scholarly journals Biological Control ofSolenopsisFire Ants byPseudacteonParasitoids: Theory and Practice

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Lloyd W. Morrison
Keyword(s):  
Biological Control ◽  
Population Regulation ◽  
Field Experiments ◽  
Competitive Exclusion ◽  
Theory And Practice ◽  
Fire Ants ◽  
Relative Importance ◽  
Top Down ◽  
Host System ◽  
Research Findings

Pseudacteonparasitoids are potential biocontrol agents of invasiveSolenopsisfire ants.Pseudacteonspecies that parasitize the invasiveS. invictaBuren andS. richteriForel have been introduced to, and naturally dispersed across, the southeastern USA, although there is no evidence yet thatSolenopsishost ant populations have decreased. The ability of introducedPseudacteonspecies to regulateSolenopsispopulations will depend upon the relative importance of top-down effects in the recipient communities. In this paper, I examine the characteristics of thePseudacteon/Solenopsisparasitoid/host system and evaluate the extent to which research findings are consistent with top-down control. Laboratory and field experiments evaluatingSolenopsispopulation regulation have been equivocal, and overall the available evidence provides little support for strong top-down effects in this system. Competitive exclusion may occur among introducedPseudacteonspecies, and future efforts at biological control are likely to be more efficacious if they focus on other types of natural enemies.

scholarly journals Ecosystem engineering strengthens bottom-up and weakens top-down effects via trait-mediated indirect interactions

2017 ◽  
Vol 284 (1863) ◽  
pp. 20170894 ◽  
Author(s):  
Zhiwei Zhong ◽  
Xiaofei Li ◽  
Dean Pearson ◽  
Deli Wang ◽  
Dirk Sanders ◽  
...  
Keyword(s):  
Trophic Interactions ◽  
Large Scale ◽  
Field Experiments ◽  
Ecosystem Engineering ◽  
Relative Importance ◽  
Top Down ◽  
Bottom Up ◽  
Spatial And Temporal Scales ◽  
Natural Systems ◽  
Ecological Scale

Trophic interactions and ecosystem engineering are ubiquitous and powerful forces structuring ecosystems, yet how these processes interact to shape natural systems is poorly understood. Moreover, trophic effects can be driven by both density- and trait-mediated interactions. Microcosm studies demonstrate that trait-mediated interactions may be as strong as density-mediated interactions, but the relative importance of these pathways at natural spatial and temporal scales is underexplored. Here, we integrate large-scale field experiments and microcosms to examine the effects of ecosystem engineering on trophic interactions while also exploring how ecological scale influences density- and trait-mediated interaction pathways. We demonstrate that (i) ecosystem engineering can shift the balance between top-down and bottom-up interactions, (ii) such effects can be driven by cryptic trait-mediated interactions, and (iii) the relative importance of density- versus trait-mediated interaction pathways can be scale dependent. Our findings reveal the complex interplay between ecosystem engineering, trophic interactions, and ecological scale in structuring natural systems.

Over De Functionaliteit Van Conversatie-Analyse

1992 ◽  
Vol 42 ◽  
pp. 102-114
Author(s):  
Ton van der Geest
Keyword(s):  
Conversation Analysis ◽  
Human Mind ◽  
Theory And Practice ◽  
Theoretical Development ◽  
Conversational Analysis ◽  
Top Down ◽  
Bottom Up ◽  
Cognitive Principles ◽  
Research Findings ◽  
Working Method

In this article conversational analysis is criticised as to theory and practice. In terms of internal criticism it is argued that 1. there is a lack of theoretical starting points which makes observation less fruitful than possible; 2. the anti-structural attitude, however understandable, is counter-productive as to theoretical development; 3. the conversational analytic working method can be characterised as bottom-up in contrast to the cognitive principles of human mind that is organised top down to a large extent. This bottom-up approach denies the actual differences occurring in the mental activities of both participants and analyst. It, furthermore, neglects the proper questions of research as to how all kinds of information that the conversationalist has to his disposition and may put to usage when communicating, is organised mentally. Therefore, the discussion on rules, strategies, principles, etc. does not take place systematically in conversation analysis; 4. the inductive standpoint and approach of conversation analysis prohibits the formulation of generalizations. Furthermore, there is no methodology available to deal with deductive aspects of investigation; 5. the above discussed characteristics of conversational analysis lead to serious method-ological problems for the investigation of the human discourse capacity. As far as the external criticism of conversational analysis is concerned, it must be maintained, that conversational analysis isolates itself from other neighbouring disciplines, in such a way that it can but does not profit of related research findings of connected disciplines. Finally it is argued that conversation analysis is hardly interested in (or even ignores) the problem of application of research findings in every day practice.

INOVASI FONOLOGIS DENASALISASI DALAM ISOLEK BONAI ULAKPATIAN

2017 ◽  
Vol 6 (2) ◽  
pp. 235
Author(s):  
Yanti Riswara
Keyword(s):  
Historical Linguistic ◽  
Language Variation ◽  
Final Position ◽  
Process Data ◽  
Top Down ◽  
Linguistic Study ◽  
Oral Speech ◽  
Research Findings

The paper is aimed at describing a language variation, that is Ulakpatian Bonai isolect  in Riau Province. This is a kind of historical linguistic study which  is objected to describe a phonological inovation process of denasalisation among nasal phonemes at final positions or at close ultimate sillables in an isolect used by Bonai tribe in Ulakpatian, Rokan Hulu District,  Riau  Province.  Analysis  of  inavation is based on protomalayic (PM)  which  is reconstructed by Adelaar.The research applicates  top-down method of anaysis which are gaining  the  results by deductive process. Data of  this  research are oral  speech of Bonai people  based  on  200  Swadesh  words.  The  data  are  gathered  by  conversational  and listening  methods  which  applied  several  techniques.  The  results  of  the  analysis  are presented by formal and informal methods. The research findings reveal that the language of the tribe shows three kinds of denasalisation of phonological innovation at final position which  have  changed  the  nasal  phonemes  of  *PM  to  unnasal  ones  in  isolek  Bonai Ulakpatian: (*PM > BU) , i.e. 1) PM *n/-# > []/-#, 2) PM *m/-# > [p]/-#, dan 3) PM * /-# > [g]/-#.Abstrak  Makalah ini bertujuan untuk mendeskripsikan sebuah variasi bahasa, yaitu isolek Bonai Ulakpatian yang terdapat di Provinsi Riau. Kajian ini merupakan kajian linguistik historis yang memaparkan proses inovasi fonologis denasalisasi yang terjadi pada fonem-fonem nasal yang berada pada posisi akhir atau silabe ultima tertutup dalam sebuah isolek yang digunakan oleh suku Bonai di Desa Ulakpatian, Kabupaten Rokan Hulu. Analisis inovasi fonologis tersebut didasarkan pada protomalayik (PM) yang direkonstruksi oleh Adelaar. Kajian ini menerapkan mentode analisis top-down yang bersifat deduktif. Data penelitian merupakan data tuturan masyarakat suku Bonai yang mengacu pada 200 kosakata dasar yang dijadikan rujukan dalam penjaringan data kebahasaan. Data dikumpulkan dengan penerapan metode cakap dan metode simak dengan menggunakan teknik pancing dan teknik rekam. Data dideskripsikan secara fonetis dengan simbol IPA. Hasil penelitian disajikan dengan metode formal dan informal. Hasil penelitian menunjukkan bahwa isolek Bonai Ulakpatian memiliki tiga bentuk inovasi fonologis denasalisasi pada posisi akhir beberapa fonem nasal *PM menjadi taknasal pada isolek BU (*PM > BU) , yaitu 1) PM *n/-# > []/-#, 2) PM *m/-# > [p]/-#, dan 3) PM * /-# > [g]/-#.

Islamic Banking and Finance in Theory and Practice

2005 ◽  
Vol 22 (2) ◽  
pp. 69-86 ◽  
Author(s):  
Abdus Samad ◽  
Norman D. Gardner ◽  
Bradley J. Cook
Keyword(s):  
Financial System ◽  
Primary Objective ◽  
Theory And Practice ◽  
Islamic Banking ◽  
Relative Importance ◽  
Islamic Banks ◽  
Equity Financing ◽  
Banking And Finance ◽  
Financial Products ◽  
Islamic Bank

This paper’s primary objective is to identify the relative importance of various Islamic financial products, in theory and in practice, by examining the financing records of the Bank Islam Malaysia (Berhad) and the Bahrain Islamic Bank. Currently, seven available Islamic financing products are considered viable alternatives to interest-based conventional contracts: mudarabah (trust financing), musharakah (equity financing), ijarah (lease financing), murabahah (trade financing), qard al-hassan (welfare loan), bay` bi al-thaman al-ajil (deferred payment financing), and istisna` (progressive payments). Among these financial products, mudarabah and musharakah are the most distinct. Their unique characteristics (at least in theory) make Islamic banks and Islamic financing viable alternatives to the conventional interest-based financial system. The question before us is to determine the extent of mudarabah and musharakah in Islamic financing in practice. The data are as follows: the average mudarabah is 5% of total financing, and the average musharakah is less than 3%. The combined average of mudarabah and musharakah for the two Islamic banks is less than 4% of the total finance and advances. The average qard al- hassan is about 4%, while istisna` does not yet exist in practice. Murabahah is the most popular and dominates all other modes of Islamic financing. The average use of murabahah is over 54%. When the bay` bi al-thaman al-ajil is added to the murabahah, the percentage of total financing is shown to be 2.68%. This paper also explores some possible reasons why these two Islamic banks appear to prefer murabahah to mudarabah and musharakah.

Journey towards best practices in acting on early warning signs in complex projects within a Russian context

2015 ◽  
Vol 8 (4) ◽  
pp. 828-843 ◽  
Author(s):  
Gulnara Sharaborova ◽  
Derek H.T. Walker ◽  
Guinevere Gilbert
Keyword(s):  
Early Warning ◽  
Point Of View ◽  
Warning Signs ◽  
Theory And Practice ◽  
Doctoral Study ◽  
Content Type ◽  
Early Warning Signs ◽  
Complex Projects ◽  
Research Findings ◽  
Phd Thesis

Purpose – The purpose of this paper is to provide a summary report and reflect on a recently passed PhD thesis (Sharaborova, 2014b) related to project management topics. Design/methodology/approach – This paper focussed on narrative reflection upon the completed doctoral journey. Findings – This paper presents the thesis findings, the research models, the guide in dealing with the early warning signs that developed as a result of this research and the contribution made to theory and practice. Research limitations/implications – Limitations of the research and the perspectives of the further diffusion of the research findings are considered. Originality/value – This TRN is a PhD candidate’s point of view as well as the opinions of the scientific research supervisors about the doctoral study and its outcome. The paper could be useful for novice researchers who wish to conduct their research and did not yet make a decision.

scholarly journals Biological Control and Mitigation of Aflatoxin Contamination in Commodities

Toxins ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 104
Author(s):  
Ferenc Peles ◽  
Péter Sipos ◽  
Szilvia Kovács ◽  
Zoltán Győri ◽  
István Pócsi ◽  
...  
Keyword(s):  
Biological Control ◽  
Secondary Metabolites ◽  
Competitive Exclusion ◽  
Aflatoxin Contamination ◽  
Post Harvest ◽  
Physical Chemical ◽  
Synthetic Chemicals ◽  
Ruminal Degradation

Aflatoxins (AFs) are toxic secondary metabolites produced mostly by Aspergillus species. AF contamination entering the feed and food chain has been a crucial long-term issue for veterinarians, medicals, agroindustry experts, and researchers working in this field. Although different (physical, chemical, and biological) technologies have been developed, tested, and employed to mitigate the detrimental effects of mycotoxins, including AFs, universal methods are still not available to reduce AF levels in feed and food in the last decades. Possible biological control by bacteria, yeasts, and fungi, their excretes, the role of the ruminal degradation, pre-harvest biocontrol by competitive exclusion or biofungicides, and post-harvest technologies and practices based on biological agents currently used to alleviate the toxic effects of AFs are collected in this review. Pre-harvest biocontrol technologies can give us the greatest opportunity to reduce AF production on the spot. Together with post-harvest applications of bacteria or fungal cultures, these technologies can help us strictly reduce AF contamination without synthetic chemicals.

scholarly journals Biological Control of Imported Fire Ants (Hymenoptera: Formicidae)

2003 ◽  
Vol 49 (3) ◽  
pp. 150-163 ◽  
Author(s):  
David F. Williams ◽  
David H. Oi ◽  
Sanford D. Porter ◽  
Roberto M. Pereira ◽  
Juan A. Briano
Keyword(s):  
Biological Control ◽  
Fire Ants ◽  
Imported Fire Ants

Biological Control of Ducksalad (Heteranthera limosa) by the Waterlily Aphid (Rhopalosiphum nymphaeae) in Rice (Oryza sativa)

Weed Science ◽  
1992 ◽  
Vol 40 (2) ◽  
pp. 333-336 ◽  
Author(s):  
Michael J. Oraze ◽  
Albert A. Grigarick
Keyword(s):  
Biological Control ◽  
Oryza Sativa ◽  
Field Experiments ◽  
Weed Biomass ◽  
Water Vegetation

Ducksalad, an annual broadleaf weed in rice, was infested by waterlily aphid which destroyed much of the above-water vegetation. Field experiments showed aphids reduced total weed biomass by 58 and 87% in 1985 and 1986, respectively. Biomass of seed pods was reduced by more than 82% in both years.

Crossing the sea from They to We? The unfolding of knowing and practising in collaborative research

2012 ◽  
Vol 43 (4) ◽  
pp. 443-459 ◽  
Author(s):  
Javier Marcos ◽  
David Denyer
Keyword(s):  
Competitive Advantage ◽  
Collaborative Research ◽  
Knowledge Integration ◽  
Theory And Practice ◽  
Theoretical Development ◽  
Management Research ◽  
Ongoing Debate ◽  
Business Services ◽  
Institutional Pressure ◽  
Research Findings

This article addresses how knowing and practising unfolds in collaborative research amongst practitioners from a large consulting and business services group and academics from a UK School of Management. Dialogue enabled actors to cross between theory and practice by providing a ‘space’ for support, challenge, exchange and experimentation. However, this ‘space’ was fragile and the insensitive actions of one individual, driven by institutional pressure to exploit the project for competitive advantage, resulted in withdrawal and the re-establishment of traditional divisions. Our view is that collaborative research is not necessarily an exercise in producing, transferring and implementing research findings but is better thought of as knowledge integration through a dialogue of theory and practice. The article contributes to the ongoing debate about the relevance of management research and the theoretical development of knowledge co-production.

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