scholarly journals COLONIZATION BY MACROINVERTEBRATES ON AN ARTIFICIAL SUBSTRATE AND COMPARISON WITH A NATURAL SUBSTRATE IN A FLOODPLAIN: A SHORT TIME STUDY IN THE RAINY SEASON

2017 ◽  
Vol 21 (04) ◽  
pp. 407-421
Author(s):  
Carolina Vieira da Silva ◽  
Raoul Henry
Keyword(s):  
Rainy Season ◽  
Artificial Substrate ◽  
Time Study ◽  
Natural Substrate ◽  
Short Time

Walking on a natural substrate and on an artificial substrate: the effect of indigenous footwear

2015 ◽  
Vol 7 (sup1) ◽  
pp. S138-S139
Author(s):  
Catherine Willems ◽  
Gaetane Stassijns ◽  
Dirk DeClercq ◽  
Kristiaan D'Août
Keyword(s):  
Artificial Substrate ◽  
Natural Substrate

Mosquitos bred from Dry Material taken from Holes in Trees

1926 ◽  
Vol 17 (2) ◽  
pp. 183-187 ◽  
Author(s):  
Lawrence H. Dunn
Keyword(s):  
Yellow Fever ◽  
Rainy Season ◽  
Dry Season ◽  
Western Hemisphere ◽  
The Sun ◽  
Living Tree ◽  
Tree Holes ◽  
Control Work ◽  
Short Time ◽  
Selection Of

An investigation of the breeding habits of the yellow fever mosquito, Aëdes aegypti, Linn., in West Africa was begun in December 1925. This was undertaken for the purpose of ascertaining if the selection of breeding-places of this mosquito in Africa differs from that in the Western Hemisphere, and, if so, to learn if this difference is sufficient to be of material importance in yellow fever control work.Since it was believed that breeding in tree-holes constituted a problem worthy of investigation, it was decided to make a survey of the rot-holes and fork-hollows in trees in the vicinity of Lagos, in the Southern Province of Nigeria. This survey was begun on 8th December 1925, shortly after the rainy season had passed and the dry season had set in. However, after inspecting a number of trees, the fact became evident that this was not a propitious time of the year for finding larvae in such places, since practically all of the holes were without water, and their contents, consisting of leaves and débris, were dry.This early drying of the material in the holes drew my attention to the probability of mosquito eggs remaining in the holes, surviving the drought of the dry season and producing larvae with the beginning of the rains. In furtherance of this question, an examination of the dry holes was then began, and material collected from all those that were suitable. The term “ suitable ” in this sense signifies that the hole was in a living tree—of a formation to contain water, for a short time at least—that the aperture was of sufficient size to allow the débris to be removed and the inside of the hole scraped, and that the contents were dry. The distance of the trees from habitations, their location in open areas or thick bush, the height of the holes from the ground, the exposure of the holes to the sun, or the amount of débris contained caused no discrimination to be made.

scholarly journals Colonization of benthic invertebrates on artificial and natural substrate in a Neotropical lotic environment in Southern Brazil

2019 ◽  
Vol 41 ◽  
pp. e45872 ◽  
Author(s):  
Nilce Svarcz Jungles de Camargo ◽  
Atsler Luana Lehun ◽  
Jonathan Rosa ◽  
Ana Carolina de Deus Bueno-Krawczyk
Keyword(s):  
Benthic Invertebrates ◽  
Artificial Substrate ◽  
Artificial Substrates ◽  
Natural Substrate ◽  
Tropical Stream ◽  
Taxonomic Level ◽  
Lotic Environment ◽  
Significant Difference ◽  
Colonization Process ◽  
South Brazil

The objective of this research was to validate the colonization process on natural and artificial substrates by benthic invertebrates in a tropical stream in South Brazil. The samples were performed in July and August-2012, and 32 samplers were used, being 16 natural and 16 artificial substrates. In each sample, two replicas were taken for each substrate at the 2th, 4th, 7th, 14th, 21th 28th, 35th and 42th days of colonization. The organisms were identified to the lowest possible taxonomic level. In both substrates 3,070 benthic invertebrates were detected, of which 1,753 individuals were collected on the natural substrate, and 1,317 on the artificial substrate. From the identified taxa 8.5% were not dominant (Anacroneuria, Orthocladiinae, Tupiara, Smicridea, Baetodes, Tupiperla, Macrogynoplax, Gripopteryx, Cylloepus, Macrelmis, Microcylloepus, Hetaerina, Argia, Coryphaeschna, Atopsyche, Pomacea, Corydalus, Leptohyphes and Eccoptura), and 31.5% were dominant (Tanypodinae, Chironominae, and Paragripopteryx). The genus Simulium was very common, dominant and abundant, representing 65% of the collected individuals. No significant difference was found in the abundance and species composition between artificial and natural substrates. On the natural substrate, the higher colonization index was at the 35th day with 459 individuals, and the lowest was at the 14th day, with 87. On the artificial substrate the highest index was at the 42th day with 337 individuals, and the lowest was at the 4th day, with 85. Both natural and artificial substrates are efficient in characterizing the benthic community. In the evaluation of the ecological succession, it was not possible to observe a pattern that described the process, since the composition was nearly constant throughout the study period.

Short time study of the fishtail effect in Ba0.6K0.4BiO3 single crystals

1996 ◽  
Vol 267 (3-4) ◽  
pp. 270-278 ◽  
Author(s):  
W. Harneit ◽  
T. Klein ◽  
C. Escribe-Filippini ◽  
H. Rakoto ◽  
J.M. Broto ◽  
...  
Keyword(s):  
Single Crystals ◽  
Time Study ◽  
Short Time

What the replication reformation wrought

2018 ◽  
Vol 41 ◽  
Author(s):  
Barbara A. Spellman ◽  
Daniel Kahneman
Keyword(s):  
Reform Movement ◽  
Short Time

AbstractReplication failures were among the triggers of a reform movement which, in a very short time, has been enormously useful in raising standards and improving methods. As a result, the massive multilab multi-experiment replication projects have served their purpose and will die out. We describe other types of replications – both friendly and adversarial – that should continue to be beneficial.

Periodic Variations in the Coronal Green Line Intensity and their Connection with the White-light Coronal Structures

2000 ◽  
Vol 179 ◽  
pp. 197-200
Author(s):  
Milan Minarovjech ◽  
Milan Rybanský ◽  
Vojtech Rušin
Keyword(s):  
Time Resolution ◽  
White Light ◽  
Short Time Scale ◽  
High Time Resolution ◽  
Green Line ◽  
Periodic Intensity ◽  
Coronal Green Line ◽  
Significant Intensity ◽  
Short Time ◽  
Coronal Structures

AbstractWe present an analysis of short time-scale intensity variations in the coronal green line as obtained with high time resolution observations. The observed data can be divided into two groups. The first one shows periodic intensity variations with a period of 5 min. the second one does not show any significant intensity variations. We studied the relation between regions of coronal intensity oscillations and the shape of white-light coronal structures. We found that the coronal green-line oscillations occur mainly in regions where open white-light coronal structures are located.

Destruction of Actin Filaments by Osmium Tetroxide

1977 ◽  
Vol 35 ◽  
pp. 466-467
Author(s):  
P. Maupin-Szamier ◽  
T. D. Pollard
Keyword(s):  
Actin Filaments ◽  
Time Course ◽  
Osmium Tetroxide ◽  
Rabbit Muscle ◽  
Muscle Actin ◽  
Sodium Phosphate Buffer ◽  
Transmission Electron ◽  
The Difference ◽  
Rates Of Decay ◽  
Short Time

We have studied the destruction of rabbit muscle actin filaments by osmium tetroxide (OSO4) to develop methods which will preserve the structure of actin filaments during preparation for transmission electron microscopy.Negatively stained F-actin, which appears as smooth, gently curved filaments in control samples (Fig. 1a), acquire an angular, distorted profile and break into progressively shorter pieces after exposure to OSO4 (Fig. 1b,c). We followed the time course of the reaction with viscometry since it is a simple, quantitative method to assess filament integrity. The difference in rates of decay in viscosity of polymerized actin solutions after the addition of four concentrations of OSO4 is illustrated in Fig. 2. Viscometry indicated that the rate of actin filament destruction is also dependent upon temperature, buffer type, buffer concentration, and pH, and requires the continued presence of OSO4. The conditions most favorable to filament preservation are fixation in a low concentration of OSO4 for a short time at 0°C in 100mM sodium phosphate buffer, pH 6.0.

Effect of a Complex Heat Treatment on the Structure of 300M Steel

1981 ◽  
Vol 39 ◽  
pp. 312-313
Author(s):  
R. Padmanabhan ◽  
W. E. Wood
Keyword(s):  
Heat Treatment ◽  
Metal Carbides ◽  
Austenite Grain Size ◽  
300M Steel ◽  
Heat Treated ◽  
Strain Fracture ◽  
Prior Austenite Grain Size ◽  
Short Time ◽  
Final Tempering ◽  
Similar Yield

Intermediate high temperature tempering prior to subsequent reaustenitization has been shown to double the plane strain fracture toughness as compared to conventionally heat treated UHSLA steels, at similar yield strength levels. The precipitation (during tempering) of metal carbides and their subsequent partial redissolution and refinement (during reaustenitization), in addition to the reduction in the prior austenite grain size during the cycling operation have all been suggested to contribute to the observed improvement in the mechanical properties. In this investigation, 300M steel was initially austenitized at 1143°K and then subjected to intermediate tempering at 923°K for 1 hr. before reaustenitizing at 1123°K for a short time and final tempering at 583°K. The changes in the microstructure responsible for the improvement in the properties have been studied and compared with conventionally heat treated steel. Fig. 1 shows interlath films of retained austenite produced during conventionally heat treatment.

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