Local and NON-LOCAL source apportionment of black carbon and combustion generated PM2.5.

Current methods for measuring black carbon aerosol (BC) by optical methods apportion BC to fossil fuel and wood combustion. However, these results are aggregated: local and non-local combustion sources are lumped together. The spatial apportioning of carbonaceous aerosol sources is challenging in remote or suburban areas because non-local sources may be significant. Air quality modeling would require highly accurate emission inventories and unbiased dispersion models to quantify such apportionment. We propose FUSTA (FUzzy SpatioTemporal Apportionment) methodology for analyzing aethalometer results for equivalent black carbon coming from fossil fuel (eBCff) and wood combustion (eBCwb). We applied this methodology to ambient measurements at three suburban sites around Santiago, Chile, in the winter season 2021. FUSTA results showed that local sources contributed ∼80% to eBCff and eBCwb in all sites. By using PM2.5 - eBCff and PM2.5 - eBCwb scatterplots for each fuzzy cluster (or source) found by FUSTA, the estimated lower edge lines showed distinctive slopes in each measurement site. These slopes were larger for non-local sources (aged aerosols) than for local ones (fresh emissions) and were used to apportion combustion PM2.5 in each site. In sites Colina, Melipilla and San Jose de Maipo, fossil fuel combustion contributions to PM2.5 were 26 % (15.9 µg m-3), 22 % (9.9 µg m-3), and 22 % (7.8 µg m-3), respectively. Wood burning contributions to PM2.5 were 22 % (13.4 µg m-3), 19 % (8.9 µg m-3) and 22% (7.3 µg m-3), respectively. This methodology generates a joint source apportionment of eBC and PM2.5, which is consistent with available chemical speciation data for PM2.5 in Santiago.

A new methodology for source apportionment of gaseous industrial emissions.

Air quality modeling (AQM) is often used to investigate gaseous pollution around industrial zones. However, this methodology requires accurate emission inventories, unbiased AQM algorithms and realistic boundary conditions. We introduce a new methodology for source apportionment of industrial gaseous emissions, which is based on a fuzzy clustering of ambient concentrations, along with a standard AQM approach. First, by applying fuzzy clustering, ambient concentration is expressed as a sum of non-negative contributions - each corresponding to a specific spatiotemporal pattern (STP); we denote this method as FUSTA (FUzzy SpatioTemporal Apportionment). Second, AQM of the major industrial emissions in the study zone generates another set of STP. By comparing both STP sets, all major source contributions resolved by FUSTA are identified, so a source apportionment is achieved. The uncertainty in FUSTA results may be estimated by comparing results for different numbers of clusters. We have applied FUSTA in an industrial zone in central Chile, obtaining the contributions from major sources of ambient SO2: a thermal power plant complex and a copper smelter, and other contributions from local and regional sources (outside the AQM domain). The methodology also identifies SO2 episodes associated to emissions from the copper smelter.

Spatiotemporal Analysis of Black Carbon Sources: Case of Santiago, Chile, under SARS-CoV-2 Lockdowns.

BACKGROUND: The SARS-CoV-2 pandemic has temporarily decreased black carbon emissions worldwide. The use of multi-wavelength aethalometers provides a quantitative apportionment of black carbon (BC) from fossil fuels (BCff) and wood-burning sources (BCwb). However, this apportionment is aggregated: local and non-local BC sources are lumped together in the aethalometer results. METHODS: We propose a spatiotemporal analysis of BC results along with meteorological data, using a fuzzy clustering approach, to resolve local and non-local BC contributions. We apply this methodology to BC measurements taken at an urban site in Santiago, Chile, from March through December 2020, including lockdown periods of different intensities. RESULTS: BCff accounts for 85% of total BC; there was up to an 80% reduction in total BC during the most restrictive lockdowns (April-June); the reduction was 40-50% in periods with less restrictive lockdowns. The new methodology can apportion BCff and BCwb into local and non-local contributions; local traffic (wood burning) sources account for 66% (86%) of BCff (BCwb). CONCLUSIONS: The intensive lockdowns brought down ambient BC across the city. The proposed fuzzy clustering methodology can resolve local and non-local contributions to BC in urban zones.

Conditions for Feasibility of a Multicomponent Intervention to Reduce Social Isolation and Loneliness in Noninstitutionalized Older Adults.

AIMS: To identify the factors conditioning the feasibility of an intervention to reduce social isolation and loneliness in noninstitutionalized older adults from the perspective of the intervention agents. DESIGN: A Dimensional Grounded Theory study conducted from December 2019 to January 2020. METHODS: Twelve participants were recruited from an experimental study developed in a health district of a southern Spanish city. Data were collected through focus group meetings, individual interviews, biograms, anecdote notebooks, and the field diaries of two participants not included in the other techniques. Transcripts were analyzed using thematic analysis. FINDINGS: Findings were divided into three themes: (a) the elderly between the walls of loneliness, economic difficulties, losses, and the past; (b) intervention agents/volunteers between the walls of inexperience in the management of psychological/emotional processes, lack of moral authority, and difficulty in planning results adapted to the (elderly) person; and (c) intervention between the walls of (interest in) company and assistance at home, lack of involvement ("waiting for you to save them"), and withdrawal/"abandonment". CONCLUSION: A profile of the specialized intervention agent, professionalized (or at least a mentored agent), with both technical and relational competencies; a clear understanding of the purposes of the intervention (empowerment, as opposed to having company or being helped with household chores) and the commitment to active participation by the elder; or adequate management of the completion of the intervention (flexibility, attachment management) are some of the main factors contributing to the feasibility of these approaches. IMPACT: The findings have potential implications in the field of primary healthcare because primary and community healthcare services can implement corrections to the proposed intervention and ensure its effectiveness under feasible conditions. The nurse is shown as the most appropriate profile to conduct this intervention, although more research is needed to analyze the feasibility of this type of intervention in the daily practice of community nurses.

Evaluation of the Persistence and Characterization of Listeria monocytogenes in Foodservice Operations.

Listeria monocytogenes is a major foodborne pathogen that can contaminate food products and colonize food-producing facilities. Foodservice operations (FSOp) are frequently responsible for foodborne outbreaks due to food safety practices failures. We investigated the presence of and characterized L. monocytogenes from two FSOp (cafeterias) distributing ready-to-eat meals and verified FSOp's compliance with good manufacturing practices (GMP). Two facilities (FSOp-A and FSOp-B) were visited three times each over 5 months. We sampled foods, ingredients, and surfaces for microbiological analysis, and L. monocytogenes isolates were characterized by phylogenetic analyses and phenotypic characteristics. GMP audits were performed in the first and third visits. A ready-to-eat salad (FSOp-A) and a frozen ingredient (FSOp-B) were contaminated with L. monocytogenes, which was also detected on Zone 3 surfaces (floor, drains, and a boot cover). The phylogenetic analysis demonstrated that FSOp-B had persistent L. monocytogenes strains, but environmental isolates were not closely related to food or ingredient isolates. GMP audits showed that both operations worked under "fair" conditions, and "facilities and equipment" was the section with the least compliances. The presence of L. monocytogenes in the environment and GMP failures could promote food contamination with this pathogen, presenting a risk to consumers.

[Determinants for addressing social isolation and loneliness of non-institutionalized older adults from Primary Health Care]. / Condicionantes para el abordaje del aislamiento social y la soledad de adultos mayores no institucionalizados desde atención primaria de salud.

OBJECTIVE: To identify the main conditioning factors that Primary Care professionals indicate when implementing and developing interventions on isolation and loneliness. DESIGN: Qualitative research with grounded theory, systematic analysis and narrative design of topics. LOCATION: Developed in 12 Primary Care centres of the Health District of Córdoba and Guadalquivir, covering urban and rural areas. PARTICIPANTS: Three profiles were identified: family medicine/community care, community nursing and case management nursing. The selection was carried out among those who showed greater motivation and commitment to an intervention on isolation/loneliness. METHOD: Purposive sampling. The work was based on individual in-depth interviews, focus groups and dialogic interviews. RESULTS: (a) Distorted images persist about loneliness/social isolation and living alone that make it challenging to identify; (b) the main disruptive determinants in the structure and organization of the care system have to do with the absence of screening programs, the hegemony of the biomedical model and the deficit of resources (in light of this model); (c) the main facilitators are linked to the nursing role, privileged for these interventions according to the participants; and, finally, (d) personal components are necessary, both from the older adult and from the professionals. CONCLUSIONS: Intervention on social isolation and loneliness in Primary Care is conditioned by organizational and structural, professional and personal factors. It is essential to take them into account in order to guarantee their feasibility.

Combining Cluster Analysis of Air Pollution and Meteorological Data with Receptor Model Results for Ambient PM2.5 and PM10.

Air pollution regulation requires knowing major sources on any given zone, setting specific controls, and assessing how health risks evolve in response to those controls. Receptor models (RM) can identify major sources: transport, industry, residential, etc. However, RM results are typically available for short term periods, and there is a paucity of RM results for developing countries. We propose to combine a cluster analysis (CA) of air pollution and meteorological measurements with a short-term RM analysis to estimate a long-term, hourly source apportionment of ambient PM2.5 and PM10. We have developed a proof of the concept for this proposed methodology in three case studies: a large metropolitan zone, a city with dominant residential wood burning (RWB) emissions, and a city in the middle of a desert region. We have found it feasible to identify the major sources in the CA results and obtain hourly time series of their contributions, effectively extending short-term RM results to the whole ambient monitoring period. This methodology adds value to existing ambient data. The hourly time series results would allow researchers to apportion health benefits associated with specific air pollution regulations, estimate source-specific trends, improve emission inventories, and conduct environmental justice studies, among several potential applications.

The Combined Effect of Cold and Copper Stresses on the Proliferation and Transcriptional Response of Listeria monocytogenes.

Listeria monocytogenes is a foodborne pathogen that can cause severe disease in susceptible humans. This microorganism has the ability to adapt to hostile environmental conditions such as the low temperatures used by the food industry for controlling microorganisms. Bacteria are able to adjust their transcriptional response to adapt to stressful conditions in order to maintain cell homeostasis. Understanding the transcriptional response of L. monocytogenes to stressing conditions could be relevant to develop new strategies to control the pathogen. A possible alternative for controlling microorganisms in the food industry could be to use copper as an antimicrobial agent. The present study characterized three L. monocytogenes strains (List2-2, Apa13-2, and Al152-2A) adapted to low temperature and challenged with different copper concentrations. Similar MIC-Cu values were observed among studied strains, but growth kinetic parameters revealed that strain List2-2 was the least affected by the presence of copper at 8°C. This strain was selected for a global transcriptional response study after a 1 h exposition to 0.5 mM of CuSO4 × 5H2O at 8 and 37°C. The results showed that L. monocytogenes apparently decreases its metabolism in response to copper, and this reduction is greater at 8°C than at 37°C. The most affected metabolic pathways were carbohydrates, lipids and nucleotides synthesis. Finally, 15 genes were selected to evaluate the conservation of the transcriptional response in the other two strains. Results indicated that only genes related to copper homeostasis showed a high degree of conservation between the strains studied, suggesting that a low number of genes is implicated in the response to copper stress in L. monocytogenes. These results contribute to the understanding of the molecular mechanisms used by bacteria to overcome a combination of stresses. This study concluded that the application of copper in low concentrations in cold environments may help to control foodborne pathogens as L. monocytogenes in the industry.

Synergistic effect of copper and low temperature over Listeria monocytogenes.

The capacity to grow at low temperatures has allowed Listeria monocytogenes to become one of the primary food pathogens to date, representing a major public health problem worldwide. Several works have described the homeostatic response of L. monocytogenes under different copper (Cu) treatments growing at mild temperature (30 °C). The aims of this report were to evaluate if changes in the external concentration of Cu affected viability and Cu homeostasis of L. monocytogenes growing at low temperature. Ours results showed that L. monocytogenes growing at 8 °C had a reduced viability relative to 30 °C when exposed to Cu treatments. This decrease was correlated with an increase in the internal concentration of Cu, probably linked to the transcriptional down-regulation of mechanisms involved in Cu homeostasis. This combined effect of Cu and low temperature showed a synergistic impact over the viability and homeostasis of L. monocytogenes, where low temperature exacerbated the toxic effect of Cu. These results can be useful in terms of the use of Cu as an antibacterial agent.

Root Coverage of Multiple Miller Class I and II Recession Defects Using Acellular Dermal Matrix and Tunneling Technique in Maxilla and Mandible: A 1-Year Report.

The objective of the present report was to study the influence of the location (maxilla versus mandible) and class (Miller classification) of gingival recessions on the total root coverage achievement using the tunnel procedure with acellular dermal matrix in adjacent single-root teeth. Twenty-four patients with 93 recessions were treated and evaluated 1 year postsurgery. Results showed 100% of root covered in 67.9% of the maxillary recessions and 52.5% in the mandible (P = .676). In cases of partial root coverage, the initial recession diminished from 4.41 mm (SD: 1.12) to 0.82 mm (SD: 0.24) in the maxilla and from 3.78 mm (SD: 1.08) to 0.78 mm (SD: 0.30) in the mandible. Root coverage of 100% was observed in 74.07% of Miller Class I recessions in comparison with 43.59% of Class II recessions (P = .003).

Potential of Chilean native corn (Zea mays L.) accessions as natural sources of phenolic antioxidants and in vitro bioactivity for hyperglycemia and hypertension management.

Thirty-three Chilean corn accessions were screened for the first time regarding their phenolic profiles, total phenolic contents (TPC), antioxidant capacity (DPPH and ABTS), and in vitro inhibition against key enzymes relevant for hyperglycemia (α-amylase and α-glucosidase) and hypertension (angiotensin I-converting enzyme, ACE-I) in both free and cell wall-bound fractions. TPC varied from 132.2 to 262.5 mg of gallic acid equivalents/100g dry weight (DW), and around 88% of TPC and antioxidant capacity were found in the bound form. Vanillin, vanillic, protocatechuic, ferulic, and p-coumaric acids were detected by HPLC in free fractions, whereas ferulic and p-coumaric acids were found in the bound form. Pisankalla accession (red kernel) had the highest ferulic acid content (269.5 mg/100g DW). No α-amylase and ACE-I inhibition were found; however, all free fractions inhibited α-glucosidase (10.8-72.5%). Principal component analysis revealed that darker samples (free fraction) showed higher TPC and antioxidant capacity, while α-glucosidase inhibition was related to yellow-colored samples.

[Periodontal disease among patients with acute coronary syndrome]. / Enfermedad periodontal en pacientes con síndrome coronario agudo.

BACKGROUND: Epidemiological studies suggest an association between periodontal disease and coronary heart disease. It is possible that periodontal disease may contribute to plaque destabilization in patients with acute coronary syndrome. AIM: To assess the association between severity of periodontal disease, the number of acute plaques and extension of coronary artery disease in patients with acute coronary syndrome. PATIENTS AND METHODS: The severity of periodontal disease was assessed by skilled independent observers in patients with acute coronary syndrome subjected to coronary angiography. The periodental disease was classified as mild or severe. Acute plaques were defined on angiography as those with thrombi, ulcers or flow alterations. The extension of coronary disease was analyzed using the Sullivan score. RESULTS: Forty three patients (35 males) aged 41 to 83 years, were studied. Mild and severe periodontal disease was present in 18 (42%) and 25 (58%) patients respectively. Seventy six percent of those with severe disease had two or more acute plaques, compared with 17% of those with mild disease (p<0.001). Median Sullivan score was 80.6 and 57.2 in patients with severe or mild periodontal disease respectively (p=0.001). CONCLUSIONS: Severe periodontal disease was associated with a higher number of acute coronary plasques and a higher extension of coronary artery disease, in patients with acute coronary syndromes.