scholarly journals Physiological tolerances account for range limits and abundance structure in an invasive slug

2009 ◽  
Vol 276 (1661) ◽  
pp. 1459-1468 ◽  
Author(s):  
Jennifer E Lee ◽  
Charlene Janion ◽  
Elrike Marais ◽  
Bettine Jansen van Vuuren ◽  
Steven L Chown
Keyword(s):  
Laboratory Experiments ◽  
Climatic Factors ◽  
Range Limits ◽  
Sensitive Species ◽  
Species Preference ◽  
Absolute Limit ◽  
Drainage Line ◽  
Physiological Tolerances ◽  
Linear Decline ◽  
Do So

Despite the importance of understanding the mechanisms underlying range limits and abundance structure, few studies have sought to do so. Here we use a terrestrial slug species, Deroceras panormitanum , that has invaded a remote, largely predator-free, Southern Ocean island as a model system to do so. Across Marion Island, slug density does not conform to an abundant centre distribution. Rather, abundance structure is characterized by patches and gaps. These are associated with this desiccation-sensitive species' preference for biotic and drainage line habitats that share few characteristics except for their high humidity below the vegetation surface. The coastal range margin has a threshold form, rapidly rising from zero to high density. Slugs do not occur where soil-exchangeable Na values are higher than 3000 mg kg −1 , and in laboratory experiments, survival is high below this value but negligible above it. Upper elevation range margins are a function of the inability of this species to survive temperatures below an absolute limit of −6.4°C, which is regularly exceeded at 200 m altitude, above which slug density declines to zero. However, the linear decline in density from the coastal peak is probably also a function of a decline in performance or time available for activity. This is probably associated with an altitudinal decline in mean annual soil temperature. These findings support previous predictions made regarding the form of density change when substrate or climatic factors set range limits.

scholarly journals Discovery of the world’s highest-dwelling mammal

2020 ◽  
Vol 117 (31) ◽  
pp. 18169-18171 ◽  
Author(s):  
Jay F. Storz ◽  
Marcial Quiroga-Carmona ◽  
Juan C. Opazo ◽  
Thomas Bowen ◽  
Matthew Farson ◽  
...  
Keyword(s):  
High Altitude ◽  
Small Mammals ◽  
Range Limits ◽  
Northern Chile ◽  
World Record ◽  
Natural Habitats ◽  
Mountain Ranges ◽  
Physiological Tolerances ◽  
Video Documentation ◽  
Environmental Limits

Environmental limits of animal life are invariably revised when the animals themselves are investigated in their natural habitats. Here we report results of a scientific mountaineering expedition to survey the high-altitude rodent fauna of Volcán Llullaillaco in the Puna de Atacama of northern Chile, an effort motivated by video documentation of mice (genusPhyllotis) at a record altitude of 6,205 m. Among numerous trapping records at altitudes of >5,000 m, we captured a specimen of the yellow-rumped leaf-eared mouse (Phyllotis xanthopygus rupestris) on the very summit of Llullaillaco at 6,739 m. This summit specimen represents an altitudinal world record for mammals, far surpassing all specimen-based records from the Himalayas and other mountain ranges. This discovery suggests that we may have generally underestimated the altitudinal range limits and physiological tolerances of small mammals simply because the world’s high summits remain relatively unexplored by biologists.

scholarly journals Discovery of the world’s highest-dwelling mammal

2020 ◽  
Author(s):  
Jay F. Storz ◽  
Marcial Quiroga-Carmona ◽  
Juan C. Opazo ◽  
Thomas Bowen ◽  
Matthew Farson ◽  
...  
Keyword(s):  
High Altitude ◽  
Small Mammals ◽  
Range Limits ◽  
Northern Chile ◽  
World Record ◽  
Natural Habitats ◽  
The Andes ◽  
Physiological Tolerances ◽  
Video Documentation ◽  
Environmental Limits

AbstractEnvironmental limits of animal life are invariably revised upwards when the animals themselves are investigated in their natural habitats. Here we report results of a scientific mountaineering expedition to survey the high-altitude rodent fauna of Volcán Llullaillaco in the Puna de Atacama of northern Chile, an effort motivated by video documentation of mice (genus Phyllotis) at a record altitude of 6205 m. Among numerous trapping records at altitudes >5000 m, we captured a specimen of the yellow-rumped leaf-eared mouse (Phyllotis xanthopygus rupestris) on the very summit of Llullaillaco at 6739 m. This summit specimen represents an altitudinal world record for mammals, far surpassing all specimen-based records from the Himalayas and elsewhere in the Andes. This discovery suggests that we may have generally underestimated the altitudinal range limits and physiological tolerances of small mammals simply because the world’s highest summits remain relatively unexplored by biologists.

Bargaining Process and Channel Efficiency

2020 ◽  
Vol 66 (7) ◽  
pp. 2845-2860 ◽  
Author(s):  
Ernan Haruvy ◽  
Elena Katok ◽  
Valery Pavlov
Keyword(s):  
Operations Management ◽  
Laboratory Experiments ◽  
Wholesale Price ◽  
Analytical Models ◽  
Bargaining Process ◽  
Supply Chain Contracts ◽  
Channel Efficiency ◽  
Contract Performance ◽  
Do So ◽  
Additional Channel

The behavioral literature has demonstrated that the format of supply chain contracts matters even when theoretically it should not and that contracts that in theory coordinate channels fail to do so in laboratory experiments. The existing body of experimental evidence uses an ultimatum bargaining protocol to test analytical models, but there is no reason to think that bargaining in supply chains is in the form of ultimatum offers. We investigate the effect of bargaining on contract performance by extending the bargaining protocol to allow the manufacturer to make concessions. We test coordinating contract with bargaining in the laboratory by comparing wholesale price and the two-part tariff contracts using two different bargaining protocols. We then develop and estimate a statistical model of behavior with bargaining and find that this model organizes our data well. Our main finding is that the contracts that we study are more efficient when participants are allowed to make concessions. The additional channel efficiency is owing to more efficient offers made by manufacturers. The higher channel efficiency primarily benefits the retailer—the weaker party. Our main contribution is the observation that, when testing analytical models of contracts in the laboratory, the way that the bargaining process is implemented, such as the ability to make concessions, has a critical effect on conclusions. This paper was accepted by Vishal Gaur, operations management.

Field Experiments

2004 ◽  
Vol 42 (4) ◽  
pp. 1009-1055 ◽  
Author(s):  
Glenn W Harrison ◽  
John A List
Keyword(s):  
Laboratory Experiments ◽  
Field Experiments ◽  
Trading Rules ◽  
Subject Pool ◽  
The Subject ◽  
Do So

Experimental economists are leaving the reservation. They are recruiting subjects in the field rather than in the classroom, using field goods rather than induced valuations, and using field context rather than abstract terminology in instructions. We argue that there is something methodologically fundamental behind this trend. Field experiments differ from laboratory experiments in many ways. Although it is tempting to view field experiments as simply less controlled variants of laboratory experiments, we argue that to do so would be to seriously mischaracterize them. What passes for “control” in laboratory experiments might in fact be precisely the opposite if it is artificial to the subject or context of the task. We propose six factors that can be used to determine the field context of an experiment: the nature of the subject pool, the nature of the information that the subjects bring to the task, the nature of the commodity, the nature of the task or trading rules applied, the nature of the stakes, and the environment that subjects operate in.

Physiological Mechanism for Tall Morningglory (Ipomoea Purpurea) Resistance to DPX-PE350

Weed Science ◽  
1995 ◽  
Vol 43 (1) ◽  
pp. 21-27 ◽  
Author(s):  
Shay L. Sunderland ◽  
James D. Burton ◽  
Harold D. Coble ◽  
Eleanor P. Maness
Keyword(s):  
Laboratory Experiments ◽  
Physiological Mechanism ◽  
Acetolactate Synthase ◽  
Sensitive Species ◽  
Ipomoea Purpurea ◽  
Mechanism Of Resistance ◽  
Resistant Species ◽  
Site Of Action

Laboratory experiments were conducted to determine the physiological mechanism of tall morningglory resistance to the experimental cotton herbicide DPX-PE350. Tall morningglory, a resistant species, was compared with entireleaf morningglory, a sensitive species, to evaluate inhibition at the site of action, the acetolactate synthase (ALS) enzyme (E.C.4.1.3.18), by DPX-PE350 as well as uptake, translocation, and metabolism of DPX-PE350. No differences were found between species in the concentration required to inhibit the ALS enzyme by 50% (I50), or in uptake and translocation of the herbicide. Tall morningglory metabolized the herbicide more rapidly than did entireleaf morningglory. Tall morningglory contained 3.6 and 1.4 times more metabolites of DPX-PE350 than did entireleaf morningglory 6 and 24 h after treatment, respectively. Tall morningglory produced anO-desmethyl metabolite from the 3,5-dimethoxypyrimidine moiety of DPX PE350 that was not found in entireleaf morningglory. These data suggest that the ability of tall morningglory to more rapidly metabolize DPX-PE350, possibly through the production of the pyrimidinyldesmethyl metabolite, may be the mechanism of resistance to DPX-PE350.

scholarly journals Trophic interactions and range limits: the diverse roles of predation

2009 ◽  
Vol 276 (1661) ◽  
pp. 1435-1442 ◽  
Author(s):  
Robert D Holt ◽  
Michael Barfield
Keyword(s):  
Natural Enemies ◽  
Trophic Interactions ◽  
Natural World ◽  
Geographic Range ◽  
Range Limits ◽  
Evolutionary Mechanisms ◽  
Specialist Predator ◽  
Do So

Interactions between natural enemies and their victims are a pervasive feature of the natural world. In this paper, we discuss trophic interactions as determinants of geographic range limits. Predators can directly limit ranges, or do so in conjunction with competition. Dispersal can at times permit a specialist predator to constrain the distribution of its prey—and thus itself—along a gradient. Conversely, we suggest that predators can also at times permit prey to have larger ranges than would be seen without predation. We discuss several ecological and evolutionary mechanisms that can lead to this counter-intuitive outcome.

scholarly journals Fluid Dynamics Experiments for Planetary Interiors

2021 ◽  
Author(s):  
Michael Le Bars ◽  
Ankit Barik ◽  
Fabian Burmann ◽  
Daniel P. Lathrop ◽  
Jerome Noir ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Laboratory Experiments ◽  
Fluid Flows ◽  
Review Article ◽  
Planetary Interiors ◽  
Numerical Studies ◽  
Long Duration ◽  
Planetary Cores ◽  
Experimental Approaches ◽  
Do So

AbstractUnderstanding fluid flows in planetary cores and subsurface oceans, as well as their signatures in available observational data (gravity, magnetism, rotation, etc.), is a tremendous interdisciplinary challenge. In particular, it requires understanding the fundamental fluid dynamics involving turbulence and rotation at typical scales well beyond our day-to-day experience. To do so, laboratory experiments are fully complementary to numerical simulations, especially in systematically exploring extreme flow regimes for long duration. In this review article, we present some illustrative examples where experimental approaches, complemented by theoretical and numerical studies, have been key for a better understanding of planetary interior flows driven by some type of mechanical forcing. We successively address the dynamics of flows driven by precession, by libration, by differential rotation, and by boundary topography.

scholarly journals In-Group Loyalty and the Punishment of Corruption

2018 ◽  
Vol 52 (6) ◽  
pp. 896-926 ◽  
Author(s):  
Hector Solaz ◽  
Catherine E. De Vries ◽  
Roosmarijn A. de Geus
Keyword(s):  
Experimental Evidence ◽  
Identity Politics ◽  
Real World ◽  
Laboratory Experiments ◽  
Group Identity ◽  
Present Evidence ◽  
Group Loyalty ◽  
Group Identities ◽  
Ruling Party ◽  
Do So

This study suggests that in-group loyalty, defined as the degree to which people favor their own group over others, undermines the punishment of corruption. We present evidence from two studies. First, we utilize a real-world corruption scandal involving the ruling party in Spain that broke during survey fieldwork. People exposed to the scandal withhold support from the incumbent, but in-group loyalty based on partisanship weakens this effect. Second, we explore in-group loyalty beyond partisanship through laboratory experiments. These experiments artificially induce group identities, randomly assign the group identity of candidates and shut down any instrumental benefits of in-group loyalty. The experimental evidence suggests that people support corrupt candidates as long as they share a group identity and are willing to sacrifice material payoffs to do so. Our findings have important implications. Most importantly perhaps, they suggest that candidates can get away with corruption by engaging in identity politics.

scholarly journals Temperature Relations of Teneral Development and Behaviour in Aphis Fabae Scop

1957 ◽  
Vol 34 (2) ◽  
pp. 189-208
Author(s):  
L. R. TAYLOR
Keyword(s):  
Laboratory Experiments ◽  
Climatic Factors ◽  
Velocity Curve ◽  
Aphis Fabae ◽  
Ecological Context ◽  
Logistic Curve ◽  
Temperature Changes ◽  
Pearson Type ◽  
Bean Crop

1. The teneral stage in Aphis fabae Scop. is defined as the interval between eclosion of the alate imago and flight when flight is not extrinsically activated or inhibited. 2. In field marking experiments the teneral stage is shown to be usually development-limited, not behaviour-limited, by its relationship to temperature. 3. It is suggested that the logistic curve fits the rising temperature x development-velocity curve because this is a statistical distribution like the Pearson type 1. 4. The logistic curve is fitted to teneral period in naturally varying temperatures by a method of successive approximation. 5. In trapping experiments take-off is inhibited by light below c. 100 f.c. and by temperature below c. 16° C. at 1 ft. in a bean crop. 6. These behaviour responses sometimes lengthen the apparent teneral period. 7. The results are confirmed in the laboratory at constant and at varying temperatures. 8. This also confirms that temperature changes per se even over a range of c. 7-34° C., and other climatic factors, have negligible effect on rate of development during the teneral period. 9. Individual variation is a constant proportion of teneral time at all temperatures. 10. In laboratory experiments the same criteria apply to Aglais urticae L. 11. This period of inactivity warrants further examination in an ecological context.

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