Ecology and demography of a population of Anseropoda placenta (Echinodermata: Asteroidea) in the Bay of Brest, Brittany

The starfish Anseropoda placenta (Pennant) is abundant in the gravelly sands of the Bay of Brest (Finistere, France). The size, distribution and density of this animal were evaluated along a transect perpendicular to the River Aulne in the southern part of the Bay. The spawning phases, the recruitment and growth processes were defined. When the entire population was considered, three plurimodal year classes were visible from the length frequency histograms. Year-class segregations were observed. Their density varied in space and time in a manner which suggests a pattern of migration from the southern part of the transect towards the northern part. Juveniles were recruited mainly during the autumn on the gravelly bottom of the southern shallow part. By late winter, they had migrated to the deeper parts of the channel. Feeding preferences do not seem to be the main factor controlling these migrations which are discussed in relation to environmental factors and the intra- and inter-specific competition.

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Evolution of cluster size distribution in nucleation and growth processes

Journal of Non-Crystalline Solids ◽

10.1016/0022-3093(91)90489-s ◽

1991 ◽

Vol 136 (3) ◽

pp. 181-197 ◽

Cited By ~ 43

Author(s):

J. Bartels ◽

U. Lembke ◽

R. Pascova ◽

J. Schmelzer ◽

I. Gutzow

Keyword(s):

Size Distribution ◽

Cluster Size ◽

Nucleation And Growth ◽

Cluster Size Distribution ◽

Growth Processes

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Experimental collection of great scallop postlarvae and other benthic species in the Bay of Brest: settlement patterns in relation to spatio-temporal variability of environmental factors

Aquaculture International ◽

10.1007/bf00117387 ◽

1996 ◽

Vol 4 (3) ◽

pp. 263-288 ◽

Cited By ~ 20

Author(s):

Laurent Chauvaud ◽

G�rard Thouzeau ◽

Jacques Grall

Keyword(s):

Environmental Factors ◽

Temporal Variability ◽

Settlement Patterns ◽

Benthic Species ◽

Great Scallop ◽

Spatio Temporal ◽

Bay Of Brest

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Influence of Seasonal Environmental Variables on the Distribution of Presumptive Fecal Coliforms around an Antarctic Research Station

Applied and Environmental Microbiology ◽

10.1128/aem.69.8.4884-4891.2003 ◽

2003 ◽

Vol 69 (8) ◽

pp. 4884-4891 ◽

Cited By ~ 38

Author(s):

Kevin A. Hughes

Keyword(s):

Environmental Factors ◽

Solar Radiation ◽

Sea Ice ◽

Fecal Coliform ◽

Algal Blooms ◽

Austral Summer ◽

Fecal Coliforms ◽

Late Winter ◽

Research Station ◽

The Antarctic

ABSTRACT Factors affecting fecal microorganism survival and distribution in the Antarctic marine environment include solar radiation, water salinity, temperature, sea ice conditions, and fecal input by humans and local wildlife populations. This study assessed the influence of these factors on the distribution of presumptive fecal coliforms around Rothera Point, Adelaide Island, Antarctic Peninsula during the austral summer and winter of February 1999 to September 1999. Each factor had a different degree of influence depending on the time of year. In summer (February), although the station population was high, presumptive fecal coliform concentrations were low, probably due to the biologically damaging effects of solar radiation. However, summer algal blooms reduced penetration of solar radiation into the water column. By early winter (April), fecal coliform concentrations were high, due to increased fecal input by migrant wildlife, while solar radiation doses were low. By late winter (September), fecal coliform concentrations were high near the station sewage outfall, as sea ice formation limited solar radiation penetration into the sea and prevented wind-driven water circulation near the outfall. During this study, environmental factors masked the effect of station population numbers on sewage plume size. If sewage production increases throughout the Antarctic, environmental factors may become less significant and effective sewage waste management will become increasingly important. These findings highlight the need for year-round monitoring of fecal coliform distribution in Antarctic waters near research stations to produce realistic evaluations of sewage pollution persistence and dispersal.

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Size distribution and source of black carbon aerosol in urban Beijing during winter haze episodes

10.5194/acp-2016-1096 ◽

2016 ◽

Author(s):

Yunfei Wu ◽

Xiaojia Wang ◽

Jun Tao ◽

Rujin Huang ◽

Ping Tian ◽

...

Keyword(s):

Size Distribution ◽

Black Carbon ◽

Urban Areas ◽

Late Winter ◽

Equivalent Diameter ◽

Air Masses ◽

A Value ◽

Significant Linear Correlation ◽

Mass Size ◽

Black Carbon Aerosol

Abstract. Black carbon (BC) plays an important role in the climate and environment due to its light absorption, which is greatly dependent on its physicochemical properties including morphology, size and mixing state. The size distribution of the refractory BC (rBC) in urban Beijing during the late winter in 2014 was revealed by measurements obtained using a single particle soot photometer (SP2), when the hazes occurred frequently. By assuming void-free rBC with a density of 1.8 g cm−3, the mass of the rBC showed an approximately lognormal distribution as a function of the volume-equivalent diameter (VED), for which there was a peak diameter of 213 nm. This size distribution agreed well with those observed in other urban areas of China. Larger VED values of the rBC were observed during polluted periods than on clean days, implying an alteration in the rBC sources, as the mass-size of the rBC from a certain source varied little once it was emitted into the atmosphere. The potential source contribution functions showed that air masses from the south to east of the observation site brought a higher rBC loading with more thick coatings and larger core sizes. The mean VED of the rBC (VEDrBC) presented a significant linear correlation with the number fraction of thickly coated rBC (NFcoated); the VED of the entirely externally mixed rBC was inferred as the y-intercept of the linear regression. This VED, with a value of ~150 nm, was considered as the typical mean VED of the rBC from local traffic sources in this study. Accordingly, the contribution of the local traffic to the rBC was estimated based on reasonable assumptions. Local traffic contributed 35 to 100 % of the hourly rBC mass concentration with a mean of 59 %, during this campaign. A lower local traffic contribution was observed during polluted periods, suggesting increasing contributions of other sources (e.g., coal combustion/biomass burning) to the rBC. The heavy pollution in Beijing was greatly influenced by other sources in addition to the local traffic.

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REACTION OF SPRING WHEAT LINES WITH FOREIGN GENETIC MATERIAL TO THE IMPACT OF ARTIFICIALLY CREATED STRESSES

10.26897/978-5-9675-1855-3-2021-42 ◽

2021 ◽

Author(s):

O. V. Pavlova ◽

◽

L. A. Marchenkova ◽

R. F. Chavdar ◽

T. G. Orlova ◽

...

Keyword(s):

Sodium Chloride ◽

Environmental Factors ◽

Spring Wheat ◽

Genetic Material ◽

Growth Processes ◽

Genetic Characteristics ◽

Early Stages ◽

Inhibition Of Growth ◽

Wheat Lines ◽

The Impact

The adaptive properties of spring wheat lines with foreign genetic material at the early stages of ontogenesis on the backgrounds of salinization with sodium chloride and prolonged flooding of seeds in water were evaluated. In the course of the work, different degrees of inhibition of growth processes were revealed, depending on the factor used and the genetic characteristics of the studied forms, a comprehensive (summary) assessment of the index of stability characterizing adaptability to adverse environmental factors was shown.

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Investigation on the Deterioration Mechanism of Tuff Stones Used for the Exteriors at the Former Koshien Hotel

E3S Web of Conferences ◽

10.1051/e3sconf/202017220008 ◽

2020 ◽

Vol 172 ◽

pp. 20008

Author(s):

Koki Yamada ◽

Chiemi Iba ◽

Tomoko Uno ◽

Kazuma Fukui ◽

Daisuke Ogura

Keyword(s):

Hydraulic Conductivity ◽

Physical Properties ◽

Pore Size Distribution ◽

Pore Size ◽

Size Distribution ◽

Vapor Permeability ◽

Cultural Significance ◽

Water Permeation ◽

Deterioration Mechanism ◽

Main Factor

The former Koshien Hotel is an historic Japanese architectural structure, where two different tuffs called Nikkaseki and Tatsuyamaishi were used to build the exterior. Despite its cultural significance, the building’s exterior is deteriorating in many ways, with water permeation being the main factor. In this study, the hygrothermal properties of both Nikkaseki and Tatsuyamaishi were measured in order to examine the correlation between deterioration mechanisms and the tuff characteristics in detail. The basic physical properties, pore size distribution, vapor permeability, hydraulic conductivity, and sorption isotherm were measured. The results of a comparison of two tuffs led us to hypothesize that the main reason behind Nikkaseki’s deterioration is expansive freezing, while that of Tatsuyamaishi is caused by repeating dehydration or dry-wet cycles.

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Root size, distribution and soil water depletion as affected by cultivars and environmental factors

Field Crops Research ◽

10.1016/j.fcr.2009.07.006 ◽

2009 ◽

Vol 114 (1) ◽

pp. 75-83 ◽

Cited By ~ 81

Author(s):

Xiying Zhang ◽

Suying Chen ◽

Hongyong Sun ◽

Yanmei Wang ◽

Liwei Shao

Keyword(s):

Environmental Factors ◽

Size Distribution ◽

Soil Water ◽

Soil Water Depletion ◽

Water Depletion ◽

Root Size

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Relationship between flowering, fruit setting and environmental factors on consecutive clusters in greenhouse tomato (Lycopersicon lycopersicum (L) Karsten)

International Journal of Horticultural Science ◽

10.31421/ijhs/9/3-4/421 ◽

2003 ◽

Vol 9 (3-4) ◽

Author(s):

Z. Pék ◽

L. Helyes

Keyword(s):

Environmental Factors ◽

Fruit Set ◽

Early Spring ◽

Temperate Zone ◽

Late Winter ◽

Greenhouse Tomato ◽

Fruit Setting ◽

Lycopersicon Lycopersicum

The main season of greenhouse tomato begins late winter or early spring in the northern Temperate Zone. During this period decisive environmental factors affect flowering and fruit setting. In the present experiments, progress and dynamics of greenhouse tomato flowering and fruit set were examined in 1999 and 2001 spring. The beginning and the end of flowering and fruit set, the number of flowers and fruits set in each cluster were recorded. Flowering and fruit set characteristics were analysed with respect to the accumulated PAR and temperature were calculated for each cluster. One flower required 31.3 mol M-2 of accumulated PAR and 38 °C of sum temperature as an average for anthesis. One fruit required 27.9 mol m-2 of accumulated PAR and 33.3 °C of sum temperature as an average for fruit setting.

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