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1.
Braz. j. biol ; 84: e256425, 2024. tab, graf, mapas
Artigo em Inglês | LILACS-Express | LILACS, VETINDEX | ID: biblio-1364525

RESUMO

Using inventory data, this study evaluates the species composition, growing stock volume (GSV), and biomass carbon (BMC) of the five major timber species in the sub-tropical, and temperate/sub-alpine regions of Pakistan. It was found that the stem density varies between 50 and 221 trees ha -1, with a mean of 142 trees ha-1 (13.68 million trees for entire forest area). Among the species, Pinus wallichiana showed a high species composition (27.80%) followed by Picea smithiana (24.64%). The GSV was found in the range of 67.81 to 425.94 m3 ha-1, with a total GSV value of 20.68 million m3 for the entire region. Similarly, The BMC ranged from 27.04 to 169.86 Mg ha-1, with a mean BMC value of 86.80 Mg ha-1. The total amount of stored carbon was found at 8.69 million tons for a total of 95842 ha of commercially managed forest. Furthermore, the correlation analysis between the basal area (BA) and GSV and BMC showed that BA is the best predictor of GSV and BMC. The findings provide insights to the policy makers and forest managers regarding the sustainable commercial forest management as well as forest carbon management in the recent global carbon management for climate change mitigation.


Usando dados de inventário, este estudo avaliou a composição de espécies, volume de estoque crescente (GSV) e carbono de biomassa (BMC) das cinco principais espécies madeireiras nas regiões subtropicais e temperadas/subalpinas do Paquistão. Constatou-se que a densidade do caule variou entre 50 e 221 árvores ha-1, com média de 142 árvores ha-1 (13,68 milhões de árvores para toda a área florestal). Entre as espécies, Pinus wallichiana apresentou alta composição de espécies (27,80%), seguida de Picea smithiana (24,64%). O GSV foi encontrado na faixa de 67,81 a 425,94 m3 ha-1, com um valor total de 20,68 milhões de m3 para toda a região. Da mesma forma, o BMC variou de 27,04 a 169,86 mg ha-1, com valor médio de 86,80 mg ha-1. A quantidade total de carbono armazenado foi de 8,69 milhões de toneladas para um total de 95.842 ha de floresta manejada comercialmente. Além disso, a análise de correlação entre área basal (BA), GSV e BMC mostrou que BA é o melhor preditor de GSV e BMC. As descobertas fornecem insights para os formuladores de políticas e gestores florestais sobre o manejo florestal comercial sustentável, bem como o manejo florestal de carbono no recente gerenciamento global de carbono para a mitigação das mudanças climáticas.


Assuntos
Árvores/crescimento & desenvolvimento , Carbono , Florestas , Biomassa
2.
Rev. biol. trop ; 70(1)dic. 2022.
Artigo em Espanhol | LILACS-Express | LILACS, SaludCR | ID: biblio-1387712

RESUMO

Resumen Introducción: Los humedales se encuentran entre los ecosistemas más productivos, pero actualmente están siendo degradados o eliminados a un ritmo acelerado por múltiples actividades antrópicas. En la costa central de Perú, los humedales sufren incendios recurrentes, y los efectos poco estudiados incluyen el nivel de emisiones y el secuestro de carbono por quema. Objetivo: Estimar el carbono en la biomasa aérea afectada por el fuego y el carbono recuperado por la vegetación al cabo de un año. Métodos: Trabajamos en el humedal costero Los Pantanos de Villa (Lima, Perú) y comparamos áreas quemadas (32 cuadrantes, 1 m2) y no afectadas (33 cuadrantes). Resultados: La vegetación afectada fue predominantemente herbácea y dominada por Phragmites australis, Schoenoplectus americanus, Typha dominguensis y Cladium jamaicense. El incendio afectó 1 147.0 t de biomasa vegetal que almacenó 381.8 t de carbono, generando la emisión de 1 397.1 t de CO2 a la atmósfera. Al cabo de un año se había recuperado el 79 % de la cobertura vegetal, pero solo el 26 % de la biomasa vegetal viva y el 12.8 % del carbono contenido en la vegetación. Conclusiones: Los indicadores apropiados de la resiliencia de los humedales al fuego deben considerar que los humedales afectados por el fuego recuperan rápidamente la cobertura vegetal, pero no el almacenamiento de carbono y la biomasa vegetal.


Abstract Introduction: Wetlands are among the most productive ecosystems, but currently are being degraded or eliminated at accelerated rates by multiple anthropic activities. In the central coast of Peru, wetlands suffer recurring fires, and the little-studied effects include the level of emissions and carbon sequestration by burning. Objective: To estimate carbon in aerial biomass affected by fire, and carbon recovered by the vegetation after one year. Methods: We worked in Los Pantanos de Villa (Lima, Peru) coastal wetland and compared burnt (32 quadrants, 1 m2) and unaffected areas (33 quadrants). Results: The vegetation affected was predominantly herbaceous and dominated by Phragmites australis, Schoenoplectus americanus, Typha dominguensis and Cladium jamaicense. Fire affected 1 147.0 t of plant biomass that stored 381.8 t of carbon, generating the emission of 1 397.1 t of CO2 into the atmosphere. After one year, 79 % of the vegetation cover had recovered, but only 26 % of the plant biomass and 12.8 % of vegetation carbon. Conclusions: Appropriate indicators of wetland fire resilience should consider that fire-impacted wetland rapidly recovers plant cover, but not carbon storage and plant biomass.


Assuntos
Biomassa , Incêndios Florestais , Áreas Alagadas , Peru
3.
Rev. biol. trop ; 70(1)dic. 2022.
Artigo em Espanhol | LILACS-Express | LILACS, SaludCR | ID: biblio-1387700

RESUMO

Resumen Introducción: Tradicionalmente, los estudios de escarabajos coprófagos en los bosques secos tropicales (BST) del Caribe colombiano han aplicado metodologías diseñadas para zonas húmedas y andinas del país, lo cual podría estar incidiendo en el rendimiento y la eficiencia del muestreo. Objetivo: Con el fin de aportar a esta discusión, se analizó cómo la cantidad de cebo y el tiempo de operación de la trampa de caída inciden en la efectividad de captura de escarabajos coprófagos en un fragmento de BST en La Reserva Campesina la Flecha, San Jacinto, Colombia. Métodos: Para la captura de los escarabajos, se utilizó trampas de caída, cebadas con tres cantidades diferentes de atrayente: pequeño (34.6 g), mediano (53.8 g) y grande (114.9 g), las cuales permanecieron activas en campo durante 48 h. Cuatro muestreos fueron realizados entre marzo y septiembre de 2015, abarcando por igual la época seca y de lluvia. Resultados: Se registró un total de 4 563 individuos, agrupados en 10 géneros y 27 especies de escarabajos coprófagos. Los mayores valores de riqueza, abundancia y biomasa se presentaron en el cebo grande, a las 48 h, durante la época de lluvias. Sin embargo, el tiempo de operación de la trampa no tuvo efecto en la estimación de la riqueza, abundancia y biomasa de escarabajos independientemente de los tamaños de cebo. Los tres órdenes de la diversidad ( 0 D, 1 D y 2 D), presentaron valores similares entre las cantidades de cebo durante la época de lluvia, pero en la época seca, los cebos de mayor tamaño presentaron los valores de diversidad más altos. Por su parte con el cebo de mayor tamaño se capturó significativamente más riqueza, abundancia y biomasa de escarabajos de cuerpo pequeño y grande siendo esta situación más notaria durante la época seca. Conclusiones: Los resultados de este trabajo evidencian que para el estudio de los ensamblajes de escarabajos en el BST la utilización de un cebo de mayor tamaño contribuye a una mejor estimación de riqueza, abundancia, diversidad y biomasa, sobre todo durante la época seca, cuando las condiciones ambientales propician que los cebos pierdan su atractividad con mayor rapidez.


Abstract Introduction: Typically, research on dung beetles in the Tropical Dry Forests (TDF) of Colombian Caribbean region, have applied methodologies designed for wet or Andean areas of the country, which could be influencing the performance and efficiency of sampling. Objective: In order to contribute to this discussion, we analyzed how the bait amount and pitfall trap operating time influence the collection effectiveness of dung beetles in a TDF fragment at Reserva Campesina La Flecha, San Jacinto, Colombia. Methods: For the collection of beetles, we utilized pitfall traps baited with three different amounts of attractants: small (34.6 g), medium (53.8 g), and large (114.9 g), which remained active in the field for 48 h., 4 samplings between March and September 2015 were carried out, covering both, dry and rainy seasons. Results: A total of 4 563 individuals were recorded, grouped into 10 genera and 27 species of dung beetles. The highest values of richness, abundance and biomass were registered in the large bait, at 48 h, during the rainy season. However, the trap operating time had no effect on the estimation of beetles' richness, abundance, and biomass, regardless of bait sizes. The three diversity orders ( 0 D, 1 D y 2 D) showed similar values between the bait amounts during rainy season, but in the dry season, the largest baits displayed the highest diversity values. On the other hand, with the largest bait, significantly more richness, abundance, and biomass of small and large body beetles were registered, especially during the dry season. Conclusions: The results of this research show that, for the study of beetles' assemblages in the BST, the use of a larger bait contributes to a better estimate of richness, abundance, diversity and biomass, especially during the dry season, when environmental conditions promote a more rapidly loss of baits attractiveness.


Assuntos
Animais , Besouros , Biomassa , Amostragem
4.
Sci Rep ; 12(1): 14949, 2022 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-36056039

RESUMO

Bacterial degradation of sinking diatom aggregates is key for the availability of organic matter in the deep-ocean. Yet, little is known about the impact of aggregate colonization by different bacterial taxa on organic carbon and nutrient cycling within aggregates. Here, we tracked the carbon (C) and nitrogen (N) transfer from the diatom Leptocylindrus danicus to different environmental bacterial groups using a combination of 13C and 15N isotope incubation (incubated for 72 h), CARD-FISH and nanoSIMS single-cell analysis. Pseudoalteromonas bacterial group was the first colonizing diatom-aggregates, succeeded by the Alteromonas group. Within aggregates, diatom-attached bacteria were considerably more enriched in 13C and 15N than non-attached bacteria. Isotopic mass balance budget indicates that both groups showed comparable levels of diatom C in their biomass, accounting for 19 ± 7% and 15 ± 11%, respectively. In contrast to C, bacteria of the Alteromonas groups showed significantly higher levels of N derived from diatoms (77 ± 28%) than Pseudoalteromonas (47 ± 17%), suggesting a competitive advantage for Alteromonas in the N-limiting environments of the deep-sea. Our results imply that bacterial succession within diatom aggregates may largely impact taxa-specific C and N uptake, which may have important consequences for the quantity and quality of organic matter exported to the deep ocean.


Assuntos
Diatomáceas , Bactérias/metabolismo , Biomassa , Carbono/metabolismo , Diatomáceas/metabolismo , Nitrogênio/metabolismo
5.
Sci Rep ; 12(1): 14891, 2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-36050383

RESUMO

Biomass gasification by a bubbling bed gasifier has been a promising process to produce fuels from biomass. However, the performance is limited by gas aggregation in the gasifier. In this study, CFD simulations were used to investigate hydrodynamics in bubbling bed gasifiers installed with multilayer louver baffles to understand the roles of baffles on different aspects including gas aggregation, biomass-bed mixing, gas-biomass contact, and pressure drop. The designed baffles could reduce the gas aggregation particularly when the biomass is fed at the middle of the baffle zone. The baffles could enhance the biomass-bed mixing and the gas-biomass contact throughout the bed except near the biomass inlet. The installation of baffles would not significantly affect the overall pressure drop but slightly affect at the mid-level of the bed. For the system in this study, the baffled gasifier with biomass feeding at the middle of the baffled zone and the gas inlet velocity of 0.7 m/s could provide the best performance in term of hydrodynamics.


Assuntos
Hidrodinâmica , Biomassa
6.
Molecules ; 27(17)2022 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-36080423

RESUMO

The diverse utilization of pyrolysis liquid is closely related to its chemical compositions. Several factors affect PA compositions during the preparation. In this study, multivariate statistical analysis was conducted to assess PA compositions data obtained from published paper and experimental data. Results showed the chemical constituents were not significantly different in different feedstock materials. Acids and phenolics contents were 31.96% (CI: 25.30-38.62) and 26.50% (CI: 21.43-31.57), respectively, accounting for 58.46% (CI: 46.72-70.19) of the total relative contents. When pyrolysis temperatures range increased to above 350 °C, acids and ketones contents decreased by more than 5.2-fold and 1.53-fold, respectively, whereas phenolics content increased by more than 2.1-fold, and acetic acid content was the highest, reaching 34.16% (CI: 25.55-42.78). Correlation analysis demonstrated a significantly negative correlation between acids and phenolics (r2 = -0.43, p < 0.001) and significantly positive correlation between ketones and alcohols (r2 = 0.26, p < 0.05). The pyrolysis temperatures had a negative linear relationship with acids (slope = -0.07, r2 = 0.16, p < 0.001) and aldehydes (slope = -0.02, r2 = 0.09, p < 0.05) and positive linear relationship with phenolics (slope = 0.04, r2 = 0.07, p < 0.05). This study provides a theoretical reference of PA application.


Assuntos
Cetonas , Pirólise , Biomassa , Temperatura Alta , Análise Multivariada , Temperatura
7.
Fisioterapia (Madr., Ed. impr.) ; 44(5): 287-295, Sep.-Oct. 2022. ilus, tab
Artigo em Espanhol | IBECS | ID: ibc-206536

RESUMO

Introducción: La enfermedad pulmonar obstructiva crónica es una entidad de alta morbimortalidad que principalmente se genera por exposición a consumo de cigarrillo y exposición a humo de leña; estudios previos han demostrado creciente interés entre los 2 tipos de exposición. Objetivo: Comparar el efecto de la rehabilitación pulmonar en pacientes con enfermedad pulmonar obstructiva crónica que han tenido exposición a cigarrillo versus pacientes expuestos a humo de leña por biomasa en una clínica de cuarto nivel en Santiago de Cali (Colombia). Materiales y métodos: Estudio prospectivo y longitudinal, se reclutaron a todos los pacientes que asistieron durante enero de 2016 a diciembre de 2017 y cumplieron con los criterios de inclusión; posteriormente se dividieron en 2 grupos: humo de leña y cigarrillo. Se registraron pruebas de función pulmonar, evaluación de calidad de vida relacionada de la salud, valoración de síntomas y comparación de capacidad aeróbica funcional con test de caminata de 6 minutos y consumo de oxígeno estimado antes y después de rehabilitación. Resultados: Quince pacientes con exposición a leña y 17 a cigarrillo culminaron la rehabilitación. En la comparación intragrupo, se encontraron diferencias significativas (p<0,05) en la distancia recorrida, en la escala modificada de disnea del Medical Research Council (mMRC) y en el consumo de oxígeno estimado, también en el Saint George Respiratory Questionnaire. En la comparación entre grupos no se encontraron diferencias en las variables estudiadas. Conclusión: La rehabilitación pulmonar generó cambios clínicos significativos en las variables estudiadas en los 2 tipos de exposición, al ser estos cambios similares en los 2 grupos estudiados en la presente investigación. (AU)


Introduction: Chronic obstructive pulmonary disease is an entity with high morbidity and mortality that is mainly generated by exposure to cigarette smoking and exposure to wood smoke; previous studies have shown increasing interest between the 2 types of exposure. Objective: To compare the effect of pulmonary rehabilitation in patients with chronic obstructive pulmonary disease who have had exposure to cigarettes versus patients exposed to biomass wood smoke in a fourth level clinic in Santiago de Cali (Colombia). Materials and methods: Prospective and longitudinal study, all patients who attended from January 2016 to December 2017 were recruited and met the inclusion criteria, later they were divided into 2 groups: Wood Smoke and Cigarette. Pulmonary function tests, health-related quality of life assessment, symptom assessment and comparison of functional aerobic capacity were recorded with the six-minute walk test and estimated oxygen consumption before and after rehabilitation. Results: Fifteen patients with exposure to wood smoke and 17 to cigarettes completed the rehabilitation. In the intragroup comparison, significant differences (P<.05) were found in the distance traveled, in modified Medical Research Council dyspnea scale (mMRC) the estimated oxygen consumption, also in the Saint George Respiratory Questionnaire. In the comparison between groups, no differences were found in the variables studied. Conclusion: Pulmonary rehabilitation generated clinics changes significant in the variables studied in the 2 types of exposure; these changes being similar in the 2 groups studied in the present investigation. (AU)


Assuntos
Humanos , Feminino , Idoso , Doença Pulmonar Obstrutiva Crônica , Qualidade de Vida , Tolerância ao Exercício , Fumar Cigarros , Reabilitação , Biomassa , Estudos Prospectivos , Estudos Longitudinais
8.
Ying Yong Sheng Tai Xue Bao ; 33(7): 1773-1782, 2022 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-36052779

RESUMO

We selected typical croplands in the black soil region of Northeast China to analyze the characteristics of biocrusts during the growing season, including species composition, thickness, coverage, and biomass (chlorophyll content). We collected bareground soil and biocrusts samples with chlorophyll content of 5-15, 15-25, 25-35, and 35-50 mg·g-1, and measured the soil disintegration rate and soil maximum disintegration ratio of each sample using a force gauge in the laboratory. The results showed that: 1) biocrusts dominated by algae and moss were frequently developed in the croplands, with Stigeoclonium and Bryum capillare as the most common species, respectively. The thickness and biomass of algal crusts were significantly lower than moss crusts, with a successional trend from algal crusts to moss crusts. 2) The coverage, thickness, and biomass of biocrusts in croplands were negatively correlated with the frequency and intensity of tillage disturbance. For instance, the values of those characterisitics were only 27.8%, 1.52 mm, and 6.49 mg·g-1 on average, respectively, in traditional tillage croplands, and increased to 83.5%, 2.74 mm, and 34.16 mg·g-1, respectively, in the croplands with conservational tillage. 3) Biocrusts considerably reduced the disintegration of surface soil, particularly in the layer of biocrusts. Compared to the bareground soil, the soil disintegration rate of biocrusts, with four levels of biomass (with chlorophyll content of 5-15, 15-25, 25-35, and 35-50 mg·g-1), was reduced by 43.1%, 50.1%, 55.5%, and 59.8%, respectively, while the soil maximum disintegration ratios were reduced by 11.4%, 17.7%, 33.2%, and 36.6%, respectively. 4) Soil disintegration rate and maximum disintegration ratio were significantly and negatively correlated with the biomass and thickness of biocrusts, indicating that the impacts of biocrusts on soil disintegration were primarily caused by the improvements in physical properties of surface soil. In conclusion, biocrusts were frequently deve-loped in croplands in the black soil region of Northeast China, owing to less disturbance following the conversion from traditional tillage to conservational tillage. They had the potential to protect surface soil against disintegration and improve soil anti-scourability, which was critical for soil conservation in croplands in this region.


Assuntos
Briófitas , Solo , Biomassa , China , Clorofila , Produtos Agrícolas , Microbiologia do Solo
9.
Ying Yong Sheng Tai Xue Bao ; 33(7): 1937-1947, 2022 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-36052798

RESUMO

In this study, the biomass models for natural Quercus mongolica in Heilongjiang Province were constructed based on the predictors of diameter at breast height (D) and tree height (H) by several methods including multivariate likelihood analysis and seemingly unrelated regression. The results showed that the H could significantly improve the stem biomass model, with the coefficient of determination (R2) being increased from 0.953 to 0.988 and the root mean square error (RMSE) being reduced by 14 kg, but it had no significant improvement for the biomass model of branch, foliage, and root. The error structures of both biomass model systems (only D and D-H) were multiplicative, indicating that the linear models after logarithmic transformation were more appropriate. The R2 for the biomass models of stem, branch, foliage and root were 0.953-0.988, 0.982-0.983, 0.916-0.917, and 0.951-0.952, while the RMSE were 13.42-27.03, 6.84-7.00, 1.95-1.97 and 9.71-9.84 kg. Compared with the feasible generalized least squares (FGLS) approach, Bayesian estimation had similar fitting performance and provided parameter estimates with different variations. The standard errors of parameters for FGLS were 0.054-0.211. There were similar variations (standard deviations of 0.055-0.221) for the two Bayesian estimation with no prior information (DMC and Gibbs1). The Gibbs sampler with a multivariate normal distribution with a mean vector of 0, variances of 1000 and covariances of 0 (Gibbs2) or the prior information from the historical researches summary for Quercus trees biomass models (Gibbs3) produced greater variation than those of FGLS, DMC, and Gibbs1 (stan-dard deviations were 0.080-0.278), while Gibbs sampler with the prior information obtained from own data (Gibbs4) provided the lower variations than others (standard deviations were 0.004-0.013). The Gibbs4 approach provided the narrowest 95% prediction interval and produced the smaller prediction biases, with the average absolute error percentage (MAPE) for stem, branch, foliage, root and total of the only-D biomass model being 19.8%, 24.7%, 24.6%, 29.0% and 13.1%, while MAPE for the corresponding components of D-H biomass model kept same except for stem and total decreased to 10.5% and 9.8%, which indicated that Gibbs4 could provide more accurate biomass predictions. Compared with classical statistics, accurate prior information made Bayesian seemingly unrelated regression an advantage in estimation stability and uncertainty reduction.


Assuntos
Quercus , Teorema de Bayes , Biomassa , Modelos Biológicos
10.
World J Microbiol Biotechnol ; 38(11): 211, 2022 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-36053367

RESUMO

Several studies have shown that any magnetic field (MF) applied to microalgae modifies its cultivation conditions and may favor biomolecule production since it interacts with the microorganisms and affect their growth. As a result, there are changes in concentrations and compositions of biomass and biomolecules. This review aims at updating MF applications to microalga cultures that were reported by studies conducted in the last 5 years. It shows the main studies that reached positive results of carbohydrate, lipid, protein and pigment production. Effects of MFs may be positive, negative or null, depending on some factors, such as intensity, exposure time, physiological state of cells and application devices. Therefore, this review details cultivation conditions used for reaching high concentration of biomolecules, explains the action of MFs on microalgae and describes their applicability to the biorefinery concept.


Assuntos
Microalgas , Biocombustíveis , Biomassa , Campos Magnéticos , Microalgas/metabolismo
11.
Food Res Int ; 160: 111590, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36076433

RESUMO

Microalgae are photosynthetic microorganisms that stand out from conventional food sources and ingredients due to their high growth rate and adaptability. In addition to being highly sustainable, significant concentrations of proteins, lipids, and pigments accumulate in their cell structures from photosynthesis. Hence, this study sought to evaluate the food potential of Scenedesmus obliquus biomasses obtained from photosynthetic cultures enriched with 3, 5, 10, 15, 20, and 25% carbon dioxide (CO2) (v/v). Cultivations with 3, 5, and 10% CO2 showed greater amino acids and proteins synthesis; the protein content reached values above 56% of the dry biomass and high protein quality, due to the presence of most essential amino acids at recommended levels for the human diet. The highest concentrations of chlorophylls were found in cultures with 15, 20, and 25% CO2 (24.2, 23.1 and 30.8 mg g-1, respectively), although the profiles showed higher percentages of degradation compounds. Carotenoid concentrations were three times higher in cultures with 3, 5, and 10% CO2 (25.3, 22.7 and 18.1 mg g-1, respectively) and all-trans-ß-carotene was the major compound. Lipid synthesis was intensified at higher CO2 enrichment; the percentages obtained were 14.8% of lipids in the culture with 15% CO2, 15.0% with 20% CO2, and 13.7% with 25% CO2. In addition, greater polyunsaturated fatty acids accumulation and a significant reduction in the n6/n3 ratio were also observed at the highest CO2 concentrations. Our findings showed that CO2 treatments significantly altered all compounds concentrations in S. obliquus biomasses, which presented satisfactory composition for application in foods and as ingredients.


Assuntos
Clorofíceas , Scenedesmus , Biomassa , Dióxido de Carbono/metabolismo , Clorofíceas/metabolismo , Humanos , Lipídeos , Fotossíntese , Scenedesmus/metabolismo
12.
BMC Public Health ; 22(1): 1723, 2022 09 12.
Artigo em Inglês | MEDLINE | ID: mdl-36089579

RESUMO

BACKGROUND: Poor indoor air quality (IAQ) is a leading cause of respiratory and cardiopulmonary illnesses. Particulate matter (PM2.5) and carbon monoxide (CO) are critical indicators of IAQ, yet there is limited evidence of their concentrations in informal urban settlements in low-income countries. OBJECTIVE: This study assessed household characteristics that predict the concentrations of PM2.5 and CO within households in an informal settlement in Fort Portal City, Uganda. METHODOLOGY: A cross-sectional study was conducted in 374 households. Concentrations of PM2.5 and CO were measured using a multi-purpose laser particle detector and a carbon monoxide IAQ meter, respectively. Data on household characteristics were collected using a structured questionnaire and an observational checklist. Data were analysed using STATA version 14.0. Linear regression was used to establish the relationship between PM2.5, CO concentrations and household cooking characteristics. RESULTS: The majority (89%, 332/374) of the households used charcoal for cooking. More than half (52%, 194/374) cooked outdoors. Cooking areas had significantly higher PM2.5 and CO concentrations (t = 18.14, p ≤ 0.05) and (t = 5.77 p ≤ 0.05), respectively. Cooking outdoors was associated with a 0.112 increase in the PM2.5 concentrations in the cooking area (0.112 [95% CI: -0.069, 1.614; p = 0.033]). Cooking with moderately polluting fuel was associated with a 0.718 increase in CO concentrations (0.718 [95% CI: 0.084, 1.352; p = 0.027]) in the living area. CONCLUSIONS: The cooking and the living areas had high concentrations of PM2.5 and CO during the cooking time. Cooking with charcoal resulted in higher CO in the living area. Furthermore, cooking outdoors did not have a protective effect against PM2.5, and ambient PM2.5 exceeded the WHO Air quality limits. Interventions to improve the indoor air quality in informal settlements should promote a switch to cleaner cooking energy and improvement in the ambient air quality.


Assuntos
Monóxido de Carbono , Material Particulado , Biomassa , Monóxido de Carbono/análise , Carvão Vegetal , Estudos Transversais , Humanos , Material Particulado/análise , Uganda/epidemiologia
13.
Front Cell Infect Microbiol ; 12: 974910, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36093206

RESUMO

Leishmaniasis represents a serious world health problem, with 1 billion people being exposed to infection and a broad spectrum of clinical manifestations with a potentially fatal outcome. Based on the limitations observed in the treatment of leishmaniasis, such as high cost, significant adverse effects, and the potential for drug resistance, the aim of the present study was to evaluate the leishmanicidal activity of the compounds pseurotin A and monomethylsulochrin isolated from the biomass extract of Aspergillus sp. The chromatographic profiles of the extract were determined by high-performance liquid chromatography coupled with a diode-array UV-Vis detector (HPLC-DAD-UV), and the molecular identification of the pseurotin A and monomethylsulochrin were carried out by electrospray ionization mass spectrometry in tandem (LC-ESI-MS-MS) and nuclear magnetic resonance (NMR). Antileishmanial activity was assayed against promastigote and intracellular amastigote of Leishmania amazonensis. As a control, cytotoxicity assays were performed in non-infected BALB/c peritoneal macrophages. Ultrastructural alterations in parasites were evaluated by transmission electron microscopy. Changes in mitochondrial membrane potential were determined by flow cytometry. Only monomethylsulochrin inhibited the promastigote growth (IC50 18.04 ± 1.11 µM), with cytotoxicity to peritoneal macrophages (CC50 5.09 91.63 ± 1.28 µM). Activity against intracellular amastigote forms (IC50 5.09 ± 1.06 µM) revealed an increase in antileishmanial activity when compared with promastigotes. In addition to a statistically significant reduction in the evaluated infection parameters, monomethylsulochrin altered the ultrastructure of the promastigote forms with atypical vacuoles, electron-dense corpuscles in the cytoplasm, changes at the mitochondria outer membrane and abnormal disposition around the kinetoplast. It was showed that monomethylsulochrin leads to a decrease in the mitochondrial membrane potential (25.9%, p = 0.0286). Molecular modeling studies revealed that monomethylsulochrin can act as inhibitor of sterol 14-alpha-demethylase (CYP51), a therapeutic target for human trypanosomiasis and leishmaniasis. Assessed for its drug likeness, monomethylsulochrin follows the Lipinski Rule of five and Ghose, Veber, Egan, and Muegge criteria. Furthermore, monomethylsulochrin can be used as a reference in the development of novel and therapeutically useful antileishmanial agents.


Assuntos
Antiprotozoários , Leishmania mexicana , Leishmania , Leishmaniose , Animais , Antiprotozoários/química , Aspergillus , Biomassa , Humanos , Leishmaniose/tratamento farmacológico , Camundongos , Camundongos Endogâmicos BALB C , Simulação de Acoplamento Molecular , Extratos Vegetais/farmacologia
14.
PLoS One ; 17(9): e0270421, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36067149

RESUMO

In order to find out the optimized technological parameters of rice straw bowl tray, the forming test was carried out with the slurry made of rice straw as the main raw material and the pneumatic molding machine as the equipment. The orthogonal rotational combination test of ternary quadratic regression and response surface analysis method were used to study the effect of 3 molding factors (vacuum degree, pressure preservation time and adsorption time) on 3 molding technical indices (bowl hole molding rate, relaxation density and rupture-resisting strength). Design-Expert data analysis software was used to establish regression models between rice straw bowl tray molding factors and molding properties so as to obtain optimal technological parameters, which were as follows: vacuum degree: -0.09 MPa; holding time: 14 s; adsorption time: 5 s. At the moment, theoretical bowl hole molding rate was 98.62%, relaxation density was 5.8 g/cm3 and rupture-resisting strength was 27.48 N, the experimental results show that the theoretical analysis is correct, and the model fitting is better. This study can provide a theoretical basis for optimization of pneumatic molding technological of rice straw bowl tray and lay a foundation for realizing industrialized production of biomass seeding tray.


Assuntos
Oryza , Adsorção , Biomassa , Vácuo
15.
Water Res ; 223: 119041, 2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-36081254

RESUMO

Treatment technologies based on microalgal biofilms have an enormous potential for dealing with water pollution because they can efficiently redirect nutrients from wastewater to renewable biomass feedstock. However, poor light transmittance is caused by the high turbidity of wastewater, which hinders the commercial application of microalgal biofilm-based wastewater treatment. Here, a bifunctional substrate with lighting and biofilm support functions was constructed using a light guide plate. In a biofilm photobioreactor (bPBR) with a bifunctional lighting/supporting substrate (BL/S substrate), light can directly irradiate the biofilm to avoid attenuation by the turbid wastewater. Direct irradiation of light onto the biofilm led to a 93.0% enhancement of microalgal photoconversion efficiency when compared to that of a supporting substrate without lighting (SO substrate). Meanwhile, the maximum growth rate of the microalgal biofilm on the BL/S substrate was 8.7 g m-2 d-1, which was increased by 60.3%. The removal rate of ammonia nitrogen (NH4+-N) from the digested wastewater contributed by the microalgal biofilm reached 22.6 mg L-1 d-1, which was higher than the previously reported that of NH4+-N from turbid digested wastewater by the biofilms. Furthermore, the BL/S substrate can facilitate the secretion of abundant extracellular polymeric substrates, which results in the stable adhesion of the biofilm onto the BL/S substrate. The optical density of the microalgae cells at the outlet of the bPBR with BL/S substrate was below 0.1, which was 94% lower than that of the bPBR with the SO substrate. The results indicated the BL/S substrate may avoid the loss of microalgal biomass, and almost all biomass could be easily harvested from the biofilm for algae-based biomass resources. Consequently, this study can offer a promising alternative with efficient treatment technologies for wastewater with high turbidity.


Assuntos
Microalgas , Amônia , Biofilmes , Biomassa , Iluminação , Nitrogênio , Águas Residuárias
16.
Bull Math Biol ; 84(10): 115, 2022 09 09.
Artigo em Inglês | MEDLINE | ID: mdl-36085428

RESUMO

In theoretical ecology, recent field experiments on terrestrial vertebrates observe that the predator-prey interaction can not only be curtailed by direct consumption but also governed by some indirect effects such as the fear of predator which may reduce the reproduction rate of prey individuals. Based on this fact, we have developed and explored the predator-prey interaction with the influence of both cost and benefit of fear effect (felt by prey). A Holling type III functional response with the effect of habitat complexity has been taken to consume the prey biomass. Positivity and boundedness of the studied system prove that the model is well-behaved. The uniform persistence of the studied system is derived analytically under some parametric restrictions. The feasibility conditions and stability criteria of each equilibrium points have been discussed. Next, we have exhibited the existence of Hopf-bifurcation around the interior equilibrium point. Our mathematical analyses show that habitat complexity and fear effect both have a great impact on the persistence of the predator biomass. Furthermore, we have investigated the effect of breeding delay parameter such that the system loses its stability behaviour and enters into a limit cycle oscillations through Hopf-bifurcation. Numerical simulations are illustrated to verify our analytical outcomes. Numerically, we have perturbed the death rates of prey and predator species with Gaussian white noise terms due to the effects of environmental fluctuations.


Assuntos
Conceitos Matemáticos , Modelos Biológicos , Animais , Biomassa , Ecologia , Medo , Humanos
17.
Proc Natl Acad Sci U S A ; 119(38): e2205610119, 2022 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-36095180

RESUMO

Biomass burning organic aerosol (BBOA) in the atmosphere contains many compounds that absorb solar radiation, called brown carbon (BrC). While BBOA is in the atmosphere, BrC can undergo reactions with oxidants such as ozone which decrease absorbance, or whiten. The effect of temperature and relative humidity (RH) on whitening has not been well constrained, leading to uncertainties when predicting the direct radiative effect of BrC on climate. Using an aerosol flow-tube reactor, we show that the whitening of BBOA by oxidation with ozone is strongly dependent on RH and temperature. Using a poke-flow technique, we show that the viscosity of BBOA also depends strongly on these conditions. The measured whitening rate of BrC is described well with the viscosity data, assuming that the whitening is due to oxidation occurring in the bulk of the BBOA, within a thin shell beneath the surface. Using our combined datasets, we developed a kinetic model of this whitening process, and we show that the lifetime of BrC is 1 d or less below ∼1 km in altitude in the atmosphere but is often much longer than 1 d above this altitude. Including this altitude dependence of the whitening rate in a chemical transport model causes a large change in the predicted warming effect of BBOA on climate. Overall, the results illustrate that RH and temperature need to be considered to understand the role of BBOA in the atmosphere.


Assuntos
Carbono , Ozônio , Aerossóis/química , Atmosfera/química , Biomassa , Carbono/química
20.
Int J Mol Sci ; 23(17)2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-36077392

RESUMO

Biomass fly ash (BFA) from a biomass cogeneration plant was encapsulated into calcium alginate microspheres (ALG/Ca) and characterized. An FTIR analysis indicated that BFA loading weakened molecular interactions between ALG/Ca constituents (mainly hydrogen bonding and electrostatic interactions), thus changing the crosslinking density. SEM and AFM analyses revealed a wrinkled and rough surface with elongated and distorted granules. The in vitro release of BFA's main components (K, Ca, and Mg) was controlled by diffusion through the gel-like matrix, but the kinetics and released amounts differed significantly. The smaller released amounts and slower release rates of Ca and Mg compared to K resulted from the differences in the solubility of their minerals as well as from the interactions of divalent cations with alginate chains. The physicochemical properties of the novel microsphere formulation reveal significant potential for the prolonged delivery of nutrients to crops in a safe manner.


Assuntos
Alginatos , Cinza de Carvão , Alginatos/química , Biomassa , Microesferas , Solo/química
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