Mechanisms of fine particle capture by larval black flies (Diptera: Simuliidae)

1980 ◽  
Vol 58 (6) ◽  
pp. 1186-1192 ◽  
Author(s):  
Douglas H. Ross ◽  
Douglas A. Craig
Keyword(s):  
Fine Particle ◽  
Fine Particles ◽  
Marine Invertebrates ◽  
Stream Water ◽  
Fine Particulate Matter ◽  
Black Flies ◽  
Filter Feeding ◽  
Fine Particulate ◽  
Lotic Habitats ◽  
Freshwater Insects

Larval black flies remove fine particulate matter from stream water using a mucosubstance which coats their filtering organs (cephalic fans). This mechanism, common among filter feeding marine invertebrates, but not previously reported in freshwater insects, explains how simuliids capture fine particles (0.091 – ca. 30 μm) which would otherwise escape the cephalic fans. Investigations of two theoretical filter feeding models revealed that direct interception is probably the predominant mode of fine particle filtration for black flies. The ability of simuliids to capture fine particles, which are abundant in many streams and often support a rich nutritive microflora, may account in part for their occurrence and success in diverse lotic habitats.

scholarly journals Regulatory T Cells Protect Fine Particulate Matter-Induced Inflammatory Responses in Human Umbilical Vein Endothelial Cells

2014 ◽  
Vol 2014 ◽  
pp. 1-14 ◽  
Author(s):  
Wen-cai Zhang ◽  
Yan-ge Wang ◽  
Zheng-feng Zhu ◽  
Fang-qin Wu ◽  
Yu-dong Peng ◽  
...  
Keyword(s):  
T Cells ◽  
Endothelial Cells ◽  
Particulate Matter ◽  
Inflammatory Cytokines ◽  
Fine Particles ◽  
Inflammatory Responses ◽  
Umbilical Vein ◽  
Fine Particulate Matter ◽  
Fine Particulate ◽  
Umbilical Vein Endothelial Cells

Objective. To investigate the role of CD4+CD25+T cells (Tregs) in protecting fine particulate matter (PM-) induced inflammatory responses, and its potential mechanisms.Methods. Human umbilical vein endothelial cells (HUVECs) were treated with graded concentrations (2, 5, 10, 20, and 40 µg/cm2) of suspension of fine particles for 24h. For coculture experiment, HUVECs were incubated alone, with CD4+CD25−T cells (Teff), or with Tregs in the presence of anti-CD3 monoclonal antibodies for 48 hours, and then were stimulated with or without suspension of fine particles for 24 hours. The expression of adhesion molecules and inflammatory cytokines was examined.Results. Adhesion molecules, including vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1), and inflammatory cytokines, such as interleukin (IL-) 6 and IL-8, were increased in a concentration-dependent manner. Moreover, the adhesion of human acute monocytic leukemia cells (THP-1) to endothelial cells was increased and NF-κB activity was upregulated in HUVECs after treatment with fine particles. However, after Tregs treatment, fine particles-induced inflammatory responses and NF-κB activation were significantly alleviated. Transwell experiments showed that Treg-mediated suppression of HUVECs inflammatory responses impaired by fine particles required cell contact and soluble factors.Conclusions. Tregs could attenuate fine particles-induced inflammatory responses and NF-κB activation in HUVECs.

scholarly journals Occupational Exposure to Fine Particulate Matter (PM4 and PM2.5) during Hand-Made Cookware Operation: Personal, Indoor and Outdoor Levels

2020 ◽  
Vol 17 (20) ◽  
pp. 7522
Author(s):  
Busisiwe Shezi ◽  
Angela Mathee ◽  
Nokulunga Cele ◽  
Sipho Ndabandaba ◽  
Renee A. Street
Keyword(s):  
Particulate Matter ◽  
Occupational Exposure ◽  
Fine Particles ◽  
Fine Particulate Matter ◽  
Health And Safety ◽  
Chemical Characterization ◽  
Personal Exposure ◽  
Targeted Prevention ◽  
Fine Particulate ◽  
Indoor And Outdoor

(1) Exposure of informal artisanal cookware makers to fine particles has not yet been characterized. The aim of this study was to characterize occupational exposure to fine particulate matter (PM4 and PM2.5) levels and fine particulate matter (PM2.5) elemental components; (2) Artisanal cookware makers were recruited from five cookware making sites. Exposure to fine particulate matter was measured for 17 male participants. SidePak personal aerosol monitors (AM520) were used to measure personal exposure to PM4, while a DustTrak monitor and an E-sampler were used to assess indoor and outdoor PM2.5 levels, respectively. A questionnaire was administered to capture information on demographic characteristics. The chemical characterization of indoor and outdoor PM2.5 filter mass was conducted using Wavelength Dispersive X-ray Fluorescence. Time series record of 15-min averages for indoor and outdoor PM2.5 levels were assessed; (3) The median (range) was 124 µg/m3 (23−100,000), 64 µg/m3 (1−6097) and 12 µg/m3 (4−1178), respectively, for personal PM4, indoor and outdoor PM2.5. The highest levels for many of the elemental components of PM2.5 were found in the outdoor PM2.5 filter mass and (4). The information generated during this study may assist in extending occupational health and safety strategies to artisanal cookware makers and developing targeted prevention initiatives.

The Physics of Fine-Particle Movement Through Permeable Aquifers

1971 ◽  
Vol 11 (04) ◽  
pp. 367-373 ◽  
Author(s):  
Jerry B.F. Champlin
Keyword(s):  
Particulate Matter ◽  
Fine Particles ◽  
Fine Particulate Matter ◽  
Petroleum Industry ◽  
Engineering Practice ◽  
Nuclear Explosions ◽  
Waste Storage ◽  
Fine Particulate ◽  
Soluble Ions ◽  
Subsurface Reservoir

Abstract The movement of fine particles through porous, permeable materials is closely interwoven with the migration of soluble ions. Since either the particles orthe ions can represent an economic mineral accumulation as a consequence ofgeochemical concentration, it is of great importance to mineral explorationefforts to be able to establish the parameters that influence particulatemigration through aquifers. Not only are economically interesting depositsformed by such migration, but they also may be ruined, as in the case of manyoil fields where standard secondary recovery methods have caused plugging ofthe productive formations. Recent experimental work has shown close alliance between the relative movement of both trace ions and particles and the over-all concentration of common salts dissolved in ground water. Most importantly, the spacial stability of fineparticles such as the sesquioxides and the clays in formations is dependent onthe nature of the anionic portion of the dominant salt in solution. These results have great potential, applied in exploration or exploitation programs for minerals. Not only do they provide answers for particulate migration problems in the oil fields and ore concentration mechanisms in the uranium deposits, but also they explain the untoward migration of certain radioisotopes from waste storage ponds or cribs at the national reactor-fuel reprocessing plants. By careful development and engineering practice, fine particles tagged with almost any radioactive or activatable ions may become one of the most useful tools in tracing subsurface movement of fluids. Introduction Considerable concern has been expressed by several industries during the past several decades about the effects of fine-particulate matter suspended in water passing through permeable rock. An early concern of the petroleum industry included the problem of subsurface reservoir plugging by fine particles during secondary production operations. More recently, the atomic energy industry has been concerned with particulate migration because of the movement of radioactive ions. Even the interest in applications of nuclear explosions underground has included concern over the effects of the fine-particulate matter that makes up large portions of the rubble produced by the explosion.

scholarly journals Technologies to mitigate the environmental impact of broiler production

2008 ◽  
Vol 37 (spe) ◽  
pp. 239-252 ◽  
Author(s):  
Edgar O. Oviedo-Rondón
Keyword(s):  
Environmental Impact ◽  
Fine Particle ◽  
Management Practices ◽  
Ammonia Volatilization ◽  
New Technologies ◽  
Fine Particulate Matter ◽  
Trace Minerals ◽  
Microbial Decomposition ◽  
Fine Particulate ◽  
Animal Feeding

The broiler industry produces efficiently animal protein, but generates residues with high contents of N, P, K, trace minerals, and high bacterial charge. The rapid microbial decomposition of these residues cause ammonia volatilization, nuisance odor, fine particulate matter, and attract insects and rodents. This presentation will discuss the more effective methods to utilize these resources and minimize potential environmental impact. These procedures include planning, personnel training, zoning of areas used to dispose the final residues in crop lands, farm isolation, precision nutrition, litter and house management practices, and appropriate mortality disposal. Broiler litter has been used for animal feeding and power generation. Additionally, new technologies to reduce ammonia, odor and fine particle emissions, or reduction of P solubility will be presented.

Wheezing and lung function measured in subjects exposed to various levels of fine particles and polycyclic aromatic hydrocarbons

Open Medicine ◽  
2007 ◽  
Vol 2 (1) ◽  
pp. 66-78 ◽  
Author(s):  
Wieslaw Jedrychowski ◽  
Frederica Perera ◽  
Robin Whyatt ◽  
Elzbieta Mroz ◽  
Elzbieta Flak ◽  
...  
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Lung Function ◽  
Aromatic Hydrocarbons ◽  
Fine Particles ◽  
Fine Particulate Matter ◽  
Allergic Diseases ◽  
Exposed Group ◽  
Fine Particulate ◽  
Bronchial Inflammation ◽  
Polycyclic Aromatic

AbstractThe main purpose of the study was to assess the occurrence of wheezing and lung function in non-smoking women exposed to various levels of fine particulate matter(FP) and polycyclic aromatic hydrocarbons (PAH). Out of the total study group, 152 women were included in the lower exposed group (PM2.5 ≤34.3μg/m3 or PAHs ≤ 22.9ng/ m3) and 96 persons in higher concentrations of both air pollutants (PM2.5>34.3μg/m3 and PAHs > 22.9ng/ m3). Except for FVC and FEV1, all lung forced ventilatory flows (PEFR, FEF25% FEF50%, FEF75%, FEF25−75%) were significantly lower in the higher exposed group. The findings suggest bronchoconstriction within the respiratory tract, which may be related to the exposure under study. This was consistent with a higher prevalence of wheezing in more exposed subjects. It was shown that higher levels of both pollutants increased the risk of wheezing by factor 5.6 (95% CI: 1.77–17.8) after accounting for potential confounders such as allergic diseases and exposure to ETS. This study suggests that pollutants in question may have the capacity to promote broncho-constriction and asthmatic symptoms, possibly by bronchial inflammation resulting from the exposure.

scholarly journals Possible warming effect of fine particulate matter in the atmosphere

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Shau-Liang Chen ◽  
Sih-Wei Chang ◽  
Yen-Jen Chen ◽  
Hsuen-Li Chen
Keyword(s):  
Particulate Matter ◽  
Fine Particles ◽  
Fine Particulate Matter ◽  
Three Dimensional ◽  
Mie Scattering ◽  
Dust Particles ◽  
Long Wavelength ◽  
Inorganic Aerosols ◽  
Fine Particulate ◽  
Difference Time

AbstractParticulate matter emitted through human activities not only pollutes the air, but also cools the Earth by scattering shortwave solar radiation. However, coarser dust particles have been found to exert a warming effect that could, to some extent compensate for the cooling effect of fine dust. Here we investigate the radiative effects of sulfate containing aerosols of various sizes and core/shell structures using Mie scattering and three-dimensional finite difference time domain simulations of the electromagnetic fields inside and around particulate matter particles. We find that not only coarse dust, but also fine non-light-absorbing inorganic aerosols such as sulfate can have a warming effect. Specifically, although the opacity of fine particles decreases at longer wavelengths, they can strongly absorb and re-emit thermal radiation under resonance conditions at long wavelength. We suggest that these effects need to be taken into account when assessing the contribution of aerosols to climate change.

scholarly journals Gaining and losing stream reaches have opposite hydraulic conductivity distribution patterns

2013 ◽  
Vol 17 (7) ◽  
pp. 2569-2579 ◽  
Author(s):  
X. Chen ◽  
W. Dong ◽  
G. Ou ◽  
Z. Wang ◽  
C. Liu
Keyword(s):  
Hydraulic Conductivity ◽  
Fine Particle ◽  
Fine Particles ◽  
Stream Water ◽  
Sediment Cores ◽  
Distribution Patterns ◽  
Flow Mechanisms ◽  
Groundwater Systems ◽  
Permeameter Tests ◽  
Streambed Sediments

Abstract. In gaining streams, groundwater seeps out into the streams. In losing streams, stream water moves into groundwater systems. The flow moving through the streambed sediments under these two types of hydrologic conditions is generally in opposite directions (upward vs. downward). The two opposite flow mechanisms affect the pore size and fine particle content of streambeds. Thus it is very likely that the opposite flow conditions affect the streambed hydraulic conductivity. However, comparisons of the hydraulic conductivity (K) of streambeds for losing and gaining streams are not well documented. In this study, we examined the K distribution patterns of sediments below the channel surface or stream banks for the Platte River and its tributaries in Nebraska, USA. Two contrasting vertical distribution patterns were observed from the test sites. In gaining reaches, hydraulic conductivity of the streambed decreased with the depth of the sediment cores. In losing reaches, hydraulic conductivity increased with the depth of the sediment cores. These contrasting patterns in the two types of streams were mostly attributed to flow directions during stream water and groundwater exchanges. In losing reaches, downward movement of water brought fine particle into the otherwise coarse sediment matrix, partially silting the pores. For gaining reaches, upward flow winnowed fine particles, increasing the pore spacing in the top parts of streambeds, leading to higher hydraulic conductivity in shallower parts of streambeds. These flux directions can impact K values to depths of greater than 5 m. At each study site, in situ permeameter tests were conducted to measure the K values of the shallow streambed layer. Statistical analyses indicated that K values from the sites of losing reaches were significantly different from the K values from the sites of gaining reaches.

scholarly journals Protective Effect of Colla corii asini against Lung Injuries Induced by Intratracheal Instillation of Artificial Fine Particles in Rats

2018 ◽  
Vol 20 (1) ◽  
pp. 55 ◽  
Author(s):  
Tiantian Liu ◽  
Piaopiao Zhang ◽  
Yahao Ling ◽  
Guang Hu ◽  
Jianjun Gu ◽  
...  
Keyword(s):  
Fine Particles ◽  
Fine Particulate Matter ◽  
Intratracheal Instillation ◽  
Environmental Issues ◽  
Protective Effects ◽  
Lung Function Decline ◽  
Fine Particulate ◽  
Lung Injuries ◽  
Medical Materials ◽  
Colla Corii Asini

Environmental issues pose huge threats to public health, particularly the damage caused by fine particulate matter (PM2.5). However, the mechanisms of injury require further investigation and medical materials that can protect the lungs from PM2.5 are needed. We have found that Colla corii asini, a traditional Chinese medicine that has long been used to treat various ailments, is a good candidate to serve this purpose. To understand the mechanisms of PM2.5-induced lung toxicity and the protective effects of Colla corii asini, we established a rat model of lung injury via intratracheal instillation of artificial PM2.5 (aPM2.5). Our results demonstrated that Colla corii asini significantly protected against lung function decline and pathologic changes. Inflammation was ameliorated by suppression of Arg-1 to adjust the disturbed metabolic pathways induced by aPM2.5, such as arginine and nitrogen metabolism and aminoacyl-tRNA biosynthesis, for 11 weeks. Our work found that metabolomics was a useful tool that contributed to further understanding of PM2.5-induced respiratory system damage and provided useful information for further pharmacological research on Colla corii asini, which may be valuable for therapeutic intervention.

scholarly journals Randomized Trial to Reduce Air Particle Levels in Homes of Smokers and Children

2017 ◽  
Author(s):  
Vincent Berardi
Keyword(s):  
Clinical Trial ◽  
At Risk ◽  
Particulate Matter ◽  
Randomized Trial ◽  
Randomized Clinical Trial ◽  
Real Time ◽  
Fine Particles ◽  
Fine Particulate Matter ◽  
Children At Risk ◽  
Fine Particulate

Exposure to fine particulate matter in the home from sources such as smoking, cooking, and cleaning may put residents, especially children, at risk of detrimental health effects.Data from a randomized clinical trial were analyzed during 2016-2017 to determine whether real-time feedback in the home plus brief coaching of parents or guardians could reduce exposure to fine particles for children living with smokers.

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