scholarly journals Cellulolytic Protist Numbers Rise and Fall Dramatically in Termite Queens and Kings during Colony Foundation

2013 ◽  
Vol 12 (4) ◽  
pp. 545-550 ◽  
Author(s):  
Keisuke Shimada ◽  
Nathan Lo ◽  
Osamu Kitade ◽  
Akane Wakui ◽  
Kiyoto Maekawa
Keyword(s):  
Nutrient Transfer ◽  
Reproductive Tissue ◽  
Colony Foundation ◽  
Dynamic Nature ◽  
Termite Species ◽  
Reticulitermes Speratus ◽  
Content Type ◽  
Trade Offs ◽  
Critical Phase ◽  
Incipient Colonies

ABSTRACTAmong the best-known examples of mutualistic symbioses is that between lower termites and the cellulolytic flagellate protists in their hindguts. Although the symbiosis in worker termites has attracted much attention, there have been only a few studies of protists in other castes. We have performed the first examination of protist population dynamics in queens and kings during termite colony foundation. Protist numbers, as well as measurements of hindgut and reproductive tissue sizes, were undertaken at five time points over 400 days in incipient colonies ofReticulitermes speratus, as well as in other castes of mature colonies of this species. We found that protist numbers increased dramatically in both queens and kings during the first 50 days of colony foundation but began to decrease by day 100, eventually disappearing by day 400. Hindgut width followed a pattern similar to that of protist numbers, while ovary and testis widths increased significantly only at day 400. Kings were found to contain higher numbers of protists than queens in incipient colonies, which may be linked to higher levels of nutrient transfer from kings to queens than vice versa, as is known in some other termite species. Protists were found to be abundant in soldiers from mature colonies but absent in neotenics. This probably reflects feeding of soldiers by workers via proctodeal trophallaxis and of reproductives via stomodeal trophallaxis. The results reveal the dynamic nature of protist numbers during colony foundation and highlight the trade-offs that exist between reproduction and parental care during this critical phase of the termite life cycle.

scholarly journals The lose-to-win strategy of the weak: intraspecific parasitism via egg abduction in a termite

2021 ◽  
Vol 17 (12) ◽  
Author(s):  
Chihiro Tamaki ◽  
Mamoru Takata ◽  
Kenji Matsuura
Keyword(s):  
Genomic Imprinting ◽  
Social Insects ◽  
Animal Species ◽  
Colony Foundation ◽  
Reticulitermes Speratus ◽  
Major Threat ◽  
Incipient Colonies ◽  
Intraspecific Parasitism

Predation by larger conspecifics poses a major threat to small juveniles in many animal species. However, in social insects, raids perpetrated by large colonies may provide smaller colonies with opportunities for parasitization. Herein, in the termite Reticulitermes speratus , we demonstrate that small incipient colonies parasitize large mature colonies through egg abduction when attacked by raiding conspecifics. We observed that the eggs of incipient colonies were brought into raiding colonies while their parents were killed during the attack. In this species, unmated females found new colonies with female–female (FF) cooperation, in addition to the typical monogamous colony foundation. Interestingly, the abducted eggs of FF pairs developed into nymphs (reproductive caste) in the raiding colonies, whereas the eggs of male–female (MF) pairs developed into workers (non-reproductive caste). Parthenogenetic eggs are known to be developmentally predisposed to becoming female reproductives owing to genomic imprinting in termites. This study demonstrates that the plundering of small colonies by larger conspecific colonies not only results in the extinction of the weaker colonies, but also serves as a strategy that incipient colonies use to obtain the reproductive position in large colonies by stealth. The results elucidate the diversity and complexity of inter-colonial interactions in social insects.

scholarly journals Identifying integrated options for agricultural climate change mitigation

2014 ◽  
Vol 6 (2) ◽  
pp. 192-211 ◽  
Author(s):  
John Tzilivakis ◽  
Kathleen Lewis ◽  
Andrew Green ◽  
Douglas Warner
Keyword(s):  
Climate Change ◽  
Climate Change Mitigation ◽  
Effective Means ◽  
Integrated Approach ◽  
Management Options ◽  
Content Type ◽  
Mitigation Options ◽  
Trade Offs ◽  
Environmental Objectives ◽  
Change Mitigation

Purpose – In order to achieve reductions in greenhouse gas (GHG) emissions, it is essential that all industry sectors have the appropriate knowledge and tools to contribute. This includes agriculture, which is considered to contribute about a third of emissions globally. This paper reports on one such tool: IMPACCT: Integrated Management oPtions for Agricultural Climate Change miTigation. The paper aims to discuss these issues. Design/methodology/approach – IMPACCT focuses on GHGs, carbon sequestration and associated mitigation options. However, it also attempts to include information on economic and other environmental impacts in order to provide a more holistic perspective. The model identifies mitigation options, likely economic impacts and any synergies and trade-offs with other environmental objectives. The model has been applied on 22 case study farms in seven Member States. Findings – The tool presents some useful concepts for developing carbon calculators in the future. It has highlighted that calculators need to evolve from simply calculating emissions to identifying cost-effective and integrated emissions reduction options. Practical implications – IMPACCT has potential to become an effective means of provided targeted guidance, as part of a broader knowledge transfer programme based on an integrated suite of guidance, tools and advice delivered via different media. Originality/value – IMPACCT is a new model that demonstrates how to take a more integrated approach to mitigating GHGs on farms across Europe. It is a holistic carbon calculator that presents mitigation options in the context other environmental and economic objectives in the search for more sustainable methods of food production.

Characteristics analysis of behavioural portfolio theory in the Markowitz portfolio theory framework

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Saksham Mittal ◽  
Sujoy Bhattacharya ◽  
Satrajit Mandal
Keyword(s):  
Emerging Markets ◽  
Asset Allocation ◽  
Portfolio Theory ◽  
Optimal Portfolio ◽  
Content Type ◽  
Major Index ◽  
Brics Countries ◽  
Trade Offs ◽  
Characteristics Analysis ◽  
Mean Variance

PurposeIn recent times, behavioural models for asset allocation have been getting more attention due to their probabilistic modelling for scenario consideration. Many investors are thinking about the trade-offs and benefits of using behavioural models over conventional mean-variance models. In this study, the authors compare asset allocations generated by the behavioural portfolio theory (BPT) developed by Shefrin and Statman (2000) against the Markowitz (1952) mean-variance theory (MVT).Design/methodology/approachThe data used have been culled from BRICS countries' major index constituents from 2009 to 2019. The authors consider a single period economy and generate future probable outcomes based on historical data in order to determine BPT optimal portfolios.FindingsThis study shows that a fair number of portfolios satisfy the first entry constraint of the BPT model. BPT optimal portfolio exhibits high risk and higher returns as compared to typical Markowitz optimal portfolio.Originality/valueThe BRICS countries' data were used because the dynamics of the emerging markets are significantly different from the developed markets, and many investors have been considering emerging markets as their new investment avenues.

Alternatives to solve SDG trade-offs and to enforce SDG synergies: a systematic literature review

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Andrei Boar ◽  
Erola Palau Pinyana ◽  
Marc Oliveras-Villanueva
Keyword(s):  
Sustainable Development ◽  
Developing Countries ◽  
Literature Review ◽  
Systematic Literature Review ◽  
Business Models ◽  
Economic Models ◽  
Clean Energy ◽  
Content Type ◽  
Trade Offs

PurposeThis paper takes a critical view of synergies and trade-offs and discloses the practices that countries and companies should apply to achieve sustainable development.Design/methodology/approachThis paper offers a systematic literature review of 408 papers to find models of sustainable development goals (SDGs) interaction with the aim of shedding light on the existing synergies and trade-offs and finding solutions to enhance these synergies and minimize the trade-offs.FindingsBoth rich and developing countries should follow multiple strategies to improve the quality of life of their citizens. Developing countries should focus on eradicating poverty. Rich countries should apply new economic models that are more likely to be environmental-friendly. Finally, the topic of SDGs should be revisited by the United Nations.Practical implicationsBoosting the quality of education and providing clean energy are two of the most relevant actions that should to be taken by countries, as they will accelerate the fulfilment of all the other SDGs. The use of circular economic models or new business models, such as the sharing economy, is essential to the achievement of sustained economic growth without negative environmental impact.Originality/valueThe paper analyzes SDG interactions and offers a critical vision of practices that countries and companies should adhere to for achieving sustainable development.

Research on risk management of medical and health care integration projects based on fuzzy WINGS-G1

Kybernetes ◽  
2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Yu Zhang ◽  
Lan Xu
Keyword(s):  
Risk Factors ◽  
Health Care ◽  
Risk Management ◽  
Fuzzy Theory ◽  
Dynamic Nature ◽  
Content Type ◽  
Care Integration ◽  
Rational Allocation ◽  
Control And Prevention ◽  
Risk Potential

PurposeThis study establishes a risk management system for medical and health care integration projects to address the problem of high-risk potential and a strong correlation between risk factors.Design/methodology/approachA new fuzzy WINGS-G1 model for identifying key risk factors in medical and health care integration projects is proposed by introducing the fuzzy theory and the concept of risk incidence into the Weighted Influence Non-linear Gauge System (WINGS) method.FindingsThe authors analyze the fluidity of project risk factors through complex networks to control direct risks and cut off risk transmission paths to provide a reference for risk control and prevention of medical and health care integration projects.Originality/value(1) The integration of fuzzy theory into the WINGS method solves the problem of strong subjectivity of expert scoring in the traditional WINGS method; (2) By the different probabilities of risk factors, the concept of risk incidence is introduced in the WINGS model, which is more conducive to the identification of the critical risk factors and the rational allocation and utilization of organizational resources; (3) The use of the complex network for risk interactivity analysis fully reflects the dynamic nature of risk factors in medical and health care integration projects.

Food quality vs food patriotism

2019 ◽  
Vol 121 (2) ◽  
pp. 371-385 ◽  
Author(s):  
Mirzobobo Yormirzoev ◽  
Ramona Teuber ◽  
Tongzhe Li
Keyword(s):  
Food Quality ◽  
Food Products ◽  
Russian Government ◽  
Content Type ◽  
Valuation Model ◽  
Trade Offs ◽  
Food Market ◽  
Imported Food ◽  
The Right ◽  
Domestic Food

Purpose The purpose of this paper is to investigate the role of perceived food quality and consumer ethnocentrism and potential trade-offs between these two concepts in Russian consumers’ food purchase decisions after the implementation of the Russian import ban. Design/methodology/approach Survey data were collected via in-person interviews in the City of Perm, which is one of the largest and most industrial cities in Russia. A double-bounded dichotomous-choice contingent valuation model is utilized to estimate willingness to pay (WTP) and to analyze factors that affect consumers’ choice. Findings The results suggest that most respondents do not consider domestically produced cheese as a risky product in terms of food safety but simply of lower quality than imported cheese. However, the average respondent’s WTP discount for domestic cheese compared to imported cheese is 8 percent, which is relatively small. This corresponds to participants’ opinion that buying domestic cheese is the right thing to do since it supports Russian farmers and producers. The results indicate further that with increasing education and income levels, individuals are less likely to prefer domestically produced cheese for either economic or quality reasons. This effect is stronger for the quality preference. Research limitations/implications The results indicate that if the Russian government aims at expanding the domestic food market further, more attention needs to be paid to ensuring the quality of domestic food products in order to increase consumer acceptance and WTP. Originality/value This is the first study providing empirical evidence on Russian consumers’ attitudes and perceptions of domestically vs imported food products after the implementation of the Russian import ban, which can be considered as an external policy shock.

scholarly journals Achieve a low carbon supply chain through product mix

2017 ◽  
Vol 117 (10) ◽  
pp. 2468-2484 ◽  
Author(s):  
Xu Chen ◽  
Xiaojun Wang
Keyword(s):  
Supply Chain ◽  
Trade Policy ◽  
Carbon Emissions ◽  
Channel Structure ◽  
Low Carbon ◽  
Cap And Trade ◽  
Product Mix ◽  
Content Type ◽  
Carbon Supply ◽  
Trade Offs

Purpose In the era of climate change, industrial organizations are under increasing pressure from consumers and regulators to reduce greenhouse gas emissions. The purpose of this paper is to examine the effectiveness of product mix as a strategy to deliver the low carbon supply chain under the cap-and-trade policy. Design/methodology/approach The authors incorporate the cap-and-trade policy into the green product mix decision models by using game-theoretic approach and compare these decisions in a decentralized model and a centralized model, respectively. The research explores potential behavioral changes under the cap-and-trade in the context of a two-echelon supply chain. Findings The analysis results show that the channel structure has significant impact on both economic and environmental performances. An integrated supply chain generates more profits. In contrast, a decentralized supply chain has lower carbon emissions. The cap-and-trade policy makes a different impact on the economic and environmental performances of the supply chain. Balancing the trade-offs is critical to ensure the long-term sustainability. Originality/value The research offers many interesting observations with respect to the effect of product mix strategy on operational decisions and the trade-offs between costs and carbon emissions under the cap-and-trade policy. The insights derived from the analysis not only help firms to make important operational and strategic decisions to reduce carbon emissions while maintaining their economic competitiveness, but also make meaningful contribution to governments’ policy making for carbon emissions control.

Attitudes and behaviour towards organic products: an exploratory study

2008 ◽  
Vol 36 (2) ◽  
pp. 158-175 ◽  
Author(s):  
Efthimia Tsakiridou ◽  
Christina Boutsouki ◽  
Yorgos Zotos ◽  
Kostantinos Mattas
Keyword(s):  
Organic Food ◽  
Food Products ◽  
Local Economy ◽  
Health Concern ◽  
Future Research ◽  
Consumer Decision Making ◽  
Content Type ◽  
Actual Behaviour ◽  
Trade Offs ◽  
Organic Products

PurposeThe aim of this paper is to identify consumers' attitudes and behaviour towards organic products in Greece.Design/methodology/approachThis paper draws on a non‐probability quota sample of 660 respondents to explore the attitudes and behaviour of Greek consumers towards organic food products.FindingsGreek consumers seem to be informed about environmental and health issues. They seek information about the nutritional value of food and demand more products free from chemical residues. The results show that most consumers associate organic consumption mainly with fruit and vegetables. Although demographics seem to affect attitudes towards organics, their value in explaining actual behaviour is minimal.Research limitations/implicationsIt is recognized that the data gathered in this study focus on the metropolitan area of Thessaloniki, Greece. The specific area though, is considered to be representative of the total Greek population. The results confirm that health, concern for the environment, animal welfare and support of the local economy are drivers of organic consumption. However, there is an indication that the importance of motives and barriers may vary for different product categories and perhaps future research should focus on product segmentation.Practical implicationsAlthough certain similarities in consumers' attitudes towards organic food products have been identified, this paper records the variation in behaviour towards organics among the various consumer groups examined in Greece, and highlights the gap between attitudes and actual behaviour. Given the complexity of consumer decision making, future research should explore the other value trade‐offs that consumers make.Originality/valueThis paper attempts to provide evidence on the relatively under researched area of organics attitudes and behaviour in Greece.

A new framework for time-cost trade-off considering float loss impact

2017 ◽  
Vol 22 (1) ◽  
pp. 20-36 ◽  
Author(s):  
Sameh Monir El-Sayegh ◽  
Rana Al-Haj
Keyword(s):  
Optimization Technique ◽  
Time Cost ◽  
Trade Off ◽  
Deterministic Optimization ◽  
Content Type ◽  
Project Duration ◽  
Trade Offs ◽  
Project Objectives ◽  
The Impact ◽  
New Framework

Purpose The purpose of this paper is to propose a new framework for time–cost trade-off. The new framework provides the optimum time–cost value taking into account the float loss impact. Design/methodology/approach The stochastic framework uses Monte Carlo Simulation to calculate the effect of float loss on risk. This is later translated into an added cost to the trade-off problem. Five examples, from literature, are solved using the proposed framework to test the applicability of the developed framework. Findings The results confirmed the research hypothesis that the new optimum solution will be at a higher duration and cost but at a lower risk compared to traditional methods. The probabilities of finishing the project on time using the developed framework in all five cases were better than those using the classical deterministic optimization technique. Originality/value The objective of time–cost trade-off is to determine the optimum project duration corresponding to the minimum total cost. Time–cost trade-off techniques result in reducing the available float for noncritical activities and thus increasing the schedule risks. Existing deterministic optimization technique does not consider the impact of the float loss within the noncritical activities when the project duration is being crashed. The new framework allows project managers to exercise new trade-offs between time, cost and risk which will ultimately improve the chances of achieving project objectives.

A systematic review of the literature on supply chain agility

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Bharat Singh Patel ◽  
Murali Sambasivan
Keyword(s):  
Supply Chain ◽  
Cost Benefit ◽  
Business Environment ◽  
Future Research ◽  
Research Directions ◽  
Content Type ◽  
Trade Offs ◽  
Supply Chain Agility ◽  
Agility Assessment ◽  
Future Research Directions

Purpose The purpose of this study is to critically examine the scholarly articles associated Murali Sambasivan with the diverse aspects of supply chain agility (SCA). The review highlights research insights, existing gaps and future research directions that can help academicians and practitioners gain a comprehensive understanding of SCA. Design/methodology/approach The present study has adopted author co-citation analysis as the research methodology, with a view to thoroughly investigating the good-quality articles related to SCA that have been published over a period of 22 years (1999-2020). In this study, 126 research papers on SCA – featuring diverse aspects of agility – from various reputed journals have been examined, analysed and assimilated. Findings The salient findings of this research are, namely, agility is different from other similar concepts, such as flexibility, leanness, adaptability and resilience; of the 13 dimensions of agility discussed in the literature, the prominent ones are quickness, responsiveness, competency and flexibility; literature related to SCA can be categorised as related to modelling the enablers, agility assessment, agility implementation, leagility and agility maximisation. This research proposes a more practical definition and framework for SCA. The probable areas for future research are, namely, impediments to agility, effective approaches to agility assessment, cost-benefit trade-offs to be considered whilst implementing agility, empirical research to validate the framework and SCA in the domain of healthcare and disaster relief supply chains. Practical implications This paper provides substantial insights to practitioners who primarily focus on measuring and implementing agility in the supply chain. The findings of this study will help the supply chain manager gain a better idea about how to become competitive in today’s dynamic and turbulent business environment. Originality/value The originality of this study is in: comprehensively identifying the various issues related to SCA, such as related concepts, definitions, dimensions and different categories of studies covered in literature, proposing a new definition and framework for SCA and identifying potential areas for future research, to provide deeper insights into the subject and highlight areas for future research.

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