Low-Cost Sensor Performance Intercomparison, Correction Factor Development, and 2+ Years of Ambient PM2.5 Monitoring in Accra, Ghana

Particulate matter air pollution is a leading cause of global mortality, particularly in Asia and Africa. Addressing the high and wide-ranging air pollution levels requires ambient monitoring, but many low- and middle-income countries (LMICs) remain scarcely monitored. To address these data gaps, recent studies have utilized low-cost sensors. These sensors have varied performance, and little literature exists about sensor intercomparison in Africa. By colocating 2 QuantAQ Modulair-PM, 2 PurpleAir PA-II SD, and 16 Clarity Node-S Generation II monitors with a reference-grade Teledyne monitor in Accra, Ghana, we present the first intercomparisons of different brands of low-cost sensors in Africa, demonstrating that each type of low-cost sensor PM2.5 is strongly correlated with reference PM2.5, but biased high for ambient mixture of sources found in Accra. When compared to a reference monitor, the QuantAQ Modulair-PM has the lowest mean absolute error at 3.04 μg/m3, followed by PurpleAir PA-II (4.54 μg/m3) and Clarity Node-S (13.68 μg/m3). We also compare the usage of 4 statistical or machine learning models (Multiple Linear Regression, Random Forest, Gaussian Mixture Regression, and XGBoost) to correct low-cost sensors data, and find that XGBoost performs the best in testing (R2: 0.97, 0.94, 0.96; mean absolute error: 0.56, 0.80, and 0.68 μg/m3 for PurpleAir PA-II, Clarity Node-S, and Modulair-PM, respectively), but tree-based models do not perform well when correcting data outside the range of the colocation training. Therefore, we used Gaussian Mixture Regression to correct data from the network of 17 Clarity Node-S monitors deployed around Accra, Ghana, from 2018 to 2021. We find that the network daily average PM2.5 concentration in Accra is 23.4 μg/m3, which is 1.6 times the World Health Organization Daily PM2.5 guideline of 15 μg/m3. While this level is lower than those seen in some larger African cities (such as Kinshasa, Democratic Republic of the Congo), mitigation strategies should be developed soon to prevent further impairment to air quality as Accra, and Ghana as a whole, rapidly grow.

Effect of feed particle size and solvent flow rate on soybean oil extraction in a percolation type extractor

The influence of particle size and solvent flow rate on the kinetics of oil extraction from soybean (eight fractions from 0.433 to 0.122 mm) was studied using hexane, simulating commercial percolation type extractor. The reduction in particle size from 0.433 mm to 0.141 mm showed an increase in the oil yield. However, further reduction to 0.129 mm and 0.122 mm affected the yield due to bed compaction, reducing porosity and contact area. The yield (21.5%) of the ground mass was similar to the major mass fractions (0.239-0.353 mm). The rate of extraction increased drastically with the solvent flow rate. The highest flow rate (9.67 mL/min) exhibited the highest mass transfer coefficient (km) 1.62 × 10-3 s-1 and the diffusion coefficient (De) 1.77 × 10-12 m2/s. At 7.33 mL/min, the yield and the rate of extraction were optimal and no potential benefits were obtained at higher flow rates.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-022-05554-6.

A novel approach to improve network validity using various soft computing techniques

Mobile Adhoc Networks (MANET) in modern research have many optimal energy conservation mechanisms that can be deployed easily and in a faster manner. The routing approaches associated with energy consumption play a dominant role in routing the data packets between the mobile sensor nodes within the range of optimization. However, major challenges associated with energy consumption in MANETs include reduced lifetime of sensor nodes, poor coverage, and throughput. Most methods tend to reduce the interference of data while traversing between the sensor nodes and increase the capacity of the network. This results in delays while transmitting the packets across the network, and this may result in failure of packets being transmitted. To resolve this issue, in this paper, we propose an ant colony optimization combined with a flower pollination algorithm for minimal energy consumption and throughput maximisation in MANETs. This hybrid meta-heuristic model resolves the issues, including delays, poor coverage, and reduced network lifetime. This hybrid model uses the estimation of neighbourhood distance among the nodes for optimal placement of nodes for effective location. The estimation of location is found using a flower pollination algorithm with a levy flight mechanism. The estimation is carried out in a hyper sphere model that helps in finding the coverage area of the sensor nodes. Depending upon the estimation of neighbourhood distance among the sensor nodes, the consumption of energy among the sensor nodes in MANETs is reduced. The simulation was conducted between the proposed hybrid approach and conventional soft computing heuristics, where the results show that the proposed model achieves a higher rate of energy conservation and reduces delay than other methods.

Using patching asymmetric regions to assess ischemic stroke lesion in neuro imaging

Ischemic stroke is a universal ailment that endangers the life of patients and makes them bedridden until death. Over a decade, doctors and radiologists have been dissecting patient status straightforwardly from the printouts of the slice images delivered by different diagnostic imaging modalities. Computed Tomography (CT) is a frequently used imaging strategy for therapeutic analysis and neuroanatomical investigations. The main objective of the paper is to develop a simple technique with less architectural complication and power consumption. The proposed work is to section the ischemic stroke lesion more efficiently from multi-succession CT images using patching the asymmetric region. The Hough transform segment and extracts the features from the asymmetric region of the CT image and finally, the random forest is implemented to classify the unusual tissues from the CT image dependent on their pathological properties. RF classifier has been trained for different parts of the cerebrum for fragmenting the stroke lesion. The acquired outcomes produce better segmentation accuracy when compared with different strategies. The overall efficiency of the proposed method determines the Ischemic stroke with an accuracy of 95% with an RF classifier. Hence this method can be used in the segmentation process of stroke lesions.

Using a recurrent neural network with S2 characteristics, efficient identification of localised cortical dysplasia

Focal cortical dysplasia (FCD) is an inborn anomaly in brain growth and morphological deformation in lesions of the brain which induces focal seizures. Neurosurgical therapies were performed for the detection of FCD. Furthermore, it can be overcome through the presurgical evaluation of epilepsy. The surgical result is attained basically through the output of the presurgical output. In preprocessing the process of increasing true positives with the decrease in false negatives occurs which results in an effective outcome. MRI (Magnetic Resonance Imaging) outputs are efficient to predict the FCD lesions through T1- MPRAGE and T2- FLAIR efficient output can be obtained. In our proposed work we extract the S2 features through the testing of T1, T2 images. Using RNN-LSTM (Recurrent neural network-Long short-term memory) test images were trained and the FCD lesions were segmented. The output of our work is compared with the proposed work yields better results compared to the existing system such as artificial neural network (ANN), support vector machine (SVM), and convolution neural network (CNN). This approach obtained an accuracy rate of 0.195% (ANN), 0.20% (SVM), 0.14% (CNN), specificity rate of 0.23% (ANN), 0.15% (SVM), 0.13% (CNN) and sensitivity rate of 0.22% (ANN), 0.14% (SVM), 0.08% (CNN) respectively in comparison with RNN-LSTM.

Air-Q ILA as a conduit for orotracheal intubation in children: A randomized control trial for comparison between supine and lateral patient positions

Background and Aims

Airway management in children is always challenging and becomes a concern if required in the lateral position. We evaluated the efficacy of orotracheal intubation using the Air-Q intubating laryngeal Airway (Air-Q ILA) in supine and lateral positions in children.

Material and Methods

This study included 100 children weighing 7-30 kg, scheduled for elective surgeries under general anesthesia. They were randomized into the supine (S) group or lateral (L) group. After anesthesia induction, the child was placed in a standard sniffing position for conventional laryngoscopy in the S group, and the child was turned into the lateral position in the L group. Both Air-Q ILA and endotracheal tube were placed blindly in the supine position in the S group and lateral position in group L. The grading of glottic view, success rate, insertion time of the Air-Q ILA, and endotracheal intubation were noted in both the groups.

Results

The Air-Q ILA was successfully placed at the first attempt in 47 children in group S and 48 in group L. The overall blind orotracheal intubations, including first and second attempts, were successful in 45 children in the S group and 47 in the L group (P = 0.715). Eighty percent of patients in group L and 70% in group S had glottis grade 1 or 2 compared to grade 3, 4,5 (P = 0.249). The mean time of Air-Q ILA placement in groups S and L was 15.73 ± 5.64 s and 14.42 ± 4.16 s (P = 0.195). The mean duration of blind endotracheal intubation through the Air-Q ILA was 24.88 ± 14.75 s in group S and 17.57 ± 5.35 s in group L (P = 0.002). In both the groups, none of the children had bronchospasm, laryngospasm, desaturation, or aspiration. The airway trauma evident by blood staining on the Air-Q ILA on removal was revealed in 2 cases in group S, and 3 cases in group L. None of the children in group S and 4 children in group L had postoperative stridor. Postoperative hoarseness was reported in 3 children in group S and none in group L within 24 hours.

Conclusion

The Air-Q ILA can be used as a conduit for blind orotracheal intubation in children in both supine and lateral positions while maintaining an effective airway seal.

Optimum time of LMA ProSeal removal in adult patients undergoing isoflurane anesthesia: A randomized controlled trial

Background and Aims:

Optimum timing of laryngeal mask airway (LMA) removal after general anesthesia with isoflurane is debatable. The objective was to investigate the potential benefits of removing LMA ProSeal at ≤0.4 Minimum alveolar concentration (MAC) isoflurane over awake and “deep plane” extubation after short duration laparoscopic gynecological surgery.

Material and Methods:

In this prospective randomized trial 90 adult female patients undergoing elective laparoscopic surgery under general anesthesia using LMA ProSeal™ as airway device were included. At the end of surgery, LMA ProSeal™ was removed when the patient was awake, could open mouth following verbal command (Group A); at MAC ≤0.4 (Group B); or at MAC of 0.6 (Group C). Adverse airway events like nausea, vomiting, airway obstruction, coughing, bucking, laryngospasm were noted. Statistical analyses were done by SPSS statistical software (IBM SPSS Statistics for Mac OS X, Version 21.0. IBM Corp, Armonk, NY).

Results:

Baseline demographic characteristics were comparable in all three groups. Coughing or bucking at the time of LMA removal was higher in group A (P = 0.004). Snoring and airway obstruction after LMA removal was significantly higher in group C compared to group A and group B (P = 0.002 and P = 0.011, respectively). There was significant change in mean arterial pressure and heart rate between before and after LMA removal on group A (P = 0.008 and P < 0.001, respectively) but not in other groups.

Conclusion:

MAC ≤0.4 can be considered optimum depth of anesthesia for removal of LMA Proseal in adult patients undergoing isoflurane anesthesia.

Characterizing the Aging of Alphasense NO2 Sensors in Long-Term Field Deployments

Low-cost NO₂ sensors have been widely deployed for atmospheric sampling. While their initial performance has been characterized, few studies have examined their long-term degradation. This study focused on the performance of Alphasense low-cost NO₂ sensors (NO2-B42F and NO2-B43F) over 4 years (2016-2020). A total of 29 NO₂ sensors from 10 batches were collocated 78 times at two sites with reference instruments. Raw signals from "functional" NO₂ sensors correlated linearly with reference NO₂ concentrations. After long-term deployment, sensor raw signals started to deviate from reference NO₂ concentrations due to sensor aging, an accumulated effect after sensor unpacking. Several sensors eventually became "non-functional" as sensor raw signals showed no correlation with reference NO₂ concentrations. Sensor aging and non-functionality may be primarily caused by expiration of the ozone (O₃) scrubber built into these sensors so that sensors responded to both ambient NO₂ and O₃. The influence of O₃ on sensor response is quantified through the permutation importance method. Most of the sensors are non-functional after approximately 200-400 days of deployment, and no sensor was functional after 400 days of deployment. This result agrees well with the estimated lifetime of the built-in ozone scrubbers considering the ambient ozone concentration in the Pittsburgh area where these sensors were deployed. To ensure reliable data quality in long-term field deployments, we recommend collocating NO₂ sensors with reference instruments regularly after 200-400 days of deployment to identify and replace non-functional sensors in a timely manner.

843 Improving Practical Skills Training with In-Situ Trauma Simulation

Introduction

Safe and effective management of trauma patients requires numerous practical skills. Our in-situ trauma simulation identified key areas requiring increased training and exposure. This enabled improvement to education, patient safety and efficiency when managing these emergencies.

Method

We carried out a simulated trauma call according to ATLS principles, recording the time and person completing each task. Key areas for improvement were identified; most notably the application of Femoral Traction Splints (FTS). 0/7 doctors present were not able to do this. Subsequently, a formal training day was delivered, with 38 attendees across specialties, assessing confidence before and after the session.

Results

Prior to the training session, 52.6% of attendees did not have formal teaching using FTS and 65.8% had never used one. Confidence with FTS application was measured on a scale of 1 (not confident) to 5 (very confident), with an average score of 2.6/5.

After training, the average confidence score was 4.7/5 (p &lt; 0.01). 100% of participants found the session very useful.

Conclusions

In-situ simulation allows identification of key areas for improvement in training of practical skills. Essential tailored teaching can then be delivered to increase exposure and confidence for these necessary practical skills.

Intraoperative lung protective ventilation in peritonitis patients undergoing emergency laparotomy: A randomised controlled trial

Background and Aims:

Lung protective ventilation (LPV) is recommended in acute respiratory distress syndrome. However, role of intraoperative LPV in elective laparotomy is controversial and it has not been evaluated in emergency laparotomy (EL). The aim of the study was to identify whether use of intraoperative LPV in EL in peritonitis patients reduces postoperative pulmonary complications (POPC).

Methods:

After institutional ethics committee approval and informed written consent, 98 adult patients undergoing EL for peritonitis were randomised into two groups. Patients in group 1 received LPV (tidal volume 6–8 ml/kg, positive end expiratory pressure (PEEP) 6–8 cm H₂O and recruitment manoeuvre every 30 min) and patients in group 2 received conventional ventilation (tidal volume 10-12 ml/kg, without PEEP/recruitment). Primary outcome was incidence of POPC on day 7.

Results:

Data of 94 patients (n = 45 in group 1 & n = 49 in group 2) were available. Baseline demographic & laboratory parameters were comparable. Incidence of POPC was similar in both the groups [42.9% in group 1 vs. 53.3% in group 2; risk difference -10.4% (-30.6%, 9.6%); P = 0.31]. Mortality during hospital stay was 26.7% patients in group 1 and 26.5% patients in group 2 [risk difference (95% CI) 0.14%, (-17.7, 18.0); P = 0.98]. Length of hospital stay [median interquartile range (IQR) 13 (9–18) days in group 1 vs. 13 (8–21) days in group 2; P = 0.82] and length of intensive care unit stay [median (IQR) 7 (4–10) days vs. 6 (3–12) days; P = 0.88] were also similar in both groups.

Conclusion:

LPV during EL in peritonitis patients does not reduce the incidence of POPC compared to conventional ventilation.

Using a network of lower-cost monitors to identify the influence of modifiable factors driving spatial patterns in fine particulate matter concentrations in an urban environment

BACKGROUND

There is substantial interest in using networks of lower-cost air quality sensors to characterize urban population exposure to fine particulate matter mass (PM_2.5). However, sensor uncertainty is a concern with these monitors.

OBJECTIVES

(1) Quantify the uncertainty of lower-cost PM_2.5 sensors; (2) Use the high spatiotemporal resolution of a lower-cost sensor network to quantify the contribution of different modifiable and non-modifiable factors to urban PM_2.5.

METHODS

A network of 64 lower-cost monitors was deployed across Pittsburgh, PA, USA. Measurement and sampling uncertainties were quantified by comparison to local reference monitors. Data were sorted by land-use characteristics, time of day, and wind direction.

RESULTS

Careful calibration, temporal averaging, and reference site corrections reduced sensor uncertainty to 1 μg/m³, ~10% of typical long-term average PM_2.5 concentrations in Pittsburgh. Episodic and long-term enhancements to urban PM_2.5 due to a nearby large metallurgical coke manufacturing facility were 1.6 ± 0.36 μg/m³ and 0.3 ± 0.2 μg/m³, respectively. Daytime land-use regression models identified restaurants as an important local contributor to urban PM_2.5. PM_2.5 above EPA and WHO daily health standards was observed at several sites across the city.

SIGNIFICANCE

With proper management, a large network of lower-cost sensors can identify statistically significant trends and factors in urban exposure.

0155 SUVN-G3031, A Potent and Selective Histamine H3 Receptor Inverse Agonist - Differentiating Features Over Current Treatments of Narcolepsy

Introduction

Majority of pharmacological agents used in the treatment of narcolepsy have several limitations. Both nonclinical and clinical evidences suggest usefulness of the histamine H3 receptor (H3R) inverse agonists for the treatment of narcolepsy and addressing several of the current limitations.

Methods

Extensive nonclinical studies were carried out for SUVN-G3031 and other pharmacological agents that are currently being used for the treatment of narcolepsy. Nonclinical parameters like inter-species binding affinity, selectivity profile, in vivo and in vitro ADME features, nonclinical efficacy, neurochemistry and safety were compared.

Results

SUVN-G3031 has no inter-species variation in binding affinity at H3R with less than 50% inhibition at 1 µM against 70 other targets. Unlike pitolisant, SUVN-G3031 has no significant binding affinity at sigma 1 and 2 receptor. SUVN-G3031 has no inhibition and induction liability towards major CYP enzymes and transporters. Pitolisant is reported to be a CYP3A4, CYP2B6, and CYP1A2 inducer and a CYP2D6 and OCT1 inhibitor. SUVN-G3031 has robust wake promoting effects. SUVN-G3031 showed negligible affinity towards hERG channel with IC50 &gt; 10 µM and had no effects on any ECG parameters in dog telemetry study. SUVN-G3031 did not show convulsion in rats up to the tested dose of 100 mg/kg, p.o. Most of the pharmacological agents used for the treatment of narcolepsy have abuse liability; SUVN-G3031 produced no change in the striatal and accumbal dopamine levels in rats suggesting no propensity to induce abuse liability. Unlike competing H3R inverse agonists, SUVN-G3031 has no effects on fertility and embryo-fetal development up to the highest tested doses.

Conclusion

Nonclinical studies demonstrate superiority of SUVN-G3031 over pharmacological agents currently used in the treatment of narcolepsy. SUVN-G3031 is being evaluated in a Phase 2 study as monotherapy for the treatment of narcolepsy with and without cataplexy (ClinicalTrials.gov Identifier: NCT04072380).

Support

None

0072 Preclinical Characterization of SUVN-G3031, a Histamine H3 Receptor Inverse Agonist for the Treatment of Narcolepsy

Introduction

Narcolepsy is a chronic sleep disorder characterized by overwhelming daytime drowsiness, sudden attacks of sleep and sometimes accompanied by cataplexy. Although the orexin deficiency is considered to be the primary cause of this disorder, lot of attention has been focused recently on targeting histaminergic neurotransmission by blockade of histamine H3 receptor (H3R). SUVN-G3031 is one of the potent and selective H3R inverse agonist currently being evaluated in a Phase 2 study as monotherapy for the treatment of narcolepsy with and without cataplexy (ClinicalTrials.gov Identifier: NCT04072380).

Methods

Binding of SUVN-G3031 in human and rat histamine H3R was evaluated in in vitro radioligand binding assay and functionality was assessed in GTPγS assay. Pharmacokinetic properties were evaluated after oral administration in rat and dog. Neurotransmitters like histamine, dopamine and norepinephrine were estimated in rat cortex using microdialysis.

Results

SUVN-G3031 is an inverse agonist at histamine H3R with hKi of 8.7 nM and showed minimal binding against over 70 target sites. SUVN-G3031 exhibited desired pharmacokinetic properties in rat and dog with excellent brain penetration in rats. SUVN-G3031 produced significant increase in histamine, dopamine and norepinephrine levels in cortex. SUVN-G3031 produced no change in the striatal and accumbal dopamine levels in rats, suggesting no propensity to induce abuse liability. SUVN-G3031 blocked R-α-methylhistamine induced water intake and produced dose dependent increase in tele-methylhistamine levels in various brain regions and in cerebrospinal fluid of male Wistar rats.

Conclusion

SUVN-G3031 is an inverse agonist at histamine H3 receptor and results from the preclinical studies presented here provide a strong evidence for the potential utility of SUVN-G3031 in the treatment of narcolepsy with and without cataplexy.

Support

None

0008 SUVN-G3031, A Histamine H3 Receptor Inverse Agonist Produces Robust Wake Promoting and Anticataplectic Activity in Orexin Knockout Mice

Introduction

Narcolepsy is a sleep disorder characterized by excessive daytime sleepiness, sleep paralysis, hallucinations, and in some cases episodes of cataplexy. Results from animal studies indicate the involvement of deficient orexin transmission in narcolepsy which can be circumvented by the activation of histaminergic neurons. SUVN-G3031 is a potent and selective histamine H3 receptor inverse agonist with hKi of 8.7 nM and shows less than 50% inhibition at 1 µM against 70 other targets. SUVN-G3031 exhibited excellent pharmacokinetic properties and brain penetration in preclinical species. Oral administration of SUVN-G3031 produces significant increase in histamine, dopamine and norepinephrine levels in the rat cortex. Long-term safety studies in animals have been successfully completed without any concern for further development of SUVN-G3031. In the present study, the effects of SUVN-G3031 were evaluated in orexin knockout mice, a reliable animal model of narcolepsy as a proof-of-concept study for the treatment of narcolepsy with and without cataplexy.

Methods

Male orexin knockout mice (10 - 15 weeks old, 25 - 35 g at the time of surgery) were implanted with telemetric device for simultaneous monitoring of electroencephalography (EEG) and electromyography. Animals were allowed surgical recovery of 3 weeks prior to EEG recording. Effects of SUVN-G3031 (3 and 10 mg/kg, p.o.) were evaluated during active period of animals.

Results

SUVN-G3031 produced significant increase in wakefulness with concomitant decrease in non-rapid eye movement sleep in orexin knockout mice. SUVN-G3031 also significantly decreased the number of cataplectic episodes in orexin knockout mice.

Conclusion

Results from the current preclinical study provide a strong basis for the utility of SUVN-G3031 for the treatment of narcolepsy with and without cataplexy. SUVN-G3031 is currently being evaluated in a Phase 2 study as monotherapy for the treatment of narcolepsy with and without cataplexy (ClinicalTrials.gov Identifier: NCT04072380).

Support

None

Correlation between thromboelastography and rotational thromboelastometry values in adult liver transplant recipients

Background and Aims:

Viscoelastic haemostatic assays (VHA) namely Thromboelastogram (TEG) and Rotational thromboelastometry (ROTEM) are used for global assessment of coagulopathy and guiding transfusion during living donor liver transplant (LDLT).We conducted a study to compare the interchangeability of the values obtained from these devices in patients with End stage liver disease (ESLD) undergoing LDLT.

Methods:

In 76 patients undergoing LDLT, ROTEM and TEG were performed and assessed for interchangeability using Spearman Correlation. The direction and strength of correlation between equivalent parameters was calculated using Inter Class Correlation (ICC) and Bland Altman analysis.

Results:

The correlation ρ between CT (clotting time) of ROTEM and R of TEG was 0.16 (P = 0.19).The ICC was 0.15, with 95% confidence interval (CI) of -0.38-0.48 (P = 0.25).The ρ of CFT (ROTEM) with K (TEG) was 0.425 (P=<0.001). The ICC was0.49 with 95% CI of 0.17-0.69, P = 0.003.Alpha of ROTEM correlated with Angle of TEG with ρ of 0.475 (P=<0.001). The ICC was 0.61, with 95% CI of 0.36-0.76, P=<0.001.Maximum Clot firmness (MCF) correlated with maximum amplitude (MA) with ρ=0.76 (P=<0.001).The ICC was 0.86, with 95% CI of 0.77-0.92, P=<0.001. Lysis index (L30) of ROTEM correlated clot lysis (CL30) of TEG with ρ of 0.16 (P = 0.18).However, the ICC was 0.45, with 95% CI of 0.11-0.66, P = 0.08. The correlation between CT of ROTEM and R of TEG as well as L30 of ROTEM and CL30 of TEG was not significant.The strongest correlation was found between MCF and MA (P < 0.001). However the MCF/MA showed an agreement of only 86% (ICC = 0.86).

Conclusion:

Values from ROTEM and TEG were not found to be interchangeable.

Demonstration of a Low-Cost Multi-Pollutant Network to Quantify Intra-Urban Spatial Variations in Air Pollutant Source Impacts and to Evaluate Environmental Justice

Air quality monitoring has traditionally been conducted using sparsely distributed, expensive reference monitors. To understand variations in PM_2.5 on a finely resolved spatiotemporal scale a dense network of over 40 low-cost monitors was deployed throughout and around Pittsburgh, Pennsylvania, USA. Monitor locations covered a wide range of site types with varying traffic and restaurant density, varying influences from local sources, and varying socioeconomic (environmental justice, EJ) characteristics. Variability between and within site groupings was observed. Concentrations were higher near the source-influenced sites than the Urban or Suburban Residential sites. Gaseous pollutants (NO₂ and SO₂) were used to differentiate between traffic (higher NO₂ concentrations) and industrial (higher SO₂ concentrations) sources of PM_2.5. Statistical analysis proved these differences to be significant (coefficient of divergence > 0.2). The highest mean PM_2.5 concentrations were measured downwind (east) of the two industrial facilities while background level PM_2.5 concentrations were measured at similar distances upwind (west) of the point sources. Socioeconomic factors, including the fraction of non-white population and fraction of population living under the poverty line, were not correlated with increases in PM_2.5 or NO₂ concentration. The analysis conducted here highlights differences in PM_2.5 concentration within site groupings that have similar land use thus demonstrating the utility of a dense sensor network. Our network captures temporospatial pollutant patterns that sparse regulatory networks cannot.

Deliberating performance targets workshop: Potential paths for emerging PM2.5 and O3 air sensor progress

The United States Environmental Protection Agency held an international two-day workshop in June 2018 to deliberate possible performance targets for non-regulatory fine particulate matter (PM_2.5) and ozone (O₃) air sensors. The need for a workshop arose from the lack of any market-wide manufacturer requirement for Ozone documented sensor performance evaluations, the lack of any independent third party or government-based sensor performance certification program, and uncertainty among all users as to the general usability of air sensor data. A multi-sector subject matter expert panel was assembled to facilitate an open discussion on these issues with multiple stakeholders. This summary provides an overview of the workshop purpose, key findings from the deliberations, and considerations for future actions specific to sensors. Important findings concerning PM_2.5 and O₃ sensors included the lack of consistent performance indicators and statistical metrics as well as highly variable data quality requirements depending on the intended use. While the workshop did not attempt to yield consensus on any topic, a key message was that a number of possible future actions would be beneficial to all stakeholders regarding sensor technologies. These included documentation of best practices, sharing quality assurance results along with sensor data, and the development of a common performance target lexicon, performance targets, and test protocols.

Quantifying high-resolution spatial variations and local source impacts of urban ultrafine particle concentrations

To quantify the fine-scale spatial variations and local source impacts of urban ultrafine particle (UFP) concentrations, we conducted 3-6 weeks of continuous measurements of particle number (a proxy for UFP) and other air pollutant (CO, NO₂, and PM_2.5) concentrations at 32 sites in Pittsburgh, Pennsylvania during the winters of 2017 and 2018. Sites were selected to span a range of urban land use attributes, including urban background, near local and arterial roads, traffic intersections, urban street canyon, near-highway, near large industrial source, and restaurant density. The spatial variations in urban particle number concentrations varied by about a factor of three. Particle number concentrations are 2-3 times more spatially heterogeneous than PM_2.5 mass. The observed order of spatial heterogeneity is UFP > NO₂ > CO > PM_2.5. On average, particle number concentrations near local roads with a cluster of restaurants and near arterial roads are roughly two times higher than the urban background. Particle number concentrations in the urban street canyon, downwind of a major highway, and near large industrial sources are 2-4 times higher than background concentrations. While traffic is known as an important contributor to particle number concentrations, restaurants and industrial emissions also contribute significantly to spatial variations in Pittsburgh. Particle size distribution measurements using a mobile laboratory show that the local spatial variations in particle number concentrations are dictated by concentrations of particles smaller than 50 nm. A large fraction of urban residents (e.g., ~50%) in Pittsburgh live near local sources and are therefore exposed to 50%-300% higher particle number concentrations than urban background location. These locally emitted particles may have greater health effects than background particles.

Correlation of early ROTEM parameters with conventional coagulation tests in patients with chronic liver disease undergoing liver transplant

Background and Aims:

Viscoelastic tests such as rotational thromboelastometry (ROTEM) provide a quick and holistic assessment of coagulation status to guide transfusion during liver transplant (LT). Conventional coagulation tests (CCTs) measure single parameters in isolation, and also the results are delayed hampering management of patients during surgery. We evaluated the correlation of early ROTEM-derived parameters with CCTs and also assessed the ability of ROTEM-derived parameters to predict thrombocytopaenia and hypofibrinogenaemia during LT in patients with end-stage liver disease (ESLD).

Methods:

This retrospective study was carried out in 100 patients with decompensated ESLD undergoing LT. Correlation between CCTs and ROTEM parameters was analyzed. Receiver operating characteristic curves with area under the curve were used to determine the cut-off values of A5 andA10 on EXTEM and FIBTEM.

Results:

The values of A5_EXTEM and A10_EXTEM highly correlated with fibrinogen levels and platelet count, whereas A5_FIBTEM and A10_FIBTEM correlated well with fibrinogen levels. A5_EXTEM<21 mm and A10_EXTEM<28 mm correlated with a platelet count <75,000 mm⁻³, whereas A5_EXTEM<18 mm and A10_EXTEM<25 mm correlated with a platelet count <50,000 mm⁻³. Fibrinogen levels <100 mg/dL better correlated with A5_FIBTEM<5 mm, A10_FIBTEM<6 mm, A5_EXTEM<21 mm and A10_EXTEM<30 mm.

Conclusion:

Early ROTEM parameters A5 and A10 of both EXTEM and FIBTEM had an excellent correlation with thrombocytopaenia and hypofibrinogenaemia and may potentially guide early transfusion of relevant blood products during LT.

Perioperative anesthetic management of a combined right atrial thrombectomy with living donor liver transplantation

Hepatocellular carcinoma (HCC) with vascular invasion is usually considered inoperable. We describe a case of HCC with vascular invasion and right atrial thrombus that was successfully down staged. Patient underwent combined right atrial thrombectomy and living donor liver transplantation (LDLT) in the same setting. Perioperative anesthesia management and perioperative concerns of two major combined procedures are discussed.

Aerosol Optical Properties and Climate Implications of Emissions from Traditional and Improved Cookstoves

Cookstove emissions are a major global source of black carbon but their impact on climate is uncertain because of limited understanding of their optical properties. We measured optical properties of fresh aerosol emissions from 32 different stove/fuel combinations, ranging from simple open fires to high-performing forced-draft stoves. Stoves were tested in the laboratory using the firepower sweep protocol, which measures emissions across the entire range of functional firepower. There is large variability in measured optical properties across the entire range of firepower. This variability is strongly correlated with black carbon-to-particulate matter mass ratio (BC/PM). In comparison, stove type, fuel, and operational metrics were poor predictors of optical properties. We developed parametrizations of the mass absorption cross-section, the absorption angstrom exponent, and the single scattering albedo of fresh emissions as a function of BC/PM. These parametrizations, derived from laboratory data, also reproduce previously reported field measurements of optical properties of real-world cooking emissions. We combined our new parametrizations of intensive optical properties with published emissions data to estimate the direct radiative effect of emissions for different stove technologies. Our data suggest that so-called "improved" stove reduce CO₂ equivalent emission (i.e., climate benefits) by 20-30% compared to traditional stoves.

Methane Emissions from Natural Gas Production Sites in the United States: Data Synthesis and National Estimate

We used site-level methane (CH₄) emissions data from over 1000 natural gas (NG) production sites in eight basins, including 92 new site-level CH₄ measurements in the Uinta, northeastern Marcellus, and Denver-Julesburg basins, to investigate CH₄ emissions characteristics and develop a new national CH₄ emission estimate for the NG production sector. The distribution of site-level emissions is highly skewed, with the top 5% of sites accounting for 50% of cumulative emissions. High emitting sites are predominantly also high producing (>10 Mcfd). However, low NG production sites emit a larger fraction of their CH₄ production. When combined with activity data, we predict that this creates substantial variability in the basin-level CH₄ emissions which, as a fraction of basin-level CH₄ production, range from 0.90% for the Appalachian and Greater Green River to >4.5% in the San Juan and San Joaquin. This suggests that much of the basin-level differences in production-normalized CH₄ emissions reported by aircraft studies can be explained by differences in site size and distribution of site-level production rates. We estimate that NG production sites emit total CH₄ emissions of 830 Mg/h (95% CI: 530-1200), 63% of which come from the sites producing <100 Mcfd that account for only 10% of total NG production. Our total CH₄ emissions estimate is 2.3 times higher than the U.S. Environmental Protection Agency's estimate and likely attributable to the disproportionate influence of high emitting sites.

The Firepower Sweep Test: A novel approach to cookstove laboratory testing

Emissions from solid-fuel cookstoves have been linked to indoor and outdoor air pollution, climate forcing, and human disease. Although task-based laboratory protocols, such as the Water Boiling Test (WBT), overestimate the ability of improved stoves to lower emissions, WBT emissions data are commonly used to benchmark cookstove performance, estimate indoor and outdoor air pollution concentrations, estimate impacts of stove intervention projects, and select stoves for large-scale control trials. Multiple-firepower testing has been proposed as an alternative to the WBT and is the basis for a new standardized protocol (ISO 19867-1:2018); however, data are needed to assess the value of this approach. In this work, we (a) developed a Firepower Sweep Test [FST], (b) compared emissions from the FST, WBT, and in-home cooking, and (c) quantified the relationship between firepower and emissions using correlation analysis and linear model selection. Twenty-three stove-fuel combinations were evaluated. The FST reproduced the range of PM_2.5 and CO emissions observed in the field, including high emissions events not typically observed under the WBT. Firepower was modestly correlated with emissions, although the relationship varied between stove-fuel combinations. Our results justify incorporating multiple-firepower testing into laboratory-based protocols but demonstrate that firepower alone cannot explain the observed variability in cookstove emissions.

Influence of milling on the nutritional composition of bran from different rice varieties

The nutritional composition of bran from four rice varieties namely, Jyothi/IR64, Basmati and Agonibora representing high amylose, intermediate amylose and waxy, respectively were evaluated with friction and abrasive mills at different degrees of milling (DOM). Fat and protein content of the bran inversely correlated to amylose content of rice variety. The fat and fibre contents reduced with increased DOM due to increasing starch influx from the endosperm. Abrasive milling produced bran with higher protein content and total dietary fibre, resulting in superior quality bran, while friction milling led to higher fat. Agonibora bran was found to be superior in terms of nutritional quality. Industrial milling resulted in higher protein content in bran, and Jyothi variety had a better amino acid profile.

Neurosurgery and pregnancy

Pregnant patients rarely present with neurosurgical emergencies, but can cause significant morbidity and mortality to the mother and the foetus. Physiological changes of pregnancy in relevance to neurosurgery, effects of anaesthetic agents on the foetus, common neurosurgical emergencies, and anaesthetic implications both from obstetric and neurosurgical point of view are discussed in this review.

Comorbidities and related factors in rheumatoid arthritis patients of south India- Karnataka Rheumatoid Arthritis Comorbidity (KRAC) study

The aim was to study the prevalence of comorbidities in rheumatoid arthritis (RA) patients in everyday clinical practice and their association with disease-specific and demographic factors. The multi-center study recruited 3,247 (at 14 centers, and 265) were excluded due to incomplete data. The number of subjects considered for the analysis was 2982. The mean (±standard deviation) age was 48.98±12.64 years and the male-to-female ratio was 1:5. The data was collected based on a pre-structured pro forma by trained clinical research associates through interview and verification of charts and reports available in the patient records. The following comorbidities were studied: cardiovascular disease, hypertension, diabetes mellitus, hypercholesterolemia, thyroid disease, psychiatric diseases like depression, and pulmonary disease. Hypertension (20.7%), diabetes mellitus (14.4%) and thyroid disease (18.3%) were the most prevalent comorbidities. Hypercholesterolemia (5.3%), pulmonary diseases (2.1%), cardiovascular diseases (0.2%) and depression (0.03%) were prevalent in ≤5% of the study population. The overall presence of comorbidity increased with age and reduced with the duration of illness prior (DOIP). The age, gender, and DOIP differed significantly between groups with and without hypercholesterolemia. Females had a statistically increased prevalence of thyroid disease. The prevalence of comorbidities in RA patients from south India is around 40% and the incidence of comorbidity increased with age. As per the literature evidence, the prevalence in the current study subjects was higher when compared to prevalence of similar diseases occurring in the general south Indian population.