Prior work has indicated that preventing Cdc42 interacting with its downstream effector proteins can reverse Ras-driven oncogenesis. The experiments demonstrating this used the G protein binding region (GBD) of the Cdc42-specific effector ACK, which is 42 amino acids long and binds with 40 nM affinity. The aim of this work was to find a peptide which exhibits similar effects in reversing oncogenic characteristics in cells but with more promising therapeutic properties: for example, a smaller size, improved binding and improved protease resistance. Firstly, the Cdc42-ACK binding interface was characterised thermodynamically, producing a comprehensive dataset of the contribution of individual ACK residues to complex affinity. This information revealed regions of the ACK GBD with higher concentrations of vital interactions but also residues that were unimportant for maintaining affinity. An \emph{in vitro} display technology (CIS-display) was employed to select for shorter peptides with improved binding to Cdc42. By selecting the best binders from libraries based on the ACK GBD, peptides have been generated that are half the length of the full binding domain but bind with affinities approaching the wild-type ($\approx$100 nM). More interestingly, a serendipitous discovery in a na\"{\i}ve cyclic library revealed a 16-residue sequence that binds with 350 nM affinity, subsequently called C1. The biophysical properties of selected peptides were characterised and demonstrate that C1 is reliant on an intramolecular disulphide bond for tight binding. An N-terminal nona-arginine sequence was added to C1 to facilitate entry into cells: internalisation was confirmed by confocal microscopy. Subsequently it was found that C1 reduced signalling through the ACK and PAK effector pathways, negatively impinging on MAPK signalling. Levels of signalling returned to baseline within 24 hours, however, and the transiency of the effect was thought to be linked to peptide degradation: an effect likely in a construct dependent on a disulphide bond for cyclisation and binding affinity. Subsequent maturation of C1 using a focussed CIS-display library has selected second generation peptides. These have been characterized and display binding affinities to Cdc42 of $\approx$20 nM: a 17-fold increase in binding over C1. This has enhanced the affinity to a level even higher than wild-type ACK and should improve the cellular potency of the peptides identified in this selection. %any more?! Having successfully selected peptides both shorter in length and with higher affinity than the wild-type sequence, efforts were channelled into developing a method to cyclize the peptide by a chemical linkage that would be stable in a cellular environment. The most successful approach involved desulphurisation of the disulphide bond to a thioether, making the cyclic linkage non-labile in the reducing environment of the cytosol, while retaining original binding affinity. The peptides developed in this work bind to Cdc42 with nanomolar affinity \emph{in vitro} and can enter cells and impact upon signalling processes connected with oncogenesis. As such, they provide a potential therapeutic lead for future development.

This thesis deals with a proposal for flood area in cadastral district of a town Hluk. Proposed area is defined from 12,805 to 15,495 rkm, total lenght of proposal is 2,69 km. Data for the creation of flood area of Hluk were provided by The Moravia River Basin, s.e. Brno. The analysis of flood area was done by using the computer program HEC - RAS. The final flood area for proposed flow Q100 was done in the computer program AutoCAD. The thesis is complemented by drawing documentation and photografic documentation. Key words: flood, HEC - RAS, transverse profile, the river Okluky

This thesis is focused to flood protection in Bělá nad Radbuzou. Flood protection is designed only for central part of this town, there are, in the central part, most interesting buildings, like city office, shopes, hotel. Protection of buildings, situated in pheriphery in this town are not solved, because of economic and esthetic reasons. Purpose of this work is solution of flood protection in downtown, in range of documentation for area project. This thesis is focused in the first step to detected floods lines and submersion of buildings. In this work are solved suitable grounds for find correct trace of flood protection. Next step is hydrotechnical modelling of water surface for Q5, Q20, and mainly for Q100. Then are solved height and direction of flood protection. In this work are solved statics paramerters of flood protection and separately is created designing part. Economic part and calculating acreage is solved too. In conclusion is complex valorization of flood defences and calculating of total costs. This work were solved on foundations of hydrologic and geodetic data. Data were proces in softwares HEC-RAS, ArcGis, Kros plus and AutoCad. Contribution of this thesis si solving and calculating range flood protection for this town. The main purpose is solved direction and height of flood protection and calculating finance part of this construction. The results of this thesis shows a comprehensive summary about flood protection in Bělá nad Radbuzou.

During the past decade, a series of record flood stages have occurred along the Tisza River, resulting in extensive damage and displacing the local floodplain population. Previous research on the Tisza River in Hungary showed increases in flood stages for fixed discharges (above bankfull). These results suggest that a loss of conveyance has taken place on the Tisza River, contributing to recent record flood levels. In order to assess the potential causes of flood conveyance losses, new hydrological and geospatial data were obtained from the Hungarian Federal Hydrological Authority (VITUKI) in order to develop hydrodynamic models for two reference conditions, 1979 and 1999, along two study reaches on the Middle Tisza River. In addition to these models of actual conditions at each time step (i.e., "retro-models"), four "scenario models" were developed in order to test the individual impacts of each of the hypothesized causal mechanisms: 1) channel geometry, 2) levees, 3) floodplain roughness (land cover), and (4) channel roughness. Comparison of the models for actual conditions ("retro-model") and the scenario models allows for quantitative assessments of the impacts of each of these parameters on flood conveyance. In addition to these four scenario models, an additional land cover scenario-model was created to further assess the impact of floodplain roughness on stage. Assessment of the two retro-models showed changes in flood stage along both study reaches over the 20-year time step. Along the upper study reach, changes in stage ranged between 0.64 and 1.64 m. On the lower study reach, changes in stage ranged from 0 to 1.75 m. These changes in stage were larger on average than changes in stage previously detected by Venzcel, 2008. Contributions from the channel geometry scenario model were significant on the upper study reach where channel geometry decreased flood stage by up to 0.58 m at Kisköre over the 20-year time step. This was attributed to the dam that was constructed immediately upstream from the Kisköre gauge on the upper study reach. Construction of a dam would cause incision downstream, and therefore, a decrease in flood stage over time due to channel geometry. On the lower study reach, change in stage due to channel geometry was negligible. Contributions from the levee scenario model were negligible on both the upper and lower study reach with a maximum change in stage over the 20-year time step at only 0.11 m. However, during the time step analyzed, no significant change in levee configuration occurred. Changes in stage due to changes in land cover were also negligible along both study reaches. An additional land cover scenario model was created to assess the impact of land cover change on modern flood levels. This scenario model set Manning's n values for floodplain roughness to 0.04, which approximates roughness for pasture and cropland. This scenario model showed that flood stages will decrease by 0.34-0.40 m, but only if the entire floodplain is converted from woodland to pasture/cropland. Channel roughness accounted for the majority of change in stage during the 20-year time step. Along the upper study reach, channel roughness accounted for an average of 1.51 m of change over the 20-year time step. On the lower study reach, channel roughness accounted for 1.03 m of change. Change in the stage/discharge relationship is the best explanation for changes in stage due to channel roughness. Most likely, the channel did not experience such a large change in roughness during the 20-year time step. Instead, the two flood years used in this analysis were different "types" of floods (with differing degrees of hysteresis), and the stage/discharge relationships could not be easily compared. Comparing these two floods may have exaggerated the total change in stage between the two retro-models. Backwater effects are a likely explanation for the change in hysteresis between the two flood years.

The RAB guanosine triphosphates (RAS-related in brain) belong to the Ras superfamily of GTPases, and loss of RAB 25 expression has been reported in a number of breast cancer cases containing H-Ras point mutations, particularly triple negative breast cancers (TNBC), one of the most aggressive subtypes of breast cancer and associated with a poor prognosis. The mechanism involved in the progression of these tumors is poorly understood. In this study, we are trying to understand if loss of RAB25 expression in Human Mammary Epithelial Cell (HMEC) lines co-operates with H-Ras mutations and contributes to tumorigenesis. HMEC were immortalized by transduction with LXSN CDK4 R24C, a mutant form of cyclin-dependent kinase, followed by transduction with hTERT, catalytic subunit of the telomerase enzyme that permits the cells to exceed the Hayflick Limit and become immortal. We have found that with loss of RAB25 and over expression of mutant H-Ras61L, immortal HMEC undergo transformation. We have looked into the co-operativity between loss of Rab25 and H-Ras61L mutant by in-vitro studies to show their anchorage independent growth and increased ability to migrate. Furthermore, cells express low CD24, high CD44, and very low levels of Claudin indicating that cells acquire stem-like properties upon transformation. Loss of RAB25 and over-expression of H-ras61L resulted in increased expression of transcription markers Snail and Slug that drive these cells to lose E-cadherin and undergo Epithelial Mesenchymal Transition (EMT). This study shows that loss of RAB25 and over-expression of mutant H-Ras can transform HMEC and give rise to mesenchymal stem-like tumors. Our findings reveal that RAB25 functions as a tumor suppressor gene, and loss of RAB25 could serve as a novel biomarker in the prognosis of Claudin-low type of TNBC.

Dam failure mechanism produces the rapidly varied unsteady flow situation and the appropriate analysis to determine the flow condition is necessary. Over the world, more than 80,000 dams were constructed. There have been more than 200 distinguished dam failures occurred within the twentieth century. The history of dam construction exists together with the probability of dam failure causing casualties and catastrophic situations. As climate change effect has caused the change in flow situations, the safety concern in the dam is also necessary. Casualties and damages due to dam break events depend upon the depth, flow velocity, population distribution as per geography and warning time related to the time to reach the peak flow to the downstream areas. Prediction of actual breaching scenario is not certain and is related to the geographical and geological features of the site, embankment type, type of breach, reservoir storage and flow conditions. Estimating the accurate breaching scenarios and modeling of the dam break situation to characterize the hydrodynamic risk is necessary. Among the numerous techniques of modeling dam break situation, this study focused on the use of HEC-RAS for analyzing the dam break situation. Most of the simulation of a dam break situation used one-dimensional analysis to solve flow conditions after the break of the dam. The Latest development of HEC-RAS 2D capabilities is also used in conjunction with 1D HEC-RAS dam break analysis to compare and explore both analysis capabilities of HEC-RAS. The effect of HEC-RAS simulation altering the breaching conditions is analyzed for the dam failure case of Big Bay dam located in Lamar County, Mississippi. The study area is chosen to obtain the simulation of piping dam failure, which was the real cause of the dam failure event. In addition, the overtopping failure parameters established by the different breaching regression equations were analyzed. Results obtained with both one- dimensional and two- dimensional analysis is compared along with the modeling procedure and concept of analysis. From the analysis, it is found that the time of peak water surface elevation and its magnitude is responsible in determining the extent of vulnerable areas to the dam break scenarios. The present study showed the variation in peak flow condition between different breach parameters. Breach bottom width found to be more sensitive parameters in dam failure events. HEC-RAS analysis is found to be suitable to predict the uncertain hydraulic behavior of dam break situation.

No description available.

No description available.

Following starvation, Dictyostelium discoideum cells aggregate, a response that requires chemotaxis to cyclic AMP (cAMP) and the relay of the cAMP signal by the activation of adenylyl cyclase (ACA). Insertional inactivation of the rasG gene resulted in delayed aggregation and a partial inhibition of early gene expression, suggesting that RasG does have a role in early development. When the responses of rasG⁻ cells to cAMP were compared with the responses of rasC⁻ strain, these studies revealed that signal transduction through RasG is more important in chemotaxis and early gene expression, but that signal transduction through RasC is more important in ACA activation. Characterization of a rasC⁻/rasG⁻ mutant revealed that both cAMP chemotaxis and adenylyl cyclase (ACA) activation were negligible in this strain. The ectopic expression of carA from the actin 15 promoter restored early developmental gene expression to the rasC⁻/rasG⁻ strain, rendering it suitable for an analysis of cAMP signal transduction. Since there was negligible signaling through either the cAMP chemotactic pathway or the adenylyl cyclase activation pathway in this strain, it is clear that RasG and RasC are the only two Ras subfamily proteins that directly control these pathways. The mutational analysis of Switch I and Switch II regions also defined the key residues that generate functional differences between RasC and RasG. Rap1 is also activated in response to cAMP but its position in the signal transduction cascade was clarified by the finding that its activation was totally abolished in rasC⁻/rasG⁻/[act15]:carA and in rasG⁻ cells, but only slightly reduced in rasC⁻ cells. The finding that in vitro guanylyl cyclase activation is also abolished in the rasC/rasG⁻4act15]:carA strain identifies RasG⁻/RasC⁻ as the presumptive monomeric GTPases required for this activation. The phenotypes of the vegetative ras null mutants were also examined. The results indicate that RasG plays an important role in cytokinesis. The partial absence of chemotaxis to folate in rase cells compared to the total absence of chemotaxis to folate in rasC⁻/rasG⁻, and rasC⁻/rasG⁻/[act15]:carA cells suggests a compensatory role of RasC for RasG during this process, a similar phenomenon to that observed for cAMP chemotaxis by aggregating cells. / Science, Faculty of / Microbiology and Immunology, Department of / Graduate

Denna studie beskriver svarta kvinnors erfarenheter och upplevelser av den perinatala vården i Sverige. Ras är ett för många obekvämt begrepp i Sverige, ändå tycks ras i social mening påverka ens möjligheter i samhället. Det saknas statistik utifrån ras och hudfärg i Sverige. Forskning på hur just ens hudfärg påverkar den vård en får saknas i svensk kontext. Genom en kvalitativ innehållsanalys har därför svarta kvinnors beskrivningar av möten och upplevelse med/av vården analyserats för att söka svaren till studiens frågeställning. Det vill säga, om och hur yttrar sig afrofobi i den perinatala vården i Sverige? Det empiriska materialet är insamlat från flera olika mediala forum, böcker, sociala media och nyhetsmedia. Analysen tar avstamp i kategoriserings- och stereotypifieringsteori samt kompletteras detta med att beskriva hur stereotypifiering påverkas av rasideologier formade i historien. Vidare beskrivs tidigare forskning i temat, ur både svensk och internationell kontext. Syftet med studien är att undersöka om och beskriva hur afrofobi kan yttra sig i den perinatala vården i Sverige. Studiens resultat kan endast svara för hur afrofobi upplevs vara förekommande i just de studerade sammanhangen, vilket innebär att slutsatserna inte kan generaliseras för hela befolkningen av afrosvenskar. Slutsatsen är att afrofobi upplevs, av dessa svarta kvinnor, vara vanligt förekommande i den perinatala vården i Sverige. Dessa studerade kvinnors erfarenheter av den perinatala vården tyder på att afrosvenska kvinnors smärta inte tas på allvar och att dessa afrosvenska kvinnor blir homogeniserade utifrån en stereotyp föreställning om den svarta kvinnan. Vidare tycks det finnas både strukturella och internaliserade hinder för att få bukt med problemen.