scholarly journals Laboratory experiments on the effects of some environmental conditions on the growth of larvae of the mosquito, Culex pipiens s.l.

1963 ◽  
Vol 14 (1) ◽  
pp. 7-15 ◽  
Author(s):  
Takeshi Kurihara
Keyword(s):  
Environmental Conditions ◽  
Culex Pipiens ◽  
Laboratory Experiments ◽  
Culex Pipiens S.L

Characterization and Host-Feeding Patterns of Culex pipiens s.l. Taxa in a West Nile Virus-Endemic Area in Southeastern Romania

2021 ◽  
Author(s):  
Georgiana Victorița Tiron ◽  
Ioana Georgeta Stancu ◽  
Sorin Dinu ◽  
Florian Liviu Prioteasa ◽  
Elena Fălcuță ◽  
...  
Keyword(s):  
West Nile Virus ◽  
Culex Pipiens ◽  
Endemic Area ◽  
Host Feeding ◽  
Feeding Patterns ◽  
West Nile ◽  
Culex Pipiens S.L

scholarly journals Covariation of metabolic rates and cell size in coccolithophores

2015 ◽  
Vol 12 (15) ◽  
pp. 4665-4692 ◽  
Author(s):  
G. Aloisi
Keyword(s):  
Growth Rate ◽  
Environmental Change ◽  
Cell Size ◽  
Environmental Conditions ◽  
Laboratory Experiments ◽  
Opposite Effect ◽  
Cell Structure ◽  
Metabolic Rates ◽  
The Future ◽  
Phytoplankton Group

Abstract. Coccolithophores are sensitive recorders of environmental change. The size of their coccosphere varies in the ocean along gradients of environmental conditions and provides a key for understanding the fate of this important phytoplankton group in the future ocean. But interpreting field changes in coccosphere size in terms of laboratory observations is hard, mainly because the marine signal reflects the response of multiple morphotypes to changes in a combination of environmental variables. In this paper I examine the large corpus of published laboratory experiments with coccolithophores looking for relations between environmental conditions, metabolic rates and cell size (a proxy for coccosphere size). I show that growth, photosynthesis and, to a lesser extent, calcification covary with cell size when pCO2, irradiance, temperature, nitrate, phosphate and iron conditions change. With the exception of phosphate and temperature, a change from limiting to non-limiting conditions always results in an increase in cell size. An increase in phosphate or temperature (below the optimum temperature for growth) produces the opposite effect. The magnitude of the coccosphere-size changes observed in the laboratory is comparable to that observed in the ocean. If the biological reasons behind the environment–metabolism–size link are understood, it will be possible to use coccosphere-size changes in the modern ocean and in marine sediments to investigate the fate of coccolithophores in the future ocean. This reasoning can be extended to the size of coccoliths if, as recent experiments are starting to show, coccolith size reacts to environmental change proportionally to coccosphere size. The coccolithophore database is strongly biased in favour of experiments with the coccolithophore Emiliania huxleyi (E. huxleyi; 82 % of database entries), and more experiments with other species are needed to understand whether these observations can be extended to coccolithophores in general. I introduce a simple model that simulates the growth rate and the size of cells forced by nitrate and phosphate concentrations. By considering a simple rule that allocates the energy flow from nutrient acquisition to cell structure (biomass) and cell maturity (biological complexity, eventually leading to cell division), the model is able to reproduce the covariation of growth rate and cell size observed in laboratory experiments with E. huxleyi when these nutrients become limiting. These results support ongoing efforts to interpret coccosphere and coccolith size measurements in the context of climate change.

Methodologies for Evaluating and Qualifying External Pipeline Coatings for Northern Pipelines

2006 ◽  
Author(s):  
S. Papavinasam ◽  
A. Doiron ◽  
T. Panneerselvam ◽  
Y. Lafrenie`re ◽  
M. Attard ◽  
...  
Keyword(s):  
Environmental Conditions ◽  
Low Temperatures ◽  
Laboratory Experiments ◽  
Field Experiments ◽  
Climatic Conditions ◽  
Limited Data ◽  
The North

The design of coatings must be adequate to protect pipelines under long-term, severe environmental conditions, including the extreme climatic conditions that will apply in the North before the pipe is installed and operation begins. Practices and standardised methodologies for evaluating and qualifying pipeline coatings for application in northern pipelines are discussed. Results from laboratory and field experiments, carried out under the conditions to which coatings will be exposed during construction, are presented. Based on 1-year laboratory experiments in which samples were exposed to temperatures as low as −45°C and limited data from the field experiments, it is concluded that Canadian Standards Association (CSA) standards CSA Z662, CSA Z245.20 and CSA Z245.21 adequately cover evaluation of coatings for northern pipelines. However, in order to evaluate the effects of low-temperatures, the specimens should be exposed for at least 4 months. Coatings qualified by CSA Z245.21 (System B1 and B2) are less affected from exposure to low-temperatures than those qualified by CSA Z245.21 (System A1) and CSA Z245.20.

Effect of constant and fluctuating temperature regimes and seed source on the coleoptile length of tall and semidwarf wheats

1987 ◽  
Vol 27 (1) ◽  
pp. 113 ◽  
Author(s):  
BJ Radford
Keyword(s):  
Environmental Conditions ◽  
Laboratory Experiments ◽  
Seed Source ◽  
Seed Maturation ◽  
Wheat Cultivars ◽  
Coleoptile Length ◽  
Fluctuating Temperature ◽  
Temperature Regimes ◽  
The Mean ◽  
Constant And Fluctuating Temperature

Laboratory experiments were carried out to determine the effects of constant and fluctuating temperature regimes on the final coleoptile length of 8 wheat cultivars (Banks, Cook, Gatcher, Hartog, Kite, Oxley, Shortim and Spica) and the effect of environmental conditions during seed maturation (seed source) on the coleoptile length of 5 cultivars (Banks, Bass, Cook, Kite and Oxley). Mean coleoptile length decreased from 10.8 cm at 15�C to only 3.1 cm at 35�C, a reduction within this temperature range of 1 cm for every 2.6�C rise in temperature. This indicates that, in warm soil, shallow sowing is necessary for satisfactory wheat establishment. Fluctuating temperatures (� 5�C about the mean) further reduced coleoptile length. The temperature x cultivar interaction was significant, differences among cultivars in coleoptile length occurring more at low than at high temperatures. The mean coleoptile lengths of the 8 cultivars varied from 8.7 to 14.5 cm at 15�C, but only from 2.7 to 3.6 cm at 35�C. Tall wheat cultivars (Gatcher and Spica) generally had longer coleoptiles than the 6 semidwarf cultivars. Tall wheats also had near-maximum coleoptile length at a wider range of temperatures than semidwarfs. Different environmental conditions during seed maturation (glasshouse v. field) changed the ranking of cultivars with respect to coleoptile length. The coleoptiles of Cook and Oxley were significantly longer when seed was field-ripened rather than glasshouse ripened, while those of Banks, Bass and Kite were similar in length under both ripening environments.

scholarly journals Ecology of West Nile Virus in the Danube Delta, Romania: Phylogeography, Xenosurveillance and Mosquito Host-Feeding Patterns

Viruses ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 1159 ◽  
Author(s):  
Alexandru Tomazatos ◽  
Stephanie Jansen ◽  
Stefan Pfister ◽  
Edina Török ◽  
Iulia Maranda ◽  
...  
Keyword(s):  
West Nile Virus ◽  
Culex Pipiens ◽  
Biosphere Reserve ◽  
Host Feeding ◽  
Danube Delta ◽  
Feeding Patterns ◽  
West Nile ◽  
Specific Antibodies ◽  
Lineage 2 ◽  
Culex Pipiens S.L

The ecology of West Nile virus (WNV) in the Danube Delta Biosphere Reserve (Romania) was investigated by combining studies on the virus genetics, phylogeography, xenosurveillance and host-feeding patterns of mosquitoes. Between 2014 and 2016, 655,667 unfed and 3842 engorged mosquito females were collected from four sampling sites. Blood-fed mosquitoes were negative for WNV-RNA, but two pools of unfed Culex pipiens s.l./torrentium collected in 2014 were tested positive. Our results suggest that Romania experienced at least two separate WNV lineage 2 introductions: from Africa into Danube Delta and from Greece into south-eastern Romania in the 1990s and early 2000s, respectively. The genetic diversity of WNV in Romania is primarily shaped by in situ evolution. WNV-specific antibodies were detected for 19 blood-meals from dogs and horses, but not from birds or humans. The hosts of mosquitoes were dominated by non-human mammals (19 species), followed by human and birds (23 species). Thereby, the catholic host-feeding pattern of Culex pipiens s.l./torrentium with a relatively high proportion of birds indicates the species’ importance as a potential bridge vector. The low virus prevalence in combination with WNV-specific antibodies indicate continuous, but low activity of WNV in the Danube Delta during the study period.

scholarly journals A simplified method for the analysis of various sugars fed the mosquito, Culex pipiens s.l.

1973 ◽  
Vol 24 (1) ◽  
pp. 17-21
Author(s):  
Mamoru WATANABE ◽  
Kiyoshi KAMIMURA ◽  
Kentaro KUBOTA
Keyword(s):  
Culex Pipiens ◽  
Simplified Method ◽  
Culex Pipiens S.L
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