Experimental Studies on the Ecology of Intertidal Environments at Heron Island. II. The Effect of Substratum

1961 ◽  
Vol 12 (2) ◽  
pp. 164 ◽  
Author(s):  
W Stephenson
Keyword(s):  
Survival Rate ◽  
Green Algae ◽  
Brown Alga ◽  
Experimental Studies ◽  
Rock Surface ◽  
Open Surface ◽  
Algal Cover ◽  
Beach Rock ◽  
Per Se ◽  
Intertidal Environments

Different kinds of rocks were cemented to the beach rock at Heron Island both upon the open surface to permit fish browsing, and within cages to prevent it. During a 12-month period, a negligible number of intertidal animals colonized these rocks, and their sparsity upon the surrounding beach rock is evidently not due to a substratum effect per se. Minor effects of the substratum on the flora were noted. On the harder rocks the brown alga, Ralfsia, was a conspicuous newcomer, while green algae were best developed on the calcareous substrata. The intensity of fish browsing was inversely related to the hardness of the rock surface, but the effect was concluded to be an indirect one, hardness affecting the thickness of the algal cover, and this, in turn, affecting the browsing intensity. Hard concrete placed upon the beach 7 years previously was appreciably higher than the general surface, and (after making certain assumptions) it appears that rock is removed by fish browsing to a thickness of about 0.5 mm per year. In a preliminary experiment acorn barnacles were transplanted from the reef crest to the beach rock, and a higher survival rate was observed on caged specimens.

Experimental Studies on the Ecology of Intertidal Environments at Heron Island. I. Exclusion of Fish from Beach Rock.

1960 ◽  
Vol 11 (2) ◽  
pp. 241 ◽  
Author(s):  
W Stephenson ◽  
RB Searles
Keyword(s):  
Unit Area ◽  
Chlorophyll Concentration ◽  
Experimental Studies ◽  
Controlling Factor ◽  
General Observation ◽  
Beach Rock ◽  
Surrounding Areas ◽  
Intertidal Environments

The zonation of dominant organisms on the beach rock at Heron Island was reinvestigated following the work of Endean, Stephenson, and Kenny (1956) and three zoning algae were noticed. Field indications suggested the apparent sparsity of the biota was due to the browsing activities of fish. Fish-proof enclosures were constructed, some containing browsing molluscs, and the fauna and flora therein were compared with the surrounding areas by means of detailed general observation, and by estimation of the chlorophyll concentration per unit area of surface. The results confirmed that browsing fish are the most important single controlling factor.

THE VALUE OF ORGANOLEPTIC INDICATORS OF DRINKING WATER THE ROSTOV REGION, AS FACTORS OF THE EPIDEMIC SAFETY OF POPULATION HEALTH

2019 ◽  
pp. 24-34
Author(s):  
Timur Khetsuriani ◽  
Elena Chaplygina ◽  
Tatyana Zhukova ◽  
Elgudzha Khetsuriani
Keyword(s):  
Public Health ◽  
Drinking Water ◽  
Green Algae ◽  
Experimental Studies ◽  
Environmental Safety ◽  
Blue Green Algae ◽  
Rostov Region ◽  
Organoleptic Characteristics ◽  
Aesthetic Appearance ◽  
Mass Development

The article presents an overview of the mass development of cyanobacteria (blue-green algae) in the don river of the Rostov region, which leads to the phenomenon, received in the literature the name of harmful “flowering” of water. The harmfulness of the mass development of cyanobacteria is changes in organoleptic characteristics of drinking water, which lead to the production of a large number of dangerous to human health and animal toxins, to reduce water quality, violation of the aesthetic appearance of the reservoir, the loss of useful human properties of the aquatic ecosystem and are factors of epidemic safety of public health. Experimental studies of the properties of cyanobacteria and toxins produced by blue-green algae are pre-sented. The first studies were carried out at the pilot plant on the technology of purification of flowering don water to ensure environmental safety of drinking water and public health.

Glucocorticoids produce whole body insulin resistance with changes in cardiac metabolism

2007 ◽  
Vol 292 (3) ◽  
pp. E654-E667 ◽  
Author(s):  
Dake Qi ◽  
Brian Rodrigues
Keyword(s):  
Insulin Resistance ◽  
Fatty Acid ◽  
Glucose Utilization ◽  
Experimental Studies ◽  
Cardiac Metabolism ◽  
Multiple Organ ◽  
Whole Body ◽  
Metabolic Abnormalities ◽  
Organ Systems ◽  
Per Se

Insulin resistance is viewed as an insufficiency in insulin action, with glucocorticoids being recognized to play a key role in its pathogenesis. With insulin resistance, metabolism in multiple organ systems such as skeletal muscle, liver, and adipose tissue is altered. These metabolic alterations are widely believed to be important factors in the morbidity and mortality of cardiovascular disease. More importantly, clinical and experimental studies have established that metabolic abnormalities in the heart per se also play a crucial role in the development of heart failure. Following glucocorticoids, glucose utilization is compromised in the heart. This attenuated glucose metabolism is associated with altered fatty acid supply, composition, and utilization. In the heart, elevated fatty acid use has been implicated in a number of metabolic, morphological, and mechanical changes and, more recently, in “lipotoxicity”. In the present article, we review the action of glucocorticoids, their role in insulin resistance, and their influence in modulating peripheral and cardiac metabolism and heart disease.

The White Bear Suppression Inventory (WBSI) focuses on failing suppression attempts

2003 ◽  
Vol 17 (4) ◽  
pp. 285-298 ◽  
Author(s):  
Eric Rassin
Keyword(s):  
Factor Analysis ◽  
Control Strategy ◽  
Large Study ◽  
Thought Suppression ◽  
Clinical Sample ◽  
Experimental Studies ◽  
Intrusive Thoughts ◽  
Per Se ◽  
Unwanted Thoughts

Experimental studies have produced evidence to suggest that suppressing unwanted thoughts paradoxically results in even more unwanted thoughts. Therefore, suppression is considered to be an inadequate control strategy. Wegner and Zanakos (1994; Journal of Personality, 62, 615–640) introduced the White Bear Suppression Inventory (WBSI) as a measure to identify people who chronically tend to suppress unwanted thoughts. However, recent studies suggest that the WBSI does not exclusively measure thought suppression, but also addresses the experience of intrusive thoughts. Hence, the WBSI does not seem to measure suppression per se, but rather failing suppression. Three studies elaborate on this idea. In study 1, factor analysis of 674 non‐clinical WBSI scores is found to support the hypothesis that the WBSI addresses both suppression and intrusion. By and large, study 2 replicates these findings in a clinical sample (N=106). In study 3, an alternative suppression questionnaire is introduced, focusing on suppression and intrusions, but also on successful suppression. It is concluded that the WBSI, and thought suppression research in general, is biased toward failing suppression attempts, and has ignored the possibility of successful suppression. Copyright © 2003 John Wiley & Sons, Ltd.

scholarly journals Welcome to the jungle: Algal turf negatively affects recruitment of a Caribbean octocoral

2020 ◽  
Author(s):  
Christopher D. Wells ◽  
Ángela Martínez-Quintana ◽  
Kaitlyn J. Tonra ◽  
Howard R. Lasker
Keyword(s):  
Survival Rate ◽  
Coral Cover ◽  
Survival Rates ◽  
Recruitment Rate ◽  
Algal Turf ◽  
List Type ◽  
Algal Cover ◽  
Turf Algae ◽  
Caribbean Coral Reefs ◽  
Invertebrate Herbivores

ABSTRACTAlgal cover has increased and scleractinian coral cover has steadily declined over the past 40 years on Caribbean coral reefs. In contrast, octocoral abundance has increased at those sites where octocoral abundances have been monitored. The effects of algal cover on recruitment may be a key component in these patterns, as upright octocoral recruits have the potential to escape competition with algae by growing above the ubiquitous algal turfs. However, the impacts of algal turf on octocorals have not been tested.We used laboratory and field recruitment experiments to examine impacts of algal turf on settlement and then survival of newly-settled octocorals. Tiles were preconditioned on a Caribbean reef, allowing algae to settle and grow. Tiles were then partitioned into three treatments: lightly scrubbed (0% turf cover), left alone (19% turf cover), or kept for 15 days in a sea table without fish or large invertebrate herbivores (50% turf cover). Planulae of the common Caribbean octocoral Plexaura homomalla were allowed to settle and metamorphose on the tiles for six days. Tiles were then deployed onto a reef and survival of those recruits was monitored for seven weeks. Settlers that recruited to the tiles after deployment to the reef were also monitored.Laboratory recruitment rate was significantly higher in lower turf cover treatments. Field survival was significantly reduced by increased turf cover; for every 1% increase in turf cover, polyps died 1.3% faster. In a model parameterized by the observed field survival, polyps exposed to 100% turf cover had a 2% survival rate over 51 days, while polyps exposed to no turf cover had a 32% survival rate over the same time.Synthesis. We found that high densities of turf algae can significantly inhibit recruitment of octocorals. Octocoral survival rates were similar to those published for scleractinians, but field settlement rates were much higher, which likely contributes to the higher resilience of octocorals to disturbances. The factors that influence recruitment are critical in understanding the dynamics of octocorals on Caribbean reefs as continuing declines in scleractinian cover may lead to more octocoral-dominated communities in the Caribbean.

scholarly journals Fertility and timing of the embryonic development of Cameraria ohridella Deschka & Dimic, 1986 (Lepidoptera: Gracillariidae) in laboratory conditions at different temperatures

2019 ◽  
pp. 27-28
Author(s):  
M. Bashchenko ◽  
V. Chayka
Keyword(s):  
Survival Rate ◽  
Environmental Factors ◽  
Embryonic Development ◽  
Experimental Studies ◽  
Biological Data ◽  
The State ◽  
Egg Laying ◽  
Effect Of Temperature ◽  
Moth Population ◽  
Laboratory Conditions

Goal. The effect of temperature on fertility and the timing of the embryonic development of the chestnut moth under laboratory conditions was studied. Methods. Laboratory. Selected pupae of the chestnut moth were placed in thermostats (at a temperature of 15, 20, 25, 30). Then, 5 pairs of pupae of different sexes were placed in glass cages in which the paper was pre-inserted, as a substrate for egg laying. Experiments were performed in four versions — 10 replications each. Cages with each variant were placed in polythermostats at temperatures of 15, 20, 25 and 30°С. After the butterflies flew out, the paper was taken out of the cage regularly (every two days) and under a microscope of MBS-9 (eyepiece 0.6 magnification 2), the number of laid eggs and caterpillars that hatch were counted. The results were processed statistically by standard methods for biological data. Results. It was determined that at a temperature of 15°C 50% of caterpillars were released from 40 eggs. At 25°C, out of 187 laid chestnut moth eggs, 65% of caterpillars were released. At 20°C, butterflies laid aside 83 instances. 54% of the caterpillars were released. At 30°C, the female chestnut moth was set aside on 17 instances eggs whose embryonic development has not occurred. It was revealed that at 15 and 30°С females are the least active, thus, optimal temperatures for keeping the chestnut moth in laboratory conditions are in the range of 20—25°С. Under these conditions, butterflies mate and lay eggs, the survival rate of which reaches 54—65%. The technique makes it possible in the laboratory to investigate the influence of environmental factors on the state of the chestnut moth population. Findings. It was determined that in laboratory conditions the optimum temperature for the deposition of chestnut moth eggs is 25°C. Butterflies favor the green substrate. Embryonic development lasts 6.1 ± 0.12 days, the survival rate of the populations is 25%. The method of obtaining chestnut moth eggs allows for in-depth experimental studies of the influence of environmental factors on the state of the chestnut moth population.

scholarly journals Sterol composition of the Adriatic sea algae Ulva lactuca, Codium dichotomum, Cystoseira adriatica and Fucus virsoides

2005 ◽  
Vol 70 (12) ◽  
pp. 1395-1400 ◽  
Author(s):  
Radomir Kapetanovic ◽  
Dusan Sladic ◽  
Simeon Popov ◽  
Mario Zlatovic ◽  
Zoran Kljajic ◽  
...  
Keyword(s):  
Green Algae ◽  
Green Alga ◽  
Brown Algae ◽  
Brown Alga ◽  
Adriatic Sea ◽  
Sterol Composition ◽  
Ulva Lactuca ◽  
The South ◽  
Low Concentration

The sterol composition of two green algae and two brown algae from the South Adriatic was determined. In the green alga Ulva lactuca, the principal sterols were cholesterol and isofucosterol. In the brown alga Cystoseira adriatica, the main sterols were cholesterol and stigmast-5-en-3?-ol, while the characteristic sterol of the brown algae, fucosterol, was found only in low concentration. The sterol fractions of the green alga Codium dichotomum and the brown alga Fucus virsoides contained practically only one sterol each, comprising more than 90 % of the total sterols (clerosterol in the former and fucosterol in the latter).

Morphological reconstruction ofMiaohephyton bifurcatum, a possible brown alga from the Neoproterozoic Doushantuo Formation, South China

1998 ◽  
Vol 72 (6) ◽  
pp. 1072-1086 ◽  
Author(s):  
Shuhai Xiao ◽  
Andrew H. Knoll ◽  
Xunlai Yuan
Keyword(s):  
Green Algae ◽  
South China ◽  
Brown Algae ◽  
Brown Alga ◽  
Sensu Stricto ◽  
Sample Population ◽  
Secondary Endosymbiosis ◽  
Doushantuo Formation ◽  
Morphological Reconstruction ◽  
Meristematic Growth

On the basis of morphological and taphonomic study of a large sample population,Miaohephyton bifurcatumSteiner, emend. from the terminal Proterozoic Doushantuo Formation (600-550 Ma), South China, is interpreted as algal fragments shed from their parent thalli for reproductive or environmental reasons. Characters such as regularly dichotomous, multicellular thalli with forked tips, apical and intercalary meristematic growth, abscission structures, and possible conceptacles collectively suggest an affinity with the brown algae, in particular the order Fucales. In conjunction with reports of xanthophyte fossils in older Neoproterozoic rocks, this reinterpretation ofMiaohephyton bifurcatumindicates that photosynthetic stramenopiles (chrysophytes, synurophytes, xanthophytes, phaeophytes, and diatoms; or chromophytes sensu stricto) diversified during the Neoproterozoic Era along with the red and green algae. This, in turn, suggests that the secondary endosymbiosis that gave rise to the photosynthetic stramenopiles took place relatively soon after the evolutionary transformation of cyanobacteria to rhodophyte plastids.

scholarly journals Answer to Böhmert et al

2020 ◽  
Vol 19 (1) ◽  
Author(s):  
Maël Dieudonné
Keyword(s):  
Experimental Studies ◽  
Comprehensive Model ◽  
Per Se ◽  
Aims And Scope

AbstractI thank Böhmert et al. for their commentary of my review, although their criticisms suggest a misunderstanding of its aims and scope. It does not discuss their comprehensive model per se, but as the latest formulation of a hypothesis that was put forward almost 15 years ago, and only as regards its ability to explain EHS symptoms as they are known to occur. While the authors reassert the strengths of their model, they do not properly address the limitations pointed out in my review, pertaining to: (1) the lack of proven explanations for the origins of beliefs in EMF harmfulness; (2) the realism of experimental studies of EHS; (3) the existence of situations contradicting predictions of their model. Thus, while it seems promising, its applicability to EHS remains to be properly demonstrated. A diversification of the methods used to study EHS seems the only way forward.

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