The interplay of environmental constraints and bioturbation on matground development along the marine depositional profile during the Ordovician Radiation

Geobiology ◽  
2021 ◽  
Author(s):  
Aram Bayet‐Goll ◽  
Luis A. Buatois ◽  
Maria Gabriela Mángano ◽  
Mehdi Daraei
Keyword(s):  
Environmental Constraints

Preliminary Report of a Comparative Study of Seminiferous Tubular Epithelium from Rats Flown on Cosmos 1887 and SL3

1988 ◽  
Vol 46 ◽  
pp. 276-277
Author(s):  
Walter J. Sapp ◽  
D.E. Philpott ◽  
C.S. Williams ◽  
K. Kato ◽  
J. Stevenson ◽  
...  
Keyword(s):  
Space Flight ◽  
Physiological Response ◽  
Preliminary Report ◽  
Complete Recovery ◽  
Environmental Constraints ◽  
Tubular Epithelium ◽  
Testicular Weight ◽  
Testicular Morphology ◽  
Normal Offspring ◽  
Rats And Mice

Space flight, with its unique environmental constraints such as immobilization, decreased and increased pressures, and radiation, is known to affect testicular morphology and spermatogenesis. Selye, summarized the manifestations of physiological response to nonspecific stress and he pointed out that atrophy of the gonads always occurred. Reports of data collected from two dogs flown in space for 22 days (Cosmos 110) indicate that there was an increase of 30 to 70% atypical spermatozoa when compared to ground based controls. Seventy-five days after the flight the abnormalities had decreased to the high normal value of 30% and mating of these dogs after this period produced normal offspring, suggesting complete recovery. Effects of immobilization and increased gravity were investigated by spinning rats and mice at 2x g for 8-9 weeks. A decrease in testicular weight was noted in spun animals when compared to controls. Immobilization has been show to cause arrest of spermatogenesis in Macaca meminstrins.

Ecological Limits and the Meaning of Freedom: A Defense of Liberty as Non-Domination

2017 ◽  
Vol 3 (3) ◽  
pp. 33-49 ◽  
Author(s):  
Augustin Fragnière
Keyword(s):  
Conceptual Analysis ◽  
Environmental Policies ◽  
Environmental Constraints ◽  
Political Arena ◽  
Individual Liberty ◽  
Philosophical Debate ◽  
Political Issues ◽  
Global Environmental Problems ◽  
Global Environmental ◽  
Two Alternatives

It is now widely acknowledged that global environmental problems raise pressing social and political issues, but relatively little philosophical attention has been paid to their bearing on the concept of liberty. This must surprise us, because the question of whether environmental policies are at odds with individual liberty is bound to be controversial in the political arena. First, this article explains why a thorough philosophical debate about the relation between liberty and environmental constraints is needed. Second, based on Philip Pettit’s typology of liberty, it assesses how different conceptions of liberty fare in a context of stringent ecological limits. Indeed, a simple conceptual analysis shows that some conceptions of liberty are more compatible than others with such limits, and with the policies necessary to avoid overshooting them. The article concludes that Pettit’s conception of liberty as non-domination is more compatible with the existence of stringent ecological limits than the two alternatives considered.

Mitigating Environmental Constraints at Airports through Long Term Planning: A Decision Support Approach

2004 ◽  
Vol 12 (2) ◽  
pp. 107-124 ◽  
Author(s):  
Paul Upham ◽  
Yingjie Yang ◽  
David Raper ◽  
Callum Thomas ◽  
David Gillingwater ◽  
...  
Keyword(s):  
Decision Support ◽  
Environmental Constraints

DESIGN-BUILD: AN EFFECTIVE APPROACH FOR ARCHITECTURE STUDIO EDUCATION

2018 ◽  
Vol 12 (2) ◽  
pp. 146 ◽  
Author(s):  
Nabil Mohareb ◽  
Sara Maassarani
Keyword(s):  
Material Selection ◽  
Environmental Constraints ◽  
Design Project ◽  
Construction Methods ◽  
Physical Scale ◽  
Design Build ◽  
Simulation Results ◽  
Education Process ◽  
Real Target

Current architecture studios are missing an important phase in the education process, which is constructing the students’ conceptual ideas on a real physical scale. The design-build approach enables the students to test their ideas, theories, material selection, construction methods, environmental constraints, simulation results, level of space functionality and other important aspects when used by real target clients in an existing context. This paper aims to highlight the importance of using the design-build method through discussing a design project case study carried out by the Masters of Architecture design programme students at Beirut Arab University, who have built prototype units for refugees on a 1:1 scale.

The Economic Cost of Hydropower Environmental Constraints Under Decreasing Price Volatility

2020 ◽  
Author(s):  
Hannu Huuki ◽  
Santtu Karhinen ◽  
Faisal Ashraf ◽  
Ali Torabi Haghighi ◽  
Hannu Marttila
Keyword(s):  
Price Volatility ◽  
Economic Cost ◽  
Environmental Constraints

ENVIRONMENTAL CONSTRAINTS ON THE DISTRIBUTION OF THE BLUE LAND CRAB IN THE BAHAMAS: IMPLICATIONS FOR PALEO-SHORELINE RECONSTRUCTION

2018 ◽  
Author(s):  
Christopher A. Sparacio ◽  
◽  
Ilya V. Buynevich ◽  
H. Allen Curran ◽  
Karen A. Kopcznski ◽  
...  
Keyword(s):  
Environmental Constraints ◽  
The Bahamas ◽  
Land Crab ◽  
Blue Land Crab

Phosphorus equivalence ofaspergillus nigerphytase for growing pigs

1995 ◽  
Vol 1995 ◽  
pp. 40-40
Author(s):  
Naheeda Khan ◽  
D.J.A. Cole
Keyword(s):  
Total Phosphorus ◽  
Current Literature ◽  
Livestock Production ◽  
Growing Pigs ◽  
Environmental Constraints ◽  
Experimental Conditions ◽  
Production Sector ◽  
Soil Phosphate ◽  
Phosphorus Requirements ◽  
Inorganic Phosphates

Inconsistencies in the estimated phosphorus requirements of growing pigs have come to light in recent years due to environmental constraints being imposed on the livestock production sector. Values of a net requirement estimated by the ARC (1981) extend from 4.6 g/day for 25kg liveweight to 5.2 g/day for 45kg pigs, but current literature suggesting that the actual requirement may be lower (eg Jongbloed and Everts, 1991) calls for a revision of previous recommendations.Around two thirds of the total phosphorus in cereals exists in the form of insoluble phytates which must be degraded before the phosphorus can be absorbed in the intestine. Under experimental conditions, the use of phytase in pig diets has demonstrated consistent improvements in phosphorus digestibility. The enzyme hydrolyses phytate by stepwise removal of orthophosphates, which become available for absorption in the gut. Although quantification of phytase/phosphorus substitution is as yet undetermined, digestibility results so far indicate that if used correctly the enzyme could largely replace inorganic phosphates, particularly in regions where soil phosphate levels are of concern.

scholarly journals Long-Term Experimental Evolution in Escherichia coli. VI. Environmental Constraints on Adaptation and Divergence

Genetics ◽  
1997 ◽  
Vol 146 (2) ◽  
pp. 471-479 ◽  
Author(s):  
Michael Travisano
Keyword(s):  
Escherichia Coli ◽  
Genetic Variation ◽  
Experimental Evolution ◽  
Population Genetic ◽  
Environmental Constraints ◽  
Asymmetric Pattern ◽  
Nutrient Environment ◽  
Mean Fitness ◽  
Population Genetic Variation

The effect of environment on adaptation and divergence was examined in two sets of populations of Escherichia coli selected for 1000 generations in either maltose- or glucose-limited media. Twelve replicate populations selected in maltose-limited medium improved in fitness in the selected environment, by an average of 22.5%. Statistically significant among-population genetic variation for fitness was observed during the course of the propagation, but this variation was small relative to the fitness improvement. Mean fitness in a novel nutrient environment, glucose-limited medium, improved to the same extent as in the selected environment, with no statistically significant among-population genetic variation. In contrast, 12 replicate populations previously selected for 1000 generations in glucose-limited medium showed no improvement, as a group, in fitness in maltose-limited medium and substantial genetic variation. This asymmetric pattern of correlated responses suggests that small changes in the environment can have profound effects on adaptation and divergence.

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