Grazing of Marine Copepod Developmental Stages on Naturally Occurring Particles

1977 ◽  
Vol 34 (12) ◽  
pp. 2381-2387 ◽  
Author(s):  
S. A. Poulet
Keyword(s):  
Particulate Matter ◽  
Nutritive Value ◽  
Fine Particles ◽  
Developmental Stages ◽  
Standing Stock ◽  
Mesh Size ◽  
Particle Spectrum ◽  
Calanoid Copepods ◽  
Marine Copepod ◽  
Naturally Occurring

Grazing experiments were performed with copepodids (stages CI–IV) of Pseudocalanus minutus feeding on naturally occurring particulate matter. Variations in the feeding rate of copepodids were associated with seasonal changes in the standing stock of particulate matter. Copepodids adapted to seasonal variations within the particle spectrum. Particle sizes < 22 μm contributed most of the standing stock of particles during the period studied. Maximum consumption was recorded when copepodids fed on small-size particles. The importance of fine particles is illustrated in comparative feeding experiments performed with adults and copepodids fed simultaneously on the same particles. The differences between the mean consumption of copepodids and adults are highly significant in the particle size ranges below 22 μm. The fact that copepodids obtain more food than adults on particles < 10 μm is probably related to the smaller mesh size and to the higher frequency of vibration of their mouth appendages. Although all copepod stages are opportunistic feeders, such a mechanism allows copepodids to reduce feeding competition with adults and allows them to fulfil their higher requirements for energy from food particles that have a high productive potential and a high nutritive value. This provides the evidence that feeding niches are partially separated between young and adult copepods. Key words: calanoid copepods, copepodids, Pseudocalanus minutus, grazing, competition, naturally occurring particles

Spectral and Biochemical Characteristics of the Particulate Matter in Bedford Basin

1979 ◽  
Vol 36 (2) ◽  
pp. 211-218 ◽  
Author(s):  
P. Mayzaud ◽  
S. Taguchi
Keyword(s):  
Particulate Matter ◽  
Nutritive Value ◽  
Small Particles ◽  
Cell Counts ◽  
Naturally Occurring ◽  
Single Chemical ◽  
Chemical Variable ◽  
Early Fall ◽  
Neritic Habitat ◽  
Counter Data

A survey of the distribution, nature, and biochemical composition of particulate matter (less than 153 μm diam) showed that small particles (< 18 μm) made up the bulk of the particulate matter during most of the summer. Relatively large amounts of microzooplankton (tintinnids) were also recorded during the period of stable hydrographic conditions. Diatoms and dinoflagellates were abundant only in early fall prior to the fall bloom. All cell counts were transformed into parts per million on a volume basis to compare with Coulter Counter data. Cell counts on preserved samples strongly underestimated the number and volume of small particles and did not take into account the detritus. Considerations of the ATP content strongly suggested that for naturally occurring particulate matter there is not a constant ATP to carbon ratio but rather an upper and lower limit. Small particles were the main repository for protein whereas phytoplankton was the repository for carbohydrates. The high variability of both quality and quantity of particles in the neritic habitat suggests that a single chemical variable cannot describe fully the nutritive value of naturally occurring suspended matter. Key words: particulate matter, phytoplankton, microzooplankton, flagellates, protein, carbohydrates, ATP, carbon

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 Ambient Particulate Matter Air Pollution in Mpererwe District, Kampala, Uganda: A Pilot Study

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Stephan Schwander ◽  
Clement D. Okello ◽  
Juergen Freers ◽  
Judith C. Chow ◽  
John G. Watson ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Air Quality ◽  
Pilot Study ◽  
Fine Particles ◽  
Airborne Particulate Matter ◽  
Personal Exposure ◽  
Ambient Air ◽  
Combustion Products ◽  
Carbonaceous Aerosol ◽  
Coarse Particles

Air quality in Kampala, the capital of Uganda, has deteriorated significantly in the past two decades. We made spot measurements in Mpererwe district for airborne particulate matter PM2.5(fine particles) and coarse particles. PM was collected on Teflon-membrane filters and analyzed for mass, 51 elements, 3 anions, and 5 cations. Both fine and coarse particle concentrations were above 100 µg/m3in all the samples collected. Markers for crustal/soil (e.g., Si and Al) were the most abundant in the PM2.5fraction, followed by primary combustion products from biomass burning and incinerator emissions (e.g., K and Cl). Over 90% of the measured PM2.5mass can be explained by crustal species (41% and 59%) and carbonaceous aerosol (33%–55%). Crustal elements dominated the coarse particles collected from Kampala. The results of this pilot study are indicative of unhealthy air and suggest that exposure to ambient air in Kampala may increase the burden of environmentally induced cardiovascular, metabolic, and respiratory diseases including infections. Greater awareness and more extensive research are required to confirm our findings, to identify personal exposure and pollution sources, and to develop air quality management plans and policies to protect public health.

scholarly journals Interrelationship of Indoor particulate matter and Respiratory dust deposition of women in the residence of Dhanbad City, India

2021 ◽  
Author(s):  
SHRAVAN KUMAR ◽  
Manish Kumar Jain
Keyword(s):  
Particulate Matter ◽  
Health Risks ◽  
Indoor Air ◽  
Air Pollutants ◽  
Fine Particles ◽  
Dust Deposition ◽  
Respiratory Problems ◽  
Indoor Particulate Matter ◽  
Indoor Air Pollutants ◽  
Indoor Conditions

Abstract Women spend relatively more time in indoor conditions in developing countries. Exposure to various indoor air pollutants leads them to higher health risks according to Household air quality in which they reside. Particulate matter (PM) exposure with their exposure duration inside the household plays a significant role in women's Respiratory problems. We measured size segregated particulate matter concentrations in 63 residences at different locations. Respiratory dust depositions (RDDs) for 118 women in their different respiratory regions like head-airway (HD), tracheobronchial (TB), and alveolar (AL) region for the three PM size fractions (PM10, PM2.5 & PM1) were investigated. For different positions like Light exercise and the Sitting condition, RDD values found for AL region was 0.091 µgmin− 1 (SD: 0.067, 0.012–0.408) and 0.028 µgmin− 1 (SD: 0.021, 0.003–0.126) for PM10, 0.325 µgmin− 1 (SD: 0.254, 0.053–1.521) and 0.183 µgmin− 1 (SD: 0.143, 0.031–0.857) for PM2.5, 0.257 µgmin− 1 (SD: 0.197, 0.043–1.04) and 0.057 µgmin− 1 (SD: 0.044, 0.009–0.233) respectively for PM1 to females. RDDs values in the AL region significantly increases as PM10 (11%), PM2.5 (68%), and PM1 (21%), confirm that for women, the AL region is the most prominent affected zone by fine particles (PM2.5).

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.

scholarly journals Vertical distribution of Paracalanus crassirostris (Copepoda, Calanoidea): analysis by the general linear model

1979 ◽  
Vol 28 (2) ◽  
pp. 65-78 ◽  
Author(s):  
Ana Milstein
Keyword(s):  
Vertical Distribution ◽  
Developmental Stage ◽  
Linear Model ◽  
Fine Particles ◽  
Developmental Stages ◽  
General Linear Model ◽  
General Linear ◽  
Tide Height ◽  
Recorded Data ◽  
The Vertical Distribution

The vertical distribution of each developmental stage of Paracalanus crassirostris was studied in a shallow water station at Ubatuba, SP, Brazil (23º30'S-45º07'W). Samples were collected monthly at the surface, 2m and near bottom levels . Salinity, temperature, dissolved oxygen, tide height, light penetration arid solar radiation were also recorded. Data were analysed by the general linear model. It showed that the amount of individuals at any developmental stage is affected diversely by hour, depth, hour-depth interaction and environmental factors throughout the year and that these effects are stronger in summer. All developmental stages were spread in the water column showing no regular vertical migrations. On the other hand, the number of organisms caught in a particular hour seemed to dependmore on the tide than on the animals behaviour. The results of the present paper showed, as observed by some other authors, the lack of vertical migration of a coastal copepod which is a grazer of fine particles throughout its life.

scholarly journals Estimation of Reduced Air Emissions as a Result of the Implementation of the Measure to Reduce Burned Sugarcane in Thailand

Atmosphere ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 366 ◽  
Author(s):  
Agapol Junpen ◽  
Jirataya Pansuk ◽  
Savitri Garivait
Keyword(s):  
Particulate Matter ◽  
Financial Support ◽  
Fine Particles ◽  
Air Emissions ◽  
First Year ◽  
Study Results ◽  
Reduction Measure ◽  
Human Labor ◽  
The Government ◽  
Pm2.5 Emissions

In the middle of 2019, Thailand introduced an urgent measure to solve the haze and fine particles problem caused by preharvest sugarcane. The measure is to eradicate the burning of sugarcane before harvesting within the next four years. This study focuses on estimation of future reduced air emissions from the implementation of this measure. The study results showed that without the implementation of the measure in the production season 2022/23, the amount of burned sugarcane will be as high as 102.4 ± 1.0 Mt/yr, resulting in the release of small particulate matter of 2.5 microns or less in diameter (PM2.5) emissions into the atmosphere at 30.6 ± 8.6 kt/yr, which is about a 21% increase in emissions from the 2018/19 season. However, with the government’s enforcement of the measure to reduce burned sugarcane, the amount of air emissions will immediately be reduced in the first year. In order to effectively implement the sugarcane burning reduction measure, in which the harvesting methods will change from cutting burned sugarcane to cutting fresh sugarcane with human labor and with machinery, the government must provide financial support, to farmers, of approximately 3.3 USD per ton of fresh sugarcane for the use of human labor and 2.9 USD per ton of fresh sugarcane for the use of machinery. The costs of investment to reduce PM2.5 emissions can be calculated in the range of 9.7−11.0 million USD per kiloton of PM2.5.

scholarly journals Acetyl-CoA:4-Hydroxybutinylbithiophene O-Acetyltransferase Isoenzymes from Tagetes patula Seedlings

1987 ◽  
Vol 42 (7-8) ◽  
pp. 885-890 ◽  
Author(s):  
Gernot Metschulat ◽  
Rainer Sütfeld
Keyword(s):  
Coenzyme A ◽  
Developmental Stages ◽  
Complete Separation ◽  
Tagetes Patula ◽  
Acetyl Coa ◽  
Ph Optimum ◽  
Acyltransferase Activity ◽  
Enzyme Preparations ◽  
Naturally Occurring ◽  
Acyl Coenzyme A

Naturally-occurring hydroxybutinylbithiophene derivatives were acylated by enzyme preparations of Tagetes patula seedlings in the presence of distinct acyl-Coenzyme A esters. The O-acyltransferase activity could only be detected after almost complete separation of the enzyme from counter-currently acting esterases which were present in the same extracts. This was achieved by affinity chromatography on Cibachron Blue A. During this procedure, the O-acyl-transferase was split, yielding two active fractions. Both had a Mr of 37,000 (±5,000), equal isoelectric properties, a pH optimum of pH 7.0, and were considerably inhibited in the presence of free Coenzyme A. Small differences existed in their affinities for their thiophenic substrates (3,4-dihydroxybutinylbithiophene and 4-hydroxybutinylbithiophene, respectively), as well as for various acyl-CoA esters as cosubstrates. With the preferred cosubstrate, acetyl-CoA, acylation took place at the 4-position of the butinyl side chain of the molecules, forming the naturally- occurring 4-acetoxybutinylbithiophene and 3-OH,4-OAc-butinylbithiophene, respectively. From the other acyl-CoA esters employed, only propionyl-CoA was likewise converted, forming the corresponding O-propionyl esters. The reactions observed are suggested to be catalyzed by two acetyl-CoA: 4-hydroxybutinylbithiophene O-acetyltransferase isoenzymes which exhibit different affinities for particular substrates and cosubstrates. The activities of both the isoenzymes changed drastically if plant material from different developmental stages was used as enzyme source. Therefore, it may be suggested that these isoenzymes play an important regulatory role in the metabolism of naturally-occurring hydroxy- and acetoxybutinylbithiophenes and their derivatives.

scholarly journals Analysis of air pollution caused by particle matter emission from the copper smelter complex Bor (Serbia)

2010 ◽  
Vol 16 (3) ◽  
pp. 219-228 ◽  
Author(s):  
Visa Tasic ◽  
Novica Milosevic ◽  
Renata Kovacevic ◽  
Nevenka Petrovic
Keyword(s):  
Particulate Matter ◽  
Wind Speed ◽  
Ultrafine Particles ◽  
Fine Particles ◽  
Copper Smelter ◽  
Temporal Variations ◽  
Copper Production ◽  
Copper Smelting ◽  
Particulate Emissions ◽  
Limit Values

The main aim of this paper is to present analyses of temporal variations of particulate matter in Bor (Serbia) influenced by copper production at the Copper Smelter Complex Bor. Particulate emissions are of concern because the presence of fine particles (PM2.5 - particles with diametar less than 2.5 ?m) and ultrafine particles (PM0.1 - particles with diametar less than 0.1 ?m) assume higher risk for human health. Such particles can penetrate deeper into respiratory organs and, at the same time, a probability for such penetration and deposition in the respiratory system is greater. The analysis is based on comparison of SO2 and PM measurements at several locations in the area of Bor town in the close vicinity of Copper Smelter. PM concentrations were highly correlated with sulfur dioxide and inversely correlated with local wind speed during pollution episodes. Presented results indicate that the dominant source of coarse and fine particles in Bor town is the Copper Smelting Complex Bor. The most significant factors for particulate matter distribution are meteorological parameters of wind speed and direction. It was found that exceeding of daily limit values of concentrations of PM10 (50 ?g/m3) usually occurs due to very high concentrations in a period of several hours during the day.

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