Fine particulate matter in the tropical environment: monsoonal effects, source apportionment, and health risk assessment

The health implications of PM2:5 in the tropical region of Southeast Asia (SEA) are significant as PM2:5 can pose serious health concerns. PM2:5 concentration and sources here are strongly influenced by changes in the monsoon regime from the south-west quadrant to the north-east quadrant in the region. In this work, PM2:5 samples were collected at a semi-urban area using a high-volume air sampler at different seasons on 24 h basis. Analysis of trace elements and water-soluble ions was performed using inductively coupled plasma mass spectroscopy (ICP-MS) and ion chromatography (IC), respectively. Apportionment analysis of PM2:5 was carried out using the United States Environmental Protection Agency (US EPA) positive matrix factorization (PMF) 5.0 and a mass closure model. We quantitatively characterized the health risks posed to human populations through the inhalation of selected heavy metals in PM2:5. 48% of the samples collected exceeded the World Health Organization (WHO) 24 h PM2:5 guideline but only 19% of the samples exceeded 24 h US EPA National Ambient Air Quality Standard (NAAQS). The PM2:5 concentration was slightly higher during the north-east monsoon compared to south-west monsoon. The main trace metals identified were As, Pb, Cd, Ni, Mn, V, and Cr while the main ions were SO

The impact of a virtual orthopaedic surgery symposium on medical students: Increasing awareness and knowledge of the field

UNLABELLED: Orthopaedic surgery has become an increasingly popular field of residency training for medical students. Many institutions offer elective time to explore areas of interest through clinical rotations and research; however, most of these opportunities are reserved for senior medical students. The purpose of this study was to evaluate the impact of a dedicated medical student orthopaedic surgery symposium to increase awareness about the field and to assess students\u27 interest and knowledge of orthopaedic surgery before and after the symposium. METHODS: Medical students were invited to submit orthopaedic surgery-related research to a free, 1-day virtual symposium held in April 2022. Abstracts were reviewed and selected from 9 different orthopaedic surgery subspecialty categories. Survey assessments were sent to medical students to complete before and after the symposium. The surveys included questions related to participant demographics as well as interest and knowledge about the field of orthopaedic surgery. Statistical analyses were completed to compare the participants\u27 responses before and after the symposium. RESULTS: In total, 962 medical students registered for the 4-hour symposium. Of these, 58.5% completed the presymposium survey and 48.0% completed the postsymposium survey. 13.3% of the respondents reported being very knowledgeable about the various orthopaedic surgery subspecialties before the symposium, which increased to 18.4% after the symposium. 46.9% of the participants stated that they were knowledgeable about the daily life of an orthopaedic surgery resident before the symposium, which increased to 67.3% after the symposium. Similarly, the percentage of respondents who reported that they were very knowledgeable about the residency match process increased from 12.2% presymposium to 22.4% postsymposium. CONCLUSIONS: As interest in pursuing a career in orthopaedic surgery increases, medical students will continue to seek information, mentorship, and opportunities to present their research in preparation for residency applications. Our study demonstrated that a large-scale, national, virtual orthopaedic surgery symposium provided a platform to augment medical students\u27 knowledge of the field, present their research, and interact with faculty members. LEVEL OF EVIDENCE: Level V

The Social Significance of the Cluster in the Economy

Transition of the Russian Federation's policy to the innovative way of economic and social development is indispensable imperative to ensure its output to a leading position in the modern globalized world. Among the wide range of means, methods, forms, the mechanisms by which it is possible sharp acceleration of the process of formation of an innovative economy in our country, a special place belongs to the cluster approach. International scientific community is justified, and the practice of developed countries proved that the cluster approach to the structuring of the national economy and regional systems are an important source to improve production efficiency, increase its competitiveness, and increase public welfare. Questions of cluster formation and management of the development of the Russian economy in recent years, becomes the subject of numerous studies by Russian scientists - economists. Cluster policies are becoming increasingly recognized in public authorities. Moreover, there are already official documents, which examine the content and direction of the cluster policy. Keywords: society, cluster, economy, innovation, importance, competitiveness JEL Classifications: A19, O35, O3

Respiratory and mental health effects of wildfires: an ecological study in Galician municipalities (north-west Spain)

<p>Abstract</p> <p>Background</p> <p>During the summer of 2006, a wave of wildfires struck Galicia (north-west Spain), giving rise to a disaster situation in which a great deal of the territory was destroyed. Unlike other occasions, the wildfires in this case also threatened farms, houses and even human lives, with the result that the perception of disaster and helplessness was the most acute experienced in recent years. This study sought to analyse the respiratory and mental health effects of the August-2006 fires, using consumption of anxiolytics-hypnotics and drugs for obstructive airway diseases as indicators.</p> <p>Methods</p> <p>We conducted an analytical, ecological geographical- and temporal-cluster study, using municipality-month as the study unit. The independent variable was exposure to wildfires in August 2006, with municipalities thus being classified into the following three categories: no exposure; medium exposure; and high exposure. Dependent variables were: (1) anxiolytics-hypnotics; and (2) drugs for obstructive airway diseases consumption. These variables were calculated for the two 12-month periods before and after August 2006. Additive models for time series were used for statistical analysis purposes.</p> <p>Results</p> <p>The results revealed a higher consumption of drugs for obstructive airway diseases among pensioners during the months following the wildfires, in municipalities affected versus those unaffected by fire. In terms of consumption of anxiolytics-hypnotics, the results showed a significant increase among men among men overall -pensioners and non-pensioners- in fire-affected municipalities.</p> <p>Conclusions</p> <p>Our study indicates that wildfires have a significant effect on population health. The coherence of these results suggests that drug utilisation research is a useful tool for studying morbidity associated with environmental incidents.</p

New Vehicle Characteristics and the Cost of the Corporate Average Fuel Economy Standard

Recent legislation has increased the Corporate Average Fuel Economy (CAFE) standard by 40 percent, which represents the first major increase in the standard since its creation in 1975. Previous analysis of the CAFE standard has analyzed the short run effects (1-2 years), in which vehicle characteristics are held fixed, or the long run effects (10 years or more), when firms can adopt new power train technology. This paper focuses on the medium run, when firms can choose characteristics such as weight and power, and have a limited ability to adopt technology. We first document the historical importance of the medium run and then estimate consumers' willingness-to-pay for fuel efficiency, power and weight. We employ a novel empirical strategy that accounts for the characteristics' endogeneity, which has not been addressed in the literature, by using variation in the set of engine models used in vehicle models. The results imply that an increase in power has a similar effect on vehicle sales to a proportional increase in fuel efficiency. We then simulate the medium run effects of an increase in the CAFE standard. The policy reduces producer and consumer welfare and causes substantial transfers across firms, but the effects are significantly smaller than found in previous studies

Fine particulate matter in the tropical environment: monsoonal effects, source apportionment, and health risk assessment

The health implications of PM_2.5 in the tropical region of Southeast Asia (SEA) are significant as PM_2.5 can pose serious health concerns. PM_2.5 concentration and sources here are strongly influenced by changes in the monsoon regime from the south-west quadrant to the north-east quadrant in the region. In this work, PM_2.5 samples were collected at a semi-urban area using a high-volume air sampler at different seasons on 24 h basis. Analysis of trace elements and water-soluble ions was performed using inductively coupled plasma mass spectroscopy (ICP-MS) and ion chromatography (IC), respectively. Apportionment analysis of PM_2.5 was carried out using the United States Environmental Protection Agency (US EPA) positive matrix factorization (PMF) 5.0 and a mass closure model. We quantitatively characterized the health risks posed to human populations through the inhalation of selected heavy metals in PM_2.5. 48 % of the samples collected exceeded the World Health Organization (WHO) 24 h PM_2.5 guideline but only 19 % of the samples exceeded 24 h US EPA National Ambient Air Quality Standard (NAAQS). The PM_2.5 concentration was slightly higher during the north-east monsoon compared to south-west monsoon. The main trace metals identified were As, Pb, Cd, Ni, Mn, V, and Cr while the main ions were SO₄²⁻, NO₃⁻, NH₄⁺, and Na. The mass closure model identified four major sources of PM_2.5 that account for 55 % of total mass balance. The four sources are mineral matter (MIN) (35 %), secondary inorganic aerosol (SIA) (11 %), sea salt (SS) (7 %), and trace elements (TE) (2 %). PMF 5.0 elucidated five potential sources: motor vehicle emissions coupled with biomass burning (31 %) were the most dominant, followed by marine/sulfate aerosol (20 %), coal burning (19 %), nitrate aerosol (17 %), and mineral/road dust (13 %). The hazard quotient (HQ) for four selected metals (Pb, As, Cd, and Ni) in PM_2.5 mass was highest in PM_2.5 mass from the coal burning source and least in PM_2.5 mass originating from the mineral/road dust source. The main carcinogenic heavy metal of concern to health at the current location was As; the other heavy metals (Ni, Pb, and Cd) did not pose a significant cancer risk in PM_2.5 mass concentration. Overall, the associated lifetime cancer risk posed by the exposure of hazardous metals in PM_2.5 is 3–4 per 1 000 000 people at this location

Annual variations of carbonaceous PM_2.5 in Malaysia: influence by Indonesian peatland fires

In this study, we quantified carbonaceous PM_2.5 in Malaysia through annual observations of PM_2.5, focusing on organic compounds derived from biomass burning. We determined organic carbon (OC), elemental carbon and concentrations of solvent-extractable organic compounds (biomarkers derived from biomass burning sources and <i>n</i>-alkanes). We observed seasonal variations in the concentrations of pyrolyzed OC (OP), levoglucosan (LG), mannosan (MN), galactosan, syringaldehyde, vanillic acid (VA) and cholesterol. The average concentrations of OP, LG, MN, galactosan, VA and cholesterol were higher during the southwestern monsoon season (June–September) than during the northeastern monsoon season (December–March), and these differences were statistically significant. Conversely, the syringaldehyde concentration during the southwestern monsoon season was lower. The PM_2.5 OP / OC4 mass ratio allowed distinguishing the seven samples, which have been affected by the Indonesian peatland fires (IPFs). In addition, we observed significant differences in the concentrations between the Indonesian peatland fire (IPF) and other samples of many chemical species. Thus, the chemical characteristics of PM_2.5 in Malaysia appeared to be significantly influenced by IPFs during the southwestern monsoon season. Furthermore, we evaluated two indicators, the vanillic acid / syringic acid (VA / SA) and LG / MN mass ratios, which have been suggested as indicators of IPFs. The LG / MN mass ratio ranged from 14 to 22 in the IPF samples and from 11 to 31 in the other samples. Thus, the respective variation ranges partially overlapped. Consequently, this ratio did not satisfactorily reflect the effects of IPFs in Malaysia. In contrast, the VA / SA mass ratio may serve as a good indicator, since it significantly differed between the IPF and other samples. However, the OP / OC4 mass ratio provided more remarkable differences than the VA / SA mass ratio, offering an even better indicator. Finally, we extracted biomass burning emissions' sources such as IPF, softwood/hardwood burning and meat cooking through varimax-rotated principal component analysis

Load frequency stabilization of distinct hybrid conventional and renewable power systems incorporated with electrical vehicles and capacitive energy storage

Abstract Maintaining a power balance between generation and demand is generally acknowledged as being essential to maintaining a system frequency within reasonable bounds. This is especially important for linked renewable-based hybrid power systems (HPS), where disruptions are more likely to occur. This paper suggests a prominent modified “Fractional order-proportional-integral with double derivative (FOPIDD2) controller” as an innovative HPS controller in order to navigate these obstacles. The recommended control approach has been validated in power systems including wind, reheat thermal, solar, and hydro generating, as well as capacitive energy storage and electric vehicle. The improved controller’s performance is evaluated by comparing it to regular FOPID, PID, and PIDD2 controllers. Furthermore, the gains of the newly structured FOPIDD2 controller are optimized using a newly intended algorithm terms as squid game optimizer (SGO). The controller’s performance is compared to benchmarks such as the grey wolf optimizer (GWO) and jellyfish search optimization. By comparing performance characteristics such as maximum frequency undershoot/overshoot, and steadying time, the SGO-FOPIDD2 controller outperforms the other techniques. The suggested SGO optimized FOPIDD2 controller was analyzed and validated for its ability to withstand the influence of power system parameter uncertainties under various loading scenarios and situations. Without any complicated design, the results show that the new controller can work steadily and regulate frequency with an appropriate controller coefficient