Importance of allelopathy as peudo-mixotrophy for the dynamics and diversity of phytoplankton

Understanding the dynamics and diversity of marine phytoplankton is essential for predicting oceanic primary production, oxygen generation and carbon sequestration. Several top-down and bottom-up factors lead to complex phytoplankton dynamics. Complexities further arise from inter-species interactions within phytoplankton communities. Consequently, some of the basic questions on phytoplankton diversity, identified long ago, still puzzle the ecologists: for example, what regulates the diversity in simple systems where species compete for limiting resources? In this context, allelopathic interaction among phytoplankton species has been identified as a potential driver of their dynamics and regulator of their diversity. This chapter deals with the importance of allelopathy in regulating the outcome of nutrient competition among phytoplankton species, through analysis of a resource-competition model. It demonstrates that, through the mechanism of pseudo-mixotrophy - proposed earlier by the author - allelopathy provides essential growth advantage to weaker competitors, and stabilizes resource competition, which ensures the coexistence of two phytoplankton on a single nutrient. In simple nutrient-phytoplankton interactions where higher-trophic influences are negligible, this mechanism theoretically promotes phytoplankton diversity, and can potentially support high diversity in natural phytoplankton communities.

Metabolic theory predicts whole-ecosystem properties

Understanding the effects of individual organisms on material cycles and energy fluxes within ecosystems is central to predicting the impacts of human-caused changes on climate, land use, and biodiversity. Here we present a theory that integrates metabolic (organism-based bottom-up) and systems (ecosystem-based top-down) approaches to characterize how the metabolism of individuals affects the flows and stores of materials and energy in ecosystems. The theory predicts how the average residence time of carbon molecules, total system throughflow (TST), and amount of recycling vary with the body size and temperature of the organisms and with trophic organization. We evaluate the theory by comparing theoretical predictions with outputs of numerical models designed to simulate diverse ecosystem types and with empirical data for real ecosystems. Although residence times within different ecosystems vary by orders of magnitude—from weeks in warm pelagic oceans with minute phytoplankton producers to centuries in cold forests with large tree producers—as predicted, all ecosystems fall along a single line: residence time increases linearly with slope = 1.0 with the ratio of whole-ecosystem biomass to primary productivity (B/P). TST was affected predominantly by primary productivity and recycling by the transfer of energy from microbial decomposers to animal consumers. The theory provides a robust basis for estimating the flux and storage of energy, carbon, and other materials in terrestrial, marine, and freshwater ecosystems and for quantifying the roles of different kinds of organisms and environments at scales from local ecosystems to the biosphere.

Possible impacts of a future grand solar minimum on climate: stratospheric and global circulation changes

It has been suggested that the Sun may evolve into a period of lower activity over the 21st century. This study examines the potential climate impacts of the onset of an extreme ‘Maunder Minimum like’ grand solar minimum using a comprehensive global climate model. Over the second half of the 21st century, the scenario assumes a decrease in total solar irradiance of 0.12% compared to a reference RCP8.5 experiment. The decrease in solar irradiance cools the stratopause (~1 hPa) in the annual and global mean by 1.4 K. The impact on global mean near-surface temperature is small (~−0.1 K), but larger changes in regional climate occur during the stratospheric dynamically active seasons. In Northern hemisphere (NH) winter-time, there is a weakening of the stratospheric westerly jet by up to ~3-4 m s1, with the largest changes occurring in January-February. This is accompanied by a deepening of the Aleutian low at the surface and an increase in blocking over northern Europe and the north Pacific. There is also an equatorward shift in the Southern hemisphere (SH) midlatitude eddy-driven jet in austral spring. The occurrence of an amplified regional response during winter and spring suggests a contribution from a top-down pathway for solar-climate coupling; this is tested using an experiment in which ultraviolet (200–320 nm) radiation is decreased in isolation of other changes. The results show that a large decline in solar activity over the 21st century could have important impacts on the stratosphere and regional surface climate.

The biogeophysical climatic impacts of anthropogenic land use change during the Holocene

The first agricultural societies were established around 10 ka BP and had spread across much of Europe and southern Asia by 5.5 ka BP with resultant anthropogenic deforestation for crop and pasture land. Various studies (e.g. Joos et al., 2004; Kaplan et al., 2011; Mitchell et al., 2013) have attempted to assess the biogeochemical implications for Holocene climate in terms of increased carbon dioxide and methane emissions. However, less work has been done to examine the biogeophysical impacts of this early land use change. In this study, global climate model simulations with Hadley Centre Coupled Model version 3 (HadCM3) were used to examine the biogeophysical effects of Holocene land cover change on climate, both globally and regionally, from the early Holocene (8 ka BP) to the early industrial era (1850 CE). Two experiments were performed with alternative descriptions of past vegetation: (i) one in which potential natural vegetation was simulated by Top-down Representation of Interactive Foliage and Flora Including Dynamics (TRIFFID) but without land use changes and (ii) one where the anthropogenic land use model Kaplan and Krumhardt 2010 (KK10; Kaplan et al., 2009, 2011) was used to set the HadCM3 crop regions. Snapshot simulations were run at 1000-year intervals to examine when the first signature of anthropogenic climate change can be detected both regionally, in the areas of land use change, and globally. Results from our model simulations indicate that in regions of early land disturbance such as Europe and south-east Asia detectable temperature changes, outside the normal range of variability, are encountered in the model as early as 7 ka BP in the June–July–August (JJA) season and throughout the entire annual cycle by 2–3 ka BP. Areas outside the regions of land disturbance are also affected, with virtually the whole globe experiencing significant temperature changes (predominantly cooling) by the early industrial period. The global annual mean temperature anomalies found in our single model simulations were −0.22 at 1850 CE, −0.11 at 2 ka BP, and −0.03 °C at 7 ka BP. Regionally, the largest temperature changes were in Europe with anomalies of −0.83 at 1850 CE, −0.58 at 2 ka BP, and −0.24 °C at 7 ka BP. Large-scale precipitation features such as the Indian monsoon, the Intertropical Convergence Zone (ITCZ), and the North Atlantic storm track are also impacted by local land use and remote teleconnections. We investigated how advection by surface winds, mean sea level pressure (MSLP) anomalies, and tropospheric stationary wave train disturbances in the mid- to high latitudes led to remote teleconnections.

Nurturing bilingual learners: challenges and concerns in Singapore

Singapore’s bilingual policy legitimises English not only as the language of governmental administration and interethnic communication, but also as the medium of instruction in all schools on all levels and across all subjects except mother tongues (MTs). As a result of these politics of language recognition, a visible shift has occurred in all ethnic groups away from MTs towards English. To rectify the language shift situation, the government has emphasised that developing bilingualism and raising bilingual children should begin in preschools. In this paper, we examine two top-down official documents: Review of Mother Tongue Languages Report, issued in 2011, and Nurturing Early Learners Framework for Mother Tongue Languages, developed in 2013. Attempting to identify some of the complex factors that influence language shift, we present an intertextual analysis of the Report and the curriculum Framework. In doing so, we compare the consistencies and locate the implicit inconsistencies in the policy position on bilingual education in preschools. We conclude the article by outlining the implications for changing the current bilingual educational models and providing teacher training programmes that maximise the learning opportunities of young bilingual learners.

Effects of intensity and positional predictability of a visual stimulus on simple reaction time

The influence of visual stimuli intensity on manual reaction time (RT) was investigated under two different attentional settings: high (Experiment 1) and low (Experiment 2) stimulus location predictability. These two experiments were also run under both binocular and monocular viewing conditions. We observed that RT decreased as stimulus intensity increased. It also decreased as the viewing condition was changed from monocular to binocular as well as the location predictability shifted from low to high. A significant interaction was found between stimulus intensity and viewing condition, but no interaction was observed between neither of these factors and location predictability. These findings support the idea that the stimulus intensity effect arises from purely sensory, pre-attentive mechanisms rather than deriving from more efficient attentional capture. (C) 2010 Elsevier Ireland Ltd. All rights reserved.

Evolutionary model trees for handling continuous classes in machine learning

Model trees are a particular case of decision trees employed to solve regression problems. They have the advantage of presenting an interpretable output, helping the end-user to get more confidence in the prediction and providing the basis for the end-user to have new insight about the data, confirming or rejecting hypotheses previously formed. Moreover, model trees present an acceptable level of predictive performance in comparison to most techniques used for solving regression problems. Since generating the optimal model tree is an NP-Complete problem, traditional model tree induction algorithms make use of a greedy top-down divide-and-conquer strategy, which may not converge to the global optimal solution. In this paper, we propose a novel algorithm based on the use of the evolutionary algorithms paradigm as an alternate heuristic to generate model trees in order to improve the convergence to globally near-optimal solutions. We call our new approach evolutionary model tree induction (E-Motion). We test its predictive performance using public UCI data sets, and we compare the results to traditional greedy regression/model trees induction algorithms, as well as to other evolutionary approaches. Results show that our method presents a good trade-off between predictive performance and model comprehensibility, which may be crucial in many machine learning applications. (C) 2010 Elsevier Inc. All rights reserved.

Upper limit on the cosmic-ray photon fraction at EeV energies from the Pierre Auger Observatory

From direct observations of the longitudinal development of ultra-high energy air showers performed with the Pierre Auger Observatory, upper limits of 3.8%, 2.4%, 3.5% and 11.7% (at 95% c.l.) are obtained on the fraction of cosmic-ray photons above 2, 3, 5 and 10 EeV (1 EeV equivalent to 10(18) eV), respectively. These are the first experimental limits on ultra-high energy photons at energies below 10 EeV. The results complement previous constraints on top-down models from array data and they reduce systematic uncertainties in the interpretation of shower data in terms of primary flux, nuclear composition and proton-air cross-section. (C) 2009 Elsevier B.V. All rights reserved.

Integration eller illusion : et deviance-perspektiv

Integration or illusion – a deviance perspective Denmark experienced one of its most successful periods of economic growth in 2004– 2008 with a tremendous reduction of unemployment, which in June 2008 was around. 1.5 percent, far below the expected level of structural unemployment. In the wake of this development the lack of utilization of migrants’ educations and skills became, once again, a core concern. The political, societal and academic debate followed to a great extent the traditional top-down approach to the problem and revolved around two axes: 1. How effective the labour market was/is to make use of migrants’ skills. 2. Whether there were patterns of over-education as expression of institutional and societal discrimination. The focus of the present study is, however, quite different: We examine the pattern of deviance in relation to labour market participation (not integration), and instead of searching for explanations for the lack of integration, we attempt to identify and explain the deviance pattern as a product of institutionally inherent possibilities and barriers on the one hand and articulating immigrants as rational actors (not victims) on the other. We argue that deviance is not only a more fruitful theoretical and analytical framework than integration and discrimination. Taking departure in empirical evidence on immigrants’ preferences and behaviour as bounded rational actors, and how they actually articulate their everyday life practical experiences, including adjustment of what they want and what they can, the deviance perspective, we believe, also reduces the theoretical and normative biases, that characterises the discrimination and integration framework, and provide more reliable explanations. 

Det är enklare i teorin… Om skolutveckling i praktiken : En fallstudie av ett skolutvecklingsprojekt i en gymnasieskola

This dissertation is a case study dealing with a school development project that took place in an upper secondary school as a result of a merger of two schools with different cultures. The project used a method called “Frirumsmodellen” and was planned to be conducted in three steps. The first was to carry out a cultural analysis in order to map the preconditions to start a school development project. The second was to carry out concrete actions and finally study eventual effects from such activities by doing a second cultural analysis. My role was to be a supervisor in the school development work, but at the same time study how this work was conducted and its impact in the ordinary school day. The dissertation takes its departure in the fact that schools are political governed. The mission of schools is never neutral; it is always an expression of behind laying social forces, ideologies and ideals of the contemporary society. Of this reason, there is a close connection between the macro political level and the micro political level. Another point of departure is the transition from a modern to a post modern society that gives the character to the changes that take place in schools. Steering of schools has partly been treated as a technical implementation problem. Schools contain on going conflicts between different interest groups that, more or less regularly, end up in educational reforms. These reforms generate school development activities in the single school. Undoubtedly, this makes school development to a complex process. At a rather late stage of the study I decided not to fulfil my task to follow the original plan. I instead let the school development project as a model to be in focus. The over all purpose was formulated: How is it possible to understand what happened in the school development project in the Falkgymnasiet and why was it not possible to carry it out as it was said in the project plan? To interpret what took place during the project I did create an interpretation frame of implementation and complexity theory that also made it possible to critically scrutinise the “Frirumsmodellen”. Already in an early stage of the process it was obvious that the “Frirumsmodellen” did not supply any tools to use and it became disconnected from the project. The project in it selves was marginalised and made invisible. The headmaster used the situation to change things she thought were important to develop. As a result, things happened, but most of the involved people did not at first hand connect this to the project. It is, of course, difficult in detail to say what caused what. The complexity theory successively made the hidden patterns revealed, hidden unofficial potentates visible, as well as unpredictable conditions that generated reactions from the personnel in front of a development work. Together this was rather efficient obstacles for not changing this school. I also discuss school development and implementation problems on a general level, for example, the possibility to transform a top-down initiated project to be bottom-up driven and using project as a tool for school development work. It was obvious that headmasters and teachers must be prepared to handle the ideological dimensions of problems schools have to face. Consequently, development work is about making problems visible and to handle these in the intersection point between the intentions of educational policies, pedagogical researchers, school administrators, headmasters, teachers and pupils. The ideological dimension also contains an existential issue. Do I as a teacher share the intentions for the development work? If not, how must I act?

Noretnätet - ett pedagogiskt utvecklingsprojekt

Vid Norets barn- och utbildningsområde i Mora kommun bedrivits ett projektet kallat Noretnätet. Rektorsområdebestår av en större centralt belägen skola och tre s k byskolor, tillsammans innefattande åk 1-9, med en integrerad 6-årsverksamhet. I början av år 1998 lämnades en ansökan in om bidrag för ettkompetens- och skolutvecklingsprojekt till Utbildningsdepartementet. Ansökan beviljades och projektetNoretnätet kom att starta från och med höstterminen 1998. Målen för projektet formulerades som att:• Öka kunskapen om läroprocesser hos elever, föräldrar och personal• Öka medvetenheten kring den egna praktiken och ett språk för pedagogiskt arbete i arbetslag• Utveckla en organisation för arbete med elevernas inlärning• En större samstämmighet i undervisningsmönster mellan våra olika åldersgrupperI samband med att projektet startade bildades s k tvärgrupper. En samtalsledarutbildning startades och pågick parallellt med tvärgruppernas arbete. Arbetslagen har därefter inom projektets ram framför alltatt arbeta vidare med frågeställningar som de själva formulerat i form av s k ”småprojekt”.Syftet med utvärdering är:a) Att försöka värdera i vilken utsträckning arbetet bedrivits i linje med de mål som formulerades för projektet och om och i vilken utsträckning dessa har uppnåttsb) Att identifiera och diskutera faktorer som kan uppfattas väsentliga för att kunna genomföra ett framgångsriktskolutvecklingsprojektc) Att resultatet av utvärderingen skall kunna utgöra en lägesbeskrivning från vilken det för de inblandade aktörernaskall vara möjligt att formulera riktlinjer för ett fortsatt utvecklingsarbeteUtvärderingen bygger dels på tre tidigare genomförda delutvärderingar, och dels på data som insamlatsför att kunna komplettera dessa. För att komplettera denna information insamlades ytterligare data slutetav vårterminen 2001. Utvärderingen bygger således på ett tämligen omfattande empiriskt material som omfattar hela projektperioden. Tolkningsbasen är vad man skulle kunna kalla en konstruktivistisk idé om att de data som finns tillgängliga tillsammans skall kunna ”vävas” samman till en mer eller mindresammanhållen bild, en av flera möjliga, av det aktuella projektets samlade verksamhet.Det förefaller som att ett tämligen omfattande arbete har lagts ner på att skapa en ökad medvetenhet och kunskap om lärprocesser. Den sammanvägda bedömningen är att verksamheten i projektet på den punkten, i förhållande till de förutsättningar som funnits, bedrivits på ett sådant sätt att en ökad medvetenhet hos personalen om de lärprocesser som sker i skolan möjliggjorts. Detta bör även på ett konkret sätt ha kommit eleverna till del och förhoppningsvis innebär det att även deras medvetenhet omlärandet kommer att öka. Även om det från en del håll uttrycks tveksamheter att medvetenheten runt den egna praktiken och ett pedagogiskt språk verkligen påverkats på ett positivt sätt. En del av svårigheten tycks just vara att kunna upptäcka vad som sker, vilket t ex till en del kan förklaras av att det rör sig om förhållandevis långsamma processer. Däremot verkar resultatet vad gäller att involvera föräldrarna inte ha utvecklats särskilt långt. Bedömningen är ändå att projektet bedrivits på ett sådant sätt attdet har haft en riktning väl i linje med målet att öka medvetenheten om den egna praktiken och att utvecklaett pedagogiskt språk. Vad gäller målet att skapa en organisation för arbetet med elevernas lärandehar detta varit inriktat på att klara de behov som Noretnätet gett upphov till och som det framstår inte som ett försök att i första hand skapa en mera permanent organisatorisk förändring. Slutsatsen bliratt Noretnätet ändå indirekt kommit att visa på vägar för att finna en organisatorisk form som gör det möjligt att bygga in ett kontinuerligt skolutvecklingsarbete och sett från en sådan utgångspunkt kanverksamheten sägas ligga i linje med det mål som sattes upp. De slutsatser man kan dra om att projektet har gett en större samstämmighet i undervisningsmönster mellan olika åldersstadier är att de är en frågeställning som varit föremål för tämligen omfattande diskussioner. Projektets verksamhet förefallerdärför även på den här punkten i huvudsak ha legat i linje med det i sammanhanget aktuella målet.Sammantaget uppfattas verksamheten i Noretnätet för samtliga fyra mål haft den ”riktning” som målenangav. Med tanke på målens konstruktion är det inte möjligt att ha någon uppfattning i vilken grad målen uppnåtts.Vad gäller Noretnätet förefaller detta i hög grad ha varit ett Top-down initierat projekt, men samtidigt med en relativt stark strävan till att när detta initierats kan ges en tydlig Bottom-up rikting. Skolledningensroll berörs sparsamt i de utsagor som projektdeltagarna gör och kritik framkommer endast i någotenstaka fall. Möjligen kan det ändå tolkas som att skolans ledning varit relativt framgångsrika med attinitiera projektet och även med att lägga över ansvaret på dess genomförande till projektdeltagarna.Frågan om tid, eller snarare bristen på tid, är i skolutvecklingssammanhang en ständigt återkommandefrågeställning. Att förändra och utveckla organisationer och deras verksamhet kräver också tid både för att initieras, implementeras och inte minst för att institutionaliseras. Vad som framstår som lite uniktmed projektet Noretnätet är att skolledningen verkar att på allvar försöka organisera verksamheten så att det frigörs tid för att kunna arbeta med projektet. Genom att Noretnätet fick utrymme att fortsättasin verksamhet ytterligare ett läsår har detta möjliggjort att en del effekter visat sig på ett sätt som annars sannolikt inte hade varit möjligt. De s k samtalsledarna har haft en viktig roll, men kan också antasha varit olika framgångsrika med att utöva sin roll, men att det ändå finns skäl att tro att de på ett personligt plan har varit utvecklande att ikläda sig denna roll. Om ingen tar denna roll riskerar ett skolutvecklingsprojektav det här slaget att bli ett skrivbordskonstruktion. De s k ”småprojekten” framstårsom en av de stora poängerna med projektet Noretnätet. Genom att så tydligt koppla dessa mindreutvecklingsprojekt till de ordinarie arbetslagen har detta samtidigt möjliggjort en vardagsnära skolutvecklingsprocess.”Småprojekten” startas som en utveckling och fördjupning av projektet genom önskemålfrån personalen. Sammanfattningsvis framstår de s k ”småprojekten” som ett viktigt uppslag tillhur skolutvecklingsarbete i en mera generell mening kan bedrivas på ett framgångsrikt sätt.Det projekt som en gång för tre år sedan började med, som en del ansåg, tämligen abstrakta idéer har så småningom tagit form och har i hög grad omvandlats till en konkret och i vardagen påtaglig verksamhet.En intressant frågeställning är naturligtvis i vilken utsträckning som vad som skett som kan tillskrivasNoretnätet och vad som ändå skulle ha inträffat. Det är naturligtvis omöjligt att besvara en sådanfråga, men att det ändå kan vara värt att något reflektera över tänkbara svar. Det förefaller lika orimligt att påstå att inget kan tillskriva projektets verksamhet, som att all utveckling beror på detta. Den tidsom ställts till förfogande, vilket det samtidigt förefaller finnas stor enighet om att detta varit betydelsefullt, de samtal som därmed initieras, de verksamheter som startats i de s k ”småprojekten” talar ändåstarkt för att projektet har spelat en viktig roll för det utvecklingsarbete som skett. Noretnätet har därmed skapat en utmärkt bas för att kunna gå vidare mot en fortsatt positiv utveckling av verksamheteninom Norets barn- och utbildningsområde.

Identificação dos fatores pedagógicos e administrativos relevantes para a avaliação da qualidade no ensino : o caso do curso de bacharelado em informática do Unicenp

A permanente busca pela qualidade como diferencial nas instituições de ensino, bem como a necessidade de atender aos critérios estabelecidos pela legislação para a revalidação da autorização de funcionamento dos Centros Universitários no Brasil, foram os elementos que determinaram a abrangência desta pesquisa. Devido à complexidade e ao amplo espectro de itens que compõem o que podemos determinar como sendo qualidade, a pesquisa limitou-se a identificar os fatores pedagógicos e administrativos relevantes para a avaliação da qualidade no ensino. Para limitar o campo da pesquisa, esta foi feita utilizando o método de estudo de caso, que é uma estratégia de pesquisa que examina um fenômeno contemporâneo dentro do seu contexto real, e para tanto, foi pesquisado o curso de Bacharelado em Informática do Centro Universitário Positivo - UnicenP, em Curitiba. Dentre as metodologias que poderiam ser utilizadas, foi escolhida a metodologia denominada Soft System Methodology, ou simplesmente SSM. Esta metodologia, proposta por Peter Checkland em 1985 na Universidade de Lancaster no Reino Unido, é uma resposta às dificuldades de aplicação de metodologias que tendem a enfatizar que os objetivos dos sistemas são mensuráveis e que estes podem ser decompostos em sub-sistemas, através da técnica top-down, quando essas metodologias são aplicadas a problemas empresariais. A SSM permite a ordenação e a estruturação de situações problemáticas complexas e que se apresentam, aparentemente inconsistentes e com múltiplas visões pelos envolvidos no processo.

O modelo instrumental e o modelo político de gestão de pessoas: uma análise em profundidade da implementação destes modelos em empresas brasileiras

A orientação teórica que divide a nossa sociedade em um modelo Industrial e em um modelo Pós-Industrial vem ganhando cada vez mais espaço e importância no estudo das organizações. Vários estudos acadêmicos nacionais e estrangeiros relatam o fato de que as organizações atuais mudam rapidamente o seu discurso a fim de adaptar-se às modificações que ocorrem nos processos produtivos e na gestão de pessoas, porém a implementação prática destas mudanças não ocorre de modo tão rápido quanto quer a mudança no discurso. Dado este período de transição, a distância entre a teoria professada e a prática efetiva nas organizações aumenta, surgindo maiores contradições entre discurso e prática, o que tem conseqüências para a produtividade. Estudamos neste projeto dois modelos de Gestão de Pessoas: O modelo Instrumental e o Modelo Político. Muitas organizações dizem que adotam o modelo Político, mas na prática mantém estruturas próximas ao modelo Instrumental. Neste relatório realizamos dois estudos de caso: Um em uma grande empresa nacional, a Souza Cruz, onde a empresa conseguiu superar a dicotomia discurso-ação implantando gradualmente o modelo Político de Recursos Humanos em consonância com a implementação de um sistema de informação que modificou toda a área de gestão de pessoas. Em segundo lugar, apresentamos um outro estudo de caso realizado em uma grande cooperativa Agro-Industrial onde já havia se consolidado práticas relativas ao modelo Político de Gestão de Pessoas e a implementação do modelo Instrumental, em uma ação top-down pelo presidente provocou fenômenos de resistência à mudança e a não implementação efetiva do ERP Entreprise Resource Planning na organização. Comparamos assim um estudo de caso que confirma a problemática levantada pela revisão da literatura (o da cooperativa) e um outro estudo de caso que oferece pistas de como evitar-se este problema, construir um sistema organizacional coerente e seguir em frente monitorando um sistema de aprendizagem baseado no modelo Político de Recursos Humanos.

Um modelo sistêmico de segurança do trabalho

O objetivo geral da tese foi desenvolver um modelo sistêmico de segurança do trabalho (também denominado 5C) com base nos fatores causais e contributivos aos acidentes do trabalho abordados na literatura, na análise macroergonômica do trabalho e no ponto de vista de quem os percebe (fator subjetivo). A revisão de literatura sobre Teorias e Modelos da Causa do Acidente e uma Modelagem para o Gerenciamento de Risco foi a base para a definição dos cinco fatores (5C) da primeira versão do Modelo Sistêmico de Segurança do Trabalho: carga de trabalho, confiabilidade, capacitação, custos e cultura de segurança. O referencial teórico sobre cada fator C, para a definição dos respectivos subfatores e para a concepção da estrutura do modelo que pressupõe hierarquia e permeabilidade entre os fatores 5C e fatores hipotéticos de distância e proximidade. A representação gráfica do modelo seguiu o tipo diagramático e configuração espiral. Os estudos de caso, cuja abordagem e procedimentos metodológicos tiveram como base o método de Análise Macroergonômica Trabalho (AMT) de Guimarães (1998; 2005), viabilizaram a submissão dos (sub)fatores 5C à realidade. Os estudos foram realizados no contexto de trabalho de operadores trens urbanos (Cenário I) e de eletricistas de redes aéreas desenergizadas do sistema de distribuição de energia elétrica (Cenário II), os quais possuem grau de risco três e periculosidade caracterizada por risco de contato ou de exposição a sistema elétrico de potência, permanente ou intermitente A avaliação do modelo seguiu aborgadem híbrida. A avaliação qualitativa consistiu na confrontação dos (sub)fatores 5C prescritos do modelo com os fatores descritos obtidos nos estudos de caso (Cenários I e II). Os resultados promoveram o estabelecimento dos parâmetros qualitativos dos subfatores 5C e, em decorrência, a confirmação dos (sub)fatores 5C do modelo. De outra parte, revelaram demandas de segurança não idênticas, o que era esperado, tendo em vista as características e peculiaridades de cada tarefa/sistema. A avaliação quantitativa foi realizada por meio de questionário elaborado a partir das informações geradas ao longo da pesquisa e testes estatísticos, aplicados sobre uma amostra da população do Cenário I. Os resultados indicaram que todos os (sub)fatores 5C impactam na segurança do trabalho em diferentes níveis (graus de importância) e que a intensidade de cada fator 5C para a ocorrência de acidentes varia em função do tipo de acidente. Verificou-se, também, a existência de correlações entre os fatores 5C, o que confirma a natureza sistêmica do modelo e, em decorrência, a estrutura hieráquica, o pressuposto de permeabilidade e os fatores hipotéticos de distância e proximidade. A versão final do Modelo Sistêmico de Segurançado Trabalho seguiu a primeira versão, acrescida pelos subfatores 5C, relações de constrangimento-resposta, quatro níveis (conceitual, estratégico, tático e operacional) e uma proposta de usabilidade segundo as perspectivas bottom-up e top-down. A validação do modelo implicará na sua aplicação em diferentes contextos de trabalho.

O processo de formação da estratégia de manufatura em empresas brasileiras de médio e pequeno porte

Esta pesquisa trata do processo de formação de estratégias de manufatura em empresas brasileiras pequenas e médias. Fazendo uso de extensa revisão bibliográfica, é desenvolvida uma ferramenta para o auxílio da tipificação e análise dos processos de formação de estratégias de manufatura, que utiliza duas principais dimensões: a direção predominante (top-down ou bottom-up) e a consideração ou não da existência de trade-offs entre critérios de desempenho no processo de formação das estratégias de manufatura. Esta ferramenta é então aplicada na análise em profundidade de quatro estudos de caso de empresas brasileiras de médio porte. Conclusões são tiradas e hipóteses formuladas sobre como as empresas brasileiras pequenas e médias formam suas estratégias de manufatura. Também com base nos achados dos estudos de caso e na revisão bibliográfica, são identificados 10 requisitos para um processo ideal de gestão da formação de estratégias de manufatura em empresas brasileiras pequenas e médias. Com base nestes requisitos, e como orientação à prática, é então desenvolvido e proposto um processo passo-a-passo para permitir que gestores das empresas brasileiras pequenas e médias possam de forma relativamente simples, gerenciar melhor seus processos de gestão da formação de suas estratégias de manufatura, beneficiando-se do estado da arte dos desenvolvimentos conceituais na área.