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Anais Da Academia Brasileira de Ciencias 2023Aerosols have implications to climate and biogeochemical cycles in the global oceans. At sites under indirect influence of dust emitted by the Patagonian semi-desert, a...
Aerosols have implications to climate and biogeochemical cycles in the global oceans. At sites under indirect influence of dust emitted by the Patagonian semi-desert, a debate exists on the potential fertilization effects of iron enriched aerossol. Considering this subject we conducted measurements of aerosols optical properties using a Microtops II sun photometer to access aerosol size distributions and other intrinsic properties oversea from Atlantic Southern mid-latitudes to Antarctica. Oceanographic cruises were developed between December 2010 to April 2011 and October 2011 to April 2012, in the context of the Brazilian Antarctic Program, and between November 2011 to December 2011. This survey was taken as part of the Global Maritime Aerosol Network (MAN/NASA). Our data of AOD (500 nm) along the South American coast depicts a steady decrease southwards following the decreased latitudinal continental extent. However, the influence of the aerosols blown from Patagonia semi-desert region was clear from latitude 53⁰S to 64⁰S. The predominance of aerosol fine mode was observed in Central Atlantic and close to the Drake Passage. An unexpected aerosol coarse mode predominance was found close to the Antarctic Peninsula. We attribute that to a possible weathering of rock outcrops due to the strong westerly winds in that region.
Topics: Humans; Seasons; Environmental Monitoring; Climate; Weather; Aerosols; Air Pollutants
PubMed: 37937655
DOI: 10.1590/0001-3765202320210816 -
The Science of the Total Environment Jul 2024The extensive emissions of black carbon (BC) from the Indo-Gangetic Plain (IGP) region of India have been well recognized. Particularly, biomass emissions from...
The extensive emissions of black carbon (BC) from the Indo-Gangetic Plain (IGP) region of India have been well recognized. Particularly, biomass emissions from month-specific crop-residue burning (April, May, October, November) and heating activities (December-February) are considered substantial contributors to BC emissions in the IGP. However, their precise contribution to ambient BC aerosol has not been quantified yet and remains an issue of debate. Therefore, this study aims to fill this gap by quantifying the contribution of these month-specific biomass emissions to ambient BC at an urban site in IGP. This study presents the analysis of BC mass concentrations (M) measured for 3 years (2020-2022) in Delhi using an optical photometer i.e., continuous soot monitoring system (COSMOS). A statistical analysis of monthly mean M and factors affecting the M (ventilation coefficients, air mass back trajectories, fire counts) is performed to derive month-wise contribution due to background concentration, conventional emission, regional transport, crop-residue burning, and heating activities. The yearly mean M (5.3 ± 4.7, 5.6 ± 5.0, and 5.3 ± 3.5 μg m during 2020, 2021, and 2022, respectively) remained relatively consistent with repetitive monthly patterns in each year. The peak concentrations were observed from November to January and low concentrations from June to September. Anthropogenic activities contributed significantly to M over Delhi with background concentration contributing only 30 % of observed M The percentage contribution of emissions from crop-residue burning varied from 15 % (May) to 37 % (November), while the contribution from heating activities ranged from 25 % (December) to 39 % (January). This source quantification study highlights the significant impact of month-specific biomass emissions in the IGP and can play a vital role in better management and control of these emissions in the region.
PubMed: 38735325
DOI: 10.1016/j.scitotenv.2024.173039 -
Frontiers in Physiology 2024Exposure of experimental rodents to controlled cycles of light, food, and temperature is important when investigating alterations in circadian cycles that profoundly...
Exposure of experimental rodents to controlled cycles of light, food, and temperature is important when investigating alterations in circadian cycles that profoundly influence health and disease. However, applying such stimuli simultaneously is difficult in practice. We aimed to design, build, test, and open-source describe a simple device that subjects a conventional mouse cage to independent cycles of physiologically relevant environmental variables. The device is based on a box enclosing the rodent cage to modify the light, feeding, and temperature environments. The device provides temperature-controlled air conditioning (heating or cooling) by a Peltier module and includes programmable feeding and illumination. All functions are set by a user-friendly front panel for independent cycle programming. Bench testing with a model simulating the CO production of mice in the cage showed: a) suitable air renewal (by measuring actual ambient CO), b) controlled realistic illumination at the mouse enclosure (measured by a photometer), c) stable temperature control, and d) correct cycling of light, feeding, and temperature. The cost of all the supplies (retail purchased by e-commerce) was <300 US$. Detailed technical information is open-source provided, allowing for any user to reliably reproduce or modify the device. This approach can considerably facilitate circadian research since using one of the described low-cost devices for any mouse group with a given light-food-temperature paradigm allows for all the experiments to be performed simultaneously, thereby requiring no changes in the light/temperature of a general-use laboratory.
PubMed: 38434139
DOI: 10.3389/fphys.2024.1356787 -
Pediatric Rheumatology Online Journal Jan 2024Juvenile Idiopathic Arthritis (JIA) Associated Uveitis (JIA-U) remains one of the most serious complications of JIA in children. Historically, pediatric JIA is diagnosed... (Observational Study)
Observational Study
BACKGROUND
Juvenile Idiopathic Arthritis (JIA) Associated Uveitis (JIA-U) remains one of the most serious complications of JIA in children. Historically, pediatric JIA is diagnosed by an Optometrist or Ophthalmologist; however, barriers to scheduling increase wait times that may delay diagnosis and treatment. The purpose of this study was to evaluate laser flare photometry (LFP) use to diagnose JIA-U in the Pediatric Rheumatology clinic for patients with JIA.
METHODS
This prospective, observational study assessed pediatric patients diagnosed with JIA without a previous history of uveitis between January 2020 and September 2022. All patients underwent at least one evaluation of both eyes using a Kowa FM-600 laser flare photometer during a routine Rheumatology appointment, as well as a standard slit lamp examination (SLE) by optometry or ophthalmology during routine clinical care. Data collected at patient visits included demographics, JIA characteristics, treatment, LFP readings, and anterior chamber (AC) cell grade score utilizing the SUN grading system. Data were summarized using descriptive analyses and the uveitis false positive rate was calculated.
RESULTS
The study cohort included 58 pediatric patients diagnosed with JIA. The mean age was 8.4 years (1.2-16.3 years) at diagnosis and 11.9 (4.8-16.5 years) at enrollment. The mean duration of disease at time of enrollment was 42 months (range; 0-157 months). Participants were predominantly female (n = 43, 74.1%) and white/Caucasian race (n = 37, 63.8%). The most common JIA subtypes included persistent oligoarticular JIA (n = 19, 32.8%), and RF negative polyarticular JIA (n = 12, 20.7%). There were 12 ANA positive patients (20.7%). At enrollment, 16 patients (27.6%) were not on medications, with 20 (34.5%) on methotrexate, 20 (34.5%) on adalimumab, 6 (10.3%) on tocilizumab, and 5 (8.6%) on etanercept. During the study period, no eye exams detected active uveitis based on SLE with a SUN grade over 0. However, of the 135 LFP readings, 131 (97.0%) were normal, yielding a false positive rate of 3% (95% CI: 0.8%, 7.4%).
CONCLUSIONS
LFP is a non-invasive tool that can be utilized in the pediatric rheumatology clinic to evaluate for JIA-U. There is a low false positive rate of LFP when compared with standard slit lamp exam.
Topics: Humans; Child; Female; Male; Arthritis, Juvenile; Prospective Studies; Rheumatology; Uveitis; Photometry; Lasers
PubMed: 38279120
DOI: 10.1186/s12969-024-00961-9 -
Optics Express Apr 2024Lidar is an effective remote sensing method to obtain the vertical distribution of aerosols, and how to select the aerosol extinction-backscattering ratio (AE-BR) during...
Lidar is an effective remote sensing method to obtain the vertical distribution of aerosols, and how to select the aerosol extinction-backscattering ratio (AE-BR) during the inversion process is a key step to guarantee the accuracy of the lidar inversion of aerosol optical thickness (AOD) and aerosol extinction coefficient profile (AECP). In this paper, an inversion algorithm for AOD and AECP based on a genetic BP (GA-BP) neural network is proposed. Simultaneous measurements are carried out using CE318 sun photometer and lidar, and the mapping relationship between the lidar echo signal and AOD is established based on the genetic BP (GA-BP) neural network method, which achieves the accurate inversion of AOD with an absolute error mean value of 0.0156. Based on the AOD output from the GA-BP neural network, the real-time best AE- BR to improve the inversion accuracy of AECP. Finally, practical tests show that the method achieves accurate inversion of AOD, determines the range of AE-BR from 20-50sr, realizes real-time dynamic correction of AECP, and has strong generalization ability and applicability in practical situations.
PubMed: 38859242
DOI: 10.1364/OE.520943 -
Environmental Science & Technology Mar 2024Nitrous acid (HONO) is an important source of hydroxyl radicals (OH) in the atmosphere. Precise determination of the absolute ultraviolet (UV) absorption cross section...
Nitrous acid (HONO) is an important source of hydroxyl radicals (OH) in the atmosphere. Precise determination of the absolute ultraviolet (UV) absorption cross section of gaseous HONO lays the basis for the accurate measurement of its concentration by optical methods and the estimation of HONO loss rate through photolysis. In this study, we performed a series of laboratory and field intercomparison experiments for HONO measurement between striping coil-liquid waveguide capillary cell (SC-LWCC) photometry and incoherent broadband cavity-enhanced absorption spectroscopy (IBBCEAS). Specified HONO concentrations prepared by an ultrapure standard HONO source were utilized for laboratory intercomparisons. Results show a consistent ∼22% negative bias in measurements of the IBBCEAS compared with a SC-LWCC photometer. It is confirmed that the discrepancies occurring between these techniques are associated with the overestimation of the absolute UV absorption cross sections through careful analysis of possible uncertainties. We quantified the absorption cross section of gaseous HONO (360-390 nm) utilizing a custom-built IBBCEAS instrument, and the results were found to be 22-34% lower than the previously published absorption cross sections widely used in HONO concentration retrieval and atmospheric chemical transport models (CTMs). This suggests that the HONO concentrations retrieved by optical methods based on absolute absorption cross sections may have been underestimated by over 20%. Plus, the daytime loss rate and unidentified sources of HONO may also have evidently been overestimated in pre-existing studies. In summary, our findings underscore the significance of revisiting the absolute absorption cross section of HONO and the re-evaluation of the previously reported HONO budgets.
Topics: Nitrous Acid; Gases; Air Pollutants; Spectrum Analysis; Photolysis
PubMed: 38373403
DOI: 10.1021/acs.est.3c08339 -
MethodsX Jun 2024In this study, a smartphone was used as the photometer for determination of iron (III) by forming a complex with thiocyanate. After color formation at concentrations of,...
In this study, a smartphone was used as the photometer for determination of iron (III) by forming a complex with thiocyanate. After color formation at concentrations of, image capture with mobile phone, signal analysis of each sample was performed by the application and converted to the absorption number. The calibration curve was completely linear in the range of 10 to 80 mg L used and the linear coefficient was better than 0.9833. The limits of detection (LOD) and quantification (LOQ) were 0.1 and 0.3 mg L, respectively. Finally, this method was successfully used to measure iron in real samples.•A smartphone was used for the determination of iron (III), showcasing its potential in color compound analysis.•The method demonstrated superior performance in terms of calibration curve range and measurement speed compared to traditional atomic absorption devices.•The technique was successfully applied in the measurement of iron in real samples, indicating its practical applicability.
PubMed: 38699467
DOI: 10.1016/j.mex.2024.102724 -
Acta Veterinaria Scandinavica Mar 2024Piglets are born with limited stores of iron, and with an increasing number of live-born piglets, there may be a risk that the sows cannot provide enough iron to their...
BACKGROUND
Piglets are born with limited stores of iron, and with an increasing number of live-born piglets, there may be a risk that the sows cannot provide enough iron to their offspring. The iron content in soil may not meet the demands of today's piglet, born and reared in an outdoor setting. The study aimed to describe the blood haemoglobin (Hb) levels in pigs reared outdoors and to determine whether piglets have higher Hb levels at weaning when an iron supplement is administered intramuscularly at three days of age, as compared to pigs not given an iron supplement. The seasonal variation in Hb-levels was also to be investigated. The Hb concentration was analysed with a HemoCue 201 + Hb photometer.
RESULTS
In total 56 litters (399 piglets) were included in the study and sampled at three days of age, while 378 piglets were sampled at weaning. The mean Hb level at three days of age was 91 g/L (48-154 g/L). In total 47% of the piglets had Hb levels < 90 g/L at three days of age. The mean Hb level at weaning was 127 g/L (76-176 g/L), with a lower level (122 g/L) in the group given the iron supplement than in the group not given an iron supplement (132 g/L). Only 1% of the piglets had Hb levels lower than 90 g/L at weaning. Results indicative of a seasonal effect on Hb levels at three days of age was demonstrated. Piglets born in spring had significantly lower Hb levels, and piglets born in autumn had significantly higher Hb levels. No seasonal effect could be demonstrated for Hb levels at day 33.
CONCLUSIONS
The results indicate that the natural uptake from the environment was sufficient, but that there was a seasonal effect on the Hb levels at three days of age. This indicates that there might be a need for different routines regarding iron supplementation in outdoor reared piglets depending on the climate and season.
Topics: Animals; Swine; Female; Iron; Weaning; Seasons; Farms; Sweden; Hemoglobins; Lactation
PubMed: 38504355
DOI: 10.1186/s13028-024-00735-z