiles of one branch from each of 99 sagebrush individual plants. Eighteen different volatiles were detected by GC-MS analysis. Among these, 4 compounds; 1.8-cineol, β-caryophyllene, α-pinene and borneol, were investigated as signals of communication under natural conditions. The branches which received either 1,8-cineol or β-caryophyllene tended to get less damage than controls. These results suggested that 1,8-cineol and β-caryophyllene should be considered further as possible candidates for generalized airborne signals in sagebrush.

  4. The risk of airborne influenza transmission in passenger cars.

    Science.gov (United States)

    Knibbs, L D; Morawska, L; Bell, S C

    2012-03-01

    Travel in passenger cars is a ubiquitous aspect of the daily activities of many people. During the 2009 influenza A(H1N1) pandemic a case of probable transmission during car travel was reported in Australia, to which spread via the airborne route may have contributed. However, there are no data to indicate the likely risks of such events, and how they may vary and be mitigated. To address this knowledge gap, we estimated the risk of airborne influenza transmission in two cars (1989 model and 2005 model) by employing ventilation measurements and a variation of the Wells-Riley model. Results suggested that infection risk can be reduced by not recirculating air; however, estimated risk ranged from 59% to 99·9% for a 90-min trip when air was recirculated in the newer vehicle. These results have implications for interrupting in-car transmission of other illnesses spread by the airborne route.

  5. SGA-WZ: A New Strapdown Airborne Gravimeter

    DEFF Research Database (Denmark)

    Huang, Yangming; Olesen, Arne Vestergaard; Wu, Meiping

    2012-01-01

    Inertial navigation systems and gravimeters are now routinely used to map the regional gravitational quantities from an aircraft with mGal accuracy and a spatial resolution of a few kilometers. However, airborne gravimeter of this kind is limited by the inaccuracy of the inertial sensor performance......, the integrated navigation technique and the kinematic acceleration determination. As the GPS technique developed, the vehicle acceleration determination is no longer the limiting factor in airborne gravity due to the cancellation of the common mode acceleration in differential mode. A new airborne gravimeter...... taking full advantage of the inertial navigation system is described with improved mechanical design, high precision time synchronization, better thermal control and optimized sensor modeling. Apart from the general usage, the Global Positioning System (GPS) after differentiation is integrated...

  6. Parametric estimation of time varying baselines in airborne interferometric SAR

    DEFF Research Database (Denmark)

    Mohr, Johan Jacob; Madsen, Søren Nørvang

    1996-01-01

    A method for estimation of time varying spatial baselines in airborne interferometric synthetic aperture radar (SAR) is described. The range and azimuth distortions between two images acquired with a non-linear baseline are derived. A parametric model of the baseline is then, in a least square...... sense, estimated from image shifts obtained by cross correlation of numerous small patches throughout the image. The method has been applied to airborne EMISAR imagery from the 1995 campaign over the Storstrommen Glacier in North East Greenland conducted by the Danish Center for Remote Sensing. This has...... reduced the baseline uncertainties from several meters to the centimeter level in a 36 km scene. Though developed for airborne SAR the method can easily be adopted to satellite data...

  7. Data System for HS3 Airborne Field Campaign

    Science.gov (United States)

    Maskey, M.; Mceniry, M.; Berendes, T.; Bugbee, K.; Conover, H.; Ramachandran, R.

    2014-12-01

    Hurricane and Severe Storm Sentinel (HS3) is a NASA airborne field campaign aimed at better understanding the physical processes that control hurricane intensity change. HS3 will help answer questions related to the roles of environmental conditions and internal storm structures to storm intensification. Due to the nature of the questions that HS3 mission is addressing, it involves a variety of in-situ, satellite observations, airborne data, meteorological analyses, and simulation data. This variety of datasets presents numerous data management challenges for HS3. The methods used for airborne data management differ greatly from the methods used for space-borne data. In particular, metadata extraction, spatial and temporal indexing, and the large number of instruments and subsequent variables are a few of the data management challenges unique to airborne missions. A robust data system is required to successfully help HS3 scientist achieve their mission goals. Furthermore, the data system also needs to provide for data management that assists in broader use of HS3 data to enable future research activities. The Global Hydrology Resource Center (GHRC) is considering all these needs and designing a data system for HS3. Experience with past airborne field campaign puts GHRC in a good position to address HS3 needs. However, the scale of this mission along with science requirements separates HS3 from previous field campaigns. The HS3 data system will include automated services for geo-location, metadata extraction, discovery, and distribution for all HS3 data. To answer the science questions, the data system will include a visual data exploration tool that is fully integrated into the data catalog. The tool will allow visually augmenting airborne data with analyses and simulations. Satellite data will provide contextual information during such data explorations. All HS3 tools will be supported by an enterprise service architecture that will allow scaling, easy integration

  8. APEX Airborne Imaging Spectrometer Uncertainty Budget and Vicarious Validation Method

    Science.gov (United States)

    Hueni, A.; Woolliams, E.; Schlaepfer, D.; Wulf, H.

    2017-12-01

    ESA's Airborne Imaging Spectrometer APEX (Airborne Prism Experiment) was developed by a Swiss-Belgian consortium and entered its operational phase at the end of 2010 (Schaepman et al. 2015). Work on the sensor model and on propagated uncertainties from the laboratory to the in-flight case has been carried out extensively within the framework of EMRP (European Metrology Research Program) as part of the Metrology for Earth Observation and Climate (MetEOC and MetEOC2). The uncertainty propagation has been implemented in the APEX Calibration Information System (Hueni et al. 2013) and the APEX Level 1 processor (Hueni et al. 2009), thus allowing the operational computation of uncertainties for any at-sensor radiance APEX imaging cube. This fosters a better understanding and aids evaluation of the results of vicarious validation using spectral ground control points stored in the spectral information system SPECCHIO (Hueni et al. 2016). The presented work ultimately benefits the production of traceable higher-level products and enables sensitivity analyses of models, e.g. 3D canopy simulations, parameterised by APEX radiances. Hueni, A., Biesemans, J., Meuleman, K., Dell'Endice, F., Schläpfer, D., et al (2009). "Structure, Components and Interfaces of the Airborne Prism Experiment (APEX) Processing and Archiving Facility." IEEE TGRS 47(1): 29-43. Hueni, A., Damm, A., Kneubuehler, M., Schläpfer, D. and Schaepman, M. (2016). "Field and Airborne Spectroscopy Cross-Validation - Some Considerations." IEEE JSTARS 10(3): 1117 - 1135. Hueni, A., Lenhard, K., Baumgartner, A. and Schaepman, M. (2013). "The APEX (Airborne Prism Experiment - Imaging Spectrometer) Calibration Information System." IEEE TGRS 51(11): 5169-5180. Schaepman, M., Jehle, M., Hueni, A., D'Odorico, P., Damm, A., et al (2015). "Advanced radiometry measurements and Earth science applications with the Airborne Prism Experiment (APEX)." Remote Sensing of Environment 158: 207-219.

  9. Optimization and Validation of Real Time PCR Assays for Absolute Quantification of toxigenic Vibrio cholerae and Escherichia coli

    DEFF Research Database (Denmark)

    Ferdous, J.; Hossain, Z. Z.; Tulsiani, S.

    2016-01-01

    Quantitative real-time PCR (qPCR) is a dynamic and cogent assay for the detection and quantification of specified nucleic acid sequences and is more accurate compared to both traditional culture based techniques and ‘end point’ conventional PCR. Serial dilution of bacterial cell culture provides...... information on colony forming unit (CFU) counts. This is crucial for obtaining optimal standard curves representative of DNA concentration. This approach eliminates variation in the standard curves caused by loss of DNA by serial dilution of nucleic acid elute. In this study, an assay was developed to detect...... and quantify DNA by real-time PCR for two pathogenic species, Escherichia coli (E. coli) and Vibrio cholerae (V.cholerae). In order to generate a standard curve, total bacterial DNA was diluted in a 10-fold series and each sample was adjusted to an estimated cell count. The starting bacterial DNA concentration...

  10. The Multi-sensor Airborne Radiation Survey (MARS) Instrument

    Energy Technology Data Exchange (ETDEWEB)

    Fast, James E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Aalseth, Craig E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Asner, David M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Bonebrake, Christopher A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Day, Anthony R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Dorow, Kevin E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Fuller, Erin S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Glasgow, Brian D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hossbach, Todd W. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hyronimus, Brian J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Jensen, Jeffrey L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Johnson, Kenneth I. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Jordan, David V. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Morgen, Gerald P. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Morris, Scott J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Mullen, O Dennis [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Myers, Allan W. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Pitts, W. Karl [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Rohrer, John S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Runkle, Robert C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Seifert, Allen [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Shergur, Jason M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Stave, Sean C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Tatishvili, Gocha [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Thompson, Robert C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Todd, Lindsay C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Warren, Glen A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Willett, Jesse A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Wood, Lynn S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2013-01-11

    The Multi-sensor Airborne Radiation Survey (MARS) project has developed a new single cryostat detector array design for high purity germanium (HPGe) gama ray spectrometers that achieves the high detection efficiency required for stand-off detection and actionable characterization of radiological threats. This approach, we found, is necessary since a high efficiency HPGe detector can only be built as an array due to limitations in growing large germanium crystals. Moreover, the system is ruggedized and shock mounted for use in a variety of field applications, including airborne and maritime operations.

  11. Airborne campaigns for CryoSat prelaunch calibration and validation

    DEFF Research Database (Denmark)

    Skourup, Henriette; Hanson, Susanne; Hvidegaard, Sine Munk

    2011-01-01

    After the successful launch of CryoSat-2 in April 2010, the first direct validation campaign of the satellite is planned for spring 2011. DTU Space has been involved in ESA’s CryoSat Validation Experiment (CryoVEx) with airborne activities since 2003. To validate the prelaunch performance...... of the CryoSat radar altimeter (SIRAL), an airborne version of the SIRAL altimeter (ASIRAS) has been flown together with a laser scanner in 2006 and 2008. Of particular interest is to study the penetration depth of the radar altimeter over both land- and sea ice. This can be done by comparing the radar...

  12. Development of unauthorized airborne emission source identification procedure

    Science.gov (United States)

    Shtripling, L. O.; Bazhenov, V. V.; Varakina, N. S.; Kupriyanova, N. P.

    2018-01-01

    The paper presents the procedure for searching sources of unauthorized airborne emissions. To make reasonable regulation decisions on airborne pollutant emissions and to ensure the environmental safety of population, the procedure provides for the determination of a pollutant mass emission value from the source being the cause of high pollution level and the search of a previously unrecognized contamination source in a specified area. To determine the true value of mass emission from the source, the minimum of the mean-root-square mismatch criterion between the computed and measured pollutant concentration in the given location is used.

  13. Manual of respiratory protection against airborne radioactive materials

    International Nuclear Information System (INIS)

    Caplin, J.L.; Held, B.J.; Catlin, R.J.

    1976-10-01

    The manual supplements Regulatory Guide 8.15, ''Acceptable Programs for Respiratory Protection''. It provides broad guidance for the planned use of respirators to protect individuals from airborne radioactive materials that might be encountered during certain operations. The guidance is intended for use by management in establishing and supervising programs and by operating personnel in implementing programs. Guidance is primarily directed to the use of respirators to prevent the inhalation of airborne radioactive materials. Protection against other modes of intake (e.g., absorption, swallowing, wound injection) is, in general, not covered nor is the use of protective equipment for head, eye, or skin protection

  14. Manual of respiratory protection against airborne radioactive materials

    Energy Technology Data Exchange (ETDEWEB)

    Caplin, J.L.; Held, B.J.; Catlin, R.J.

    1976-10-01

    The manual supplements Regulatory Guide 8.15, ''Acceptable Programs for Respiratory Protection''. It provides broad guidance for the planned use of respirators to protect individuals from airborne radioactive materials that might be encountered during certain operations. The guidance is intended for use by management in establishing and supervising programs and by operating personnel in implementing programs. Guidance is primarily directed to the use of respirators to prevent the inhalation of airborne radioactive materials. Protection against other modes of intake (e.g., absorption, swallowing, wound injection) is, in general, not covered nor is the use of protective equipment for head, eye, or skin protection.

  15. Issues relating to airborne applications of HTS SQUIDs

    International Nuclear Information System (INIS)

    Foley, C P; Leslie, K E; Binks, R A; Lam, S H K; Du, J; Tilbrook, D L; Mitchell, E E; Macfarlane, J C; Lee, J B; Turner, R; Downey, M; Maddever, A

    2002-01-01

    Airborne application of HTS SQUIDs is the most difficult environment for their successful deployment. In order to operate with the sensitivity required for a particular application, there are many issues to be addressed such as the need for very wide dynamic range electronics, motion noise elimination, immunity to large changing magnetic fields and cultural noise sources. This paper reviews what is necessary to achieve an airborne system giving examples in geophysical mineral exploration. It will consider issues relating to device design and fabrication, electronics, dewar design, suspension system requirements and noise elimination methods

  16. Computer-controlled sampling system for airborne particulates

    International Nuclear Information System (INIS)

    Hall, C.F.; Anspaugh, L.R.; Koval, J.S.; Phelps, P.L.; Steinhaus, R.J.

    1975-01-01

    A self-contained, mobile, computer-controlled air-sampling system has been designed and fabricated that also collects and records the data from eight meteorological sensors. The air-samplers are activated automatically when the collected meteorological data meet the criteria specified at the beginning of the data-collection run. The filters from the samplers are intended to collect airborne 239 Pu for later radionuclide analysis and correlation with the meteorological data for the study of resuspended airborne radioactivity and for the development of a predictive model. This paper describes the system hardware, discusses the system and software concepts, and outlines the operational procedures for the system

  17. Studies on the effects of ionization on bacterial aerosols in a burns and plastic surgery unit.

    Science.gov (United States)

    Mäkelä, P; Ojajärvi, J; Graeffe, G; Lehtimäki, M

    1979-10-01

    The effect of the ionization of the air on the decay of bacterial aerosols was studied in a Burns and Plastic Surgery Unit. Ions were generated by free corona needles. The air content of bacteria measured by settle plates was found to be smaller during the ionization period than during the controls period. The number of individual phage typed Staph. aureus strains was especially found to be lower during ionization. The opposite potential increased the disappearance of bacteria from the air. The size of skin particles carrying bacteria is not optimum, but the results obtained show that the ionization may have applications in controlling airborne infection.

  18. Molecular quantification of genes encoding for green-fluorescent proteins

    DEFF Research Database (Denmark)

    Felske, A; Vandieken, V; Pauling, B V

    2003-01-01

    A quantitative PCR approach is presented to analyze the amount of recombinant green fluorescent protein (gfp) genes in environmental DNA samples. The quantification assay is a combination of specific PCR amplification and temperature gradient gel electrophoresis (TGGE). Gene quantification...

  19. Aerotaxis in Bacterial Turbulence

    Science.gov (United States)

    Fernandez, Vicente; Bisson, Antoine; Bitton, Cindy; Waisbord, Nicolas; Smriga, Steven; Rusconi, Roberto; Stocker, Roman

    2012-11-01

    Concentrated suspensions of motile bacteria exhibit correlated dynamics on spatial scales much larger than an individual bacterium. The resulting flows, visually similar to turbulence, can increase mixing and decrease viscosity. However, it remains unclear to what degree the collective dynamics depend on the motile behavior of bacteria at the individual level. Using a new microfluidic device to create controlled horizontal oxygen gradients, we studied the two dimensional behavior of dense suspensions of Bacillus subtilis. This system makes it possible to assess the interplay between the coherent large-scale motions of the suspension, oxygen transport, and the directional response of cells to oxygen gradients (aerotaxis). At the same time, this device has enabled us to examine the onset of bacterial turbulence and its influence on the propagation of the diffusing oxygen front, as the bacteria begin in a dormant state and transition to swimming when exposed to oxygen.

  20. Bacterial intermediate filaments

    DEFF Research Database (Denmark)

    Charbon, Godefroid; Cabeen, M.; Jacobs-Wagner, C.

    2009-01-01

    Crescentin, which is the founding member of a rapidly growing family of bacterial cytoskeletal proteins, was previously proposed to resemble eukaryotic intermediate filament (IF) proteins based on structural prediction and in vitro polymerization properties. Here, we demonstrate that crescentin...... also shares in vivo properties of assembly and dynamics with IF proteins by forming stable filamentous structures that continuously incorporate subunits along their length and that grow in a nonpolar fashion. De novo assembly of crescentin is biphasic and involves a cell size-dependent mechanism...... a new function for MreB and providing a parallel to the role of actin in IF assembly and organization in metazoan cells. Additionally, analysis of an MreB localization mutant suggests that cell wall insertion during cell elongation normally occurs along two helices of opposite handedness, each...

  1. Bacterial polyhydroxyalkanoates: Still fabulous?

    Science.gov (United States)

    Możejko-Ciesielska, Justyna; Kiewisz, Robert

    2016-11-01

    Bacterial polyhydroxyalkanoates (PHA) are polyesters accumulated as carbon and energy storage materials under limited growth conditions in the presence of excess carbon sources. They have been developed as biomaterials with unique properties for the past many years being considered as a potential substitute for conventional non-degradable plastics. Due to the increasing concern towards global climate change, depleting petroleum resource and problems with an utilization of a growing number of synthetic plastics, PHAs have gained much more attention from industry and research. These environmentally friendly microbial polymers have great potential in biomedical, agricultural, and industrial applications. However, their production on a large scale is still limited. This paper describes the backgrounds of PHAs and discussed the current state of knowledge on the polyhydroxyalkanoates. Ability of bacteria to convert different carbon sources to PHAs, the opportunities and challenges of their introduction to global market as valuable renewable products have been also discussed. Copyright © 2016 Elsevier GmbH. All rights reserved.

  2. Biosensors of bacterial cells.

    Science.gov (United States)

    Burlage, Robert S; Tillmann, Joshua

    2017-07-01

    Biosensors are devices which utilize both an electrical component (transducer) and a biological component to study an environment. They are typically used to examine biological structures, organisms and processes. The field of biosensors has now become so large and varied that the technology can often seem impenetrable. Yet the principles which underlie the technology are uncomplicated, even if the details of the mechanisms are elusive. In this review we confine our analysis to relatively current advancements in biosensors for the detection of whole bacterial cells. This includes biosensors which rely on an added labeled component and biosensors which do not have a labeled component and instead detect the binding event or bound structure on the transducer. Methods to concentrate the bacteria prior to biosensor analysis are also described. The variety of biosensor types and their actual and potential uses are described. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Bacterial proteases and virulence

    DEFF Research Database (Denmark)

    Frees, Dorte; Brøndsted, Lone; Ingmer, Hanne

    2013-01-01

    with the proteases either encoded within the same polypeptide or on separate subunits. In contrast, substrate recognition by extracellular proteases is less selective and therefore these enzymes are generally expressed as zymogens to prevent premature proteolytic activity that would be detrimental to the cell......Bacterial pathogens rely on proteolysis for variety of purposes during the infection process. In the cytosol, the main proteolytic players are the conserved Clp and Lon proteases that directly contribute to virulence through the timely degradation of virulence regulators and indirectly by providing...... signalling to short-circuit host cell processes. Common to both intra- and extracellular proteases is the tight control of their proteolytic activities. In general, substrate recognition by the intracellular proteases is highly selective which is, in part, attributed to the chaperone activity associated...

  4. INNOVATIV AIRBORNE SENSORS FOR DISASTER MANAGEMENT

    Directory of Open Access Journals (Sweden)

    M. O. Altan

    2016-06-01

    Lidar supports Disaster management by analyzing changes in the DSM before and after the “event”. Advantage of Lidar is that beside rain and clouds, no other weather conditions limit their use. As an active sensor, missions in the nighttime are possible. The new mid-format cameras that make use CMOS sensors (e.g. Phase One IXU1000 can capture data also under poor and difficult light conditions and might will be the first choice for remotely sensed data acquisition in aircrafts and UAVs. UAVs will surely be more and more part of the disaster management on the detailed level. Today equipped with video live cams using RGB and Thermal IR, they assist in looking inside buildings and behind. Thus, they can continue with the aerial survey where airborne anomalies have been detected.

  5. 78 FR 33894 - Proposed Information Collection (Open Burn Pit Registry Airborne Hazard Self-Assessment...

    Science.gov (United States)

    2013-06-05

    ... Burn Pit Registry Airborne Hazard Self-Assessment Questionnaire) Activity: Comment Request AGENCY... to ``OMB Control No. 2900-NEW, Open Burn Pit Registry Airborne Hazard Self-Assessment Questionnaire.... Title: Open Burn Pit Registry Airborne Hazard Self-Assessment Questionnaire, VA Form 10-10066. OMB...

  6. 78 FR 54956 - Agency Information Collection (Open Burn Pit Registry Airborne Hazard Self-Assessment...

    Science.gov (United States)

    2013-09-06

    ... Pit Registry Airborne Hazard Self-Assessment Questionnaire) Activities Under OMB Review AGENCY... Burn Pit Registry Airborne Hazard Self-Assessment Questionnaire.'' SUPPLEMENTARY INFORMATION: Title: Open Burn Pit Registry Airborne Hazard Self-Assessment Questionnaire, VA Form 10-10066. Type of Review...

  7. 30 CFR 56.5005 - Control of exposure to airborne contaminants.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Control of exposure to airborne contaminants... Air Quality and Physical Agents Air Quality § 56.5005 Control of exposure to airborne contaminants. Control of employee exposure to harmful airborne contaminants shall be, insofar as feasible, by prevention...

  8. 30 CFR 57.5005 - Control of exposure to airborne contaminants.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Control of exposure to airborne contaminants... Underground § 57.5005 Control of exposure to airborne contaminants. Control of employee exposure to harmful airborne contaminants shall be, insofar as feasible, by prevention of contamination, removal by exhaust...

  9. Quantification of bioavailable chlortetracycline in pig feces using a bacterial whole-cell biosensor

    DEFF Research Database (Denmark)

    Hansen, L. H.; Aarestrup, Frank Møller; Sørensen, S. J.

    2002-01-01

    and maintenance of fecal coliform bacteria resistant to tetracycline. Initially, large quantities of water-extractable CTC were excreted from the pigs and measurable amounts were detected even at 30 days after treatment cessation. This led to a sharp rise in the number of tetracycline resistant coliform bacteria...... in the feces, to within the same order of magnitude as the total coliform count. The high level of tetracycline resistance was maintained in spite of the declining concentration of tetracycline. (C) 2002 Elsevier Science B.V. All rights reserved....

  10. Bacterial growth on surfaces: Automated image analysis for quantification of growth rate-related parameters

    DEFF Research Database (Denmark)

    Møller, S.; Sternberg, Claus; Poulsen, L. K.

    1995-01-01

    species-specific hybridizations with fluorescence-labelled ribosomal probes to estimate the single-cell concentration of RNA. By automated analysis of digitized images of stained cells, we determined four independent growth rate-related parameters: cellular RNA and DNA contents, cell volume......, and the frequency of dividing cells in a cell population. These parameters were used to compare physiological states of liquid-suspended and surfacegrowing Pseudomonas putida KT2442 in chemostat cultures. The major finding is that the correlation between substrate availability and cellular growth rate found...

  11. The Effects of Mineral Matrices and Extraction Method on Quantification of Bacterial Phospholipid Fatty Acids.

    Science.gov (United States)

    Ford, S.; McKelvie, J. R. M.; Sherwood Lollar, B.; Slater, G. F.

    2017-12-01

    Understanding the distribution, abundances and metabolic activities of microbial life in the subsurface is fundamental to our understanding of biogeochemical cycling on Earth. Given that the most likely environments for life to still exist, or be preserved, on other planets and moons in the solar system are in the subsurface, a better understanding of subsurface life on Earth is also a key factor in our ability to search for life beyond the Earth. While we have made progress in investigating life in the continental subsurface in recent years, significant challenges remain. In particular, the low biomass abundance, heterogeneous distribution of biomass, and the potential for matrix effects during sampling and analysis mean that further development and optimization of methods to study subsurface life are needed. Phospholipid fatty acids (PLFA) are a useful biosignature of extant, viable microbial communities that are applied in a wide range of environments. Here we test the sensitivity of two methods of PLFA analysis (modified Bligh and Dyer, Microwave Assisted Extraction) to detect known numbers of cells doped into two distinct matrices (bentonite, crushed granite). Samples were prepared by adding known cellular concentrations of Basciullus subtilis subtilis (ATCC 6051) to crushed bentonite, or to granite, respectively, to create dilution series. Samples were extracted for PLFA using a dichloromethane-methanol modified Bligh & Dyer (mBD) or Microwave Assisted Extraction (MAE) and then quantified using GC - MS and GC - FID. Pure culture extractions yielded a linearly decreasing trend to the level of the process blank. The ratio of cells to PLFA for this trend was 2.4x104 +/- 1.9x104 cells/pmol at the lower end of the generic range of 2 to 6 x105 cells/pmol. For bentonite the PLFA results were lower than for the pure culture. PLFA results for bentonite followed a linear trend at higher concentrations, but departed from this at low concentrations indicating the potential for interference for low biomass samples. The ratio of cells to PLFA for the bentonite was to 6.2x104 +/- 4.5x104 cells/pmol, at the upper end of generic range. Ongoing comparison of the efficiency of microwave extraction and the effect of different matrices (e.g. granite) aims to optimize detection of PLFA for low biomass samples relevant to subsurface systems.

  12. Bacteriële meningitis

    NARCIS (Netherlands)

    Brouwer, M. C.; van de Beek, D.

    2012-01-01

    Bacterial meningitis is a severe disease which affects 35.000 Europeans each year and has a mortality rate of about 20%. During the past 25 years the epidemiology of bacterial meningitis has changed significantly due to the implementation of vaccination against Haemophilus influenzae, Neisseria

  13. Bacterial meningitis in immunocompromised patients

    NARCIS (Netherlands)

    van Veen, K.E.B.

    2018-01-01

    Bacterial meningitis is an acute infection of the meninges, in The Netherlands most commonly caused by Streptococcus pneumoniae and Neisseria meningitides. Risk factors for acquiring bacterial meningitis include a decreased function of the immune system. The aim of this thesis was to study

  14. HPC Analytics Support. Requirements for Uncertainty Quantification Benchmarks

    Energy Technology Data Exchange (ETDEWEB)

    Paulson, Patrick R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Purohit, Sumit [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Rodriguez, Luke R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-05-01

    This report outlines techniques for extending benchmark generation products so they support uncertainty quantification by benchmarked systems. We describe how uncertainty quantification requirements can be presented to candidate analytical tools supporting SPARQL. We describe benchmark data sets for evaluating uncertainty quantification, as well as an approach for using our benchmark generator to produce data sets for generating benchmark data sets.

  15. Quantification analysis of CT for aphasic patients

    International Nuclear Information System (INIS)

    Watanabe, Shunzo; Ooyama, Hiroshi; Hojo, Kei; Tasaki, Hiroichi; Hanazono, Toshihide; Sato, Tokijiro; Metoki, Hirobumi; Totsuka, Motokichi; Oosumi, Noboru.

    1987-01-01

    Using a microcomputer, the locus and extent of the lesions, as demonstrated by computed tomography, for 44 aphasic patients with various types of aphasia were superimposed onto standardized matrices, composed of 10 slices with 3000 points (50 by 60). The relationships between the foci of the lesions and types of aphasia were investigated on the slices numbered 3, 4, 5, and 6 using a quantification theory, Type 3 (pattern analysis). Some types of regularities were observed on Slices 3, 4, 5, and 6. The group of patients with Broca's aphasia and the group with Wernicke's aphasia were generally separated on the 1st component and the 2nd component of the quantification theory, Type 3. On the other hand, the group with global aphasia existed between the group with Broca's aphasia and that with Wernicke's aphasia. The group of patients with amnestic aphasia had no specific findings, and the group with conduction aphasia existed near those with Wernicke's aphasia. The above results serve to establish the quantification theory, Type 2 (discrimination analysis) and the quantification theory, Type 1 (regression analysis). (author)

  16. Quantification of Cannabinoid Content in Cannabis

    Science.gov (United States)

    Tian, Y.; Zhang, F.; Jia, K.; Wen, M.; Yuan, Ch.

    2015-09-01

    Cannabis is an economically important plant that is used in many fields, in addition to being the most commonly consumed illicit drug worldwide. Monitoring the spatial distribution of cannabis cultivation and judging whether it is drug- or fiber-type cannabis is critical for governments and international communities to understand the scale of the illegal drug trade. The aim of this study was to investigate whether the cannabinoids content in cannabis could be spectrally quantified using a spectrometer and to identify the optimal wavebands for quantifying the cannabinoid content. Spectral reflectance data of dried cannabis leaf samples and the cannabis canopy were measured in the laboratory and in the field, respectively. Correlation analysis and the stepwise multivariate regression method were used to select the optimal wavebands for cannabinoid content quantification based on the laboratory-measured spectral data. The results indicated that the delta-9-tetrahydrocannabinol (THC) content in cannabis leaves could be quantified using laboratory-measured spectral reflectance data and that the 695 nm band is the optimal band for THC content quantification. This study provides prerequisite information for designing spectral equipment to enable immediate quantification of THC content in cannabis and to discriminate drug- from fiber-type cannabis based on THC content quantification in the field.

  17. Source Specific Quantification, Characterisation and Management of ...

    African Journals Online (AJOL)

    The most important aspect of solid waste management is the quantity and characteristics of waste to be managed. Lapai town lacks data on quantity of waste generated and their characteristics for efficient and sustainable waste management. This study is the quantification, characterisation and management of solid waste ...

  18. Recurrence quantification analysis in Liu's attractor

    International Nuclear Information System (INIS)

    Balibrea, Francisco; Caballero, M. Victoria; Molera, Lourdes

    2008-01-01

    Recurrence Quantification Analysis is used to detect transitions chaos to periodical states or chaos to chaos in a new dynamical system proposed by Liu et al. This system contains a control parameter in the second equation and was originally introduced to investigate the forming mechanism of the compound structure of the chaotic attractor which exists when the control parameter is zero

  19. Colour thresholding and objective quantification in bioimaging

    Science.gov (United States)

    Fermin, C. D.; Gerber, M. A.; Torre-Bueno, J. R.

    1992-01-01

    Computer imaging is rapidly becoming an indispensable tool for the quantification of variables in research and medicine. Whilst its use in medicine has largely been limited to qualitative observations, imaging in applied basic sciences, medical research and biotechnology demands objective quantification of the variables in question. In black and white densitometry (0-256 levels of intensity) the separation of subtle differences between closely related hues from stains is sometimes very difficult. True-colour and real-time video microscopy analysis offer choices not previously available with monochrome systems. In this paper we demonstrate the usefulness of colour thresholding, which has so far proven indispensable for proper objective quantification of the products of histochemical reactions and/or subtle differences in tissue and cells. In addition, we provide interested, but untrained readers with basic information that may assist decisions regarding the most suitable set-up for a project under consideration. Data from projects in progress at Tulane are shown to illustrate the advantage of colour thresholding over monochrome densitometry and for objective quantification of subtle colour differences between experimental and control samples.

  20. Molecular approaches for bacterial azoreductases

    Directory of Open Access Journals (Sweden)

    Montira Leelakriangsak

    2013-12-01

    Full Text Available Azo dyes are the dominant types of synthetic dyes, widely used in textiles, foods, leather, printing, tattooing, cosmetics, and pharmaceutical industries. Many microorganisms are able to decolorize azo dyes, and there is increasing interest in biological waste treatment methods. Bacterial azoreductases can cleave azo linkages (-N=N- in azo dyes, forming aromatic amines. This review mainly focuses on employing molecular approaches, including gene manipulation and recombinant strains, to study bacterial azoreductases. The construction of the recombinant protein by cloning and the overexpression of azoreductase is described. The mechanisms and function of bacterial azoreductases can be studied by other molecular techniques discussed in this review, such as RT-PCR, southern blot analysis, western blot analysis, zymography, and muta-genesis in order to understand bacterial azoreductase properties, function and application. In addition, understanding the regulation of azoreductase gene expression will lead to the systematic use of gene manipulation in bacterial strains for new strategies in future waste remediation technologies.