Stationary Sites Research Articles

Experimental Investigation of Ocean Wave Measurement Using Short-Range K-Band Radar: Dock-Based and Boat-Based Wind Wave Measurements

In this paper, an ocean wave measurement technique and a newly developed short-range K-band radar are tested. In previous work, the technique and its feasibility were studied based on numerical simulations and wave tank experiments, while its performance at sea was still unknown. Surface current, Stokes drift, and wave breaking can greatly complicate interpreting radar backscatters. The feasibility of the technique needed to be further investigated with sea experiments. Experiments were carried out at a stationary site and from a moving platform. The short-range K-band radar transmitted continuous wave and received backscatters at low-grazing angles. The Bragg-scattering from the radar’s effective footprint dominated the backscatters. The Doppler shift frequency of the Bragg-scattering was attributed to the phase velocity of Bragg waves and modulated by the surface motions induced by current, Stokes drift, platform, and gravity waves. These sources of the Doppler shift frequency were analyzed, and the components induced by wind waves were successfully retrieved and converted into wave spectra that were consistent with the measurements of wave rider buoy. The experimental investigation further validated the feasibility of using short-range K-band radar to measure ocean waves.

Sex-specific difference in migration schedule as a precursor of protandry in a long-distance migratory bird.

Protandry, the earlier arrival of males at the breeding grounds relative to females, is common in migratory birds. However, due to difficulties in following individual birds on migration, we still lack knowledge about the spatiotemporal origin of protandry during the annual cycle, impeding our understanding of the proximate drivers of this phenomenon. Here, we use full annual cycle tracking data of red-backed shrikes Lanius collurio to investigate the occurrence of sex-related differences in migratory pattern, which could be viewed as precursors (proximate causes) to protandry. We find protandry with males arriving an estimated 8.3days (SE = 4.1) earlier at the breeding area than females. Furthermore, we find that, averaged across all departure and arrival events throughout the annual cycle, males migrate an estimated 5.3days earlier than females during spring compared to 0.01days in autumn. Event-wise estimates suggest that a divergence between male and female migratory schedules is initiated at departure from the main non-breeding area, thousands of kilometres from-, and several months prior to arrival at the breeding area. Duration of migration, flight speed during migration and spatial locations of stationary sites were similar between sexes. Our results reveal that protandry might arise from sex-differential migratory schedules emerging at the departure from the main non-breeding area in southern Africa and retained throughout spring migration, supporting the view that sex-differential selection pressure operates during spring migration rather than autumn migration.

Black Carbon and Particulate Matter Concentrations in Eastern Mediterranean Urban Conditions: An Assessment Based on Integrated Stationary and Mobile Observations

There is a paucity of comprehensive air quality data from urban areas in the Middle East. In this study, portable instrumentation was used to measure size-fractioned aerosol number, mass, and black carbon concentrations in Amman and Zarqa, Jordan. Submicron particle number concentrations at stationary urban background sites in Amman and Zarqa exhibited a characteristic diurnal pattern, with the highest concentrations during traffic rush hours (2–5 × 104 cm−3 in Amman and 2–7 × 104 cm−3 in Zarqa). Super-micron particle number concentrations varied considerably in Amman (1–10 cm−3). Mobile measurements identified spatial variations and local hotspots in aerosol levels within both cities. Walking paths around the University of Jordan campus showed increasing concentrations with proximity to main roads with mean values of 8 × 104 cm−3, 87 µg/m3, 62 µg/m3, and 7.7 µg/m3 for submicron, PM10, PM2.5, and black carbon (BC), respectively. Walking paths in the Amman city center showed moderately high concentrations (mean 105 cm−3, 120 µg/m3, 85 µg/m3, and 8.1 µg/m3 for submicron aerosols, PM10, PM2.5, and black carbon, respectively). Similar levels were found along walking paths in the Zarqa city center. On-road measurements showed high submicron concentrations (>105 cm−3). The lowest submicron concentration (<104 cm−3) was observed near a remote site outside of the cities.

Inference of genetic forces using a Poisson random field model with non-constant population size

Aligned DNA sequences have been widely used for quantitatively analyzing and interpreting evolutionary processes. By comparing the information between intraspecific polymorphism with interspecific divergence in two sibling species, Poisson random field (PRF) theory offers a statistical framework with which various genetic parameters such as natural selection intensity, mutation rate and speciation time can be effectively estimated. A recently developed time-inhomogeneous PRF model has reinforced the original method by removing the assumption of stationary site frequency, but it keeps the assumption that the two sibling species share same effective population size with their ancestral species. This paper explores a relaxation of this biologically unrealistic assumption by hypothesizing that each of the two descendant species experienced a sudden change in population size at the times of the divergence from their most recent common ancestor. The newly developed PRF model with non-constant population size is applied to a set of 91 genes in African population of Drosophila to make statistical inference of the various genetic parameters under a hierarchical Bayesian framework and carried out with a multi-layer Markov chain Monte Carlo sampling scheme. In order to meet the intensive computational demand, a R program is integrated with C++ code and a parallel executing technique is designed to run the program with multiple CPU cores.

Specific Features of Transport and Transformation of Atmospheric Aerosol and Gas Admixtures in the Coastal Zone of Lake Baikal

Diurnal dynamics of atmospheric gases and the meteorological characteristics of the atmosphere at different altitudes on the southeastern coast of Lake Baikal are experimentally studied. The measurements were performed at the Boyarsky stationary site (51.84° N, 106.06° E) in July–August 2015–2016. Simultaneously, lidar measurements were carried out to study the formation of the vertical structure of aerosol fields both under natural (background) conditions and in the presence of sources of smoke from forest fires.

Determination of Fucose Concentration in a Lectin-Based Displacement Microfluidic Assay

We compare three different methods to quantify the monosaccharide fucose in solutions using the displacement of a large glycoprotein, lactoferrin. Two microfluidic analysis methods, namely fluorescence detection of (labeled) lactoferrin as it is displaced by unlabeled fucose and the displacement of (unlabeled) lactoferrin in SPR, provide fast responses and continuous data during the experiment, theoretically providing significant information regarding the interaction kinetics between the saccharide groups and binding sites. For comparison, we also performed a static displacement ELISA. The stationary binding site in all cases was immobilized S2-AAL, a monovalent polypeptide based on Aleuria aurantia lectin. Although all three assays showed a similar dynamic range, the microfluidic assays with fluorescent or SPR detection show an advantage in short analysis times. Furthermore, the microfluidic displacement assays provide a possibility to develop a one-step analytical platform.

Annual GPS tracking reveals unexpected wintering area in a long-distance migratory songbird

Recent technological development has made it possible to pinpoint precise locations of small migratory songbirds throughout their annual cycle, providing the opportunity for improving our understanding of year-round habitat use. Here, we use GPS loggers to map the exact location and habitat use at stationary sites throughout the annual cycle of a long-distance migratory songbird, the Red-backed Shrike Lanius collurio. Although the main staging sites confirmed previous findings from light-level geolocation studies, one individual wintered in south-western Chad, an area with only a few historical records of this species. This study highlights opportunities for answering new questions and gaining more knowledge using fine-scale tracking of migratory songbirds.

Assessment and management of pesticide pollution at a river basin level part II: Optimization of pesticide monitoring networks on surface aquatic ecosystems by data analysis methods

The high cost of extensive pesticide monitoring studies, required for the protection of water resources, and the necessity of early identification of environmental threats, highlighted the need for prioritization of pesticides and sampling sites to be monitored. The aim of this study was to develop an optimum surface water monitoring network at a catchment scale including only the sites of a catchment vulnerable to pesticide pollution. The identification of sampling sites vulnerable to pesticide pollution (VPS) was based on the data of an intensive monitoring survey of 302 pesticides in 102 stationary sampling sites located on the surface water network of a river basin. In the proposed methodology the left-censored data of the analytical results derived from the above mentioned monitoring campaign were included in the statistical analyses by transforming all the raw data into categorical variables and arranging them in ordinal scales based on ecotoxicological thresholds derived from pesticide toxicity tests on aquatic non-target organisms. The categorized data were subjected to Categorical Principal Component Analysis with Optimal Scaling. For the identification of the VPS, the Squared Mahalanobis Distance criterion was applied on the extracted values (scores) of the significant principal components. With this methodology a 46% reduction in the number of the monitoring stations was achieved. This approach will be valuable in establishing more cost effective monitoring schemes in the future in other basins and in developing targeted measures to eliminate or limit the effect of critical pollution sources in surface aquatic systems. Moreover, by applying the proposed methodology, historical monitoring data can be used to initiate more efficient pesticide monitoring campaigns in the future.

Polyamine-appended porous organic polymers for efficient post-combustion CO2 capture

Carbon capture and sequestration (CCS) has been proposed to reduce CO2 emissions from large stationary sites such as coal-fired power plants. Currently, however, implementing CCS in power plants is not economically feasible due to the high expense of removing CO2 from flue gas. There is therefore an urgent need for cost-effective CO2 capture technologies, such as efficient solid adsorbents. In this study, we develop a facile strategy that converts a cost-effective porous organic polymer (denoted as PP), which is synthesized by Friedel-Crafts alkylation reaction of dichloro-p-xylene, into outstanding CO2 adsorbents through one-step post-synthesis functionalization with polyamines. Among the adsorbents synthesized, PP-2-DETA and PP-2-TEPA show superior high CO2 uptake capacities, excellent CO2 selectivity over N2, and appropriate Qst. Furthermore, the adsorbents show good CO2 uptake capacity and excellent stability toward both water vapor and regeneration cycles under dynamic flow conditions. Significantly, our samples exhibite much faster adsorption-desorption kinetics than mmen-Mg2(dobpdc) and MCM-41-NH2, which are two outstanding amine-functionalized adsorbents.

Combined interpretation of marine controlled source electromagnetic and reflection seismic data in the German North Sea: a case study

This paper focuses on the combined analysis and interpretation of controlled source electromagnetic (CSEM) and multichannel reflection seismic (MCS) data along one profile in the German North Sea with the goal to reduce ambiguities in interpretation. The shallow water environment of the North Sea is characterized by a complex geological development which includes rifting, several ice age cycles, a propagating shelf margin, mass-transport deposits and salt dome formation. Seismic and electromagnetic methods are sensitive to different physical properties of the seabed and therefore complement each other. We analyse the MCS data with a migration velocity tomography and an amplitude variation with offset analysis and discuss seismic velocities and densities. For true amplitude recovery the amplitude distortions are calibrated with in situ logging data. The CSEM data are analysed in 2-D, for which, for the first time, data were included that were acquired while the instrument was towed on the seafloor in addition to the stationary sites. The CSEM inversions are constrained by seismic horizons. The joint interpretation focuses on two seismic reflectors: One can be interpreted as an unconformity marking a lithological change from fresh water-bearing glacial deposits to compacted sediments below, and the other one as a layer of fine-grained deposits potentially capping patchy shallow gas occurrences. This exemplary case study shows how the combination of both methods can benefit by interpreting complex geology and eliminating ambiguous explanations.

The Sky's the Limit: 3D Air Pollution Sensing Using Drones

Current air quality monitoring networks rely on stationary sites, which do not effectively capture transient and localized pollutants such as methane leakage and anthropogenic volatile organic comp...

Full-year tracking suggests endogenous control of migration timing in a long-distance migratory songbird

Following ongoing technological advances, an increasing amount of full-year tracking data on individual migratory movements is becoming available. This opens up the opportunity to study how migration develops within individuals in consecutive years and the extent to which the migratory program is constrained. Such knowledge is essential for understanding the degree of individual flexibility during the annual cycle, which may help identifying potential bottlenecks, where the range of individual decisions is restricted. In this study, we investigate repeatability in time of a long-distance migratory songbird, the red-backed shrike Lanius collurio, tracked across consecutive years (n = 7). Furthermore, we explore the population variability and dependencies between consecutive events of departure and arrival throughout the annual cycle in this species (n = 15). We find that individuals show high repeatability in timing of departure from their two main non-breeding areas in sub-Saharan Africa. In contrast, low repeatability is found in timing of arrivals to stationary sites throughout the annual cycle. Population variation in timing of departure and arrival was similar across all events, ranging from 30 to 41 days, and was highly dependent on timing of preceding events. We conclude that timing of departures is the key event potentially controlled by the individual innate migration program, while arrivals are more flexible, likely dependent on the environmental conditions experienced en route in red-backed shrikes. Still, apparent flexibility in the individual schedule may be hampered by overall constraints of the annual cycle. The annual migration schedule of migratory animals is controlled by a combination of endogenous and exogenous factors. Understanding the temporal dynamics within and between individuals across the annual cycle is important to assess to which extent the migratory schedule is constrained in time. By using full-annual cycle tracking data of individual red-backed shrikes tracked across consecutive years, we find that individuals are highly consistent in their decision to depart from their main non-breeding areas in sub-Saharan Africa, whereas arrivals are less consistent throughout the annual cycle. Overall, the migration schedule is highly constrained across the annual cycle, with each arrival and departure event being dependent on the previous event. Our results suggest that departure decision is underlying endogenous control and that little flexibility is available throughout this complex migration system.

COMPLEX ELECTROMAGNETIC MONITORING OF GEODYNAMIC PROCESSES IN THE NORTHERN TIEN SHAN (BISHKEK GEODYNAMIC TEST AREA)

At the Bishkek geodynamic test area in the Northern Tien Shan, complex electromagnetic monitoring was conducted, including a wide frequency range by magnetotelluric sounding in various modifications and induction sounding with a controlled impulse source (method of sounding in the far zone, SFZ). The geoelectrical sections of the lithosphere were constructed for the study area. Based on the geophysical monitoring data and the profile MT moni‐ toring data on the Baitik depression, the main faults belonging to the Northern Tien Shan fault system were detected: Shamsi‐Tyundyuk (Predkirgizsky), Baitik, Chonkurchak, and Issyk‐Ata. From the geoelectrical data, we obtained new information that is independent of other geophysical methods used for studying the deep structure of the Earth – the hidden fault structures and the geoelectrical segmentation of the study area were revealed. The latter reflects the main elements of the block structure of the junction zone of the Chuya basin and the Kirghiz ridge. This information needs to be taken into account when constructing a comprehensive model showing the geological, geophysical and geodynamical features of the development of the Tien Shan, a vivid example of an intracontinental orogen. The MTS, FS and SFZ data from the Ak‐Suu and Chon‐Kurchak electromagnetic monitoring stations were interpreted. Based on the representative array of experimental electromagnetic data, we analyzed the effective depths of field penetration, which are most sensitive to changes in the electromagnetic parameters of the medium for the stationary and routine observation sites with respect to the clusters of seismic events. This paper discusses the development of the azimuth MT monitoring technique and the analysis of the time series of electromagnetic parameters, which were used for de‐ termining the contribution of each component of the impedance tensor to the informativeness of the monitoring stu‐ dies. The data from the 2004–2016 KNET Catalogue of the Research Station of RAS were analyzed in order to investi‐ gate the relationship between the space‐time seismicity distribution and the electrical conductivity variations that correspond to the features of the seismicity pattern at depth. Examples discussed are the time‐frequency series of MT monitoring in 2007 and 2016 at the Ak‐Suu and Chon‐Kurchak stations that identified anomalous electromagnetic parameters corresponding to the fluid redistribution model for the pore‐cracked medium: syn‐phase decreasing and increasing values of the parameter by the orthogonal azimuths. Thus, a phenomenological model has been tested. It relates the change in the stress‐strain state of the medium with the redistribution of fluids between the systems of fractures, which causes variations in the active and reactive components of the electrical resistance.

Urban Green Zones Planning Concept and Ecological Functionality (Through the Example of Poltava, Ukraine)

In the article major peculiarities and problems in architectural and planning decisions concerning Poltava urban greening are represented, and ways of solving them are suggested. The town’s green zones appropriation, their ecological, town-planning, sanitary and hygienic, recreational, and in case of some of them nature-sanctuary importance is considered. Structure and economical constituents of Poltava urban green zones planning, which represents average town urban ecosystems in the central (forest-steppe) zone of Ukraine, is analyzed. Maps and figures depicting typical schemes of manufacturing, transportation structure, density of population and urban greening are provided. Outraging of acceptable concentrations in dust and formaldehyde while analyzing urban atmospheric air pollution level according to the data obtained from stationary sites, is shown. These proves importance of taking into account consideration of interdependence between levels and locating of town’s natural resources polluting sources, first of all atmospheric air, with urban territory greening planned decisions. Based on materials concerning study of green zones ecological functionality effectiveness peculiarities, the concept of Poltava urban green zones planning is suggested. Modern town architectural and planning decisions ecological aspects should be integrated into local strategies and development programs, town general lay-outs, transportation systems planning, strategy referring environmental protection, and require local self-government and state support.

Combining Measurements from Mobile Monitoring and a Reference Site To Develop Models of Ambient Ultrafine Particle Number Concentration at Residences.

Significant spatial and temporal variation in ultrafine particle (UFP; <100 nm in diameter) concentrations creates challenges in developing predictive models for epidemiological investigations. We compared the performance of land-use regression models built by combining mobile and stationary measurements (hybrid model) with a regression model built using mobile measurements only (mobile model) in Chelsea and Boston, MA (USA). In each study area, particle number concentration (PNC; a proxy for UFP) was measured at a stationary reference site and with a mobile laboratory driven along a fixed route during an ∼1-year monitoring period. In comparing PNC measured at 20 residences and PNC estimates from hybrid and mobile models, the hybrid model showed higher Pearson correlations of natural log-transformed PNC ( r = 0.73 vs 0.51 in Chelsea; r = 0.74 vs 0.47 in Boston) and lower root-mean-square error in Chelsea (0.61 vs 0.72) but no benefit in Boston (0.72 vs 0.71). All models overpredicted log-transformed PNC by 3-6% at residences, yet the hybrid model reduced the standard deviation of the residuals by 15% in Chelsea and 31% in Boston with better tracking of overnight decreases in PNC. Overall, the hybrid model considerably outperformed the mobile model and could offer reduced exposure error for UFP epidemiology.

Reduction of atmospheric fine particle level by restricting the idling vehicles around a sensitive area

ABSTRACTAtmospheric particles are a major problem that could lead to harmful effects on human health, especially in densely populated urban areas. Chiayi is a typical city with very high population and traffic density, as well as being located at the downwind side of several pollution sources. Multiple contributors for PM2.5 (particulate matter with an aerodynamic diameter ≥2.5 μm) and ultrafine particles cause complicated air quality problems. This study focused on the inhibition of local emission sources by restricting the idling vehicles around a school area and evaluating the changes in surrounding atmospheric PM conditions. Two stationary sites were monitored, including a background site on the upwind side of the school and a campus site inside the school, to monitor the exposure level, before and after the idling prohibition. In the base condition, the PM2.5 mass concentrations were found to increase 15% from the background, whereas the nitrate (NO3−) content had a significant increase at the campus site. The anthropogenic metal contents in PM2.5 were higher at the campus site than the background site. Mobile emissions were found to be the most likely contributor to the school hot spot area by chemical mass balance modeling (CMB8.2). On the other hand, the PM2.5 in the school campus fell to only 2% after idling vehicle control, when the mobile source contribution reduced from 42.8% to 36.7%. The mobile monitoring also showed significant reductions in atmospheric PM2.5, PM0.1, polycyclic aromatic hydrocarbons (PAHs), and black carbon (BC) levels by 16.5%, 33.3%, 48.0%, and 11.5%, respectively. Consequently, the restriction of local idling emission was proven to significantly reduce PM and harmful pollutants in the hot spots around the school environment.Implications: The emission of idling vehicles strongly affects the levels of particles and relative pollutants in near-ground air around a school area. The PM2.5 mass concentration at a campus site increased from the background site by 15%, whereas NO3− and anthropogenic metals also significantly increased. Meanwhile, the PM2.5 contribution from mobile source in the campus increased 6.6% from the upwind site. An idling prohibition took place and showed impressive results. Reductions of PM2.5, ionic component, and non-natural metal contents were found after the idling prohibition. The mobile monitoring also pointed out a significant improvement with the spatial analysis of PM2.5, PM0.1, PAH, and black carbon concentrations. These findings are very useful to effectively improve the local air quality of a densely city during the rush hour.

COMPREHENSIVE STUDY OF ATMOSPHERIC POLLUTION IN CITIES

Assessment of air pollution level of Poltava is performed by using statistical data of enterprises inventory, stationary sites and results of calculations by program EOL-2000. Assessment and correlation the results by new researches (bioindication, air pollution indexes) according to the standards of Ukraine and the world ones are performed. The possibility of performance the further project for an impact of technology-related air pollution on the environment and human health is proved. Implementation of GIS for monitoring the air pollution of Poltava is proposed. This system can be used as a model of such GIS for other similar cities. The process of occurrence of the heat-island affect over cities and its influence on the atmospheric component is described. The importance and efficiency of the comprehensive study of atmospheric air pollution in cities are proved.

The Economics of Biomass Logistics and Conversion Facility Mobility: An Oregon Case Study

Abstract. This article presents an analysis of transportable biomass conversion facilities to evaluate the conceptual and economic viability of a highly mobile and modular biomass conversion supply chain in the Pacific Northwest of the United States. The goal of this work is to support a broader effort to more effectively and sustainably use residual biomass from commercial harvesting operations that are currently piled and burned as part of site preparation. A structural representation is first developed to include sources of biomass feedstock, distributed preprocessing hubs (centralized landings), and centralized processing facilities (biomass to product conversion sites) to produce desired products and byproducts. A facility costing model was developed to evaluate potential economics of scale, which then informed the optimization study. A mixed integer linear programming model was developed to characterize, evaluate, and optimize biomass collection, extraction, logistics, and facility placement over a regional landscape from a strategic level to evaluate the mobility concept. The objective was to minimize supply chain operational costs in order to quantify financial advantages and identify challenges of the proposed system modularity and mobility. A Lakeview, Oregon case study was evaluated with an assumed modular biochar facility servicing the region. In particular, we review economies of scale, mobility, energy costs, and biomass availability tradeoffs. This analysis points towards a modular system design of movement frequency between 1 to 2 years being most viable in the conditions evaluated. It was found that the impact of plant movement, scale, and biomass availability can increase supply chain costs by $11/BDMT ($10/BDT), $33/BDMT ($30/BDT), and $22/BDMT ($20/BDT) above the base case cost of $182/BDMT ($165/BDT) for a large-scale facility [45,000 BDMT yr-1(50,000 BDT yr-1)]in the conditions evaluated. Additionally, potential energy cost savings of a non-mobile modular stationary site as compared to one which utilizes off-grid electrical powers about $11/BDMT ($10/BDT) for a biochar facility. From the cases evaluated, a large-scale plant with limited mobility would be preferred under low availability of biomass conditions, whereas a stationary grid-connected plant would be more cost effective under higher availability conditions. Results depend greatly on the region, assumed harvest schedule, biomass composition, and governing biomass plant assumptions. Keywords: Biomass products, Biomass supply, Facility location, Mixed integer programming, Strategic planning, Transportable plants.

Effectiveness of a Mobile Mammography Program.

Mobile mammography units have increasingly been used to address patient health care disparities; however, there are limited data comparing mobile units to stationary sites. This study aims to evaluate the characteristics of women who underwent mammography screening in a mobile unit versus those who underwent mammography screening at a cancer center. In this retrospective study, we analyzed all screening mammography examinations performed in a mobile unit in 2014 (n = 1433 examinations). For comparison, we randomized and reviewed an equivalent number of screening mammography examinations performed at our cancer center in 2014 (n = 1434 examinations). BI-RADS assessment, adherence to follow-up, biopsies performed, cancer detection rate, and sociodemographic variables were recorded. An independent-samples t test was conducted to identify potential differences in age between cancer center patients and mobile unit patients. Chi-square analyses were used to test for associations between location and factors such as health insurance, race, marital status, geographic area, adherence to screening guidelines, recall rate, adherence to follow-up, and cancer detection rates. Patients visiting our cancer center (mean = 57.74 years; SD = 10.55) were significantly older than those visiting the mobile unit (mean = 52.58 years; SD = 8.19; p < 0.001). There was a significant association between location and health insurance status (χ2 = 610.92; p < 0.001) with more uninsured patients undergoing screening in the mobile van (cancer center = 3.70%, mobile unit = 38.73%). There was a significant association between screening location and patient race (χ2 = 118.75, p < 0.001), with more white patients being screened at the cancer center (cancer center = 47.28%, mobile unit = 33.30%), more black patients being screened in the mobile van (cancer center = 49.30%, mobile unit = 54.15%), and more Hispanic patients being screened in the mobile van (cancer center = 1.05%, mobile unit = 6.77%). There was a significant association between location and patient marital status (χ2 = 135.61, p < 0.001), with more married patients screened at the cancer center (cancer center = 49.16%, mobile unit = 38.31%), more single patients screened in the mobile van (cancer center = 25.17%, mobile unit = 34.47%), and more widowed patients being screened at the cancer center (cancer center = 8.09%, mobile unit = 4.47%). There was a significant association between location and geographic area (χ2 = 33.33, p < 0.001), with both locations reaching more urban than rural patients (cancer center = 79.99%, mobile unit = 70.62%). There was a significant association between location and adherence to screening guidelines (χ2 = 179.60, p < 0.001), with patients screened at the cancer center being more compliant (cancer center = 56.90%, mobile unit = 34.47%). Finally, there was a significant association between location and recall rate (χ2 = 4.06, p < 0.001). The cancer center had a lower recall rate (13.32%) than the mobile van (15.98%). Of those patients with BI-RADS 0, there was a significant association between location and adherence to follow-up (χ2 = 22.75, p < 0.001) with patients using the mobile unit less likely to return for additional imaging (cancer center = 2.65%, mobile unit = 17.03%). Significant differences were found among patients visiting the cancer center versus the mobile mammography van. The cancer center's population is older and more adherent to guidelines, whereas the mobile mammography population exhibited greater racial and marital diversity, higher recall rate, and lack of adherence to follow-up recommendations. By identifying these characteristics, we can develop programs and materials that meet these populations' needs and behaviors, ultimately increasing mammography screening and follow-up rates among underserved populations.

Robustness of intra urban land-use regression models for ultrafine particles and black carbon based on mobile monitoring

Land-use regression (LUR) models for ultrafine particles (UFP) and Black Carbon (BC) in urban areas have been developed using short-term stationary monitoring or mobile platforms in order to capture the high variability of these pollutants. However, little is known about the comparability of predictions of mobile and short-term stationary models and especially the validity of these models for assessing residential exposures and the robustness of model predictions developed in different campaigns.We used an electric car to collect mobile measurements (n = 5236 unique road segments) and short-term stationary measurements (3 × 30min, n = 240) of UFP and BC in three Dutch cities (Amsterdam, Utrecht, Maastricht) in 2014–2015. Predictions of LUR models based on mobile measurements were compared to (i) measured concentrations at the short-term stationary sites, (ii) LUR model predictions based on short-term stationary measurements at 1500 random addresses in the three cities, (iii) externally obtained home outdoor measurements (3 × 24h samples; n = 42) and (iv) predictions of a LUR model developed based upon a 2013 mobile campaign in two cities (Amsterdam, Rotterdam).Despite the poor model R2 of 15%, the ability of mobile UFP models to predict measurements with longer averaging time increased substantially from 36% for short-term stationary measurements to 57% for home outdoor measurements. In contrast, the mobile BC model only predicted 14% of the variation in the short-term stationary sites and also 14% of the home outdoor sites. Models based upon mobile and short-term stationary monitoring provided fairly high correlated predictions of UFP concentrations at 1500 randomly selected addresses in the three Dutch cities (R2 = 0.64). We found higher UFP predictions (of about 30%) based on mobile models opposed to short-term model predictions and home outdoor measurements with no clear geospatial patterns. The mobile model for UFP was stable over different settings as the model predicted concentration levels highly correlated to predictions made by a previously developed LUR model with another spatial extent and in a different year at the 1500 random addresses (R2 = 0.80). In conclusion, mobile monitoring provided robust LUR models for UFP, valid to use in epidemiological studies.