932 resultados para Damage of flood


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Los mapas de riesgo de inundaciones deberían mostrar las inundaciones en relación con los impactos potenciales que éstas pueden llegar a producir en personas, bienes y actividades. Por ello, es preciso añadir el concepto de vulnerabilidad al mero estudio del fenómeno físico. Así pues, los mapas de riesgo de daños por inundación son los verdaderos mapas de riesgo, ya que se elaboran, por una parte, a partir de cartografía que localiza y caracteriza el fenómeno físico de las inundaciones, y, por la otra, a partir de cartografía que localiza y caracteriza los elementos expuestos. El uso de las llamadas «nuevas tecnologías», como los SIG, la percepción remota, los sensores hidrológicos o Internet, representa un potencial de gran valor para el desarrollo de los mapas de riesgo de inundaciones, que es, hoy por hoy, un campo abierto a la investigación

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Malondialdehyde (MDA) is a small reactive molecule which occurs ubiqui¬tous among eukaryotes. Interest in this molecule stems from the fact that it can be highly reactive. In green tissues of plants it is apparently formed pre¬dominantly by reactive oxygen species (ROS)-mediated non-enzymatic oxi¬dation (nLPO) of triunsaturated fatty acids (TFAs). MDA which is formed by nLPO is widely used as a disease marker and is regarded to be a cel-lular toxin. Surprisingly, sites of ROS production like mitochondria and chloroplasts possess membranes which are enriched in nLPO-prone polyun¬saturated fatty acids (PUFAs). In this work we showed that chloroplasts are the major site of MDA production in leaves of adult Arabidopsis thaliana plants, whereas analyses in seedlings revealed accumulation in meristematic tissues like the root tip, lateral roots and the apical meristem region. Char-acterizing the MDA pools in more detail, we could show that MDA in plants was predominantly present in a free, non-reactive enolate form. This might explain why it is tolerated in sites where its protonated form could poten¬tially damage the genome and proteome. Analyzing the biological fate of MDA in leaves using labeled MDA-isotopes. we were able to show that MDA is metabolized and used to assemble lipids. The major end-point metabolite was identified as 18:3-16:3-monqgalactosyldiacylglycerol (MGDG), which is the most abundant lipid in chloroplasts. We hypothesize that PUFAs in sites of ROS production, like at PS II in chloroplasts, might act as buffers pre¬venting damage of proteins, thereby generating molecules such as MDA. The MDA produced in this way appears predominantly in a non-reactive enolate form in the cell until it fulfills a biological function or until it is metabo¬lized in order to assemble polyunsaturated MGDGs. Additionally, nLPO has been reported to increase in pathogenesis and we challenged seedlings and adult plants with necrotrophic fungi. Monitoring MDA during the in¬fections, we found MDA pools in seedlings were highly inducible although they were tightly controlled in the leaves of adult plants. - Malondialdehyde (MDA) est une petite molecule réactive présente de manière ubiquitaire dans les eucaryotes. L'intérêt de cette molécule vient du fait que celle-ci pourrait être très réactive. Dans les tissus verts des plantes, la majorité du MDA est apparement formée par l'oxydation non-enzymatique (nLPO) des acides gras polyinsaturés (PUFAs) transmis par des espèces ac¬tives d'oxygène (ROS). Le MDA formé par nLPO est souvent utilisé comme marqueur de maladies et il est considéré comme une toxine cellulaire. Etonnament, les sites de production comme les mitochondries et les chloro- plastes sont riches en PUFAs qui sont sensibles à la nLPO. Dans cette thèse nous montrons que les chloroplastes répresentent le site de production de MDA dans les feuilles adultes d'Arabidopsis thaliana. Les analyses de MDA dans les plantules ont révélé que le MDA s'accumule dans les tissus meris- tematiques comme celles de la pointe de la racine, des racines latéralles et du meristème apical. Par la caractérisation du MDA présent nous avons pu montrer que la majorité du MDA était présent sous la forme d'un énolate non-réactif. Ceci pourrait expliquer pourquoi le MDA est toléré dans les sites où il pourrait casser le genome ou le protéome s'il est présent sous sa forme protonée. Les analyses du devenir du MDA dans les feuilles par des isotopes du MDA ont montré que celui-ci est metabolisé et utilisé pour assembler des lipides. Le lipide majoritairement métabolisé a été identifié comme étant le 18:3-16:3-monogalactosyldiacylglycerole (MGDG); le lipide le plus abondant dans les chloroplastes. Nous supposons que la présence des PUFAs dans les sites de production du ROS, tout comme le PS II dans les chloroplastes, pourrait jouer un rôle de tampon pour prevenir les protéines de différentes dégradations et ainsi générer des molécules telle que le MDA. La majorité du MDA produit par cette réaction est présente dans la cellule sous la forme d'énolate non-réactif, jusqu'au moment de son utilisation ou lorsqu'il serra metabolisé pour produire des MGDGs polyinsaturés. De plus, il a été décrit que nLPO pourait augmenter dans la pathogenèse, et nous avons testé des plantes adultes et des plantules en présence de champignons nécrotrophiques. L'observation du MDA pendant les infections a montré que les concentrations en MDA sont fortement induites dans les plantules mais contrôlées dans les plantes adultes.

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Cervical cancer results from infection with high-risk type human papillomaviruses (HPV). Therapeutic vaccines aiming at controlling existing genital HPV infections and associated lesions are usually tested in mice with HPV-expressing tumor cells subcutaneously implanted into their flank. However, effective vaccine-induced regression of these ectopic tumors strongly contrasts with the poor clinical results of these vaccines produced in patients with HPV-associated genital neoplasia. To assess HPV therapeutic vaccines in a more relevant setting, we have, here, established an orthotopic mouse model where tumors in the genital mucosa (GM) develop after an intravaginal instillation of HPV16 E6/E7-expressing tumor cells transduced with a luciferase-encoding lentiviral vector for in vivo imaging of tumor growth. Tumor take was 80-90% after nonoxynol-9 induced damage of the epithelium. Tumors remained localized in the genital tract, and histological analysis showed that most tumors grew within the squamous epithelium of the vaginal wall. Those tumors induced (i) E7-specific CD8 T cells restricted to the GM and draining lymph nodes, in agreement with their mucosal location and (ii) high Foxp3+ CD4+ infiltrates, similarly to those found in natural non-regressing HPV lesions. This novel genital HPV-tumor model by requiring GM homing of vaccine-induced immune responses able to overcome local immuno-suppression may be more representative of the situation occurring in patients upon therapeutic vaccination.

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This work deals with the elaboration of flood hazard maps. These maps reflect the areas prone to floods based on the effects of Hurricane Mitch in the Municipality of Jucuarán of El Salvador. Stream channels located in the coastal range in the SE of El Salvador flow into the Pacific Ocean and generate alluvial fans. Communities often inhabit these fans can be affected by floods. The geomorphology of these stream basins is associated with small areas, steep slopes, well developed regolite and extensive deforestation. These features play a key role in the generation of flash-floods. This zone lacks comprehensive rainfall data and gauging stations. The most detailed topographic maps are on a scale of 1:25 000. Given that the scale was not sufficiently detailed, we used aerial photographs enlarged to the scale of 1:8000. The effects of Hurricane Mitch mapped on these photographs were regarded as the reference event. Flood maps have a dual purpose (1) community emergency plans, (2) regional land use planning carried out by local authorities. The geomorphological method is based on mapping the geomorphological evidence (alluvial fans, preferential stream channels, erosion and sedimentation, man-made terraces). Following the interpretation of the photographs this information was validated on the field and complemented by eyewitness reports such as the height of water and flow typology. In addition, community workshops were organized to obtain information about the evolution and the impact of the phenomena. The superimposition of this information enables us to obtain a comprehensive geomorphological map. Another aim of the study was the calculation of the peak discharge using the Manning and the paleohydraulic methods and estimates based on geomorphologic criterion. The results were compared with those obtained using the rational method. Significant differences in the order of magnitude of the calculated discharges were noted. The rational method underestimated the results owing to short and discontinuous periods of rainfall data with the result that probabilistic equations cannot be applied. The Manning method yields a wide range of results because of its dependence on the roughness coefficient. The paleohydraulic method yielded higher values than the rational and Manning methods. However, it should be pointed out that it is possible that bigger boulders could have been moved had they existed. These discharge values are lower than those obtained by the geomorphological estimates, i.e. much closer to reality. The flood hazard maps were derived from the comprehensive geomorphological map. Three categories of hazard were established (very high, high and moderate) using flood energy, water height and velocity flow deduced from geomorphological and eyewitness reports.

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Research has found that both flood magnitude and frequency in the UK may have increased over the last five decades. However, evaluating whether or not this is a systematic trend is difficult because of the lack of longer records. Here we compile and consider an extreme flood record that extends back to 1770. Since 1770, there have been 137 recorded extreme floods. However, over this period, there is not a unidirectional trend of rising extreme flood risk over time. Instead, there are clear flood-rich and flood-poor periods. Three main flood-rich periods were identified: 18731904, 19231933, and 1994 onwards. To provide a first analysis of what is driving these periods, and given the paucity of more sophisticated datasets that extend back to the 18th century, objective Lamb weather types were used. Of the 27 objective Lamb weather types, only 11 could be associated with the extreme floods during the gauged period, and only 5 of these accounted for > 80% of recorded extreme floods The importance of these five weather types over a longer timescale for flood risk in Carlisle was assessed, through calculating the proportion of each hydrological year classified as being associated with these flood-generating weather types. Two periods clearly had more than the average proportions of the year classified as one of the flood causing weather types; 19001940 and 19832007; and these two periods both contained flood-rich hydrological records. Thus, the analysis suggests that systematic organisation of the North Atlantic climate system may be manifest as periods of elevated and reduced flood risk, an observation that has major implications for analyses that assume that climatic drivers of flood risk can be either statistically stationary or are following a simple trend. Copyright (c) 2011 Royal Meteorological Society

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The purpose of this research was to evaluate the materials Iowa uses as a granular subbase and to determine if it provides adequate drainage. Numerous laboratory and in-situ tests were conducted on the materials currently being used in Iowa. The follow conclusions can be made based on the test results: 1. The crushed concrete that is used as a subbase material has a relatively low permeability compared to many other materials used by other states. 2. Further research and tests are needed to find the necessary parameters for crushed concrete to make sure it is providing its optimum drainage and preventing premature damage of the pavement. 3. We have definitely made improvements in drainage in the past few months, but there are many areas that we can improve on that will increase the permeability of this material and insure that the pavement system is safe from premature damage due to water. The current gradation specification for granular subbase material at the start of this study was: Sieve # % Passing 1” 100 #8 10-35 #50 0-15 #200 0-6

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PURPOSE: To evaluate the photodynamic potential of a new hydrosoluble photosensitizer (WST-11, Stakel; Steba Biotech, Toussus-Le-Noble, France), for use in occlusion of normal choroidal vessels in the rabbit eye and CNV (choroidal neovascularization) in the rat eye. METHODS: Occlusive and nonocclusive parameters of Stakel and verteporfin photodynamic therapy (PDT) were investigated in pigmented rabbits. Eyes were followed by fluorescein angiography (FA) and histology at various intervals after PDT. RESULTS: When occlusive parameters (fluence of 50 J/cm(2), 5 mg/kg drug dose and DLI [distance to light illumination] of 1 minute) were used, Stakel PDT was efficient immediately after treatment without associated structural damage of the RPE and retina overlying the treated choroid in the rabbit eye. Two days later, total occlusion of the choriocapillaries was seen in 100% of the treated eyes, along with accompanying histologic structural changes in the overlying retina. When the occlusive parameters (fluence, 100 J/cm2; drug dose, 12 mg/m2; and DLI, 5 minutes) of verteporfin PDT were used, occlusion of the choriocapillaries was observed in 89% of the treated eyes. Histology performed immediately after treatment demonstrated structural damage of the overlying retina and RPE layer. Weaker, nonocclusive Stakel PDT parameters (25 J/cm2, 5 mg/kg, and DLI of 10 minutes) did not induce choriocapillary occlusion or retinal lesions on FA or histology. Weaker, nonocclusive verteporfin PDT parameters (10 J/cm2, 0.2 mg/kg, and DLI of 5 minutes) did not induce choriocapillary occlusion. However, histology of these eyes showed the presence of damage in the retinal and choroidal tissues. Moreover, preliminary results indicate that selective CNV occlusion can be achieved with Stakel PDT in the rat eye. CONCLUSIONS: Unlike verteporfin PDT, Stakel PDT does not cause direct damage to the RPE cell layer or retina. These observations indicate that Stakel PDT may have a high potential for beneficial therapeutic outcomes in treatment of AMD.

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Severe flooding occurred during July 19-25, 1999, in the Wapsipinicon and Cedar River Basins following two thunderstorms over northeast Iowa. During July 18-19, as much as 6 inches ofrainfall was centered over Cerro Gordo, Floyd, Mitchell, and Worth Counties. During July 20-21, a second storm occurred in which an additional rainfall of as much as 8 inches was centered over Chickasaw and Floyd Counties. The cumulative effect of the storms produced floods with new maximum peak discharges at the following streamflow-gaging stations: Wapsipinicon River near Tripoli, 19,400 cubic feet per second; Cedar River at Charles City, 31,200 cubic feet per second (recurrence interval about 90 years); Cedar River at Janesville, 42,200 cubic feet per second (recurrence interval about 80 years); and Flood Creek near Powersville, 19,000 cubic feet per second. Profiles of flood elevations for the July 1999 flood are presented in this report for selected reaches along the Wapsipinicon, Cedar, and Shell Rock Rivers and along Flood Creek. Information about the river basins, rain storms, and flooding are presented along with information on temporary bench marks and reference points in the Wapsipinicon and Cedar River Basins.

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Major highway concrete pavements in Iowa have exhibited premature deterioration attributed to effects of ettringite formation, alkali-silica expansive reactions, and to frost attack, or some combination of them. These pavements were constructed in the mid- 1980s as non-reinforced, dual-lane, roads ranging in thickness between 200 mm and 300 mm, with skewed joints reinforced with dowels. Deterioration was initially recognized with a darkening of joint regions, which occurred for some pavements as soon as four years after construction. Pavement condition ranges from severe damage to none, and there appeared to be no unequivocal materials or processing variables correlated with failure. Based upon visual examinations, petrographic evaluation, and application of materials models, the deterioration of concrete highway pavements in Iowa appear related to a freeze-thaw failure of the coarse aggregate and the mortar. Crack patterns sub-parallel to the concrete surface transecting the mortar fraction and the coarse aggregate are indicative of freeze-thaw damage of both the mortar and aggregate. The entrained air void system was marginal to substandard, and filling of some of the finer-sized voids by ettringite appears to have further degraded the air void system. The formation of secondary ettringite within the entrained air voids probably reflects a relatively high degree of concrete saturation causing the smaller voids to be filled with pore solution when the concrete freezes. Alkali-silica reaction (ASR) affects some quartz and shale in the fine aggregate, but is not considered to be a significant cause of the deterioration. Delayed ettringite formation was not deemed likely as no evidence of a uniform paste expansion was observed. The lack of field-observed expansion is also evidence against the ASR and DEF modes of deterioration. The utilization of fly ash does not appear to have affected the deterioration as all pavements with or without fly ash exhibiting substantial damage also exhibit significant filling of the entrained air void system, and specimens containing fly ash from sound pavements do not have significant filling. The influence of the mixture design, mixing, and placing must be evaluated with respect to development of an adequate entrained air void system, concrete homogeneity, longterm drying shrinkage, and microcracking. A high-sand mix may have contributed to the difficult mixture characteristics noted upon placement and exacerbate concrete heterogeneity problems, difficulty in developing an adequate entrained air void system, poor consolidation potential, and increased drying shrinkage and cracking. Finally, the availability of moisture must also be considered, as the secondary precipitation of ettringite in entrained air voids indicates they were at least partially filled with pore solution at times. Water availability at the base of the slabs, in joints, and cracks may have provided a means for absorbing water to a point of critical saturation.

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Large Dynamic Message Signs (DMSs) have been increasingly used on freeways, expressways and major arterials to better manage the traffic flow by providing accurate and timely information to drivers. Overhead truss structures are typically employed to support those DMSs allowing them to provide wider display to more lanes. In recent years, there is increasing evidence that the truss structures supporting these large and heavy signs are subjected to much more complex loadings than are typically accounted for in the codified design procedures. Consequently, some of these structures have required frequent inspections, retrofitting, and even premature replacement. Two manufacturing processes are primarily utilized on truss structures - welding and bolting. Recently, cracks at welding toes were reported for the structures employed in some states. Extremely large loads (e.g., due to high winds) could cause brittle fractures, and cyclic vibration (e.g., due to diurnal variation in temperature or due to oscillations in the wind force induced by vortex shedding behind the DMS) may lead to fatigue damage, as these are two major failures for the metallic material. Wind and strain resulting from temperature changes are the main loads that affect the structures during their lifetime. The American Association of State Highway and Transportation Officials (AASHTO) Specification defines the limit loads in dead load, wind load, ice load, and fatigue design for natural wind gust and truck-induced gust. The objectives of this study are to investigate wind and thermal effects in the bridge type overhead DMS truss structures and improve the current design specifications (e.g., for thermal design). In order to accomplish the objective, it is necessary to study structural behavior and detailed strain-stress of the truss structures caused by wind load on the DMS cabinet and thermal load on the truss supporting the DMS cabinet. The study is divided into two parts. The Computational Fluid Dynamics (CFD) component and part of the structural analysis component of the study were conducted at the University of Iowa while the field study and related structural analysis computations were conducted at the Iowa State University. The CFD simulations were used to determine the air-induced forces (wind loads) on the DMS cabinets and the finite element analysis was used to determine the response of the supporting trusses to these pressure forces. The field observation portion consisted of short-term monitoring of several DMS Cabinet/Trusses and long-term monitoring of one DMS Cabinet/Truss. The short-term monitoring was a single (or two) day event in which several message sign panel/trusses were tested. The long-term monitoring field study extended over several months. Analysis of the data focused on trying to identify important behaviors under both ambient and truck induced winds and the effect of daily temperature changes. Results of the CFD investigation, field experiments and structural analysis of the wind induced forces on the DMS cabinets and their effect on the supporting trusses showed that the passage of trucks cannot be responsible for the problems observed to develop at trusses supporting DMS cabinets. Rather the data pointed toward the important effect of the thermal load induced by cyclic (diurnal) variations of the temperature. Thermal influence is not discussed in the specification, either in limit load or fatigue design. Although the frequency of the thermal load is low, results showed that when temperature range is large the restress range would be significant to the structure, especially near welding areas where stress concentrations may occur. Moreover stress amplitude and range are the primary parameters for brittle fracture and fatigue life estimation. Long-term field monitoring of one of the overhead truss structures in Iowa was used as the research baseline to estimate the effects of diurnal temperature changes to fatigue damage. The evaluation of the collected data is an important approach for understanding the structural behavior and for the advancement of future code provisions. Finite element modeling was developed to estimate the strain and stress magnitudes, which were compared with the field monitoring data. Fatigue life of the truss structures was also estimated based on AASHTO specifications and the numerical modeling. The main conclusion of the study is that thermal induced fatigue damage of the truss structures supporting DMS cabinets is likely a significant contributing cause for the cracks observed to develop at such structures. Other probable causes for fatigue damage not investigated in this study are the cyclic oscillations of the total wind load associated with the vortex shedding behind the DMS cabinet at high wind conditions and fabrication tolerances and induced stresses due to fitting of tube to tube connections.

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A series of 4 experiments examined the performance of rats with retrohippocampal lesions on a spatial water-maze task. The animals were trained to find and escape onto a hidden platform after swimming in a large pool of opaque water. The platform was invisible and could not be located using olfactory cues. Successful escape performance required the rats to develop strategies of approaching the correct location with reference solely to distal extramaze cues. The lesions encompassed the entire rostro-caudal extent of the lateral and medial entorhinal cortex, and included parts of the pre- and para-subiculum, angular bundle and subiculum. Groups ECR 1 and 2 sustained only partial damage of the subiculum, while Group ECR+S sustained extensive damage. These groups were compared with sham-lesion and unoperated control groups. In Expt 1A, a profound deficit in spatial localisation was found in groups ECR 1 and ECR+S, the rats receiving all training postoperatively. In Expt 1B, these two groups showed hyperactivity in an open-field. In Expt 2, extensive preoperative training caused a transitory saving in performance of the spatial task by group ECR 2, but comparisons with the groups of Expt 1A revealed no sustained improvement, except on one measure of performance in a post-training transfer test. All rats were then given (Expt 3) training on a cueing procedure using a visible platform. The spatial deficit disappeared but, on returning to the normal hidden platform procedure, it reappeared. Nevertheless, a final transfer test, during which the platform was removed from the apparatus, revealed a dissociation between two independent measures of performance: the rats with ECR lesions failed to search for the hidden platform but repeatedly crossed its correct location accurately during traverses of the entire pool. This partial recovery of performance was not (Expt 4) associated with any ability to discriminate between two locations in the pool. The apparently selective recovery of aspects of spatial memory is discussed in relation to O'Keefe and Nadel's (1978) spatial mapping theory of hippocampal function. We propose a modification of the theory in terms of a dissociation between procedural and declarative subcomponents of spatial memory. The declarative component is a flexible access system in which information is stored in a form independent of action. It is permanently lost after the lesion. The procedural component is "unmasked" by the retrohippocampal lesion giving rise to the partial recovery of spatial localisation performance.

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Hydrograph convolution is a product of tributary inputs from across the watershed. The time-space distribution of precipitation, the biophysical processes that control the conversion of precipitation to runoff and channel flow conveyance processes, are heterogeneous and different areas respond to rainfall in different ways. We take a subwatershed approach to this and account for tributary flow magnitude, relative timing, and sequencing. We hypothesize that as the scale of the watershed increases so we may start to see systematic differences in subwatershed hydrological response. We test this hypothesis for a large flood (T >100 years) in a large watershed in northern England. We undertake a sensitivity analysis of the effects of changing subwatershed hydrological response using a hydraulic model. Delaying upstream tributary peak flow timing to make them asynchronous from downstream subwatersheds reduced flood magnitude. However, significant hydrograph adjustment in any one subwatershed was needed for meaningful reductions in stage downstream, although smaller adjustments in multiple tributaries resulted in comparable impacts. For larger hydrograph adjustments, the effect of changing the timing of two tributaries together was lower than the effect of changing each one separately. For smaller adjustments synergy between two subwatersheds meant the effect of changing them together could be greater than the sum of the parts. Thus, this work shows that while the effects of modifying biophysical catchment properties diminishes with scale due to dilution effects, their impact on relative timing of tributaries may, if applied in the right locations, be an important element of flood management.

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Spectra of "white LEDs" are characterized by an intense emission in the blue region of the visible spectrum, absent in daylight spectra. This blue component and the high intensity of emission are the main sources of concern about the health risks of LEDs with respect to their toxicity to the eye and the retina. The aim of our study was to elucidate the role of blue light from LEDs in retinal damage. Commercially available white LEDs and four different blue LEDs (507, 473, 467, and 449nm) were used for exposure experiments on Wistar rats. Immunohistochemical stain, transmission electron microscopy, and Western blot were used to exam the retinas. We evaluated LED-induced retinal cell damage by studying oxidative stress, stress response pathways, and the identification of cell death pathways. LED light caused a state of suffering of the retina with oxidative damage and retinal injury. We observed a loss of photoreceptors and the activation of caspase-independent apoptosis, necroptosis, and necrosis. A wavelength dependence of the effects was observed. Phototoxicity of LEDs on the retina is characterized by a strong damage of photoreceptors and by the induction of necrosis.

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Head blight of wheat is a disease of global importance. In Brazil, it can cause damage of up to 27%. As resistant cultivars are not available yet, short-term disease control relies on the use of fungicides. The first step to reach effective management is to identify potent fungicides. In vitro experiments were conducted to determine the inhibitory concentration 50% (IC50) for mycelial growth or conidial germination, according to the chemical group of fungicides, of five Fusarium graminearum isolates of different origins. The following demethylation inhibitor (DMI) fungicides were tested: epoxiconazole, cyproconazole, metconazole, prochloraz, protioconazole and tebuconazole. In addition, azoxystrobin, kresoxim-methyl, pyraclostrobin and trifloxystrobin were included in the study, representing Quinone outside inhibitor fungicides (QoI), as well as a tubulin synthesis inhibitor, carbendazim and two ready mixtures, trifloxystrobin + tebuconazole or trifloxistrobin + prothioconazole. DMI's showed lower IC50 values compared to the QoI's. For the five tested isolates, in the overall mean, IC50 considering mycelial growth ranged for DMI's from 0.01 mg/L (metconazole, prochloraz and prothioconazole) to 0.12 mg/L (cyproconazole) and considering conidial germination for QoI's from 0.21 mg/L (azoxystrobin) to 1.33 mg/L (trifloxystrobin). The IC50 for carbendazim was 0.07 mg/L. All tested isolates can be considered sensitive to the studied DMI's, although certain differences in sensitivity could be detected between the isolates originating from one same state.

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Uskelanjoki virtaa Salon kaupungin läpi ja varsinkin jääpato tulvatilanteissa tulvavedenkorkeudet uhkaavat nousta maa-alueille. Tässä työssä tutkittiin valittujen tulvasuojelutoimenpiteiden vaikutuksia tulvavedenkorkeuksiin Uskelanjoessa sekä Salon kaupungin keskusta-alueella. Tavoitteena oli löytää Uskelanjoen tulvimisen ehkäisyyn kustannustehokas ratkaisu. Työssä mallinnettiin Uskelanjoen vedenkorkeuksia yksidimensionaalisesti käyttäen HEC-RAS -mallia. Mallinnus suoritettiin mitoitustulvalla tulvasuojelutoimenpiteille, jotka olivat jäidenpidätysrakennelmien rakentaminen, ruoppaus, pengerrys sekä näiden vaihtoehtojen yhdistelmät. Mallinnuksesta saatujen tulvavedenkorkeuksien avulla laadittiin tarkastellulta uomaosuudelta tulvavaarakartat sekä tulvavahinkoarviot. Näiden tietojen pohjalta voitiin vaihtoehtojen hyötyjä vertailla käyttämällä kustannus-hyötyanalyysia. Kustannus-hyötyanalyysin tuloksista havaittiin, että jäidenpidätysrakennelmat osoittautuivat parhaaksi tulvasuojeluvaihtoehdoksi Uskelanjoessa. Muutkin työssä tutkitut vaihtoehdot osoittautuivat kannattaviksi. Epävarmuuden kumuloituminen vedenkorkeuksien mallinnuksesta hyötyjen ja haittojen arviointiin luo oman epävarmuutensa tässä työssä laskettuihin arvoihin. Tätä epävarmuutta on tutkittu työssä käyttämällä herkkyysanalyysia. Herkkyysanalyysin tuloksia tarkastelemalla jäidenpidätysrakennelmien rakentaminen osoittautui kaikkein riskivapaimmaksi vaihtoehdoksi Uskelanjoen tulvasuojelussa.