Visual and fluorescence characterisation of particulate aerosols in ice cores with imaging flow cytometry

2020 ◽  
Author(s):  
Matthew Harris ◽  
Chris Fogwill ◽  
Ann Power ◽  
Chris Turney ◽  
John Love ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Ice Cores ◽  
Ocean Dynamics ◽  
Back Trajectory ◽  
Hysplit Model ◽  
Back Trajectory Analysis ◽  
Standard Flow Cytometry ◽  
Exciting Potential ◽  
Pre Treatment ◽  
Nucleic Acid Stain

<p>Current efforts to examine and quantify so-called ‘biomarkers’ present in polar ice samples offer exciting potential as biological and biochemical proxies for past climate and ocean dynamics. Here we present a new rapid and easily replicable method to provide measurements of the microscopic particulate content of ice samples from polar environments. Using an Amnis® Imagestream® Imaging Flow Cytometer, melted snow and ice samples from Patriot Hills in the Ellsworth Mountains, Antarctica were analysed for their particulate (biological and non-biological) content. Selective use of a nucleic acid stain pre-treatment allows for a straightforward gating strategy that resolves both autofluorescent and non-autofluorescent biological material in sample replicates. In the Patriot Hills samples this method clearly identifies marine picoplankton, along with non-biological particulates such as tephra and minerogenic material. Crucially, the 60x Brightfield images provided by the Imagestream offer a significant additional capability above standard flow cytometry systems; each object identified by the machine can be visually differentiated (automatically or manually) from particulates with similar fluorescence properties. Back-trajectory analysis with the NOAA Hybrid Single-Particle Lagrangian Integrated Trajectory (HySPLIT) model indicates that these ice-bound marine organisms originate from the Weddell and Amundsen-Bellingshausen Seas. This technique, when paired with established chemical and biochemical methods, shows considerable potential in providing valuable information about the nature and origin of aerosols and biomarker signals trapped in past ice layers.</p>

scholarly journals Use of Low-Cost Ambient Particulate Sensors in Nablus, Palestine with Application to the Assessment of Regional Dust Storms

Atmosphere ◽  
2019 ◽  
Vol 10 (9) ◽  
pp. 539
Author(s):  
Abdelhaleem Khader ◽  
Randal S. Martin
Keyword(s):  
Low Cost ◽  
Dust Storms ◽  
Air Pollutant ◽  
World Health ◽  
Back Trajectory ◽  
Hysplit Model ◽  
Air Masses ◽  
Palestinian Territories ◽  
Back Trajectory Analysis ◽  
Lower Elevation

Few air pollutant studies within the Palestinian territories have been reported in the literature. In March–April and May–June of 2018, three low-cost, locally calibrated particulate monitors (AirU’s) were deployed at different elevations and source areas throughout the city of Nablus in Northern West Bank, Palestine. During each of the three-week periods, high but site-to-site similar particulate matter less than 2.5 µm in aerodynamic diameter (PM2.5) and less than 10 µm (PM10) concentrations were observed. The PM2.5 concentrations at the three sampling locations and during both sampling periods averaged 38.2 ± 3.6 µg/m3, well above the World Health Organization’s (WHO) 24 h guidelines. Likewise, the PM10 concentrations exceeded or were just below the WHO’s 24 h guidelines, averaging 48.5 ± 4.3 µg/m3. During both periods, short episodes were identified in which the particulate levels at all three sites increased substantially (≈2×) above the regional baseline. Air mass back trajectory analyses using U.S. National Oceanic and Atmospheric Administration’s (NOAA) Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model suggested that, during these peak episodes, the arriving air masses spent recent days over desert areas (e.g., the Saharan Desert in North Africa). On days with regionally low PM2.5 concentrations (≈20 µg/m3), back trajectory analysis showed that air masses were directed in from the Mediterranean Sea area. Further, the lower elevation (downtown) site often recorded markedly higher particulate levels than the valley wall sites. This would suggest locally derived particulate sources are significant and may be beneficial in the identification of potential remediation options.

scholarly journals Linking ground-satellite observations with HYSPLIT Back trajectory modeling to identify dust sources affecting Western Iran: A case study in Lorestan province

2021 ◽  
Vol 8 (2) ◽  
pp. 77-86
Author(s):  
Elham Borna ◽  
Maryam Kiani Sadr ◽  
Seyed Ahmad Hosseini
Keyword(s):  
Dust Storms ◽  
Satellite Observations ◽  
Dust Exposure ◽  
Back Trajectory ◽  
Zagros Mountains ◽  
Hysplit Model ◽  
Western Iran ◽  
Back Trajectory Analysis ◽  
Dust Sources ◽  
Spatial Coverage

Background: This study combined ground and satellite observations with the results of HYSPLIT model to identify the origin, transport, and deposition of sand and dust storms (SDSs) affecting Western Iran. Methods: Field-measured dust exposure data were obtained during 2000-2014 to analyze variability of dust concentration and dust intensity at annual, monthly, and daily scales. Remote sensing measurements in this research include the analysis of a total of eight (Level 1B Calibrated Radiances 1 km (MOD021KM)) MODIS tiles selected based on interpreting the results of ground observations to capture the major SDS events occurred between 2000 and 2014. Results: The results, indicating a sharp rise in the number of dusty days from 2008 onwards, were used as a basis to identify the spatial coverage and intensity of SDSs over the central part of the Middle East and the study province using a number of eight MODIS images. According to the back trajectory analysis of Hybrid Single-Particle Lagrangian Integrated Trajectory Model (HYSPLIT), the MODIS-derived SDSs were found to have both national and international sources. The most prevalent and powerful source was likely to initiate from deserts of Syria and Iraq by air masses coming from the Mediterranean Sea and terminate in Western Iran where the Zagros Mountains Chain blocks easterly winds. Conclusion: Despite the evident link between timing of regional SDSs and in situ observations, the contribution of local dust sources in the west of the province should be also investigated to provide insights into the development and spread of SDS events affecting Western Iran, especially Lorestan Province.

scholarly journals Cupressaceae Pollen in the City of Évora, South of Portugal: Disruption of the Pollen during Air Transport Facilitates Allergen Exposure

Forests ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 64
Author(s):  
Ana Galveias ◽  
Ana R. Costa ◽  
Daniele Bortoli ◽  
Russell Alpizar-Jara ◽  
Rui Salgado ◽  
...  
Keyword(s):  
Wind Speed ◽  
Ornamental Plants ◽  
Global Solar Radiation ◽  
Early Spring ◽  
Back Trajectory ◽  
Late Winter ◽  
Hysplit Model ◽  
Back Trajectories ◽  
Factors Affecting ◽  
Back Trajectory Analysis

Research Highlights: Daily airborne Cupressaceae pollen disruption ranged from 20 to 90%; relative humidity (RH), rainfall and atmospheric pressure (AtP) were the major meteorological determinants of this phenomenon. Background and Objectives: Cupressaceae family includes several species that are widely used as ornamental plants pollinating in late winter-early spring and might be responsible for allergic outbreaks. Cupressaceae pollen disruption may favour allergen dissemination, potentiating its allergenicity. The aim of this work was to characterize the Cupressaceae pollen aerobiology in Évora, South of Portugal, in 2017 and 2018, particularly the pollen disruption, and to identify the meteorological parameters contributing to this phenomenon. Materials and Methods: Pollen was collected using a Hirst type 7-day pollen trap and was identified following the standard methodology. Temperature, RH, rainfall, global solar radiation (Global Srad), AtP, wind speed and direction were obtained from a weather station installed side-by-side to the Hirst platform. Back trajectories (12-h) of air masses arriving at Évora were calculated using the HYSPLIT model. Results: Cupressaceae pollen index was higher in 2017 compared to 2018 (>5994 and 3175 pollen/m3, respectively) and 36 ± 19% (2017) and 59 ± 23% (2018) of the pollen was disrupted. Higher levels of disrupted pollen coincided with RH > 60% and rainfall. Temperature, Global Srad and AtP correlated negatively with pollen disruption. Wind speed and wind direction did not significantly correlate with pollen disruption. Intra-diurnal pollen pattern peaked between 9:00 am–2:00 pm, suggesting local origin, confirmed by the back trajectory analysis. Intra-diurnal pollen disruption profile followed hourly pollen pattern and it negatively correlated with AtP, temperature and Global Srad but was uncorrelated with RH. Conclusions: The results suggest that RH, rainfall and AtP are the main factors affecting airborne Cupressaceae pollen integrity and in conjunction with daily pollen concentration may be used to predict the risk of allergy outbreaks to this pollen type.

scholarly journals Aerobiology in High Latitudes: Evidence of Bacteria Acting as Tracer of Warm Air Mass Advection reaching Northern Antarctic Peninsula

2021 ◽  
Author(s):  
CESAR R.L. AMARAL ◽  
Alexandre Alencar ◽  
Marcelo Sampaio ◽  
Emanuele Kuhn ◽  
Vivian Pellizari ◽  
...  
Keyword(s):  
Antarctic Peninsula ◽  
Back Trajectory ◽  
Wind Component ◽  
Species Classification ◽  
Hysplit Model ◽  
Air Mass ◽  
Geochemical Tracers ◽  
Back Trajectory Analysis ◽  
Southern Patagonia ◽  
The Antarctic

Despite the extent use of geochemical tracers to track warm air mass origin reaching the Antarctic continent, we present here evidences that microorganisms being transported by the atmosphere and deposited in fresh snow layers of Antarctic ice sheets do act as tracers of air mass advection from the Southern Patagonia region to Northern Antarctic Peninsula. We combined atmospheric circulation data with microorganism content in snow/firn samples collected in two sites of the Antarctic Peninsula (King George Island/Wanda glacier and Detroit Plateau) by using flow cytometer quantification. In addition, we cultivated, isolated and submitted samples to molecular sequencing to precise species classification. Viable gram-positive bacteria were found and recovered in different snow/firn layers samples, among dead and living cells, their number concentration was compared to northern wind component, stable isotopes of oxygen, and the concentration of crustal elements (Fe, Ti and Ca). Use of satellite images combined with air mass back-trajectory analysis obtained from the NOAA/ HYSPLIT model corroborated the results.

scholarly journals Measuring Biofouling Potential in SWRO Plants with a Flow-Cytometry-Based Bacterial Growth Potential Method

Membranes ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 76
Author(s):  
Nirajan Dhakal ◽  
Sergio G. Salinas-Rodriguez ◽  
Joshua Ampah ◽  
Jan C. Schippers ◽  
Maria D. Kennedy
Keyword(s):  
Flow Cytometry ◽  
Bacterial Growth ◽  
Potential Method ◽  
Absolute Number ◽  
Growth Potential ◽  
Added Value ◽  
Feed Water ◽  
Dissolved Air Flotation ◽  
Ultra Filtration ◽  
Pre Treatment

Measuring the bacterial growth potential of seawater reverse osmosis (SWRO) feed water is an issue that is receiving growing attention. This study developed and demonstrated the applicability of the flow-cytometry (FCM)-based bacterial growth potential (BGP) method to assess the biofouling potential in SWRO systems using natural microbial consortium. This method is relatively fast (2–3 days) compared to conventional bioassays. The effect of the potential introduction of nutrients during measurement has been studied thoroughly to achieve the lowest measure value of about 45,000 cells/mL, which is equivalent to about (10 µg-C glucose/L). The BGP method was applied in two full-scale SWRO plants that included (i) dissolved air flotation (DAF) and ultra-filtration (UF); (ii) dual-media filtration (DMF) and cartridge filter (CF), which were compared with the cleaning frequency of the plants. A significant reduction (54%) in BGP was observed through DAF–UF as pre-treatment (with 0.5 mg Fe3+/L), while there was a 40% reduction by DMF–CF (with 0.8 mg Fe3+/L). In terms of the absolute number, the SWRO feed water after DAF–UF supports 1.5 × 106 cells/mL, which is 1.25 times higher than after DMF–CF. This corresponds to the higher cleaning-in-place (CIP) frequency of SWRO with DAF–UF compared to DMF–CF as pre-treatment, indicating that the BGP method has an added value in monitoring the biofouling potential in SWRO systems.

scholarly journals Randomized Open-Labeled Academic Trial Comparing Standard AZA Therapy with Combination of G-CSF with AZA in High Risk MDS Patients - Interim Analysis

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 1729-1729
Author(s):  
Anna Jonasova ◽  
Lubomir Minarik ◽  
Vojtech Kulvait ◽  
Michal Pesta ◽  
Adel Schaffartzikova ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Mixed Model ◽  
Proportional Hazards Model ◽  
Patient Survival ◽  
Conflicts Of Interest ◽  
Cox Proportional Hazards ◽  
Cox Proportional Hazards Model ◽  
P Value ◽  
Pre Treatment ◽  
Time Varying Covariates

Introduction: Myelodysplastic syndrome (MDS) is characterized by differentiation blockade, cytopenias with commontransfusion dependency and immune defects. Upon progression the myeloblasts accumulate and the patients become vulnerable to severe infection complications. Based on the Prague Charles University General Hospital registry (N=164, median age 73), the AZA therapy in higher-risk MDS patients results in median OS 13.8 Mo with ORR 48.5%. We also noted from our retrospective data that AZA-treated patients with higher G-CSF consumption had significantly reduced occurrence of Grade 4 neutropenias and longer OS (19 vs 16 Mo, p value 0.039). Rationale: To improve poor clinical outcomes we initiated a randomized open labeled academic trial that compares standard AZA therapy (A) with novel AZA-based therapy combination involving use of G-CSF added prior AZA (GA). Both AZA and also decitabine were preclinically shown to induce myeloid differentiation upon G-CSF preincubation. G-CSF binds its receptor in granulocytic precursors and neutrophils to stimulate their survival, proliferation, and differentiation via myeloid master regulator transcription factor and leukemia-suppressor PU.1. We also have previously shown that AZA increases PU.1. expression. Study design & Methods: GA/MDS-2013 (EudraCT No 2013-001639-38). Expected for enrollment are 134 patients, currently enrolled 53 patients (GA arm N=29, A arm N=24) with median age 74 years, M:F ratio 32:21 (GA 16:16, A 13:8),median IPSS-R 6, median follow up 11.2 Mo, median cycles of therapy 6. Diagnosis included:MDS (EB1, EB 2) with IPSS int-2/high (75%), MDS/AML<30% MB (22.5%), and CMML II (2.5%). Transplant candidates were excluded. Randomization is 2:1 for GA vs A arm. Primary endpoints: OS, PFS, time to AML transformation, ORR, infections & QoL. Secondary endpoints: biomarkers. Therapy schedule: 75mg/m2 of AZA 5-2-2, in GA: G-CSF s.c. injected 48 hrs before dose 1 and dose 6. G-CSF is measured in patient sera (prior therapy), myeloid surface markers are determined by flow cytometry (day -2, day 1, and day 9 of cycle 1). Genomic libraries from whole bone marrow are prepared by NEBNext Direct Kit involving 33 gene panel, sequencing runs are performed on Illumina platform. Statistics involved longitudinal multivariate data analysis including the joint models for the OS and response. Results: The presented data include 2.5 years since the beginning of the trial. Median survival for GA arm was 11 vs 6 Mo in the A arm. ORR (CR, CRm, PR, HI) was 56% in GA arm vs 33% in the A arm. Transformation to AML for both arms was comparable. The stratified longitudinal Cox proportional hazards model containing time-varying covariates together with the ordinal multilevel logistic mixed model were utilized. From this joint fitted model, a negative coefficient for the G-AZA treatment (significant p-value 0.0442) can be noticed in the case of the Cox Proportional Hazard part of the model. This means that G-AZA treatment improves patient survival. The estimated odds for the GA arm that responded to the therapy with remission rather than progression is 12.4x higher than for the A arm, controlling for the remaining patients' characteristics (p-value 0.0016).Both the GA and A arms are comparably tolerated. Data on serious infections and neutropenia gr4 were not yet available. The levels of G-CSF in sera prior the study in both arms (GA vs A) were comparable. Flow cytometry revealed G-CSF mediated upregulation of FCgRI (CD64) in the GA but not in the A arm. Multivariate analysis indicates the following: mutated genes: DNMT3A (p-value 0.0157), EZH2 (p-value 0.0091), TP53 (borderline p-value 0.0510), & CSF3R (p-value 0.0057) shorten the overall survival. The significant negative effects on response was noted for mutated EZH2 (p-value 0.0208) and CSF3R (p-value 0.0424) genes. Conclusions: The current results supported by different methods and statistics indicates a beneficial effect of G-CSF pre-treatment to standard AZA therapy in higher risk MDS patients. G-CSF pre-treatment to AZA increases OS and ORR. In addition, we identified biomarkers that are negatively associated with patient survival and response including EZH2, DNMT3A, TP53, & CSF3R. Grant Support: Ministry of Health, #16-27790A. Institutional resources: Progres Q49 & Q26, UNCE/MED/016, LQ1604, SVV 260374/2017, RVO-64165. Disclosures No relevant conflicts of interest to declare.

scholarly journals An investigation of processes controlling the evolution of the boundary layer aerosol size distribution properties at the Swedish background station Aspvreten

2004 ◽  
Vol 4 (4) ◽  
pp. 4507-4543 ◽  
Author(s):  
P. Tunved ◽  
J. Ström ◽  
H.-C. Hansson
Keyword(s):  
Size Distribution ◽  
Wet Deposition ◽  
Source Area ◽  
Aerosol Size Distribution ◽  
Back Trajectory ◽  
Main Process ◽  
Size Distributions ◽  
Back Trajectory Analysis ◽  
The One ◽  
Precipitating Clouds

Abstract. Aerosol size distributions have been measured at the Swedish background station Aspvreten (58.8° N, 17.4° E). Different states of the aerosol were determined using a novel application of cluster analysis. The analysis resulted in eight different clusters capturing the different stages of the aerosol lifecycle. The aerosol was interpreted as belonging to fresh, intermediate and aged type of size distribution and different magnitudes thereof. With aid of back trajectory analysis we present statistics concerning the relation of source area and different meteorological parameters using a non-lagrangian approach. Source area is argued to be important although not sufficient to describe the observed aerosol properties. Especially processing by clouds and precipitation is shown to be crucial for the evolution of the aerosol size distribution. As much as 60% of the observed size distributions present features likely related to cloud processes or wet deposition. The lifetime properties of different sized aerosols are discussed by means of measured variability. Processing by non-precipitating clouds most obviously affect aerosols in the size range 100 nm and larger. This indicates an approximate limit for activation in clouds to 100 nm in this type of environment. The aerosol lifecycle is discussed. Size distributions bearing signs of recent new particle formation (~30% of the observed size distributions) represent the first stage in the lifecycle. Aging may proceed in two directions: either growth by condensation and coagulation or processing by non-precipitating clouds. In both cases mass is accumulated. Wet removal is the main process capable of removing aerosol mass. Wet deposition is argued to be an important mechanism in reaching a state where nucleation may occur (i.e. sufficiently low aerosol surface area) in environments similar to the one studied.

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