1,721,397 research outputs found
I feel and think, therefore I am”: An Affect-Cognitive Theory of management decisions
Full text linkI propose an Affect-Cognitive Theory to comprehensively understand how decisions occur in organizations. To this aim, I first review the assumptions of sensemaking and decision-making streams of research, especially the influence of bounded rationality, affective states and their relationships with cognition; then, I integrate them on the common basis of socially situated cognition. This new theory emphasizes the role of affective states in determining/being determined by cognition and its errors, pointing out decision makers’ affect as the result of multi-level adaptations to the physical and social environment. Management decisions are path dependent but not immutable; they, indeed, bank on the predominant feeling resulting from the modifying interactions and regulations of decision makers with their physical and social environment. Here, decision makers are proposed as “emotional cognizers” overcoming the thinking-feeling dichotomy that has often featured in the study of management decisions. This theory is beneficial for behavioral strategy, offering the needed assumptions to intertwine human cognition, emotions, and social behavior
A new aceria species (Acari:Trombidiformes: Eriophyoidea) from west Asia, a potential biological control agent for the invasive weed camelthorn, alhagi maurorum medik. (Leguminosae)
No full textA new species of eriophyoid mite Aceria alhagi n. sp. inhabiting the weed Alhagi maurorum Medik., is described from the type locality in Iran, but it was also collected from Uzbekistan, Turkey and Armenia. This mite causes changes of the leaves and inflorescence. Infested plants develop cauliflower-like galls on the inflorescence and leaves deforming the reproductive structures and inhibiting seed production. The potential reduction in seed set suggests that this mite could constitute a potential biological control agent against this noxious weed. To investigate intraspecific variability between A. alhagi n. sp. populations from Iran, Turkey and Armenia, we analysed molecular sequences of the mitochondrial cytochrome oxidase subunit I (mtCOI). These results indicated that there are no significant intraspecific divergences among populations of A.alhagi n. sp. from the five different localities in three West Asia countries. This finding can be used in the future research of certain mite populations as biological control agent. © Vidović B. et al
The impact of the flower mite Aceria acroptiloni on the invasive plant Russian knapweed, Rhaponticum repens, in its native range
No full textRhaponticum repens (L.) Hidalgo is a clonal Asteraceae plant native to Asia and highly invasive in North America. We conducted open-field experiments in Iran to assess the impact of the biological control candidate, Aceria acroptiloni Shevchenko & Kovalev (Acari, Eriophyidae), on the target weed. Using three different experimental approaches, we found that mite attack reduced the biomass of R. repens shoots by 40-75 %. Except for the initial year of artificial infestation by A. acroptiloni of R. repens shoots, the number of seed heads was reduced by 60-80 % and the number of seeds by 95-98 %. Morphological investigations of the mite complex attacking R. repens at the experimental field site revealed that A. acroptiloni was by far the dominant mite species. We conclude that the mite A. acroptiloni is a promising biological control candidate inflicting significant impact on the above-ground biomass and reproductive output of the invasive plant R. repens. � 2014 International Organization for Biological Control (IOBC)
Insights into the microbes and nematodes hosted by pupae of the arundo leaf miner, lasioptera donacis (Diptera: Cecidomyiidae)
No full textSummary The leaf miner Lasioptera donacis Coutin (Diptera: Cecidomyiidae) is a biological control agent of the invasive weed, Arundo donax L. (Poaceae), that was approved for release in the U.S. and Mexico. Pupae are preferred for shipment of living material to quarantine facilities. There is a question of whether emerged females would carry conidia of a potential mutualist fungus, and in particular the saprophyte Arthrinium arundinis, from the pupa or if they would have to acquire the conidia exclusively from the plant to start the oviposition process. We artificially smeared leaf-sheaths of growing plants with A. arundinis before being exposed to female midges, and maintained these host plants until the pupal stage of the midge developed. Polymerase chain reaction methods were applied to detect A. arundinis and any other potential fungi in these pupae. Only 9% of the pupae were infested by fungi or yeast, predominantly belonging to the genus Sarocladium, but not A. arundinis, confirming that the newly emerged females are free of this fungus and will have to acquire conidia present on the leaf-sheath for successful oviposition. We also tentatively tested by PCR for the presence of parasitic nematodes in these pupae. More than 42% of the pupae were shown to be infested specifically by T. gyraloura. Such high infection rate calls for developing methods to eliminate this parasite or to find a parasitefree native population prior to release of L. donacis adults in North America for biological control of A. donax. © 2018 E-flow BioOne. All rights reserved
A framework for understanding heuristic shifts and adaptation
Full text linkHeuristic research has developed along three major traditions: heuristics-as-biases, fast-and-frugal tools, and simple rules. While each has contributed substantially, they remain theoretically fragmented, offering limited insight into how heuristics change over time, across contexts, or between levels of analysis. This conceptual article addresses that gap by introducing the Heuristic Spectrum—a novel framework that conceptualizes heuristics not as fixed types, but as positionally fluid cognitive logics. Heuristics are mapped across four core dimensions: cognitive effort, intentionality, domain specificity, and goal alignment. Shift from one logic to another is theorized not as a categorical transformation but as a movement along this spectrum, shaped by mechanisms such as feedback and performance monitoring, socialization and knowledge transfer, codification and institutionalization, and contextual pressures and scaling demands. This dynamic, multidimensional framework advances Simon’s vision of bounded rationality as adaptive behavior under constraint. By enabling comparisons, the framework bridges paradigmatic divides and offers practical tools for the design, evaluation, and evolution of heuristics in strategy, AI, and public policy
Cochliotoxin, a Dihydropyranopyran-4,5-dione, and Its Analogues Produced by Cochliobolus australiensis Display Phytotoxic Activity against Buffelgrass (Cenchrus ciliaris)
No full textBuffelgrass (Pennisetum ciliare or Cenchrus ciliaris) is a perennial grass that has become highly invasive in the Sonoran Desert of southern Arizona. In the search for novel control strategies against this weed, strains of the foliar fungal pathogen Cochliobolus australiensis from buffelgrass have been screened for their ability to produce phytotoxic metabolites that could potentially be used as natural herbicides in an integrated pest management strategy. A new phytotoxin, named cochliotoxin, was isolated from liquid culture of this fungus together with radicinin, radicinol, and their 3-epimers. Cochliotoxin was characterized, essentially by spectroscopic methods, as 3-hydroxy-2-methyl-7-(3-methyloxiranyl)-2,3-dihydropyrano[4,3-b]pyran-4,5-dione. Its relative stereochemistry was assigned by 1H NMR techniques, while the absolute configuration (2S,3S) was determined applying the advanced Mosher's method by esterification of its hydroxy group at C-3. When bioassayed in a buffelgrass coleoptile elongation test and by leaf puncture bioassay against the host weed and two nontarget grasses, cochliotoxin showed strong phytotoxicity. In the same tests, radicinin and 3-epi-radicinin also showed phytotoxic activity, while radicinol and 3-epi-radicinol were largely inactive. All five compounds were more active in leaf puncture bioassays on buffelgrass than on the nontarget grass tanglehead (Heteropogon contortus), while the nontarget grass Arizona cottontop (Digitaria californica) was more sensitive to radicinin and 3-epi-radicinin. Cochliotoxin at low concentration was significantly more active on buffelgrass than on either native grass, but the difference was small. © 2017 The American Chemical Society and American Society of Pharmacognosy
Genetic and morphological studies of Trichosirocalus species introduced to North America, Australia and New Zealand for the biological control of thistles
No full textTrichosirocalus horridus sensu lato has been used as a biological control agent of several invasive thistles (Carduus spp., Cirsium spp. and Onopordum spp.) since 1974. It has been recognized as a single species until 2002, when it was split into three species based on morphological characters: T. horridus, Trichosirocalus briesei and Trichosirocalus mortadelo, each purported to have different host plants. Because of this taxonomic change, uncertainty exists as to which species were released in various countries; furthermore, there appears to be some exceptions to the purported host plants of some of these species. To resolve these questions, we conducted an integrative taxonomic study of the T. horridus species complex using molecular genetic and morphological analyses of specimens from three continents. Both mitochondrial cytochrome c oxidase subunit I and nuclear elongation factor 1α markers clearly indicate that there are only two distinct species, T. horridus and T. briesei. Molecular evidence, morphological analysis and host plant associations support the synonymy of T. horridus (Panzer, 1801) and T. mortadelo Alonso-Zarazaga & Sánchez-Ruiz, 2002. We determine that T. horridus has been established in Canada, USA, New Zealand and Australia and that T. briesei is established in Australia. The former species was collected from Carduus, Cirsium and Onopordum spp. in the field, whereas the latter appears to be specific to Onopordum. Copyright © Cambridge University Press 2015
Eriophyid mite Aceria artemisiifoliae sp.nov. (Acari: Eriophyoidea) potential biological control agent of invasive common ragweed, Ambrosia artemisiifolia L. (Asteraceae) in Serbia
No full textCommon ragweed, Ambrosia artemisiifolia L. (Asterales: Asteraceae), is an annual harmful weed of North American origin, now widely distributed in Central and Southern Europe, Asia and Australia. It is an agricultural weed, but it represents a serious risk for human health because its pollen can cause severe allergies. Recently, in the framework of the EU-COST Action ‘SMARTER’, an European program was started with the aim to develop sustainable management strategies for ragweed in Europe, with a special emphasis in the search and selection of biological control agents. Among them, the record of a new eriophyid mite Aceria species in Serbia has been considered as potential important biological control candidate. This paper describes the species following both morphological and bio-molecular approaches, and is giving some preliminary data on the geographical distribution and on the biology of the eriophyid mite on its host plant. © Systematic & Applied Acarology Society
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