This diploma thesis deals with the impact of real exchange rate volatility on real export of the Czech Republic. In the first part, theoretical aspects of this relationship are examined, explaining both - positive and negative ? effects on bilateral and aggregate trade flows. Further on, empirical data and econometric tools are employed to capture the relationship between real export and its main determinants for the case of Czech Republic in the past decade. After the brief theoretical introduction to time series econometrics, the particular export demand model is proposed and various cointegration techniques are explained and applied to examine the long-run equilibrium but also short-run dynamics.

The phenotypic variability in human populations is partly the result of gene polymorphisms and differential gene expression. Studying the variability of gene expression across human populations is essential to understanding the molecular basis for diversity. However, key issues remain unanswered with respect to human expression variability. For example, the role of gene methylation in expression variability is uncertain, nor is it clear what role tissue-specific factors may have. Moreover, the contribution that expression variability has in aging and development is unknown. Here we classified human genes based on their expression variability in normal human breast and brain samples and identified functional aspects associated with high and low expression variability. Interestingly, both high variability and low variability gene sets are enriched for developmentally essential genes. There is limited overlap between the variably expressed genes of different tissues, indicating that tissue-specific rather than individual-specific factors are at work. We also find that methylation likely has a key role in controlling expression variability insofar as genes with low expression variability are likely to be non-methylated. Importantly, we find that genes with high population expression variability are likely to have age-, but not sex-dependent expression. Taken together, our work indicates that gene expression variability is tissue-specific, methylation-dependent, and is an important component of the natural aging process.

Language development and the ability to access reinforcement in young children with autism may be impeded by lack of behavioral variability in verbal behavior. The purpose of this study was to investigate the effects of simultaneously teaching multiple responses and extinction of repetition on producing varied verbal behavior in young children with autism. In particular, we examined the effects of these procedures on increasing the behavioral variability of mands used to request edibles in preschool children with autism. For all three participants, neither increasing mand repertoires via teaching multiple responses, nor extinction of repetition, by themselves or in combination were effective at producing stable behavioral variability. However, antecedent strategies (presence of visual cues) were effective at producing varied manding for all three participants.

No description available.

<p>In many parts of the tropics irregular and erratic rainfall has great national economic as well as socio-economic effects. In Kenya, where a large part of the population live in rural areas and rainfed agriculture is the main livelihood, droughts and floods have farreaching impacts on communities. One form of mitigating the negative effects of drought is the implementation of simple, small-scale, low cost schemes called rainwater harvesting. This involves the capture, storing and redirection of rainfall, runoff, and groundwater. In Kenya, such schemes are being implemented in rural areas through different actors. Two Non-Governmental Organizations involved are the Kenya Rainwater Association and the German Agro Action that work in Tseikuru, a semi-arid area with water availability and sanitation issues. The main livelihood is agropastorialism and there is little experience with rainwater harvesting. Commonly, water is collected by digging shallow holes into dry river beds where groundwater tables are high. These areas are prone to contamination and could be situated many kilometres away, making water collection laborious. By implementing rainwater harvesting schemes water availability as well as water quality is expected to be improved. However, due to great rainfall variability and effects of climate change these schemes may fall short of their expectations. Also the potential change on water demand may affect communities’ response to prolonged dry spells. This study aims to examine whether the implemented rainwater harvesting schemes in rural Tseikuru are reliable in times of adverse rainfall and if increased water availability (and potentially also increased water demand) affects the communities’ vulnerability towards droughts. The study is based on interviews with local stakeholders and technicians during a Minor Field Study in Tseikuru, as well as statistical analysis on rainfall data over the area and literature studies. Results showed that rainwater harvesting schemes are generally successful in supplying readily available and safe water. However the rural population of Tseikuru have not completely abandoned their old habits of collecting water from dry riverbeds, choosing instead to treat the schemes as an alternative source to water, thereby avoiding dependency towards the schemes.</p>

In many parts of the tropics irregular and erratic rainfall has great national economic as well as socio-economic effects. In Kenya, where a large part of the population live in rural areas and rainfed agriculture is the main livelihood, droughts and floods have farreaching impacts on communities. One form of mitigating the negative effects of drought is the implementation of simple, small-scale, low cost schemes called rainwater harvesting. This involves the capture, storing and redirection of rainfall, runoff, and groundwater. In Kenya, such schemes are being implemented in rural areas through different actors. Two Non-Governmental Organizations involved are the Kenya Rainwater Association and the German Agro Action that work in Tseikuru, a semi-arid area with water availability and sanitation issues. The main livelihood is agropastorialism and there is little experience with rainwater harvesting. Commonly, water is collected by digging shallow holes into dry river beds where groundwater tables are high. These areas are prone to contamination and could be situated many kilometres away, making water collection laborious. By implementing rainwater harvesting schemes water availability as well as water quality is expected to be improved. However, due to great rainfall variability and effects of climate change these schemes may fall short of their expectations. Also the potential change on water demand may affect communities’ response to prolonged dry spells. This study aims to examine whether the implemented rainwater harvesting schemes in rural Tseikuru are reliable in times of adverse rainfall and if increased water availability (and potentially also increased water demand) affects the communities’ vulnerability towards droughts. The study is based on interviews with local stakeholders and technicians during a Minor Field Study in Tseikuru, as well as statistical analysis on rainfall data over the area and literature studies. Results showed that rainwater harvesting schemes are generally successful in supplying readily available and safe water. However the rural population of Tseikuru have not completely abandoned their old habits of collecting water from dry riverbeds, choosing instead to treat the schemes as an alternative source to water, thereby avoiding dependency towards the schemes.

We use models to simulate the real world mainly for prediction purposes. However, since any model is a simplification of reality, there remains a great deal of uncertainty even after the calibration of model parameters. The model’s identifiability of realistic model parameters becomes questionable when the watershed of interest is small, and its time of concentration is shorter than the computational time step of the model. To improve the discovery of more reliable and more realistic sets of model parameters instead of mathematical solutions, a new algorithm is needed. This algorithm should be able to identify mathematically inferior but more robust solutions as well as to take samples uniformly from high-dimensional search spaces for the purpose of uncertainty analysis. Various watershed configurations were considered to test the Soil and Water Assessment Tool (SWAT) model’s identifiability of the realistic spatial distribution of land use, soil type, and precipitation data. The spatial variability in small watersheds did not significantly affect the hydrographs at the watershed outlet, and the SWAT model was not able to identify more realistic sets of spatial data. A new populationbased heuristic called the Isolated Speciation-based Particle Swarm Optimization (ISPSO) was developed to enhance the explorability and the uniformity of samples in high-dimensional problems. The algorithm was tested on seven mathematical functions and outperformed other similar algorithms in terms of computational cost, consistency, and scalability. One of the test functions was the Griewank function, whose number of minima is not well defined although the function serves as the basis for evaluating multi-modal optimization algorithms. Numerical and analytical methods were proposed to count the exact number of minima of the Griewank function within a hyperrectangle. The ISPSO algorithm was applied to the SWAT model to evaluate the performance consistency of optimal solutions and perform uncertainty analysis in the Generalized Likelihood Uncertainty Estimation (GLUE) framework without assuming a statistical structure of modeling errors. The algorithm successfully found hundreds of acceptable sets of model parameters, which were used to estimate their prediction limits. The uncertainty bounds of this approach were comparable to those of the typical GLUE approach.

The variation of El Nino Southern Oscillation (ENSO) events from the mid-nineteenth century until the beginning of the twenty-first century is explored using an ocean reanalysis. Decadal variability and trends in the strength, frequency, duration, and propagation direction of ENSO events is investigated. The hypothesis that there are different types of ENSO and that the location of ENSO is shifting to the west Pacific is also studied. The study uses the latest version of an ocean reanalysis, called SODA 2.2.4 (Simple Ocean Data Assimilation), which covers the period from 1871 through 2008. The reanalysis uses an eddy-permitting resolution model of the ocean forced with boundary conditions available from an atmospheric reanalysis that covers the same period. SODA 2.2.4 assimilates all available hydrographic and surface marine observations of temperature and salinity to produce a "best estimate" of the ocean state in terms of temperature, current, salinity, and sea surface height. A new index based on the first moment of anomalous sea surface temperature over the equatorial Pacific is used to describe the location and strength of warm and cold events. The results show strong decadal variability in the strength of El Nino events but little trend during the period of 1871-2008. The strength of La Nina events has neither prominent decadal variation nor a trend. The index also documents changes in frequency, duration, and location of ENSO events. The study shows that the frequency of El Nino varies considerably over the record. Given the large variance in the period of ENSO it is difficult to reliably determine if there has been a change in the period of El Nino events. The location of warming during El Nino can be described by a normal distribution centered at about 140 degrees W. The strength and frequency of ENSO events have very little trend indicating negligible impact from global warming.

No description available.

Understanding the spatiotemporal pattern of near-surface ozone is the key part of polar atmospheric environment. The near-surface ozone can be depleted by the catalytic bromine chemistry in the heterogeneous phase but produced due to the snow photochemistry of nitrogen. In addition to the local chemistry, ozone pattern is also affected by regional meteorology and air-mass transport. Since the polar region is quite sensitive to the climate change, these conditions can be also affected by climate change and variability. Based on the analysis of large amount of dataset combined with in-situ observations, satellite measurements, model simulations, and global reanalysis data, the characteristics of polar ozone pattern and relation to the regional and large-scale atmospheric situations were investigated. At first, the characteristics of tropospheric ozone depletion events (ODEs) in the Arctic spring (April 2008) with satellite measured BrO and backtrajectories. Analysis of these data shows that the ODEs are due to either local halogen chemistry or short-range transport from adjacent high-BrO regions. Sometimes local ozone loss is surprisingly deep, particularly the unstable boundary layer at Churchill seems contribute to free-tropospheric BrO. Continually the influences of large-scale atmospheric patterns to the polar surface ozone are investigated. In years with frequent ODEs at Barrow and Alert, the WP teleconnection pattern is usually in its negative phase, during which the Pacific jet is strengthened but the storm track from western Pacific is weakened. Both factors tend to reduce the transport of ozone-rich airmass from mid-latitudes to the Arctic, creating a favorable environment for the Arctic ODEs. Comparison between Barrow and Alert shows the initiation of ODEs in spring is decided by the solar intensity and the termination is by the surface air temperature. Monthly frequency of ODEs also indicate the wind strength from the Arctic Ocean is largely influential to ODEs. The surface ozone at South Pole reveals year-round reversal trends during 3 decades, which is consistent with what lower-tropospheric temperature shows. Their strong correlation implies the possibility of large meridional mixing in warm conditions, which enhances the background level of ozone and nitrogen at South Pole.