As cianobactérias (algas azuis) são organismos procariontes, fotossintéticos, encontrados em praticamente todo tipo de habitat líquido e que podem formar grandes massas superficiais de cor verde intensa denominadas florações. O aparecimento de florações na superfície da água ocorre com uma incidência cada vez mais elevada e é considerado um risco potencial à saúde, devido à natureza tóxica de algumas algas. As cianobactérias podem produzir hepatotoxinas, neurotoxinas e dermatotoxinas, que já causaram reações adversas e morte de animais e seres humanos. A maioria das hepatotoxinas são microcistinas (MCs), uma família de toxinas produzidas por espécies de cianobactérias de água doce. A MC-LR foi a primeira a ser identificada é a mais estudada, pois tem sido associada à maioria dos casos de intoxicação envolvendo cianotoxinas. O presente trabalho visou avaliar a toxicidade causada em camundongos pela exposição prolongada ao extrato aquoso de uma floração de cianobactérias contendo microcistinas. Para tanto, camundongos machos Swiss receberam o extrato (300 ou 900 mg/kg) por quatro semanas, sendo avaliados: ganho de peso, consumo de ração e água, comportamento no campo aberto (CA) e no labirinto em cruz elevado (LCE), hemograma, bioquímica sanguínea, achados anatomopatológicos e presença de MC no plasma e fígado. Além disso, quantificou-se as MCs presentes no extrato e avaliou-se in vitro a morte celular de leucócitos expostos a esse extrato e à MC-LR. A análise química do extrato mostrou que este possui, além das MCs, anabaenopeptinas; dentre as MCs foram encontradas a MC-LR, MC-RR, MC-YR e [D-Asp3] MC-LR. A exposição prolongada ao extrato por 28 dias não alterou o ganho de peso e o peso relativo de órgãos. Na necropsia também não foram observadas alterações macroscópicas, contudo alterações histopatológicas foram encontradas no fígado e no rim. No fígado foram observados focos discretos de necrose lítica hepatocelular associada a infiltrado de neutrófilos e células mononucleares. No rim, o tratamento com o extrato aumentou significativamente a intensidade de nefrose tubular, sendo esta mais acentuada nos animais tratados com a maior dose. O tratamento prolongado com o extrato em ambas doses causou efeitos comportamentais dosedependentes no CA: aumento significativo da distância percorrida, do número de entradas, do tempo em movimento e do número de levantamentos no centro do CA, além de um aumento do tempo de permanência no centro, com conseqüente diminuição deste parâmetro na periferia. No entanto, nenhum dos parâmetros avaliados no LCE foi alterado. A exposição prolongada ao extrato causou alterações sutis em parâmetros hematológicos e bioquímicos, caracterizadas por tendência de diminuição de leucócitos e de aumento dos níveis de creatinina sérica nos animais tratados com a maior dose do extrato. O tratamento prolongado com o extrato permitiu a detecção de MC apenas no fígado. Tanto a MC-LR como o extrato promoveram aumento das taxas de apoptose em leucócitos de camundongo in vitro. Finalizando, observou-se que a exposição prolongada a uma floração contendo MCs causou baixa toxicidade e efeitos comportamentais dose-dependentes, mostrando que o comportamento animal é bastante útil para avaliar efeitos mais sutis de agentes tóxicos sobre o sistema nervoso central. / Cyanobacteria (blue-green algae) are prokaryotic and photosynthetic organisms found in practically every type of liquid habitat and that can form great superficial masses of intense green color called blooms. The development of algal blooms on water surface occurs with a higher incidence and is recognised as being a potential health hazard due to the toxic nature of some algae. Cyanobacteria can produce hepatotoxins, neurotoxins and dermatotoxins, which already caused adverse effects and death of animals and human beings. Most of the hepatotoxins are microcystins (MCs), a family of toxins produced by species of freshwater cyanobacteria. MC-LR was the first to be identified and is the more studied, therefore, it has been associated to most of the cases of intoxication involving cyanotoxins. The present study was performed to evaluate the toxicity in mice after prolonged exposure to a cyanobacteria bloom extract containing microcystins. For this, male Swiss mice were treated with the extract (300 or 900 mg/kg) for four weeks and was evaluated: weight gain, food and water consumption, behavior in the open field (OF) and in the elevated plus-maze (EPM), blood count, clinical biochemistry, anatomopathological findings and presence of MC in the plasma and liver. Besides, the MCs present in the extract were quantified and the cellular death of leukocytes exposed in vitro to MC and to the extract was evaluated. The chemical analysis of the extract showed that it presented, besides MCs, anabaenopeptins; the MCs found were MC-LR, MC-RR, MC-YR and [D-Asp3] MC-LR. The prolonged exposure to the extract for 28 days did not alter the weight gain and the relative weight of organs. At necropsy, macroscopic alterations were not observed, however, histopathological alterations were found in the liver and in the kidney. In the liver, discreet necrosis focuses associated with neutrophils and mononuclear cells were found. In the kidney, the treatment with the extract increased significantly the intensity of tubular nephrosis, and this was more accentuated in the animals treated with the largest dose. The prolonged treatment with both doses caused dose-dependent behavioral effects in the OF: significant increase of moved distance, number of entries, time moving and rearing in the center of the OF, besides an increase of time spent in the center, with consequent decrease of this parameter in the periphery. None of the parameters evaluated in EPM were altered. The prolonged exposure to the extract caused subtle alterations in hematological and biochemical parameters, characterized by tendency for leukocyte decrease and increase of the levels of serum creatinine in the animals treated with the largest dose of the extract. The prolonged treatment with the extract allowed the detection of MC just in the liver. As much MC-LR as the extract promoted increase of the apoptosis levels in mouse leukocytes in vitro. Concluding, it was observed that the prolonged exposure to the cyanobacteria bloom containing MCs caused low toxicity and dose-dependent behavioral effects, showing that animal behavior is useful to evaluate subtler effects of toxic agents on the central nervous system.

Karenia brevis is a toxic marine dinoflagellate species that blooms almost every year in the Gulf of Mexico. These blooms have had devastating effects on local economies, as well as on the fauna of the area. The ECOHAB:Florida project was founded to study the population dynamics and trophic impacts of K. brevis. The project included a series of monthly hydrographic offshore research cruises, as well as monthly surveys of a transect along the 10-meter isobath of the West Florida Shelf. This study focused on data from the alongshore transect over a three-year period (1999-2001). Physical parameters (temperature, salinity, and density) and chemical parameters (particulate carbon, nitrogen, and phosphorus; dissolved inorganic nitrogen and phosphorus) of the West Florida Shelf were analyzed. The amount of chlorophll a and the location and amount of K. brevis cells present were also examined. Clear spatial, seasonal, and interannual patterns in the hydrographic parameters, particulate matter (C, N, P), dissolved inorganic nutrient (nitrite, nitrate, and phosphate), and chlorophyll a concentrations were found. At various times throughout the study, the location of K. brevis blooms was influenced by all of these factors except for the amount of dissolved inorganic nutrients. There were differences in particulate matter ratios present in bloom and non-bloom periods. No clear-cut differences in dissolved inorganic nutrients between bloom and non-bloom periods were found. Finally, relationships between the biological indicators of blooms (i.e., chlorophyll a) and the aforementioned physical and chemical parameters were found.

Optical research has shown that Karenia brevis has distinct spectral characteristics, yet most studies have focused exclusively on absorption and chemical properties, ignoring the size, shape, internal structure, and orientation, and their effect on scattering properties. The application of a new spectral interpretation model to K. brevis is shown to provide characterization of unique spectral information, not previously reported, through the use of scattering and absorption properties. The spectroscopy models are based on light scattering and absorption theories, and the approximation of the frequency-dependent optical properties of the basic constituents of living organisms. The model uses the process of mathematically separating the cell into four components, while combining their respective scattering and absorption properties, and appropriately weighted physical and chemical characteristics. The parameters for the model are based upon both reported literature values, and experimental values obtained from laboratory grown cultures and pigment standards. Measured and mathematically derived spectra are compared to determine the adequacy of the model, contribute new spectral information, and to establish the proposed spectral interpretation approach as a new detection method for K. brevis. Absorption and scattering properties of K. brevis, such as cell size/shape, internal structure, and chemical composition, are shown to predict the spectral features observed in the measured spectra. This research documents for the first time the exploitation of every spectral feature produced by the interaction of light with the cellular components and their contribution to the total spectrum of a larger (20-40 µm) photosynthetic eukaryote, K. brevis. Overall, this approach could eventually address the detection deficiencies of current optical detection applications and facilitate the understanding of K. brevis bloom ecology.

As human populations increase along coastal watersheds, the understanding and monitoring of Harmful Algal Blooms (or red tides) is an increasingly important issue. A consistent method for accurately detecting red tides using satellite measurements would bring tremendous societal benefits to resource managers, the scientific community and to the public as well. In the West Florida Shelf, blooms of the toxic dinoflagelate Karenia brevis are responsible for massive red tides causing fish kills, massive die-offs of marine mammals, shellfish poisoning, and acute respiratory irritation in humans. In this work, for the first time a long-term dataset (2002~2006) the MODerate Resolution Imaging Spectroradiometer (MODIS) is compared (i.e., matched-up) to an extensive data set of in situ cell counts of K. brevis; provided by the Florida Fish and Wildlife Conservation Commission's Fish and Wildlife Research Institute. The pairing of remote sensing data with near-coincident field measurements of cell abundance was successfully used to derive the basis for the development of an alternative ocean color based algorithm for detecting the optical signatures associated with blooms of K. brevis in waters of the West coast of Florida. Conclusions are geographically limited to the Central West Florida Shelf during the boreal Summer-Fall (i.e., the K. brevis blooming season). The new simpler Empirical approach is compared with other two more complicated published techniques. Their potential is verified and uncertainties involved in the identification of blooms of K. brevis are presented. The results shown here indicate that the operational NOAA method for detecting red tides in the Gulf of Mexico (Stumpf et al., 2003; Tomlinson et al., 2004) performs less accurately than the other two algorithms at identifying K. brevis blooms. The sensitivity and specificity of the Bio-optical (Cannizzaro, 2004; Cannizzaro et al., 2008) and Empirical algorithms are simultaneously maximized with an optimization procedure. The combined use of these two optimized algorithms in sequence provides another new monitoring tool with improved accuracy at detecting K. brevis of blooms. The ability of this Hybrid scheme ranges about 80% for both sensitivity and specificity; and the capability at predicting a correct red tides is 70%, and ~85% for non-blooms conditions. The spatial and temporal knowledge of K. brevis blooms can improve the direction of field monitoring to areas that should receive special attention, allowing better understanding of the red tide phenomenon by the scientific community. The relevant agencies can also develop more appropriate mitigation action plans, and public health guidance can be improved with the enhancement of sustainable costal management strategies.

Revisorsnämnden har till uppgift att examinera, granska och tillgodose samhället med kompetenta revisorer. Det ställs höga krav på dem som vill bli revisorer inte minst vad gäller det professionella omdömet. Det finns två olika prov för att examinera revisorer. Provet för revisorsexamen vilket leder till titeln godkänd revisor och provet för högre revisorsexamen som leder till titeln auktoriserad revisor. När Revisorsnämnden skapar proven vill man testa det professionella omdömet. Ett led i detta är att man har satt upp normer för de olika proven vad gäller kunskaps‐ respektive förståelseinriktade frågor. Syftet med denna uppsats är att undersöka frågorna i revisorsprovet med utgångspunkt ur Blooms Taxonomi. Genom en jämförelse med revisorsnämnden normer vill vi vidare belysa i vilken grad Revisorsnämnden testar det man har för avsikt att testa genom examinationen. Vi har genom denna uppsats kommit fram till att proven i högre utsträckning än vad normerna antyder består av förståelseinriktade frågor.

We consider the distributed access enforcement problem for Role-Based Access Control (RBAC) systems. Such enforcement has become important with RBAC’s increasing adoption, and the proliferation of data that needs to be protected. Our particular interest is in the evaluation of a new data structure that has recently been proposed for enforcement: the Cascade Bloom Filter. The Cascade Bloom Filter is an extension of the Bloom filter, and provides for time- and space-efficient encodings of sets. We compare the Cascade Bloom Filter to the Bloom Filter, and another approach called Authorization Recycling that has been proposed for distributed access enforcement in RBAC. One of the challenges we address is the lack of a benchmark: we propose and justify a benchmark for the assessment. Also, we adopt a statistically rigorous approach for empirical assessment from recent work. We present our results for time- and space-efficiency based on our benchmark. We demonstrate that, of the three data structures that we consider, the Cascade Bloom Filter scales the best with the number of RBAC sessions from the standpoints of time- and space-efficiency.

Domoic acid (DA) is a neurotoxin produced by the harmful algae Pseudo-nitzschia that has been directly linked to mass stranding events of the California Sea Lion (CSL). The purpose of this paper is to review the anthropogenic influence on the production of this neurotoxin and examine how human activities are impacting this marine mammal species. A comprehensive and interdisciplinary literature review was conducted to evaluate the future sustainability of the CSL population. It was found that while Pseudo-nitzschia bloom developments are vulnerable to anthropogenic influences, the incontestable existence of natural contributing factors adds a certain complexity to the determination of causalities and the development of solutions. Strong evidence exists to show that DA can cause major and irreversible neurological damage in CSLs. Rehabilitation of DA-impacted CSLs is a polarizing issue in the U.S. and presents interesting implications for sustainable development. While the CSL population is currently healthy and plenteous, the strong abundance of future uncertainties warrants concern. A balance must be found between the involving social, economic, and environmental factors to ensure a promising future for the CSL species.

Knowledge-based assets play a very important role in the Information Age. How to organize existing knowledge and present to the user properly are important research issue for decision support. Previous literature has indicated that multiple documents can be organized in different ways and different modes of knowledge presentation may result in different learning effects. Typical presentation modes include textual summarization and graphical presentation. The purpose of this thesis is to evaluate whether textual and graphical presentations of a news event may result in different effects for the user. In particular, this study is focused on comparing the textual summary and ontology-base graphical presentation and use the Bloom Theory of Educational Objectives to measure the learning effect of the user An experiment was conducted to assess the knowledge and cognitive process dimension in the Bloom¡¦s theory. We also measured the learning time, system quality, content quality, and overall satisfaction. The result shows that the textual system performed better in learning factual knowledge, and the ontology-base system performed better in learning conceptual and procedural knowledge.

This thesis addresses the problem of local intrusion detection for SCADA (Supervisory Control and Data Acquisition) field devices in the smart grid. A methodology is proposed to detect anomalies in the communication patterns using a combination of n-gram analysis and Bloom Filter. The predictable and regular nature of the SCADA communication patterns is exploited to train the intrusion detection system. The protocol considered to test the proposed approach is MODBUS which is used for communication between a SCADA server and field devices in power system. The approach is tested for attacks like HMI compromise and Man-in-the-Middle. Bloom Filter is chosen because of its strong space advantage over other data structures like hash tables, linked lists etc. for representing sets. The advantage comes from its probabilistic nature and compact array structure. The false positive rates are found to be minimal with careful choice of parameters for Bloom Filter design. Also the memory-efficient property of Bloom Filter makes it suitable for implementation in resource constrained SCADA components. It is also established that the knowledge of physical state of the power system i.e., normal, emergency or restorative state can help in improving the accuracy of the proposed approach.

Knowledge-based assets play a very important role in the Information Age, and its increasingly influence on organizational competition makes Knowledge Management a hot issue in business research.Content analysis of documents is a core function of knowledge management. In previous research, many techniques have been developed to generate textual summary and/or generating ontology-based episodic knowledge from multipl documents. However, not much research has been done to compare different ways of organizing and presenting knowledge. Since different knowledge presentations may result in different effects on the user, the purpose of this thesis is to develop a method for investigating different document summary and presentation systems. In this research, we have developed an effect measurement method based on the extended Bloom¡¦s Taxonomy of Educational Objectives.More specifically, we proposes evaluation criteria based on memory and cognition of the user. A field experiment was conducted to compare graphical and textual systems. Results indicate that the ontology-based system has significantly superior performance in concept memorizing and procedural memorizing. On the other hand, the textual summary-based system performed better in remembering facts.