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Atmospheric Measurement Techniques 2020The atmospheric products of the Multi-Angle Implementation of Atmospheric Correction (MAIAC) algorithm include column water vapor (CWV) at a 1 km resolution, derived...
The atmospheric products of the Multi-Angle Implementation of Atmospheric Correction (MAIAC) algorithm include column water vapor (CWV) at a 1 km resolution, derived from daily overpasses of NASA's Moderate Resolution Imaging Spectroradiometer (MODIS) instruments aboard the Aqua and Terra satellites. We have recently shown that machine learning using extreme gradient boosting (XGBoost) can improve the estimation of MAIAC aerosol optical depth (AOD). Although MAIAC CWV is generally well validated (Pearson's >0.97 versus CWV from AERONET sun photometers), it has not yet been assessed whether machine-learning approaches can further improve CWV. Using a novel spatiotemporal cross-validation approach to avoid overfitting, our XGBoost model, with nine features derived from land use terms, date, and ancillary variables from the MAIAC retrieval, quantifies and can correct a substantial portion of measurement error relative to collocated measurements at AERONET sites (26.9% and 16.5% decrease in root mean square error (RMSE) for Terra and Aqua datasets, respectively) in the Northeastern USA, 2000-2015. We use machine-learning interpretation tools to illustrate complex patterns of measurement error and describe a positive bias in MAIAC Terra CWV worsening in recent summertime conditions. We validate our predictive model on MAIAC CWV estimates at independent stations from the SuomiNet GPS network where our corrections decrease the RMSE by 19.7% and 9.5% for Terra and Aqua MAIAC CWV. Empirically correcting for measurement error with machine-learning algorithms is a postprocessing opportunity to improve satellite-derived CWV data for Earth science and remote sensing applications.
PubMed: 33193906
DOI: 10.5194/amt-13-4669-2020 -
Sensors (Basel, Switzerland) Oct 2022Ubiquitous computing has enabled the proliferation of low-cost solutions for capturing information about the user's environment or biometric parameters. In this sense,...
Assessment of the Performance of a Portable, Low-Cost and Open-Source Device for Luminance Mapping through a DIY Approach for Massive Application from a Human-Centred Perspective.
Ubiquitous computing has enabled the proliferation of low-cost solutions for capturing information about the user's environment or biometric parameters. In this sense, the do-it-yourself (DIY) approach to build new low-cost systems or verify the correspondence of low-cost systems compared to professional devices allows the spread of application possibilities. Following this trend, the authors aim to present a complete DIY and replicable procedure to evaluate the performance of a low-cost video luminance meter consisting of a Raspberry Pi and a camera module. The method initially consists of designing and developing a LED panel and a light cube that serves as reference illuminance sources. The luminance distribution along the two reference light sources is determined using a Konica Minolta luminance meter. With this approach, it is possible to identify an area for each light source with an almost equal luminance value. By applying a frame that covers part of the panel and shows only the area with nearly homogeneous luminance values and applying the two systems in a dark space in front of the low-cost video luminance meter mounted on a professional reference camera photometer LMK mobile air, it is possible to check the discrepancy in luminance values between the low-cost and professional systems when pointing different homogeneous light sources. In doing so, we primarily consider the peripheral shading effect, better known as the vignetting effect. We then differentiate the correction factor S of the Radiance Pcomb function to better match the luminance values of the low-cost system to the professional device. We also introduce an algorithm to differentiate the S factor depending on the light source. In general, the DIY calibration process described in the paper is time-consuming. However, the subsequent applications in various real-life scenarios allow us to verify the satisfactory performance of the low-cost system in terms of luminance mapping and glare evaluation compared to a professional device.
Topics: Humans; Vision, Ocular; Photometry
PubMed: 36298068
DOI: 10.3390/s22207706 -
Sensors (Basel, Switzerland) May 2021To meet the demands of the chemical and pharmaceutical process industry for a combination of high measurement accuracy, product selectivity, and low cost of ownership,...
To meet the demands of the chemical and pharmaceutical process industry for a combination of high measurement accuracy, product selectivity, and low cost of ownership, the existing measurement and evaluation methods have to be further developed. This paper demonstrates the attempt to combine future Raman photometers with promising evaluation methods. As part of the investigations presented here, a new and easy-to-use evaluation method based on a self-learning algorithm is presented. This method can be applied to various measurement methods and is carried out here using an example of a Raman spectrometer system and an alcohol-water mixture as demonstration fluid. The spectra's chosen bands can be later transformed to low priced and even more robust Raman photometers. The evaluation method gives more precise results than the evaluation through classical methods like one primarily used in the software package Unscrambler. This technique increases the accuracy of detection and proves the concept of Raman process monitoring for determining concentrations. In the example of alcohol/water, the computation time is less, and it can be applied to continuous column monitoring.
Topics: Spectrum Analysis, Raman; Technology; Technology, Pharmaceutical
PubMed: 34062767
DOI: 10.3390/s21093144 -
Arhiv Za Higijenu Rada I Toksikologiju Apr 2022We investigated the influence of local meteorological conditions and number of visitors on ambient particulate matter (PM) mass concentrations and particle fraction...
Influence of number of visitors and weather conditions on airborne particulate matter mass concentrations at the Plitvice Lakes National Park, Croatia during summer and autumn.
We investigated the influence of local meteorological conditions and number of visitors on ambient particulate matter (PM) mass concentrations and particle fraction ratios at the Plitvice Lakes National Park between July and October 2018. Outdoor mass concentrations of particles with aerodynamic diameters of less than 1, 2.5, and 10 μm (PM, PM, and PM, respectively) and indoor PM were measured with two light-scattering laser photometers set up near the largest and most visited Kozjak Lake. Our findings suggest that the particles mainly originated from background sources, although some came from local anthropogenic activities. More specifically, increases in both indoor and outdoor mass concentrations coincided with the increase in the number of visitors. Indoor PM concentrations also increased with increase in outdoor air temperature, while outdoor PMs exhibited U-shaped dependence (i.e., concentrations increased only at higher outdoor air temperatures). This behaviour and the decrease in the PM/PM ratio with higher temperatures suggests that the production and growth of particles is influenced by photochemical reactions. The obtained spectra also pointed to a daily but not to weekly periodicity of PM levels.
Topics: Air Pollutants; Air Pollution, Indoor; Croatia; Environmental Monitoring; Lakes; Parks, Recreational; Particle Size; Particulate Matter; Weather
PubMed: 35390243
DOI: 10.2478/aiht-2022-73-3610 -
Cureus Jan 2022Background Anemia continues to be a major public health problem in India despite multiple initiatives to address it among various vulnerable groups including...
Background Anemia continues to be a major public health problem in India despite multiple initiatives to address it among various vulnerable groups including adolescents. Aim This study was conducted to assess the prevalence of anemia among rural adolescent girls who had attained menarche. Methods The community-based cross-sectional study was conducted in 28 villages of Ballabgarh Block of district Faridabad, Haryana. From the computerized Health Management Information System data (HMIS), a random list of 363 adolescent girls was generated. Adolescent girls who had attained menarche were included in the study. Hemoglobin level was measured for all the consented or assented participants using a digital hemoglobinometer (HemoCue201+ photometer, HemoCue AB, Angelholm, Sweden). Results A total of 272 participants were enrolled in the study. Mean (SD) age at menarche was 13.2 (1.2) years. Prevalence of anemia among adolescent girls who had attained menarche was observed to be 71.7% (95% CI: 66.3 - 77.1) as per the WHO classification. Among the 195 anemic adolescent girls, severe, moderate, and mild anemia was observed in 4.8%, 41.2%, and 25.7%, respectively. In multivariable analysis, after adjusting for the age, the mother's education was significantly associated with anemia (Adjusted Odds Ratio = 0.46, 95% CI: 0.22 - 0.96, p-value = 0.04). Conclusion The prevalence of anemia among rural adolescent girls who had attained menarche was high. Mother's education status had a protective effect on anemia among adolescent girls.
PubMed: 35165551
DOI: 10.7759/cureus.21091 -
Nan Fang Yi Ke Da Xue Xue Bao = Journal... May 2022To prepare an injectable hydrogel/staple fiber composite loaded with combretastain A-4 disodium phosphate (CA4P) and doxorubicin (DOX) and evaluate its antitumor...
OBJECTIVE
To prepare an injectable hydrogel/staple fiber composite loaded with combretastain A-4 disodium phosphate (CA4P) and doxorubicin (DOX) and evaluate its antitumor efficacy via intratumoral injection.
METHODS
DOX-loaded PELA staple fibers (F) were prepared using electro-spinning and cryo-cutting, and the drug distribution on the surface of the fibers was observed using a fluorescence microscope, and the encapsulation efficiency and loading capacity of F were determined with a fluorospectro photometer. The fibers were then dispersed in CA4P-loaded PLGA-PEG-PLGA tri-block polymer solution at room temperature to obtain the hydrogel/staple fiber composite (G/F). The thermo-sensitivity of this composite was determined by a test tube inverting method. An ultraviolet spectrophotometer and a fluorospectrophotometer were used to detect the release profile of CA4P and DOX, respectively. We observed gel formation of the composite after subcutaneous injection in mice. The cytotoxicity of G/F composite in MCF-7 and 4T1 cells was assessed using cell Counting Kit-8 (CCK-8) reagent. In a mouse model bearing breast tumor 4T1 cell xenograft, we evaluated the antitumor efficacy of the composite by monitoring tumor growth within 30 days after intratumoral injection of the composite. HE staining, immunohistochemistry for Ki67 and immunofluorescence (TUNEL) assay were used for pathological examination of the tumor tissues 21 days after the treatments.
RESULTS
The average length of F was 4.0±1.3 μm, and its drug loading capacity was (2.69±0.35)% with an encapsulation efficiency of (89.70±0.12)%. DOX was well distributed on the surface of the fibers. When the temperature increased to 37 ℃, the composite rapidly solidified to form a gel . Drug release behavior test showed that CA4P was completely released from the composite in 5 days and 87% of DOX was released in 30 days. After subcutaneous injection, the composite solidified rapidly without degradation at 24 h after injection. After incubation with G/F for 72 h, only 30.6% of MCF-7 cells and 28.9% of 4T1 cells were viable. In the tumor-bearing mice, the tumor volume was 771.9±76.9 mm in G/F treatment group at 30 days. Pathological examination revealed obvious necrosis of the tumor tissues and tumor cell apoptosis induced by intratumoral injection of G/F.
CONCLUSION
As an efficient dual drug delivery system, this hydrogel/staple fiber composite provides a new strategy for local combined chemotherapy of solid tumors.
Topics: Animals; Breast Neoplasms; Cell Line, Tumor; Delayed-Action Preparations; Doxorubicin; Female; Heterografts; Humans; Hydrogels; Mice; Mice, Inbred BALB C; Phosphates
PubMed: 35673904
DOI: 10.12122/j.issn.1673-4254.2022.05.01 -
Environment International Mar 2024A reliable determination of equivalent black carbon (eBC) mass concentrations derived from filter absorption photometers (FAPs) measurements depends on the appropriate...
A reliable determination of equivalent black carbon (eBC) mass concentrations derived from filter absorption photometers (FAPs) measurements depends on the appropriate quantification of the mass absorption cross-section (MAC) for converting the absorption coefficient (b) to eBC. This study investigates the spatial-temporal variability of the MAC obtained from simultaneous elemental carbon (EC) and b measurements performed at 22 sites. We compared different methodologies for retrieving eBC integrating different options for calculating MAC including: locally derived, median value calculated from 22 sites, and site-specific rolling MAC. The eBC concentrations that underwent correction using these methods were identified as LeBC (local MAC), MeBC (median MAC), and ReBC (Rolling MAC) respectively. Pronounced differences (up to more than 50 %) were observed between eBC as directly provided by FAPs (NeBC; Nominal instrumental MAC) and ReBC due to the differences observed between the experimental and nominal MAC values. The median MAC was 7.8 ± 3.4 m g from 12 aethalometers at 880 nm, and 10.6 ± 4.7 m g from 10 MAAPs at 637 nm. The experimental MAC showed significant site and seasonal dependencies, with heterogeneous patterns between summer and winter in different regions. In addition, long-term trend analysis revealed statistically significant (s.s.) decreasing trends in EC. Interestingly, we showed that the corresponding corrected eBC trends are not independent of the way eBC is calculated due to the variability of MAC. NeBC and EC decreasing trends were consistent at sites with no significant trend in experimental MAC. Conversely, where MAC showed s.s. trend, the NeBC and EC trends were not consistent while ReBC concentration followed the same pattern as EC. These results underscore the importance of accounting for MAC variations when deriving eBC measurements from FAPs and emphasize the necessity of incorporating EC observations to constrain the uncertainty associated with eBC.
Topics: Air Pollutants; Environmental Monitoring; Aerosols; Seasons; Soot; Carbon; Particulate Matter
PubMed: 38460240
DOI: 10.1016/j.envint.2024.108553 -
European Journal of Organic Chemistry May 2021Aldoses exist predominantly in the cyclic hemiacetal form, which is in equilibrium with the open-chain aldehyde form. The small aldehyde content hampers reactivity when...
Aldoses exist predominantly in the cyclic hemiacetal form, which is in equilibrium with the open-chain aldehyde form. The small aldehyde content hampers reactivity when chemistry addresses the carbonyl moiety. This low concentration of the available aldehyde is generally difficult to ascertain. Herein, we demonstrate a new kinetic determination of the (minute) open-chain content (OCC) of aldoses. This kinetic approach exploits the aldehyde-selectivity of 2-aminobenzamidoxime (ABAO), which furnishes a strongly UV-active adduct. Simple formation curves can be measured in a photometer or plate reader for high-throughput screening. Under pseudo-first order kinetics, these curves correlate with a prediction model yielding the relative OCC. The OCCs of all parent aldoses (pentoses and hexoses) were determined referencing against the two tetroses with exceptionally high OCCs and were in very good agreement with literature data. Additionally, the assay was extended towards higher-carbon sugars with unknown OCC and also applied to rationalise a lack of reactivity observed in a recent synthetic investigation.
PubMed: 34262391
DOI: 10.1002/ejoc.202001641 -
Data in Brief Aug 2022A Sky Quality Meter (SQM) is a photometer designed to measure night sky brightness. SQMs have been used to interpret light fields for various purposes, including studies...
A Sky Quality Meter (SQM) is a photometer designed to measure night sky brightness. SQMs have been used to interpret light fields for various purposes, including studies of relationships between directional light brightness and sea turtle hatchling orientation. This article reports SQM data collected on a sea turtle nesting beach at Delray Beach, Florida (USA) on 17 August 2020. Three hundred-and-sixty light brightness data were collected by eight consecutive readings in each of the four horizontal directions and the zenith at nine sites. The data also include landward photographic images captured at the nine light-measurement sites. The dataset supports the usefulness of the instrument for biological light-field measurements and refute blanket criticisms on inconsistent measurements that would justify discarding initial readings and averaging over a time series.
PubMed: 35855964
DOI: 10.1016/j.dib.2022.108430 -
Optics Express Aug 2020Compared with ground-based lidar, airborne lidar has a wider observation area, which is useful for studying aerosol distribution and transportation. A dual-wavelength...
Compared with ground-based lidar, airborne lidar has a wider observation area, which is useful for studying aerosol distribution and transportation. A dual-wavelength high spectral resolution Lidar (HSRL) was developed for the validation and calibration of an upcoming satellite payload. The HSRL was installed on an airplane, and field campaigns were conducted in Qinhuangdao, China. Meanwhile, four observation sites were established at different locations on the ground to verify the results of the airborne lidar. This article compares the HSRL measurements with those from ground-based micro-pulse lidar (MPL), Mie-scattering lidar, sun photometer, and spaceborne cloud-aerosol Lidar and infrared pathfinder satellite observations (CALIPSO), and Moderate Resolution Imaging Spectroradiometer (MODIS). The stability and reliability of the HSRL system were fully verified. The flight area covered several surface types, including ocean, town, mountain, and forest, which strongly affect the AOD above them. The boundary layer AOD was analyzed in different regions, based on the impact of human activities. The results demonstrated that the AOD in urban area was the largest, and smallest in marine areas, a result ascribed to the influence of industrial activities.
PubMed: 32906988
DOI: 10.1364/OE.397582