Title: Evaluation of the number drowned people in the Czech Republic in the years 1994-2010 Aim of the thesis: Evaluate the number of drowning people in the Czech republic. Methods: Searches of available sources. Collecting data from the Czech Statistical office, media, information portals. Results: All the processed data was given in the context of the current causes of drowning people in natural waters, which can not be assessed to the short time generalize. In the month of July was a positive correlation between the number of the people drowned and the temperature. Results of this work can not be compared with foreign countries and assume that the results will be the same. Keywords: Drowning, International Classificasion of Diseases, Water Rescue Service, the casuse of drowning.

Title: Evaluation of the number drowned people in the Czech Republic in the years 1994-2010 Aim of the thesis: Evaluate the number of drowning people in the Czech republic. Methods: Searches of available sources. Collecting data from the Czech Statistical office, media, information portals. Results: All processed data were given in the current context causes drowning in the Czech Republic. In this work it was found that the actual risk of drowning increases with age and is about 2,5 times higher in men than in women. There have also been some laws on the number of drowning in natural water, which can not be assessed due to the short time generalize. The month of July has been demonstrated in the period of dependence on temperature drowned Celsius. Results of this work can not be compared with other countries and assume that the results will be the same. Keywords: Drowning, International Classificasion of Diseases, Water Rescue Service, the casuse of drowning.

Rip currents are the most dangerous hazard at surf beaches. Rip currents in South Florida have previously not been studied. Beach profiles for three Florida beaches (Miami Beach, Lido Beach, Sarasota, and Pensacola Beach) and one Georgia beach (South Cumberland Island) were chosen for surveying because of their variable sand bar heights. Rip current hazard at each beach was assessed by lifeguard rip rescue and drowning statistics. A relationship was found between sand bar height, beach slope and rip current hazard. Rip current measurements in South Florida, which involved utilizing GPS drifters, laser rangefinder and drone-imaged fluorescent tracer dye, showed that the speed ranged from 0.1-0.5 m/s, which is fairly slow compared to such measurements undertaken in California and Australia. The effect of rip currents on swimmers was analyzed based on the drag force acting on swimmers and the power they generate to overcome the currents when swimming against them. The drag force and power increase quadratically and cubically, respectively, with the increase of rip current and swimming speeds. Hence, even rip currents of low velocity can be dangerous and swimming against the current should be avoided if possible. Strong rips in California have been shown to exhibit a circulatory pattern, which could bring a floater back to the safety of a shallow sand bar. Field measurements of rip currents in South Florida clearly defined the flow characteristics of a nearly straight-line current, sometimes deflected to the east-southeast. Therefore, the traditional approach of swimming left or right, parallel to the shore is the best escape strategy, but not against the longshore current if present. A logistic regression analysis was conducted to predict the occurrence of rip currents based on beach conditions. The logistic model showed that wave height, wave period and wind speed were statistically significant factors in rip generation. Rips were found to be most commonly generated by relatively small, non-threatening waves (e.g., 0.6 to 0.9m in height). These physical factors, along with social and safety considerations, pose a significant problem for coastal management.

This paper aims to investigate a relatively unexplored area in archeology. The target area is funerals located outside of the cementery in coastal areas and the landscape Bohuslän. The paper has also looked at other areas of investigation such as etnological folklore and historic research. Purpouse for this has been to broaden the perspective.  The timeperiod studied is primaly historic and by that means the studdy starts in late middle age Scandinavian time and finnish in early 20th century . The essay shows this burial form where a wast burial culture which coexisted with strictly  church controlled burial traditions. The locals named the burial tradition for ”döingerös”. From the begining it supposed to be burials for peopel who worked as sailors but this investigation shows that other people could suffer the same threatment. Keywords: Burials, Historic time, carins, funeral outside cementery, folklore, costal enviroment.

METHODE: Aus den Protokollen von Ertrunkenen des Sektionsgutes der Jahre 1991-2000 der Rechtsmedizinischen Institute der Humboldt-Universität zu Berlin (n=129) und der Ernst-Moritz-Arndt Universität Greifswald (n=209) wurde versucht die Häufigkeit und Bedeutung von Mageninhalt in den Luftwegen zu beurteilen. In diesem Zusammenhang sollte auch die Herkunft und Verwendung des Begriffs des "Sehrtschen Magentodes" durch eine Literaturrecherche ergründet werden. Der "Sehrtsche Magentod" ist per definitionem ein Erstickungstod durch Aspirieren von erbrochenem Mageninhalt beim Ertrinken. RESULTS: Von den 129 Ertrunkenen in Berlin fanden sich 8, unter den 209 Ertrunkenen in Greifswald fanden sich 12 mit Mageninhalt in Kehlkopf, Trachea oder Bronchien. Es konnte ein Hinweis auf ein mögliches häufigeres Auftreten von Mageninhalt in den Luftwegen bei Ertrunkenen mit einer Mageninhaltsmenge > 500ml gefunden werden. Es fanden sich keine Hinweise dafür, daß es häufiger zum Auffinden von Mageninhalt in den Luftwegen bei Ertrinken in kaltem Wasser, in Salzwasser oder bei starker Alkoholisierung kommt. Des weiteren wurden bei den Fällen mit Mageninhalt in den Luftwegen der Lungenbefund auf die Frage einer vitalen Aspiration kasuistisch-deskriptiv untersucht und diskutiert. Unterschiede zwischen Berlin und Greifswald hinsichtlich der statistischen Verteilung von Alter, Geschlecht, Art, Ort und Zeitpunkt des Ertrinkens, Liegezeit im Wasser, toxikologischen Befunden, Lungenbefund und Magenbefund wurden herausgearbeitet. / The coronial files of drownings from the period 1991-2000 in Berlin (n=129) and Greifswald (n=209) were analysed to assess the frequency and significance of the occurrence of gastric content in the air passages of the deceased. In this context the origin and use of the term "Sehrtscher Magentod" was also clarified by means of a literature review. The "Sehrtscher Magentod" per definition occurs through asphyxiation as vomited stomach content is aspirated during the drowning. RESULTS: From 129 drownings in Berlin, 8 showed signs of gastric content in the air passages (larynx, trachea, bronchis), whilst in Greifswald this figure amounted to 12 out of 209. The study revealed a possible higher occurrence of gastric content in air passages where the deceased were found to have a gastric content quantity exceeding 500ml. Drownings in cold or salt water, or with a high blood alcohol concentration, did not show signs of a possible higher occurrence of gastric content in the air passages. Furthermore, the lung content of those cases showing gastric content in the air passages was examined and discussed regarding the question of a vital aspiration talking in a casuistic descriptual approach. Differences between the two cities with regards to the statistical distribution of age, gender, nature, location and time of drowning, toxicological findings, and lung and gastric features are also included in the study.

OBJETIVO: Avaliar o desempenho em testes neuropsicológicos e a resposta hemodinâmica cerebral medida por ressonância magnética funcional (RMf) em tarefas de memória e motora numa amostra de pacientes vítimas de afogamento com perda de consciência comparados a um grupo de indivíduos saudáveis. MATERIAL E MÉTODO: Estudamos 15 voluntários com média de idade de 23,7 anos no grupo de pacientes, selecionados a partir de amostra de 157 vítimas de afogamento, tendo como critérios de inclusão grau 3 e 4 da Escala de Afogamento (Szpilman, D. 1997) e excluindo-se aqueles com lesões estruturais cerebrais, antecedentes de alterações neurológicas ou psiquiátricas. Este grupo foi comparado a 18 voluntários saudáveis com média de idade de 25,3 anos selecionados para o grupo controle, pareados por anos de educação formal, idade e sexo. As imagens estruturais para referência anatômica (T1 3D; FLAIR 2D) e imagens funcionais axiais eco-planar, gradiente de ecos com ponderação T2*, com voxels isotrópicos de 3mm foram adquiridas em sistema de RM de 3,0 Teslas e os estímulos apresentados visualmente e sincronizados com a aquisição das imagens. O estudo de RMf foi realizado em desenho em bloco, com tarefa motora e de memória. Os dados de RMf foram préprocessados para correção de movimento, filtro espacial e temporal e foi aplicado Modelo Geral Linearizado para identificação de áreas cerebrais associadas às tarefas e produção de mapas estatísticos limiarizados (p < 0,05) representado a resposta cerebral de cada grupo, corrigidos para comparações múltiplas. Foram realizados testes ANOVA na comparação entre os dois grupos quanto às áreas cerebrais detectadas nas duas tarefas, sem e com utilização de co-variáveis obtidas de parâmetros dos testes neuropsicológicos. Além disso, investigamos a conectividade entre as regiões de redes neurais de cada paradigma através da análise de PPI e análise de correlação média de regiões da rede clássica de memória e motora entre os grupos. RESULTADOS: O desempenho neuropsicológico dos grupos foi similar na maioria dos testes, porém os pacientes (GP) apresentaram diferença significativa com pior desempenho no teste FAS e Dígitos e melhor desempenho na parte do reconhecimento do teste BVMT em relação aos controles (GC) (FAS: GC=40,0±8,6; GP=31,7±8,9; P=0,010/ Dígitos: GC=14,3±3,7; GP=12,3±2,1; P=0,050/ BVMT reconhecimento: GC=5,6±0,05; P=6,0; P=0,005). Durante os exames de RMf o desempenho comportamental foi similar em ambos os grupos nas duas tarefas (média de acurácia: GC=70,2±11,3%; GP=73,0±10,1%; P=0,460/ Tempo de reação: GC=1328,6±196,8ms; GP=1163,7±198,5ms; P=0,020/ frequência: GC=2,9±0,9Hz; GP=2,5±0,5Hz; P=0,108). No paradigma de memória, os controles apresentaram maior ativação em relação aos pacientes na região do giro temporal médio à direita e cuneus, giro lingual e sulco intraparietal à esquerda; esta diferença foi modulada pelo desempenho em testes neuropsicológicos de Dígitos, FAS e BVMT; não houve diferença no padrão da rede neural desta tarefa na análise PPI; houve maior correlação da rede frontoparietal à direita no grupo controle. No paradigma motor, os pacientes apresentam maior ativação em relação aos controles na região do putame e ínsula à esquerda; esta diferença foi modulada pelo desempenho em testes neuropsicológicos de Dígitos e FAS; a rede neural motora apresentou diferença entre os grupos na análise PPI: houve decréscimo da conectividade funcional entre a área motora suplementar (AMS) e as regiões do giro pré e pós-central à esquerda e porção opercular do giro frontal médio à direita nos pacientes em relação aos controles; porém, houve maior correlação da série temporal dos pacientes entre a AMS e a área sensitivomotora à esquerda. CONCLUSÃO: O desempenho neuropsicológico encontrado nesta amostra de vítimas de afogamento pode ser considerado normal ou com alterações leves, o que difere de estudos nessa população com diferentes graus de agressão hipóxia. As diferenças de atividade cerebral na rede associada à tarefa de memória - uma função frequentemente descrita como alterada em casos de afogamento mais severo - pode representar mecanismo de reorganização neural. A alteração do padrão de funcionamento da rede neural motora nestes pacientes corrobora as hipóteses baseadas na literatura de pacientes com agressão severa, com alta probabilidade de acometimento estrutural em núcleos da base. Os nossos resultados mostram que alterações na rede cerebral associada à função de memória e motora estão presentes mesmo sem evidente comprometimento estrutural ou neuropsicológico / hemodynamic response measured by functional magnetic resonance imaging (fMRI) on memory and motor tasks in a sample of drowning victims with loss of consciousness compared to a group of healthy individuals. MATERIAL AND METHODS: We studied 15 volunteers (six men; mean age: 23.7 years) enlisted in the group of patients, which were selected from a sample of 157 drowning victims, with the inclusion criteria grade 3 and 4 Scale Drowning (Szpilman D., 1997) and excluding those with structural brain lesions , history of neurological or psychiatric disorders. This group was compared to 18 healthy volunteers (five men; mean age: 25.3 years matched for years of education, age and sex (control group). Structural images for anatomical reference (T1 3D, 1mm isotropic voxels; FLAIR 2D, voxels 1.2x1.2x5mm) and functional imaging axial echo - planar gradient echo T2*- weighted (Blood Oxygenation Level Dependent ) with 3mm isotropic voxels were acquired in MR system of 3.0 Tesla using a 8 Ch head coil, the stimuli presented visually and synchronized with image acquisition (Zurc & Zurc , São Paulo - Brazil). The study was conducted using fMRI block design, with motor task (finger tapping) and memory (visual recognition - part of the International Consortium for Brain Mapping). Subjects\' performance in the fMRI tasks were recorded using a response box and visual observation of hand movement frequency. fMRI data were preprocessed for motion correction , spatial and temporal filter was applied and General Linear Model (GLM) was used for identification of brain areas associated with the tasks. Statistical thresholded maps (p < 0.05) representing group response to each task were corrected for multiple comparisons. ANOVA tests were performed to compare the group maps in the two tasks, with and without using covariates obtained from neuropsychological. Furthermore, we investigated the connectivity between regions of each neural network paradigm by analyzing psychophysiological interaction (PPI) and direct correlation analysis between classical regions of the motor and memory networks. RESULTS : The neuropsychological performance of the groups were similar in most tests, but patients (PG) showed significant differences with worse performance in and Digit and FAS tests, and a better performance in the recognition part of the BVMT test compared to controls (CG) (FAS: CG =40,0±8,6; PG =31,7±8,9; P=0,010/ Digits: CG =14,3±3,7; PG =12,3±2,1; P=0,050/ Recognition BVMT: CG =5,6±0,05; PG =6,0; P=0,005). Behavioral performance was similar in both groups on both fMRI tasks (mean accuracy: CG =70,2±11,3%; PG =73,0±10,1%; P=0,460 / RT: CG =1328,6±196,8ms; PG =1163,7±198,5ms; P=0,020 / frequency: CG =2,9±0,9Hz; PG =2,5±0,5Hz; P=0,108). In the memory task, controls showed greater activation compared to patients in the middle temporal gyrus and right cuneus, lingual and borders of the left intraparietal sulcus; this difference was modulated by performance on Digits, FAS and BVMT tests; we found no difference in the pattern of neural network on PPI analysis; there was, however, a higher correlation of the right frontoparietal network in the control group. In the motor task, patients showed greater activation than controls in the region of the putamen and left insula; this difference was modulated by performance on neuropsychological tests of Digits and FAS in the left hand task; the motor neural network differed between groups in PPI analysis: there was a decrease of functional connectivity between the supplementary motor area (SMA) and the regions of the left pre- and post-central gyrus and opercular portion of the right middle frontal gyrus in patients compared to controls; on the other hand, there was greater correlation between the time series of the AMS and the left sensorimotor area in patients. CONCLUSION: The neuropsychological performance differences found in this sample of drowning victims can be considered normal or mild abnormalities, which differ from studies using drowning population with varying degrees of hypoxia. Differences in brain activity in the network associated with memory task - a function often affected in more severe cases of drowning - may represent a neural reorganization mechanism. The changes in the motor neural network in these patients confirm the hypotheses based on the literature of patients with severe aggression, who have a high probability of structural involvement in the basal ganglia. Our results show that changes in brain network associated with memory function and motor are present even without apparent structural or neuropsychological impairment

OBJETIVO: Avaliar o desempenho em testes neuropsicológicos e a resposta hemodinâmica cerebral medida por ressonância magnética funcional (RMf) em tarefas de memória e motora numa amostra de pacientes vítimas de afogamento com perda de consciência comparados a um grupo de indivíduos saudáveis. MATERIAL E MÉTODO: Estudamos 15 voluntários com média de idade de 23,7 anos no grupo de pacientes, selecionados a partir de amostra de 157 vítimas de afogamento, tendo como critérios de inclusão grau 3 e 4 da Escala de Afogamento (Szpilman, D. 1997) e excluindo-se aqueles com lesões estruturais cerebrais, antecedentes de alterações neurológicas ou psiquiátricas. Este grupo foi comparado a 18 voluntários saudáveis com média de idade de 25,3 anos selecionados para o grupo controle, pareados por anos de educação formal, idade e sexo. As imagens estruturais para referência anatômica (T1 3D; FLAIR 2D) e imagens funcionais axiais eco-planar, gradiente de ecos com ponderação T2*, com voxels isotrópicos de 3mm foram adquiridas em sistema de RM de 3,0 Teslas e os estímulos apresentados visualmente e sincronizados com a aquisição das imagens. O estudo de RMf foi realizado em desenho em bloco, com tarefa motora e de memória. Os dados de RMf foram préprocessados para correção de movimento, filtro espacial e temporal e foi aplicado Modelo Geral Linearizado para identificação de áreas cerebrais associadas às tarefas e produção de mapas estatísticos limiarizados (p < 0,05) representado a resposta cerebral de cada grupo, corrigidos para comparações múltiplas. Foram realizados testes ANOVA na comparação entre os dois grupos quanto às áreas cerebrais detectadas nas duas tarefas, sem e com utilização de co-variáveis obtidas de parâmetros dos testes neuropsicológicos. Além disso, investigamos a conectividade entre as regiões de redes neurais de cada paradigma através da análise de PPI e análise de correlação média de regiões da rede clássica de memória e motora entre os grupos. RESULTADOS: O desempenho neuropsicológico dos grupos foi similar na maioria dos testes, porém os pacientes (GP) apresentaram diferença significativa com pior desempenho no teste FAS e Dígitos e melhor desempenho na parte do reconhecimento do teste BVMT em relação aos controles (GC) (FAS: GC=40,0±8,6; GP=31,7±8,9; P=0,010/ Dígitos: GC=14,3±3,7; GP=12,3±2,1; P=0,050/ BVMT reconhecimento: GC=5,6±0,05; P=6,0; P=0,005). Durante os exames de RMf o desempenho comportamental foi similar em ambos os grupos nas duas tarefas (média de acurácia: GC=70,2±11,3%; GP=73,0±10,1%; P=0,460/ Tempo de reação: GC=1328,6±196,8ms; GP=1163,7±198,5ms; P=0,020/ frequência: GC=2,9±0,9Hz; GP=2,5±0,5Hz; P=0,108). No paradigma de memória, os controles apresentaram maior ativação em relação aos pacientes na região do giro temporal médio à direita e cuneus, giro lingual e sulco intraparietal à esquerda; esta diferença foi modulada pelo desempenho em testes neuropsicológicos de Dígitos, FAS e BVMT; não houve diferença no padrão da rede neural desta tarefa na análise PPI; houve maior correlação da rede frontoparietal à direita no grupo controle. No paradigma motor, os pacientes apresentam maior ativação em relação aos controles na região do putame e ínsula à esquerda; esta diferença foi modulada pelo desempenho em testes neuropsicológicos de Dígitos e FAS; a rede neural motora apresentou diferença entre os grupos na análise PPI: houve decréscimo da conectividade funcional entre a área motora suplementar (AMS) e as regiões do giro pré e pós-central à esquerda e porção opercular do giro frontal médio à direita nos pacientes em relação aos controles; porém, houve maior correlação da série temporal dos pacientes entre a AMS e a área sensitivomotora à esquerda. CONCLUSÃO: O desempenho neuropsicológico encontrado nesta amostra de vítimas de afogamento pode ser considerado normal ou com alterações leves, o que difere de estudos nessa população com diferentes graus de agressão hipóxia. As diferenças de atividade cerebral na rede associada à tarefa de memória - uma função frequentemente descrita como alterada em casos de afogamento mais severo - pode representar mecanismo de reorganização neural. A alteração do padrão de funcionamento da rede neural motora nestes pacientes corrobora as hipóteses baseadas na literatura de pacientes com agressão severa, com alta probabilidade de acometimento estrutural em núcleos da base. Os nossos resultados mostram que alterações na rede cerebral associada à função de memória e motora estão presentes mesmo sem evidente comprometimento estrutural ou neuropsicológico / hemodynamic response measured by functional magnetic resonance imaging (fMRI) on memory and motor tasks in a sample of drowning victims with loss of consciousness compared to a group of healthy individuals. MATERIAL AND METHODS: We studied 15 volunteers (six men; mean age: 23.7 years) enlisted in the group of patients, which were selected from a sample of 157 drowning victims, with the inclusion criteria grade 3 and 4 Scale Drowning (Szpilman D., 1997) and excluding those with structural brain lesions , history of neurological or psychiatric disorders. This group was compared to 18 healthy volunteers (five men; mean age: 25.3 years matched for years of education, age and sex (control group). Structural images for anatomical reference (T1 3D, 1mm isotropic voxels; FLAIR 2D, voxels 1.2x1.2x5mm) and functional imaging axial echo - planar gradient echo T2*- weighted (Blood Oxygenation Level Dependent ) with 3mm isotropic voxels were acquired in MR system of 3.0 Tesla using a 8 Ch head coil, the stimuli presented visually and synchronized with image acquisition (Zurc & Zurc , São Paulo - Brazil). The study was conducted using fMRI block design, with motor task (finger tapping) and memory (visual recognition - part of the International Consortium for Brain Mapping). Subjects\' performance in the fMRI tasks were recorded using a response box and visual observation of hand movement frequency. fMRI data were preprocessed for motion correction , spatial and temporal filter was applied and General Linear Model (GLM) was used for identification of brain areas associated with the tasks. Statistical thresholded maps (p < 0.05) representing group response to each task were corrected for multiple comparisons. ANOVA tests were performed to compare the group maps in the two tasks, with and without using covariates obtained from neuropsychological. Furthermore, we investigated the connectivity between regions of each neural network paradigm by analyzing psychophysiological interaction (PPI) and direct correlation analysis between classical regions of the motor and memory networks. RESULTS : The neuropsychological performance of the groups were similar in most tests, but patients (PG) showed significant differences with worse performance in and Digit and FAS tests, and a better performance in the recognition part of the BVMT test compared to controls (CG) (FAS: CG =40,0±8,6; PG =31,7±8,9; P=0,010/ Digits: CG =14,3±3,7; PG =12,3±2,1; P=0,050/ Recognition BVMT: CG =5,6±0,05; PG =6,0; P=0,005). Behavioral performance was similar in both groups on both fMRI tasks (mean accuracy: CG =70,2±11,3%; PG =73,0±10,1%; P=0,460 / RT: CG =1328,6±196,8ms; PG =1163,7±198,5ms; P=0,020 / frequency: CG =2,9±0,9Hz; PG =2,5±0,5Hz; P=0,108). In the memory task, controls showed greater activation compared to patients in the middle temporal gyrus and right cuneus, lingual and borders of the left intraparietal sulcus; this difference was modulated by performance on Digits, FAS and BVMT tests; we found no difference in the pattern of neural network on PPI analysis; there was, however, a higher correlation of the right frontoparietal network in the control group. In the motor task, patients showed greater activation than controls in the region of the putamen and left insula; this difference was modulated by performance on neuropsychological tests of Digits and FAS in the left hand task; the motor neural network differed between groups in PPI analysis: there was a decrease of functional connectivity between the supplementary motor area (SMA) and the regions of the left pre- and post-central gyrus and opercular portion of the right middle frontal gyrus in patients compared to controls; on the other hand, there was greater correlation between the time series of the AMS and the left sensorimotor area in patients. CONCLUSION: The neuropsychological performance differences found in this sample of drowning victims can be considered normal or mild abnormalities, which differ from studies using drowning population with varying degrees of hypoxia. Differences in brain activity in the network associated with memory task - a function often affected in more severe cases of drowning - may represent a neural reorganization mechanism. The changes in the motor neural network in these patients confirm the hypotheses based on the literature of patients with severe aggression, who have a high probability of structural involvement in the basal ganglia. Our results show that changes in brain network associated with memory function and motor are present even without apparent structural or neuropsychological impairment

This study evolved from concerns about the number of young people drowning in New Zealand (544 deaths between 1980-1994), the author’s long experience with surf life saving and the suspicion that participation statistics on aquatic recreation do not adequately explain why so many young people drown. It was postulated that the risk of drowning associated with aquatic recreation also was the consequence of many underlying water safety influences that operate at intrapersonal, interpersonal and community levels. Thus the purpose of the study was to obtain comprehensive data on what young people know, think and do about their safety during aquatic recreation. A 25-item questionnaire was designed to survey a randomised sample of New Zealand youth (2202, year 11, 15 – 19 year olds) to assess their participation in, knowledge about and behaviour during aquatic recreation. To develop the questionnaire, a conceptual framework was devised that constructed the risk of drowning as a complex phenomenon dependent on how often young people participate in various forms of water-based activities, but largely influenced by their water safety knowledge, attitudes and behaviour, all of which are shaped by social, cultural and demographic variables. Almost all New Zealand youth had taken part in some swimming (98%) or other aquatic activity (94%) in the previous year. Risk of drowning was exacerbated among many students because they had poor water safety skills and knowledge, held unsound water safety attitudes, and often practiced at-risk behaviours. For example, many students estimated that they could not swim more than 100 m (54%), thought that swimming was acceptable at a surf beach after patrol hours (61%), and had swum outside patrol flags (61%) or never worn lifejacket (19%) during aquatic recreation. Taken separately, any one of these dispositions is capable of heightening drowning risk; taken collectively they offer strong explanation as to why youth are at greater risk of drowning than others. When analysed by gender, the lack of water safety knowledge, the prevalence of unsafe attitudes and at-risk behaviours among males was consistent and pronounced. The effect of socio-economic status and ethnicity on these risk-enhancing dispositions was less pronounced, although the data did suggest that the knowledge base of youth from low-decile schools and of Pasifika and Asian ethnicity provided least protective potential in the event of unintentional submersion.

The thesis, which is divided into a practical and a theoretical part, examines the level of knowledge among the members of the Fire Brigade of the South Bohemia region. The theoretical part characterizes the Fire Brigade of the Czech Republic, its mission and tasks, its position within the Integrated Emergency System. The theoretical part deals with the issues of stagnant, flowing and frozen water hydrology, physiology related to staying in cold water and the possibilities to use rescue and protective aids. I also present a list of dangerous situations rescuers are exposed to when rescuing on water surfaces. Results of a questionnaire research are processed and evaluated in the practical part. The questionnaire deals with the issues of stagnant, flowing and frozen water hydrology, the basic theoretical knowledge as well as practical skills of the members of the South Bohemian Fire Brigade. The most important findings resulting from the performed research are summarized in the conclusion of the work. I evaluate the aims and hypotheses set at the beginning and propose a possible solution of the problems in question.

A cidade de Teresina, capital do estado do PiauÃ, à entrecortada pelos rios ParnaÃba e Poty, sendo o Ãltimo afluente ao primeiro, dentro da zona urbana de Teresina. O rio ParnaÃba controla uma bacia hidrogrÃfica de 237.000 km a montante de Teresina, enquanto que o rio Poty, controla uma bacia hidrogrÃfica de 51.400 kmÂ. A caracterÃstica hidrolÃgica principal das cheias nos rios ParnaÃba e Poty à que as enchentes do rio ParnaÃba sÃo passiveis de controle parcial a partir das comportas da Usina HidroelÃtrica (UHE) Boa EsperanÃa, ao passo que, tal controle inexiste para as cheias advindas da bacia do rio Poty. O presente estudo analisou a questÃo da interferÃncia das cheias do rio Poty com o sistema de microdrenagem formado pelas galerias urbanas transversais afluentes ao mesmo, constatando a possibilidade de afogamento e remanso do rio Poty sobre as galerias em determinadas condiÃÃes de cheias hidrolÃgicas. Foi analisado o caso da cheia do ano de 2009 no sistema de drenagem transversal ao rio Poty, que causou a inundaÃÃo de diversos bairros, em virtude do remanso decorrente da elevaÃÃo da cota do nÃvel d Ãgua do rio Poty acima da cota das geratrizes superiores das galerias transversais. Foi constatado que, em virtude das cotas de desague das galerias do bairro Primavera no rio Poty, as cheias deste rio com perÃodo de retorno bianual (TR = 2 anos), sÃo suficientes para promover o fluxo inverso no sistema de galerias e a inundaÃÃo de Ãreas urbanas conectadas. Conclui-se que hà necessidade de intervenÃÃes estruturais para solucionar este problema, a partir, ou do controle das cheias no rio Poty por meio de reservatÃrio de retenÃÃo, tal como a futura barragem Castelo do PiauÃ, ou a partir de emprego de bacias de detenÃÃo urbanas, comportas de marà e sistema de bombeamento das Ãguas pluviais das bacias interconectadas com o rio Poty. / The city of Teresina, Piauà state capital, is intersected by rivers ParnaÃba and Poty, the last tributary to the first, within the urban area of &#8203;&#8203;Teresina. The ParnaÃba River controls a watershed of 237,000 square kilometers upstream of Teresina, while the river Poty, controls a watershed of 51,400 kmÂ. The main hydrological characteristic of floods in the ParnaÃba and Poty rivers is that ParnaÃba River floods are likely to partial control from the gates of Hydroelectric Power Plant (HPP) Good Hope, whereas such control does not exist to floods arising from the Poty River basin. This study examined the question interference flooding of Poty river with minor drainage system formed by affluent urban galleries cross the same, noting the possibility of drowning and backwater Poty river on the galleries certain conditions of hydrological floods. Analyzed the case of the full 2009 in the transverse drainage system to Poty River, which caused the flood diverse neighborhoods, because of backwater due to the increase of share of the Poty river water level d greater than the level of the upper generating lines of the galleries cross. It was found that, because of desague quotas of galleries Spring neighborhood in Poty river, the floods of the river with two-year return period (TR = 2 years), are sufficient to promote the reverse flow in the gallery system and the Flood connected urban areas. It is concluded that there is need for structural measures to solve this problem, from, or control of Poty river floods through the sump, as a future dam Castle of PiauÃ, or from use of urban detention basins, locks tide and pumping system of rainwater in interconnected basins with the Poty River.