In this thesis a theoretical background of Nd:YAG lasers has been presented and key parameters of a design have been stated. Both pulsed mode and CW mode designs have been made / a 500mJ xenon flash lamp has been investigated as the pulsed light source and a 500W tungsten halogen lamp has been used as the continuous light source for optical pumping. Closed cooling system has been constructed. De-ionized water has been used as coolant. The goal has been acomplished by constructing a CW mode prototype. The output power has been calculated. Dependence of output power to the reflectivity of output coupler is simulated and optimum reflectivity is calculated. Theoretical emission bands of Nd:YAG have been observed experimentally.

In this work optical properties of two dimensional quantum well structures are studied. Variational calculation of the eigenstates in an isolated quantum well structure with and without the external electrical field is presented. At weak fields a quadratic Stark shift is found whose magnitude depends strongly on the finite well depth. It is observed that under external electrical field, the asymmetries due to lack of inversion symmetry leads to higher order nonlinear optical effects such as second order optical polarization and second order optical susceptibility.

Starting the own business is sometimes a dream sometimes a nightmare but undoubtedly from a macro-economic perspective it is considered to be a promising concept to secure long-term economic growth and society’s welfare, at least in Germany. Strong efforts were made to support start ups and potential entrepreneurs to run their own business. A plethora of programs were launched which were supposed to facilitate the start up process – but reality is disenchanting: The published data in the 2004 GEM indicate that the idea of an entrepreneurial society in Germany is still far beyond its realization. Germany ranks 17th out of 31 GEM states in terms of “nascent entrepreneurs” and only 22nd regarding the “young entrepreneurs”. Compared to other GEM countries the German adults are considered to be more pessimistic in terms of entrepreneurial issues: The chances of establishing a successful business are evaluated lower than the years before. On the other hand the context factors which are considered to influence the start up opportunities especially in terms of governmental support and physical infrastructure were evaluated to be one of the best. Especially concerning the latter aspect strong efforts have been made to support entrepreneurs. In this context, and maybe because of - A “… post-1970s fascination with ‘high-tech’ regions worldwide” (Cooke/Leydesdorff 2006: 9), - A continuous liberalization of the world market and its impact on national production systems (which is well discussed in the context of the conversion of cooperatives), or - The dawn of the concept of national innovations systems (e.g. Lundvall 1988; Cozzens et al. 1990), For more than two decades, one promising concept of sustaining entrepreneurs was seen in the idea of incubators1 which mainly offer support in terms of infrastructure and funding opportunities. Meantime, we observe that questions emerge of how effective and efficient incubators work as one major instrument of macroentrepreneurial (Van de Veen 1995, Chiles/Meyer 2001) activities in order to facilitate start ups and to support the first steps of a new business from its start to its growth. The value of the incubator model as an effective means of technology and knowledge transfer especially from universities is continually discussed and questioned (Cunningham 1999). For example, a study run by Allen and Kahman (1985) concluded that incubators are tools for developing enterprises which create a positive environment for small businesses to succeed. Indeed, lots of studies brought up that incubators are an efficient and effective way to sustain spin-out processes and to contribute to regional development and prosperity. However, on the other hand some shortcomings are obvious: Finer and Holberton (2000) take into question the incubator model because it takes the initiative away from the start-up team. The paper refers to these observations. We assume by means of some international empirical studies that the functions of incubators are enhanced as a result of a (evolutional) learning process. On this basis we derive hypothesis about the dealing with the upcoming challenges and provide further research questions in an explorative way. Paragraph 2 introduces a three phased model of business incubators and classifies existing incubators. It will be obvious, that there is an increasing amount of functions that are allocated by incubators. Within paragraph 3 we examine recent developments from a macroeconomic perspective and contrast to this the evolution of incubators. Paragraph 4 presents two types of incubators that take these

A la fin du XIXème siècle, sauf à l’intérieur de quelques garnisons et forts de traite européens de la côte, les prisons étaient méconnues en Afrique. Aujourd’hui, 50 ans après les indépendances, les Etats africains utilisent encore massivement le système pénitentiaire légué par les colonisateurs. Comme le rappellent toujours les prisons surpeuplées, le système carcéral s’étend désormais sur l’ensemble des sociétés au sud du Sahara. Aujourd’hui encore ce réseau architectural colonial n’a point été détruit ni remplacé. Il fournit d’ailleurs la majeure partie des bâtiments utilisés par le régime pénal des Etats contemporains. D’autre part, les arsenaux juridiques utilisés s’inspirent de ceux du système colonial et la prison fait partie d’un ensemble plus vaste d’institutions héritées de la colonisation qui sont toujours fonctionnelles dans ce contexte où la tradition est toujours présente. C’est au regard du surpeuplement des prisons au Mali, des conditions inhumaines d’incarcération et de détention et des textes dépassés et inadaptés qui les régissent que nous avons voulu réfléchir à une possible réforme dont les autorités ont toujours parlé, mais qui n’est jamais faite. Il s’agit, dans les présentes recherches, d’examiner l’histoire sociale, culturelle et politique des arsenaux répressifs apparus au Mali depuis l’esclavage au XIXème siècle jusqu’aux prisons actuelles. Il s’agit d’une tentative de compréhension des aspects intellectuels et philosophiques de la prison et l’enfermement dans la tradition des ethnies et des terroirs du Mali, ce qui nous permettra de réfléchir sur la pratique des institutions coloniales de répression dans la vie quotidienne des populations et d’analyser l’actualité des prisons au quotidien pour voir s’il est possible d’avoir des prisons humanisées reposant sur des concepts de justice traditionnelle d’une part, et d’autre part, sur des normes internationalement reconnues en la matière. Cette recherche vise surtout à comprendre les supports sociologiques d’une réforme des prisons au Mali et à répondre à des questions de légitimité qui cherchent à savoir sur quoi doit reposer la réforme : sur la tradition ou sur la modernité ou sur les deux ? En outre, elle sert à se faire une idée sur la faisabilité d’une réforme et à édifier sur l’utilité sociale de la prison dans une société qui ne l’a pas toujours connu et dont la pauvreté incite à imaginer des solutions novatrices et simples qui visent à donner un mieux vivre aux populations, à toutes les populations aussi bien à l’extérieur qu’à l’intérieur des centres de détention. L’objectif visé est de contribuer à un projet global de bonne gestion de la société malienne, car les programmes de développement initiés dans nos pays africains, mettent en marge le développement de la vie en prison. Pourtant, en prison, vivent aussi des hommes qui doivent être pris en compte par les Etats dans les programmes, les projets de réforme. C’est là, notre ambition de contribuer aux initiatives pouvant aider à développer le pays, à donner aux populations partout où elles se trouvent, le sens de la vie, la considération, enfin à permettre de cerner la place de la prison dans le vaste chantier de la réforme de l’État. Il s’agit donc de réfléchir au lien entre réforme de l’Etat et réforme de la prison, d’autant plus que la réforme pénitentiaire est transversale et ne peut atteindre la légitimité souhaitée sans toucher à beaucoup d’autres secteurs de la société comme la sécurité, la santé, la pauvreté, l’emploi etc. / At the end of the twentieth century, prisons were unknown in Africa except in a few garrison towns and European forts involved in slave trade. Today, fifty years after they achieve their independence, African countries are massively applying the prison system left by the former colonizers. Overpopulated prisons are good indicators that the penitentiary system extends to the whole of the societies in the Southern part of Sahara. Today still, this colonial architectural network has not been demolished or replaced as shown by the majority of the buildings still in place in contemporary States. Legal arsenals have also been inspired by those of the colonial system; the prison is part of a larger grid of institutions inherited from the colonization, which are still functional in an environment where tradition remains vibrant.In view of the overcrowded prisons, inhuman conditions of detention and incarceration, and inadequate and outdated legal texts, we aim at reflecting on a possible reform, which authorities have always desired to institute but never did. We seek to examine the political, cultural and social history of the repressive arsenals that have been in use in Mali since the period of slavery in the 20th century to the present prisons. Our objective is to understand the intellectual and philosophical aspects of the prison -and imprisonment- in the ethnic and regional tradition of Mali; such research will allow us to consider the influence of the colonial repressive institutions in the everyday life of the population, and to analyze the daily agenda of the prisons so as to evaluate the possibility of making prisons more human on the basis of traditional justice concepts and internationally recognized norms. Such research aims at understanding the sociological basis for a prison reform in Mali and answer those who question the legitimacy of such a reform: shall it be based on tradition or modernity or both? Moreover, this research will help to determine whether such reform would be feasible, and to enlighten on the social utility of prisons in a society that has not always known them and whose poverty incites to envision new and simple solutions, which aim at giving a better life to the population, both inside and outside detention centers. Our ultimate objective is to contribute to a global project for a good management of Malian society while we observe that the development programs that have been initiated in African countries put improvement of life in prison at the margin. Yet, human beings also live in prison and therefore, States must take them into account in their programs and reform projects. This is precisely our motivation, which is to contribute to initiatives that may impact on the development of this country, and give to the population the sense of life and consideration as well as an understanding of the place of the prisons in the vast area of State reforms. This means that we need to reflect on the link between State reform and prison reform, even more as the prison reform is a transversal issue, which cannot be legitimate if it does not consider many other sectors in society including security, health, poverty, employment, etc.

La mise en œuvre des différents textes adoptés récemment ainsi que les évolutions jurisprudentielles intervenues ces dernières années ont fait évoluer le rôle du juge administratif (l’excès de pouvoir). Dans bien des domaines, son rôle va en effet désormais au-delà de la simple confrontation d’un acte administratif avec la règle de droit. Au cœur de la décision d’annulation se place désormais, outre l’interprétation de la loi, un relevé et une appréciation des faits, éléments que l’on séparait d’ordinaire à raison du principe de la séparation entre l’administration et son juge.Quelques jurisprudences devenues très classiques, comme d’autres plus récentes, peuvent être considérées comme des manifestations caractéristiques de cette nouvelle tendance du juge à imposer une lecture pragmatique de la légalité, à concevoir une certaine cohérence entre le droit applicable et la réalité des faits, rendant ainsi utile toute annulation contentieuse prononcée dans ce sens. / The role of the administrative judge (the excess of power) has evolved due to the implementation of the various texts adopted recently as well as the developments in the case-law in recent years. In many areas, its role now goes beyond the mere confrontation of an administrative act with the rule of law. At the heart of the annulment decision is a statement and an assessment of the facts, apart from the interpretation of the law, which were usually separated by the principle of separation between the administration and its judge.Some jurisprudence which has become very classical, as well as others more recent, can be considered as characteristic manifestations of this new tendency of the judge to impose a pragmatic reading of the law, to conceive a certain coherence between the applicable law and the reality of the facts, thus rendering useful any annulment contentious pronounced in this sense.

This thesis examines how middle class Pakistani young people construct contemporary international conflicts. Little previous research has been conducted in this area, and none in Pakistan. This investigation is of interest because young people like the ones who participated in my research may become future leaders. Therefore, their perceptions and understanding of these issues may influence the way these are addressed in the future. This thesis draws on literature about the just war tradition – what are the just causes of war or jus ad bellum and how ethical warfare must be conducted or jus in bello. The theoretical framework used is that of social constructionism, especially drawing on the ideas of Jonathan Potter, Margaret Wetherell, Kenneth Gergen and Michel Foucault. The research involved six focus groups with Pakistani young people aged 17-18 years. The study found that the participants talked enthusiastically about issues related to international conflicts. They drew on a range of discourses and evidence to construct their arguments, some of which were grounded in not very reliable evidence. They argued that terrorism, whether perpetrated by state or non-state actors, was wrong, and they were highly critical of US policies and actions in the wider world. These findings are important because Pakistani society faces a serious challenge from militancy and terrorism. The thesis suggests that changes to the content and delivery of school curricula can help young people to develop a more informed and morally active sense of citizenship and world affairs.

Ground penetrating radar (GPR) is limited by depth penetration and signal-to-noise ratio (SNR), impacting the ability to resolve subsurface features. Stacking, a process of averaging multiple scans in the same location, improves SNR. Digital antennas are capable of stacking at much higher rates than analog antennas. Four sites were examined using a GSSI SIR-4000 GPR unit with a 400 MHz analog antenna and a 350 MHz digital “hyperstacking” (350 HS) antenna. Sites represent various soil conditions, with known features. Data were compared qualitatively and quantitatively for differences in antenna outputs. Visual inspection of radargrams indicate a reduction in noise in the 350 HS data compared to the 400 MHz data. Quantitative assessments identified significant differences in standard deviation of radar reflection amplitude occurring at depth with both antennas and a reduction in noise and marginal increases in depth of penetration in low-loss conditions with the 350 MHz HS antenna.

Die formelbasierte Ressourcenallokation hat sich in jüngerer Zeit zunehmend als ein Instrument zur leistungsorientierten Steuerung von Hochschulen und ihren untergeordneten Organisationseinheiten etabliert. In diesem Kontext wird in der Literatur eine Vielzahl verschiedener Gestaltungselemente für Allokationsmodelle diskutiert, denen auch in Abhängigkeit der konkreten Anwendungssituation differenzierte Steuerungswirkungen zugeschrieben werden. Belastbare empirische Ergebnisse zu den Steuerungswirkungen liegen bis heute jedoch nur in unzureichendem Maße vor. Gleichzeitig stehen die Entscheidungsträger der allokierenden Institutionen vor der Aufgabe, aus verschiedenen, mit differenzierten Steuerungswirkungen ausgestatteten Formelelementen, wie z.B. Formelindikatoren, Indikatorgewichten und Berechnungsalgorithmen, ein Allokationsmodell zu gestalten, das für die individuelle Entscheidungssituation und die individuellen Zielsetzungen der Entscheidungsträger die bestmögliche Wirkung auf die Zielgrößen entfaltet und damit seiner Steuerungsfunktion gerecht wird. Zur Unterstützung dieser Entscheidungsaufgaben schlägt die vorliegende Arbeit ein simulationsbasiertes Management Support System vor, das den Entscheidungsträger bei der Gestaltung und Bewertung von Allokationsformeln für den Hochschulbereich bedarfsgerecht unterstützt und einen Beitrag für eine auf Effizienz und Effektivität ausgerichtete Hochschulsteuerung leistet. Es wurde ein Lösungskonzept erarbeitet und prototypisch realisiert, das die Simulation mit dem Active-Data-Warehouse-Konzept kombiniert, um den Wirkungsgrad differenziert ausgestalteter Allokationsmodelle auf die Zielgrößen der allokierenden Institution zu analysieren. Ergänzt wurde das Konzept um MIS/EIS- und OLAP-Funktionen, um die gewonnenen Simulationsergebnisse aufzubereiten, zu präsentieren und dadurch den Entscheidungsträger bei der Analyse der Simulationsergebnisse und der Identifikation des wirkungsvollsten Allokationsmodells zu unterstützen.

Im Bereich Public Health besteht ein Bedarf an Theorien, welche dazu beitragen, partizipative Prozesse zu beschreiben und zu verstehen (vgl. Faltermaier/Wihofszky 2012). Den hohen programmatischen Erwartungen (z. B. vgl. WHO 1986), gesundheitspolitischen (z. B. vgl. PrävG 2015) und gesundheitswissenschaftlichen Argumenten hinsichtlich eines Qualitätsbeitrags von Partizipation (z. B. vgl. Hartung 2012; Faltermaier/Wihofszky 2012) stehen Umsetzungsdefizite in deren Ausgestaltung im Gesundheitsmanagement gegenüber (vgl. Rosenbrock 2017; Lenhardt/Rosenbrock 2017). Das zentrale Ziel dieser Forschungsarbeit liegt in der Analyse des Partizipationsphänomens und seines möglichen Zusammenhangs zur Qualität der Arbeitsbedingungen im betrieblichen Gesundheitsförderungssetting. Neben Wirkfaktoren werden unter Nutzung empirischer Daten förderliche und hemmende Bedingungen für eine partizipative Realisierung abgeleitet sowie ein theoretischer Beitrag zum Partizipationsansatz geleistet. Das Vorgehen ist durch ein Multi-Methoden-Design in Form vielfältiger (1) Methoden, (2) Daten und (3) Theorien gekennzeichnet. Es integriert qualitative Ansätze (zehn Experteninterviews, fünf Fokusgruppen) und quantitative Zugänge (zwei Mitarbeiterbefragungen; t0=2008 n=1.700; t1=2015 n=2.533). Als Datenquellen dienen zwei Gesundheitsförderungsprojekte des öffentlichen Dienstes, einer Kommunalverwaltung und eines Landesbetriebs. Hinsichtlich des Zusammenhangs und der angenommenen Qualitätsentwicklung der Arbeitsbedingungen durch partizipative Ansätze zeigt sich ein komplexes Bild. In neun der zehn untersuchten Regressionsmodelle sind höhere Effektstärken seitens genereller Partizipation mit Integration in die Gesamtorganisation im Vergleich zur BGM-bezogenen Partizipation auffällig. Die Bewertung der Effektstärken und deren Ausrichtung ist abgesehen von dem (1) Partizipationskontext der unabhängigen Variable gleichfalls abhängig vom (2) zugrunde gelegten Qualitätsverständnis der Arbeitsbedingungen als abhängige Variable, (3) Interaktionstermen und (4) dritten Kontrollvariablen. Einer realistischen Wirkungsbewertung von Partizipation hat eine eindeutige Begriffsklärung von Partizipation vorauszugehen. Aufgrund dessen werden die empirischen und theoretischen Ergebnisse genutzt, um ein eigenes Partizipationsverständnis als Theorievorschlag zu formulieren. Resümierend ist für eine gewünschte Qualitätssteigerung der Arbeitsbedingungen, basierend auf dem Gesundheitsförderungsprinzip der Partizipation, deren Einbettung in die Gesamtorganisation Voraussetzung. Eine Partizipationsreichweite, beschränkt auf Beteiligung an spezifischen Gesundheitsmaßnahmen, kann nach diesen Untersuchungen überwiegend zu keiner statistisch bedeutsamen Qualitätsoptimierung beitragen. Für eine Praxis nachhaltiger gesundheitsförderlicher Lebenswelten sind dauerhafte, umfassende Beteiligungsprozesse und förderliche, v. a. strukturelle und haltungsbezogene, Bedingungen notwendig.

Submitted by Luciana Sebin (lusebin@ufscar.br) on 2016-09-27T13:41:48Z No. of bitstreams: 1 TeseASM.pdf: 6858970 bytes, checksum: 83be7f6c0d85cb91801e150418917482 (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2016-09-27T19:51:56Z (GMT) No. of bitstreams: 1 TeseASM.pdf: 6858970 bytes, checksum: 83be7f6c0d85cb91801e150418917482 (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2016-09-27T19:52:06Z (GMT) No. of bitstreams: 1 TeseASM.pdf: 6858970 bytes, checksum: 83be7f6c0d85cb91801e150418917482 (MD5) / Made available in DSpace on 2016-09-27T19:52:15Z (GMT). No. of bitstreams: 1 TeseASM.pdf: 6858970 bytes, checksum: 83be7f6c0d85cb91801e150418917482 (MD5) Previous issue date: 2016-03-21 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / The aim of this study was to evaluate the effects of diuron and carbofuran, isolated and mixed, on Raphidocelis subcapitata, Paramecium caudatum and Ceriodaphnia silvestrii and carry out a preliminary risk assessment of these pesticides for Brazilian water bodies. For this, acute and chronic toxicity tests were performed with individual compounds and in combination, in its standard form and commercial formulations. The results showed that in individual action, these pesticides significantly inhibited the R. subcapitata population growth and caused physiological (chlorophyll a content) and morphological (complexity and cell size) changes in the cells. For this alga, the toxicity of standard active ingredients and their commercial formulations showed no significant differences. For the protozoan P. caudatum, acute toxicity tests evidenced an increase of mortality with increasing exposure time for the selected compounds. Moreover, these pesticides caused a significant decrease in population growth, number of generations and biomass of P. caudatum. The toxicity of standard diuron and its commercial formulation was similar for this protozoan, while commercial carbofuran was more toxic than its standard form, suggesting a synergistic interaction with “inert” ingredients. In contrast, for the cladoceran C. silvestrii, acute toxicity tests showed that diuron commercial product was 7.2 times more toxic than its standard active ingredient, whereas for carbofuran, commercial product was 1.5 times less toxic than its standard active ingredient. Regarding chronic toxicity of diuron herbicide, both standard and commercial form caused hormetic effects on fertility of C. silvestrii female. Carbofuran significantly reduced the reproduction of C. silvestrii at concentrations from 0.38 μg L-1 onwards. The tropical species C. silvestrii was more sensitive to these pesticides than cladocerans commonly used in temperate regions, and in addition, for carbofuran, this species was the most sensitive organism already tested (EC50-48h = 0,86 μg L-1). According to the toxicity tests results of diuron and carbofuran mixtures, acute and chronic exposures on all selected test organisms caused significant deviations from the toxicity predicted by Concentration Addition and Independent Action reference models. For P. subcapitata, data indicated the occurrence of synergism in the mixture of these compounds, especially when diuron is the dominant chemical in combination. For P. caudatum, dose ratio dependent deviation (synergism caused by carbofuran and antagonism caused by diuron) was observed in acute exposure and deviation for antagonism was verified for population growth at sublethal concentrations of the standard compounds mixtures. For C. silvestrii, antagonism was observed in low doses and synergism at high doses, predominating synergism in acute exposures of standard pesticides mixtures, while for reproduction the deviation for antagonism was found. The commercial product mixtures of diuron and carbofuran showed significantly different effects and more severe than the standard compounds mixtures for P. caudatum and C. silvestrii. Therefore, diuron and carbofuran mixture can interact and cause toxic responses different from those predicted for individual compounds. According to the concentrations found in water bodies in Brazil, these compounds can cause direct and indirect toxic effects on communities of algae, protozoa and cladocerans and may change the structure and functioning of aquatic ecosystems. In a preliminary risk assessment of these pesticides, risk quotients were larger than 1, indicating that diuron and carbofuran represent potential ecological risks to Brazilian water bodies. Given the above, it is concluded that the pesticides studied alone and in combination, caused toxicity to test organisms and represent potential ecological risk for aquatic environments, which suggests the implementation by the regulatory agencies of more stringent measures for the use of pesticides to improve the protection of aquatic biota. / O objetivo desta pesquisa foi avaliar os efeitos do diuron e do carbofuran, isolados e em mistura, sobre as espécies Raphidocelis subcapitata, Paramecium caudatum e Ceriodaphnia silvestrii e realizar uma avaliação de risco preliminar destes agrotóxicos para os corpos d’água brasileiros. Para isso, testes de toxicidade aguda e crônica foram realizados com os compostos isolados e em mistura, nas suas formas padrão e comercial. Os resultados mostraram que, em ação individual, estes agrotóxicos inibiram significativamente o crescimento populacional de R. subcapitata e causaram alterações fisiológicas (conteúdo de clorofila a) e morfológicas (complexidade e tamanho celular) nas células. Para esta espécie de alga, a toxicidade dos ingredientes ativos nas formas padrão e comercial não apresentaram diferenças significativas. Para o protozoário P. caudatum, os testes de toxicidade aguda evidenciaram um aumento da mortalidade com o aumento do tempo de exposição aos compostos selecionados. Além disso, estes agrotóxicos causaram uma diminuição significativa no crescimento populacional, no número de gerações e na biomassa de P. caudatum. A toxicidade do diuron padrão e de sua formulação comercial foi similar para este protozoário, enquanto que o carbofuran comercial foi mais tóxico do que a sua forma padrão, sugerindo a ocorrência de interações sinérgicas com os ingredientes “inertes”. Diferentemente, para o cladócero C. silvestrii, os testes de toxicidade aguda mostraram que o produto comercial de diuron foi 7,2 vezes mais tóxico do que o seu ingrediente ativo padrão, enquanto que para o carbofuran, o produto comercial foi 1,5 vezes menos tóxico do que o seu ingrediente ativo padrão. Em relação à toxicidade crônica, o herbicida diuron, tanto na forma padrão como comercial, causou efeitos horméticos sobre a fertilidade das fêmeas de C. silvestrii. Já o carbofuran reduziu significativamente a reprodução de C. silvestrii em concentrações a partir de 0,38 μg L-1. A espécie tropical C. silvestrii foi mais sensível a estes agrotóxicos do que cladóceros comumente utilizados em regiões temperadas, e além disso, para o carbofuran, esta espécie foi o organismo-teste mais sensível já registrado na literatura (CE50-48h = 0,86 μg L-1). De acordo com os resultados dos testes de toxicidade das misturas de diuron e carbofuran, exposições agudas e crônicas sobre todos os organismos-teste selecionados causaram desvios significativos da toxicidade prevista pelos modelos de referência de Adição de Concentração e Ação Independente. Para a alga R. subcapitata, os dados evidenciaram a ocorrência do sinergismo na mistura destes compostos, principalmente quando o diuron é o produto químico dominante na mistura. Para o P. caudatum, o desvio dependente da proporção da dose (sinergismo causado pelo carbofuran e antagonismo causado pelo diuron) foi observado em exposições agudas e desvio para o antagonismo foi verificado para o crescimento populacional em concentrações subletais das misturas dos compostos padrões. Para a C. silvestrii, observou-se o antagonismo em baixas doses e o sinergismo em altas doses, prevalecendo o sinergismo nas exposições agudas das misturas dos agrotóxicos padrões, enquanto que para a reprodução foi encontrado o desvio para o antagonismo. As misturas dos produtos comerciais de diuron e carbofuran apresentaram efeitos significativamente diferentes e mais graves do que as misturas dos compostos padrões para o P. caudatum e a C. silvestrii. Portanto, diuron e carbofuran em mistura podem interagir e causar respostas tóxicas diferentes das previstas para os compostos individuais. De acordo com as concentrações encontradas nos corpos d’água brasileiros, estes compostos podem causar efeitos tóxicos diretos e indiretos sobre as comunidades de algas, protozoários e cladóceros, podendo alterar a estrutura e o funcionamento dos ecossistemas aquáticos. Na avaliação de risco preliminar destes agrotóxicos, os quocientes de risco foram maiores do que 1, indicando que o diuron e o carbofuran representam riscos ecológicos potenciais para os corpos d’água brasileiros. Diante do exposto, conclui-se que os agrotóxicos estudados, isolados e em mistura, causaram toxicidade aos organismos avaliados e representam riscos ecológicos potenciais para os ambientes aquáticos, o que sugere a implantação pelas agências reguladoras de medidas mais restritivas para o uso destes agrotóxicos, visando uma melhor proteção da biota aquática.