scholarly journals Trade-offs obscure the relationship between egg size and larval traits in the diadromous fish Galaxias maculatus

2012 ◽  
Vol 461 ◽  
pp. 165-174 ◽  
Author(s):  
D Semmens ◽  
SE Swearer
Keyword(s):  
Egg Size ◽  
Diadromous Fish ◽  
Trade Offs ◽  
Galaxias Maculatus ◽  
The Relationship ◽  
Larval Traits

scholarly journals Adult body growth and reproductive investment vary markedly within and across Atlantic and Pacific herring: a meta-analysis and review of 26 stocks

2021 ◽  
Author(s):  
Thassya C. dos Santos Schmidt ◽  
Doug E. Hay ◽  
Svein Sundby ◽  
Jennifer A. Devine ◽  
Guðmundur J. Óskarsson ◽  
...  
Keyword(s):  
Egg Size ◽  
Meta Analysis ◽  
Reproductive Investment ◽  
Body Growth ◽  
Clupea Harengus ◽  
Pacific Herring ◽  
Atlantic Herring ◽  
Additional Information ◽  
Trade Offs ◽  
Investment In Reproduction

AbstractLife-history traits of Pacific (Clupea pallasii) and Atlantic (Clupea harengus) herring, comprising both local and oceanic stocks subdivided into summer-autumn and spring spawners, were extensively reviewed. The main parameters investigated were body growth, condition, and reproductive investment. Body size of Pacific herring increased with increasing latitude. This pattern was inconsistent for Atlantic herring. Pacific and local Norwegian herring showed comparable body conditions, whereas oceanic Atlantic herring generally appeared stouter. Among Atlantic herring, summer and autumn spawners produced many small eggs compared to spring spawners, which had fewer but larger eggs—findings agreeing with statements given several decades ago. The 26 herring stocks we analysed, when combined across distant waters, showed clear evidence of a trade-off between fecundity and egg size. The size-specific individual variation, often ignored, was substantial. Additional information on biometrics clarified that oceanic stocks were generally larger and had longer life spans than local herring stocks, probably related to their longer feeding migrations. Body condition was only weakly, positively related to assumingly in situ annual temperatures (0–30 m depth). Contrarily, body growth (cm × y−1), taken as an integrator of ambient environmental conditions, closely reflected the extent of investment in reproduction. Overall, Pacific and local Norwegian herring tended to cluster based on morphometric and reproductive features, whereas oceanic Atlantic herring clustered separately. Our work underlines that herring stocks are uniquely adapted to their habitats in terms of trade-offs between fecundity and egg size whereas reproductive investment mimics the productivity of the water in question.

Chinese "Cancer Villages"

2020 ◽  
Author(s):  
Ajiang Chen ◽  
Pengli Cheng ◽  
Yajuan Luo
Keyword(s):  
Public Health ◽  
Economic Growth ◽  
Cultural Change ◽  
Social Life ◽  
Social Economic ◽  
Rural China ◽  
Sociological Analysis ◽  
Complex Interactions ◽  
Trade Offs ◽  
The Relationship

The phenomenon of "cancer villages" has emerged in many parts of rural China, drawing media attention and becoming a fact of social life. However, the relationship between pollution and disease is often hard to discern. Through sociological analysis of several villages with different social and economic structures, the authors offer a comprehensive, historically grounded analysis of the coexistence between the incidence of cancer, environmental pollution and villagers’ lifestyles, as well as the perceptions, claims and responses of different actors. They situate the appearance of "cancer villages" in the context of social, economic and cultural change in China, tracing the evolution of the issue over two decades, and providing deep insights into the complex interactions and trade-offs between economic growth, environmental change and public health.

scholarly journals Research on Mediating Mechanisms and the Impact on Food Provision Services in Poor Areas from the Perspective of Stakeholders

2021 ◽  
Vol 18 (19) ◽  
pp. 10510
Author(s):  
Tianwei Geng ◽  
Hai Chen ◽  
Di Liu ◽  
Qinqin Shi ◽  
Hang Zhang
Keyword(s):  
Ecosystem Service ◽  
Behavioral Responses ◽  
The Loess Plateau ◽  
Trade Offs ◽  
Different Types ◽  
Mediating Mechanisms ◽  
The Common ◽  
Food Provision ◽  
The Impact ◽  
The Relationship

Exploring and analyzing the common demands and behavioral responses of different stakeholders is important for revealing the mediating mechanisms of ecosystem service (ES) and realizing the management and sustainable supply of ES. This study took Mizhi County, a poverty-stricken area on the Loess Plateau in China, as an example. First, the main stakeholders, common demands, and behavioral responses in the food provision services were identified. Second, the relationship among stakeholders was analyzed. Finally, this study summarized three types of mediating mechanisms of food provision services and analyzed the influence of the different types of mediating mechanisms. The main conclusions are as follows: (1) Five main stakeholders in the study area were identified: government, farmers, enterprises, cooperatives, and middlemen. (2) Increasing farmers’ income is the common demand of most stakeholders in the study area, and this common demand has different effects on the behavioral responses of different stakeholders. (3) There are three types of mediating mechanisms in the study area: government + farmers mediating corn and mutton, government + enterprises mediating millet, and government + cooperatives mediating apples. On this basis, the effects of the different types of mediating mechanisms on variations in food yield, and trade-offs and synergies in typical townships, were analyzed.

scholarly journals Security-Efficiency Tradeoffs in Searchable Encryption

2019 ◽  
Vol 2019 (4) ◽  
pp. 132-151 ◽  
Author(s):  
Raphael Bost ◽  
Pierre-Alain Fouque
Keyword(s):  
Lower Bounds ◽  
Minimum Cost ◽  
Searchable Encryption ◽  
Search Queries ◽  
Trade Offs ◽  
Encryption Schemes ◽  
Security Properties ◽  
Client State ◽  
The Relationship

Abstract Besides their security, the efficiency of searchable encryption schemes is a major criteria when it comes to their adoption: in order to replace an unencrypted database by a more secure construction, it must scale to the systems which rely on it. Unfortunately, the relationship between the efficiency and the security of searchable encryption has not been widely studied, and the minimum cost of some crucial security properties is still unclear. In this paper, we present new lower bounds on the trade-offs between the size of the client state, the efficiency and the security for searchable encryption schemes. These lower bounds target two kinds of schemes: schemes hiding the repetition of search queries, and forward-private dynamic schemes, for which updates are oblivious. We also show that these lower bounds are tight, by either constructing schemes matching them, or by showing that even a small increase in the amount of leaked information allows for constructing schemes breaking the lower bounds.

scholarly journals Value-based provider payment: towards a theoretically preferred design

2018 ◽  
Vol 15 (1) ◽  
pp. 94-112 ◽  
Author(s):  
Daniëlle Cattel ◽  
Frank Eijkenaar ◽  
Frederik T. Schut
Keyword(s):  
Health Care ◽  
Pay For Performance ◽  
Empirical Studies ◽  
Risk Profile ◽  
Provider Group ◽  
Payment Incentives ◽  
Trade Offs ◽  
Provider Payment ◽  
Group 2 ◽  
The Relationship

AbstractWorldwide, policymakers and purchasers are exploring innovative provider payment strategies promoting value in health care, known as value-based payments (VBP). What is meant by ‘value’, however, is often unclear and the relationship between value and the payment design is not explicated. This paper aims at: (1) identifying value dimensions that are ideally stimulated by VBP and (2) constructing a framework of a theoretically preferred VBP design. Based on a synthesis of both theoretical and empirical studies on payment incentives, we conclude that VBP should consist of two components: a relatively large base payment that implicitly stimulates value and a relatively small payment that explicitly rewards measurable aspects of value (pay-for-performance). Being the largest component, the base payment design is essential, but often neglected when it comes to VBP reform. We explain that this base payment ideally (1) is paid to a multidisciplinary provider group (2) for a cohesive set of care activities for a predefined population, (3) is fixed, (4) is adjusted for the population’s risk profile and (5) includes risk-mitigating measures. Finally, some important trade-offs in the practical operationalisation of VBP are discussed.

scholarly journals Shift in ecological strategy helps marginal populations of shepherd's purse ( Capsella bursa-pastoris ) to overcome a high genetic load

2020 ◽  
Vol 287 (1927) ◽  
pp. 20200463 ◽  
Author(s):  
Marion Orsucci ◽  
Pascal Milesi ◽  
Johanna Hansen ◽  
Johanna Girodolle ◽  
Sylvain Glémin ◽  
...  
Keyword(s):  
Genetic Load ◽  
Fruit Production ◽  
Ecological Strategy ◽  
Phenotypic Characteristics ◽  
Invasive Ability ◽  
Marginal Populations ◽  
The Core ◽  
Trade Offs ◽  
Natural Range ◽  
The Relationship

The outcome of species range expansion depends on the interplay of demographic, environmental and genetic factors. Self-fertilizing species usually show a higher invasive ability than outcrossers but selfing and bottlenecks during colonization also lead to an increased genetic load. The relationship between genomic and phenotypic characteristics of expanding populations has, hitherto, rarely been tested experimentally. We analysed how accessions of the shepherd's purse, Capsella bursa-pastoris , from the colonization front or from the core of the natural range performed under increasing density of competitors. First, accessions from the front showed a lower fitness than those from the core. Second, for all accessions, competitor density impacted negatively both vegetative growth and fruit production. However, despite their higher genetic load and lower absolute performances, accessions from the front were less affected by competition than accessions from the core. This seems to be due to phenotypic trade-offs and a shift in phenology that allow accessions from the front to avoid competition.

scholarly journals Brain size is correlated with endangerment status in mammals

2016 ◽  
Vol 283 (1825) ◽  
pp. 20152772 ◽  
Author(s):  
Eric S. Abelson
Keyword(s):  
Brain Size ◽  
Extinction Risk ◽  
Small Body ◽  
Cost Benefit ◽  
Metabolic Cost ◽  
Trade Offs ◽  
Extant Species ◽  
Body Sizes ◽  
The Cost ◽  
The Relationship

Increases in relative encephalization (RE), brain size after controlling for body size, comes at a great metabolic cost and is correlated with a host of cognitive traits, from the ability to count objects to higher rates of innovation. Despite many studies examining the implications and trade-offs accompanying increased RE, the relationship between mammalian extinction risk and RE is unknown. I examine whether mammals with larger levels of RE are more or less likely to be at risk of endangerment than less-encephalized species. I find that extant species with large levels of encephalization are at greater risk of endangerment, with this effect being strongest in species with small body sizes. These results suggest that RE could be a valuable asset in estimating extinction vulnerability. Additionally, these findings suggest that the cost–benefit trade-off of RE is different in large-bodied species when compared with small-bodied species.

A Vibration-Assisted Separation Method for Constrained-Surface-Based Stereolithography

2020 ◽  
Vol 143 (5) ◽  
Author(s):  
Yang Xu ◽  
Yizhen Zhu ◽  
Yifeng Sun ◽  
Jie Jin ◽  
Yong Chen
Keyword(s):  
Underlying Mechanism ◽  
Separation Method ◽  
Prototype System ◽  
Separation Performance ◽  
Separation Mechanism ◽  
Bottom Up ◽  
Trade Offs ◽  
Separation Force ◽  
The Relationship ◽  
Force Data

Abstract For the bottom-up based stereolithography (SL) process, a separation process is required to detach the newly cured layer from the constrained surface in the fabrication process. Excessive separation force will cause damage to the built layers and the constrained surface. Different surface coatings, platform motions including tilting and sliding, and the utilization of oxygen-permeable films have been developed to address the separation-related problems. Among these approaches, the vibration-assisted (VA) separation method to reduce the separation force has limited study. The underlying mechanism of the VA separation-based method remains unexplored, and the best way to use VA separation in the bottom-up based SL process is still unclear. In this paper, a new VA separation design for the SL process is presented. A prototype system was built to study the VA separation mechanism. Experiments on the separation performance under different parameters, including vibration frequency, pre-stress level, and exposure area, were conducted. Based on the collected separation force data, an analytical model based on the mechanics of fatigue fracture was built. The separation behaviors related to different shape size and topology were also studied and compared. The results showed that the separation force in SL was significantly reduced using the VA separation-based method. Furthermore, the relationship between the separation force and the separation time conforms to the stress-based fatigue model. This study also provides insights on how to choose process parameters by considering the trade-offs between separation force and building efficiency.

scholarly journals Extrapair Fertilization in the Black-Browed Reed Warbler (Acrocephalus Bistrigiceps): Effects on Mating Status and Nesting Cycle of Cuckolded and Cuckolder Males

The Auk ◽  
2005 ◽  
Vol 122 (4) ◽  
pp. 1086-1096
Author(s):  
Shoji Hamao ◽  
Daichi S. Saito
Keyword(s):  
Incubation Period ◽  
Mate Guarding ◽  
Reed Warbler ◽  
Fertile Period ◽  
Mating Status ◽  
Trade Offs ◽  
Socially Monogamous ◽  
The Relationship ◽  
Extrapair Copulation

Abstract We studied the relationship between the occurrence of extrapair fertilizations (EPFs) and mating status and nesting cycle of mates, respectively, in a population of Black-browed Reed Warblers (Acrocephalus bistrigiceps). Overall, 6.4% (9 of 140) of the chicks were sired by extrapair males, and 13.5% (5 of 37) of the broods contained at least one extrapair chick. Socially polygynous males were cuckolded more frequently than socially monogamous males (40.0% and 3.7%, respectively). In three of four cases where cuckolded males were polygynous, the fertile periods of their mates overlapped. Except for two floating males that obtained EPFs, five out of seven cuckolder males were paired. Males succeeded in EPFs when the fertile period of the extrapair females largely overlapped the incubation period of their own mates. These findings are consistent with the hypothesis that there are trade-offs between extrapair copulation activity and both mate guarding and rearing of nestlings. Fertilisation Extraconjugale chez Acrocephalus bistrigiceps: Effets des Mâles Infidèles et Cocus sur le Statut de Couple et le Cycle de Nidification

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