Towards a resolution of ‘the paradox of the plankton’: a brief overview of the proposed mechanisms

In plankton ecology, it is a fundamental question as to how a large number of competing phytoplankton species coexist in marine ecosystems under a seemingly-limited variety of resources. This ever-green question was first proposed by Hutchinson [Hutchinson, G.E., 1961. The paradox of the plankton. Am. Nat. 95, 137–145] as ‘the paradox of the plankton’. Starting from Hutchinson [Hutchinson, G.E., 1961. The paradox of the plankton. Am. Nat. 95, 137–145], over more than four decades several investigators have put forward varieties of mechanisms for the extreme diversity of phytoplankton species. In this article, within the boundary of our knowledge, we review the literature of the proposed solutions and give a brief overview of the mechanisms proposed so far. The proposed mechanisms that we discuss mainly include spatial and temporal heterogeneity in physical and biological environment, externally imposed or self-generated spatial segregation, horizontal mesoscale turbulence of ocean characterized by coherent vortices, oscillation and chaos generated by several internal and external causes, stable coexistence and compensatory dynamics under fluctuating temperature in resource competition, and finally the role of toxin-producing phytoplankton in maintaining the coexistence and biodiversity of the overall plankton population that we have proposed recently. We find that, although the different mechanisms proposed so far is potentially applicable to specific ecosystems, a universally accepted theory for explaining plankton diversity in natural waters is still an unachieved goal.

The stability of ecosystems: a brief overview of the paradox of enrichment

In theory, enrichment of resource in a predator-prey model leads to destabilization of the system, thereby collapsing the trophic interaction, a phenomenon referred to as "the paradox of enrichment". After it was first proposed by Rosenzweig (1971), a number of subsequent studies were carried out on this dilemma over many decades. In this article, we review these theoretical and experimental works and give a brief overview of the proposed solutions to the paradox. The mechanisms that have been discussed are modifications of simple predator-prey models in the presence of prey that is inedible, invulnerable, unpalatable and toxic. Another class of mechanisms includes an incorporation of a ratio-dependent functional form, inducible defence of prey and density-dependent mortality of the predator. Moreover, we find a third set of explanations based on complex population dynamics including chaos in space and time. We conclude that, although any one of the various mechanisms proposed so far might potentially prevent destabilization of the predator-prey dynamics following enrichment, in nature different mechanisms may combine to cause stability, even when a system is enriched. The exact mechanisms, which may differ among systems, need to be disentangled through extensive field studies and laboratory experiments coupled with realistic theoretical models.

Organisational politics: reconciling leadership's rational-emotional paradox

Purpose – Effective leadership action requires managers to harness power that is intrinsically political. This paper aims to study and characterise the political nature of a manager's behaviour when taking leadership action. Design/methodology/approach – The methodological approach is qualitative and examines three organisations over a three-year period when these entities experienced a major product failure. The paper analyses the actual managerial behaviour of managers and provides insight into the factors that most strongly influence the effectiveness of managers when taking leadership action. Findings – Political behaviour when taking leadership action can be conceptualised in terms of rationality and emotionality. In so doing, it can be clarified how behaviour must be modified to ensure that leadership action is consistently effective. Research limitations/implications – A case study of three multinational engineering companies engaged in the design, development and manufacturing of turbomachinery provides the platform for the research. The concepts presented in the paper will require validating in other organisations of different demographic profiles. Practical implications – The concepts presented and the implications discussed provide insight into the political nature of managerial behaviour when taking leadership action. The paper highlights the practical steps individual managers can embrace to ensure that their behaviour is appropriate to context, even under the most traumatic situations. Thus, the paper provides managers with a model that facilitates effective leadership action. Originality/value – This paper provides insight into how managers behaved in circumstances that mattered to them. Through immersion in events at the time they took place, the authors captured situations in which managers were under real pressure and, in so doing, avoided the bias inherent when interviewing a manager about past events. As such, the paper concludes that the political behaviour in which managers engage when taking leadership action is rooted in the reality of the adversity that the most capable managers have both experienced and overcome. This detailed study reports behaviour in a situation where managers' business and future prospects were in jeopardy. This paper identifies why some managers were able to use the experience positively, helping them to adopt politically intrinsic behaviour to facilitate effective leadership action.

The intelligence paradox; will ET get the metabolic syndrome? Lessons from and for Earth

Mankind is facing an unprecedented health challenge in the current pandemic of obesity and diabetes. We propose that this is the inevitable (and predictable) consequence of the evolution of intelligence, which itself could be an expression of life being an information system driven by entropy. Because of its ability to make life more adaptable and robust, intelligence evolved as an efficient adaptive response to the stresses arising from an ever-changing environment. These adaptive responses are encapsulated by the epiphenomena of “hormesis”, a phenomenon we believe to be central to the evolution of intelligence and essential for the maintenance of optimal physiological function and health. Thus, as intelligence evolved, it would eventually reach a cognitive level with the ability to control its environment through technology and have the ability remove all stressors. In effect, it would act to remove the very hormetic factors that had driven its evolution. Mankind may have reached this point, creating an environmental utopia that has reduced the very stimuli necessary for optimal health and the evolution of intelligence – “the intelligence paradox”. One of the hallmarks of this paradox is of course the rising incidence in obesity, diabetes and the metabolic syndrome. This leads to the conclusion that wherever life evolves, here on earth or in another part of the galaxy, the “intelligence paradox’” would be the inevitable side-effect of the evolution of intelligence. ET may not need to just “phone home” but may also need to “phone the local gym”. This suggests another possible reason to explain Fermi’s paradox; Enrico Fermi, the famous physicist, suggested in the 1950s that if extra-terrestrial intelligence was so prevalent, which was a common belief at the time, then where was it? Our suggestion is that if advanced life has got going elsewhere in our galaxy, it can’t afford to explore the galaxy because it has to pay its healthcare costs.

Beyond the environmentalist's paradox and the debate on weak versus strong sustainability

Environmentalists generally argue that ecological damage will (eventually) lead to declines in human well-being. From this perspective, the recent introduction of the “environmentalist’s paradox” in BioScience by Raudsepp-Hearne and colleagues (2010) is particularly significant. In essence, Raudsepp-Hearne and colleagues (2010) claimed that although ecosystem services have been degraded, human well-being—paradoxically—has increased. In this article, we show that this debate is in fact rooted in a broader discussion on weak sustainability versus strong sustainability(the substitutability of human-made capital for natural capital). We warn against the reductive nature of focusing only on a stock–flow framework in which a natural-capital stock produces ecosystem services. Concretely, we recommend a holistic approach in which the complexity, irreversibility, uncertainty, and ethical predicaments intrinsic to the natural environment and its connections to humanity are also considered.

The paradox of culture in a globalized world

Much of the work in intercultural communication studies in the past decade, especially in the field of applied linguistics, has been devoted to ‘disinventing’ the notion of culture. The problem with the word ‘culture’ as it has been used in anthropology, sociology, and in everyday life, it has been pointed out, is that it is used as a noun, conceived of as something ‘solid,’ an essential set of traits or characteristics of certain people or groups, something people ‘have’ rather than something they ‘do’ (Scollon, Scollon, & Jones, 2012). Among the most famous statements of this position is Brain Street’s classic paper ‘Culture is a Verb’ (1993), in which he argues that culture should be treated as ‘a signifying process the active construction of meaning rather than the static and reified or nominalizing’ sense in which the word is often used in anthropology, some linguistics circles, and in everyday conversation.

Generation of nonground-state condensates and adiabatic paradox

The problem of resonant generation of nonground-state condensates is addressed aiming at resolving the seeming paradox that arises when one resorts to the adiabatic representation. In this picture, the eigenvalues and eigenfunctions of a time-dependent Gross-Pitaevskii Hamiltonian are also functions of time. Since the level energies vary in time, no definite transition frequency can be introduced. Hence no external modulation with a fixed frequency can be made resonant. Thus, the resonant generation of adiabatic coherent modes is impossible. However, this paradox occurs only in the frame of the adiabatic picture. It is shown that no paradox exists in the properly formulated diabatic representation. The resonant generation of diabatic coherent modes is a well defined phenomenon. As an example, the equations are derived, describing the generation of diabatic coherent modes by the combined resonant modulation of the trapping potential and atomic scattering length.

The connectivity paradox: Students’ use of technology as both help and hindrance, and the challenge of striking a balance.

While there is research supporting the use of technology in classrooms, there is also evidence that technology often disrupts student learning. Examples of technology use in classrooms by both teachers and students will be explored, including the benefits and risks of each to the learning process. Research findings on cognition, attention, and classroom technologies will inform strategies for best practices for classroom technology use.

Sex pedagogers uppfattningar om och hur de använder lek för barnens lärande och utveckling

De flesta lekforskare är eniga om att barn lär sig när de leker och att lek har betydelse för barns utveckling. Syftet med denna undersökning var att studera vilka uppfattningar pedagoger har om lek och hur de använder lek för barns lärande i undervisningen i sina tre förskoleklasser. I studien intervjuades sex pedagoger, två barnskötare, två förskollärare och två fritidspedagoger. Resultatet visade att pedagogerna uppfattar lek som viktig för barnens lärande och utveckling och att den använder sig av både fria och styrda lekar i undervisningen.

Lek, lärande och utveckling : Sex pedagogers syn på lekens betydelse för förskolebarns utveckling och lärande

Syftet med studien är att undersöka hur pedagoger använder sig av leken i sin verksamhet och vad de har för syn på lekens betydelse för förskolebarns lärande och utveckling. Studien bygger på litteratur om tidigare forskning kring lek samt kvalitativa intervjuer med sex pedagoger verksamma inom förskola och förskoleklass. Resultatet av vår studie visar att både pedagogerna och de forskare vi tagit del av anser att leken är en viktig bit av barns lärande och utveckling. Pedagogerna lyfter fram leken som barnens arbetsredskap och poängterar hur viktigt det är att skapa goda förutsättningar för lek. De använder leken på ett medvetet sätt i sin verksamhet och är eniga om att begreppen lek, lärande och utveckling är sammanhängande och inte går att skilja åt. Studien visar att leken mestadels ses som god och befrämjande men också att leken har en baksida som enligt pedagogerna kan innehålla inslag av maktutövande och förtryck.

Varför är barns lek viktig? : en studie om fem pedagogers uppfattningar om lekens betydelse i förskolan

Denna studie handlar om pedagogers uppfattningar om barns lek och lärande. I litteraturen har vi funnit att de flesta lekforskare är eniga om att lek är viktig för barns utveckling och lärande. Syftet med studien var att beskriva om, och i så fall hur, pedagoger säger sig använda lek för barns lärande. Studien har utförts i en förskola där vi har intervjuat fem pedagoger, fyra lärare i förskolan (förskollärare) och en barnskötare. Resultatet visade att pedagogerna uppfattar lek som viktig och att de använder sig av olika lekformer för att stimulera barns lärande. De ser sig egen närvaro som viktig i barns lek. Pedagogerna är överens om att miljön inverkar på barnen och att den har betydelse för deras lek. De framhåller att de använder sig av dokumentation för att synliggöra barns lärande.

Den pedagogiska innemiljöns betydelse : Hur påverkar den pedagogiska innemiljön barnens lek och skapande

Syftet med undersökningen är att på en förskola utforska de olika avdelningarnas pedagogiska innemiljö. Hur planerar pedagogerna den pedagogiska innemiljön och vilka konsekvenser får detta för barnens lek och skapande. För att ta reda på detta genomfördes intervjuer med pedagogerna, observationer av barnens lek och beskrivning med hjälp av kort på avdelningarnas olika rum.Resultatet visar att pedagogerna anser att barnens intressen och behov styr hur de planerar den pedagogiska innemiljön. Genom observationer av barnens lek och samtal med barnen tar pedagogerna reda på detta. Eftersom många saker finns utom barnens räckhåll och de inte får använda alla material hur de vill begränsas deras skapande och lek. Den ekonomiska aspekten påverkar också den pedagogiska innemiljön på ett negativt sätt enligt pedagogerna. Men tre av pedagogerna menade att det fanns positiva saker med det också. De var tvungna att använda sin fantasi och kreativitet och ta tillvara på det som fanns i närmiljön. Pedagogernas kännedom om de olika pedagogiska teorierna var liten. Det var bara tre av pedagogerna som direkt kände till några av dem. Ingen av avdelningarna följde någon speciell teori men två pedagoger på en avdelning ansåg att de inspirerades av Reggio Emilia.

Den pedagogiska innemiljöns påverkan på barns fria lek : Ur ett pedagogperspektiv

Syftet med arbetet var att undersöka hur två pedagoger och två rektorer som arbetar på två olika kommunala förskolor ser på innemiljön och dess påverkan på lek. Det innefattar vilket material som används och hur de har utformat miljön. Vi har använt oss av kvalitativa intervjuer och ostrukturerade observationer för att samla in materialet. Resultat av undersökningen visade att båda förskolorna arbetar aktivt med miljön men att den ena förskolan precis har börjat med sitt arbete. Båda förskolorna arbetade efter samma vision, att ha en miljö som är tillgänglig för bar-nen där materialet är synligt och på barnens nivå. Det är något som också tas upp som viktigt i litteratur och forskning. Faktorer som visade sig ha betydelse för utformingen av miljön var eko-nomi, tid, personalens inställning och barnens ålder.

Lek och empowerment : de alternativa rummens roll i sociala rörelser

Play and empowerment: the role of alternative spaces in social movements The article examines the role played by alternative space in social movements and argues that it plays a crucial role in counter-acting feelings of powerlessness and facilitating the empowerment of subaltern groups. Alternative space is defined – using Benjamin’s notions ofshock, nature and history – as constituted by forms of interaction in which society is made to appear as history. To facilitate empowerment, alternative space must, firstly, provide a place for subaltern groups in which they are no longer subordinated; secondly, instill hope that social change is possible and encourage such change; and, thirdly, expand or consolidate alternative space itself. These tasks can easily enter into conflict with each other, since they sometimes appear to require alternative space to adopt more ”abstract” forms of interaction in which aspects of the social situation are bracketed and sometimes more ”concrete”ones in which such aspects are again given attention. In order to study how movements may relate to this difficulty, the article looks at three contemporary Japanese social movements with NAM, New Start / New Start Kansai and the General Freeter Union as central organizations. Only the third successfully combines the three tasks, in large measure through its skillful use of the play-element.