scholarly journals Examination of the Trexler-DeAngelis Model of Maternal Provisioning Reveals That Matrotrophy Is Costly

2021 ◽  
Vol 9 ◽  
Author(s):  
Nabila Saleh-Subaie ◽  
Gonzalo A. Ramírez-Cruz ◽  
J. Jaime Zúñiga-Vega
Keyword(s):  
Theoretical Model ◽  
Food Availability ◽  
Selective Advantage ◽  
Compelling Evidence ◽  
Stomach Fullness ◽  
Trade Off ◽  
Maternal Provisioning ◽  
Using Data ◽  
Reproductive Females ◽  
Individual Body

The evolution of matrotrophy (post-fertilization maternal provisioning to developing embryos) has been explained through several hypotheses. Trexler and DeAngelis proposed in 2003 a theoretical model that defines the ecological conditions under which matrotrophy would be favored over lecithotrophy (pre-fertilization maternal provisioning). According to this model, matrotrophy offers a selective advantage in environments with abundant and constantly available food, whereas environments with limited and fluctuating food resources should instead promote a lecithotrophic mode of maternal provisioning. This model also proposes that matrotrophy entails the consequence of leaner reproductive females and in turn shorter lifespans. In this study, we examined the Trexler-DeAngelis model using data from 45 populations of five viviparous species from the fish genus Poeciliopsis (family Poeciliidae). We used the matrotrophy index (MI) as a measure of post-fertilization maternal provisioning, and the index of stomach fullness and individual body condition (BC) as proxies for food availability. We also estimated the magnitude of fluctuations in food availability by calculating the temporal variances of these two proxies. Neither abundant nor constantly available food were associated with greater degrees of matrotrophy, which fails to support the predictions of the Trexler-DeAngelis model with respect to the ecological drivers of increased post-fertilization provisioning to embryos. Nonetheless, in all five species we observed that females with greater degrees of matrotrophy had poorer BC compared to females that provided less nutrients to embryos after fertilization. This finding is consistent with one of the expected consequences of advanced matrotrophy according to the Trexler-DeAngelis model, namely, a detriment to the nutritional status of females. Our study provides compelling evidence that gestating females experience a trade-off between post-fertilization provisioning to embryos and self-maintenance, revealing in turn that matrotrophy is a costly reproductive strategy.

scholarly journals Asset Specificity and the Secondary Market for Productive Assets

2020 ◽  
Author(s):  
Simone Boccaletti
Keyword(s):  
Theoretical Model ◽  
Financial Distress ◽  
Financial Constraints ◽  
Secondary Market ◽  
Asset Specificity ◽  
Cost Of Debt ◽  
Debt Contracts ◽  
Trade Off ◽  
Distressed Firms ◽  
Productive Assets

AbstractThe aim of this paper is to explore how debt contracts are affected by investment in asset specialization and by the dynamics of the secondary market for collateralized productive assets. Before applying for a loan, financially constrained firms face a specificity trade-off: asset specialization increases firms’ project returns, but decreases the liquidation value of assets in the secondary market if the firm is in financial distress. To study this trade-off, the paper uses a theoretical model in which the choice of asset specificity and the outcome of the secondary market for distressed firms’ assets are endogenous. High redeployability costs and a small number of participants in the secondary market are associated to low recovery values and to a high cost of debt. The paper shows the conditions under which financial constraints reduce firms’ incentive to invest in asset specificity.

scholarly journals ACTIVITY AND SPACE USE BY DEGUS: A TRADE-OFF BETWEEN THERMAL CONDITIONS AND FOOD AVAILABILITY?

2003 ◽  
Vol 84 (1) ◽  
pp. 311-318 ◽  
Author(s):  
Leonardo D. Bacigalupe ◽  
Enrico L. Rezende ◽  
G. J. Kenagy ◽  
Francisco Bozinovic
Keyword(s):  
Food Availability ◽  
Thermal Conditions ◽  
Space Use ◽  
Trade Off

scholarly journals Metropolitan governance structure and growth–inequality dynamics in the United States

2018 ◽  
Vol 51 (3) ◽  
pp. 598-616 ◽  
Author(s):  
Jaewoo Cho ◽  
Jae Hong Kim ◽  
Yonsu Kim
Keyword(s):  
Economic Growth ◽  
Metropolitan Areas ◽  
Governance Structure ◽  
The United States ◽  
Governance Structures ◽  
Least Squares Regression ◽  
Metropolitan Governance ◽  
Trade Off ◽  
Using Data ◽  
Nonlinear Fashion

While much scholarly attention has been paid to ways in which metropolitan areas are politically structured and operated to achieve a dual goal, economic growth, and equality, relatively less is known about the complex relationship between metropolitan governance structures and growth–inequality dynamics. This study investigates how and to what extent metropolitan governance structures shape regional economic growth and inequality trajectories using data for 267 US metropolitan areas from 1990 to 2010. Findings from a two-stage least squares regression analysis suggest that economic growth is associated with governance structures in a nonlinear fashion, with relatively more rapid growth rates in both highly centralized and decentralized metropolitan areas. However, these regions are also found to experience a larger increase in income inequality, indicating an important trade-off to be considered carefully in exploring ways to reform existing governance settings. These findings further suggest that the so-called growth–inequality trade-off may exist not only in their direct interactions but through their connections via governance or other variables.

scholarly journals Development of an interpreting service model at the Durban University of Technology

2012 ◽  
Author(s):  
◽  
Rosethal Loli Makhubu
Keyword(s):  
Theoretical Model ◽  
Service Delivery ◽  
Mother Tongue ◽  
Critical Issue ◽  
Critical Realist ◽  
University Of Technology ◽  
Delivery Mechanism ◽  
Using Data ◽  
Equity Of Access ◽  
Modelling Process

This research deals with the development of a model of interpreting services for a newly merged multilingual University of Technology, the Durban University of Technology. The rationale for the study was the urgent need to give students whose mother tongue is not the medium of instruction (i.e. English) equity of access to higher-degree education. The research was carried out within a critical realist approach, which seeks to transform society by practical application of theory. Unlike previous studies in interpreting, this research focuses on the service provision aspect of interpreting. It falls within the field of educational interpreting, but goes beyond the classroom situation in considering other university interpreting needs, such as seminars and in-house conferences, graduation and other ceremonies, operational meetings and labour-related meetings. Franck‟s modelling process was used to formulate a theoretical model of the interpreting service delivery mechanism using data gathered during visitations to local and international universities. The theoretical model, or system of essential functions, was used to arrive at the applied aspect of the mechanism, termed an empirical model of interpreting service delivery. The model was then validated in terms of its application in various contexts at the Durban University of Technology. It is suggested that the theoretical and practical models developed have application not only for educational interpreting, but also in other interpreting contexts. The models are also considered to have relevance for service delivery in general, which is a critical issue at present in South Africa.

scholarly journals Complementary roles of mechanotransduction and inflammation in vascular homeostasis

2021 ◽  
Vol 477 (2245) ◽  
pp. 20200622
Author(s):  
Marcos Latorre ◽  
Bart Spronck ◽  
Jay D. Humphrey
Keyword(s):  
Theoretical Model ◽  
Vascular Health ◽  
Induced Hypertension ◽  
Health And Disease ◽  
Vascular Geometry ◽  
Mechanical Homeostasis ◽  
Using Data ◽  
And Function ◽  
Insight Into ◽  
Structure Properties

Arteries are exposed to relentless pulsatile haemodynamic loads, but via mechanical homeostasis they tend to maintain near optimal structure, properties and function over long periods in maturity in health. Numerous insults can compromise such homeostatic tendencies, however, resulting in maladaptations or disease. Chronic inflammation can be counted among the detrimental insults experienced by arteries, yet inflammation can also play important homeostatic roles. In this paper, we present a new theoretical model of complementary mechanobiological and immunobiological control of vascular geometry and composition, and thus properties and function. We motivate and illustrate the model using data for aortic remodelling in a common mouse model of induced hypertension. Predictions match the available data well, noting a need for increased data for further parameter refinement. The overall approach and conclusions are general, however, and help to unify two previously disparate literatures, thus leading to deeper insight into the separate and overlapping roles of mechanobiology and immunobiology in vascular health and disease.

Ecological drivers of group size in female Alpine chamois, Rupicapra rupicapra

Mammalia ◽  
2015 ◽  
Vol 79 (4) ◽  
Author(s):  
Roberta Chirichella ◽  
Andrea Mustoni ◽  
Marco Apollonio
Keyword(s):  
Predation Risk ◽  
Energy Intake ◽  
Group Size ◽  
Food Availability ◽  
Herd Size ◽  
Rupicapra Rupicapra ◽  
Trade Off ◽  
Mammalian Herbivores ◽  
Alpine Chamois

AbstractIn large mammalian herbivores, an increase in herd size not only reduces predation risk but also energy intake. As a consequence, the size of the groups made up by herbivores is often assumed to be the outcome of a trade-off depending on local predation risk and food availability. We studied Alpine chamois (

scholarly journals Economics of Trade-off Between Urea Nitrogen and Poultry Litter for Rice Production

1994 ◽  
Vol 26 (2) ◽  
pp. 552-564 ◽  
Author(s):  
Ramu Govindasamy ◽  
Mark J. Cochran ◽  
David M. Miller ◽  
Richard J. Norman
Keyword(s):  
Soil Fertility ◽  
Cost Minimization ◽  
Poultry Litter ◽  
Rice Production ◽  
Yield Response ◽  
Urea Nitrogen ◽  
Trade Off ◽  
Relative Prices ◽  
Using Data ◽  
Fresh Litter

AbstractThis paper identifies optimal combinations of nitrogen in the form of urea, fresh litter and composted litter for rice production. Traditional cost minimization techniques using data from experimental results conducted at three sites in Arkansas during 1991 have been employed. Comparisons between different scenarios indicate that the trade-off between the use of poultry litter and urea nitrogen depends on such factors as soil fertility, the yield response to litter application and the relative prices of nitrogen and litter. The use of litter is more economical at high target yields than at low target yields.

scholarly journals Multi-generational persistence of traditions in neighbouring meerkat groups

2010 ◽  
Vol 277 (1700) ◽  
pp. 3623-3629 ◽  
Author(s):  
Alex Thornton ◽  
Jamie Samson ◽  
Tim Clutton-Brock
Keyword(s):  
Gene Flow ◽  
Genetic Differentiation ◽  
Group Size ◽  
Food Availability ◽  
Group Membership ◽  
Compelling Evidence ◽  
Suricata Suricatta ◽  
Environmental Causes

Reports of socially transmitted traditions based on behavioural differences between geographically separated groups of conspecifics are contentious because they cannot exclude genetic or environmental causes. Here, we report persistent differences between neighbouring groups of meerkats ( Suricata suricatta ) where extensive gene flow precludes genetic differentiation. Over 11 years, some groups consistently emerged later from their sleeping burrows in the morning than others, despite complete turnovers in group membership and the influx of immigrants. Group territories overlapped and, in many cases, the same sleeping burrows were used by different groups. Differences persisted even after accounting for effects of group size, weather and burrow characteristics, and were unrelated to food availability within territories. These results provide compelling evidence that the emergence times of meerkat groups represent conservative traditions.

scholarly journals The unreasonable effectiveness of traditional information retrieval in crash report deduplication

2016 ◽  
Author(s):  
Joshua Charles Campbell ◽  
Eddie Antonio Santos ◽  
Abram Hindle
Keyword(s):  
Information Retrieval ◽  
Reporting System ◽  
Software Systems ◽  
Trade Off ◽  
Unreasonable Effectiveness ◽  
Using Data

Organizations like Mozilla, Microsoft, and Apple are flooded with thousands of automated crash reports per day. Although crash reports contain valuable information for debugging, there are often too many for developers to examine individually. Therefore, in industry, crash reports are often automatically grouped together in buckets. Ubuntu’s repository contains crashes from hundreds of software systems available with Ubuntu. A variety of crash report bucketing methods are evaluated using data collected by Ubuntu’s Apport automated crash reporting system. The trade-off between precision and recall of numerous scalable crash 7 deduplication techniques is explored. A set of criteria that a crash deduplication method must meet is presented and several methods that meet these criteria are evaluated on a new dataset. The evaluations presented in this paper show that using off-the-shelf information retrieval techniques, that were not designed to be used with crash reports, outperform other techniques which are specifically designed for the task of crash bucketing at realistic industrial scales. This research indicates that automated crash bucketing still has a lot of room for improvement, especially in terms of identifier tokenization.

Sign in / Sign up

Export Citation Format

Share Document