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The 12C+16O breakup of 28Si and the 12C+12C breakup of 24Mg have been studied following the interaction of a 170 MeV 24Mg beam with 7Li, 9Be,12C and 16O target nuclei. The measurements were performed at the Australian National University in Canberra, using the technique of Resonant Particle Spectroscopy. The breakup fragments from the decay of the resonant nuclei were detected in two Gas-Si-CsI telescopes positioned on opposite sides of the beam axis. The data suggest that the same states in 28Si are populated via the 7Li(24Mg, 12C 16O)3H, 9Be(24Mg,12C 16O)5He and 12c(24Mg,12C 16O)8Be reactions. This implies that the cluster decaying states are populated by direct a-transfer. Breakup has been observed from states in 28Si at excitation energies (spins) of (26.15), 28.17 (13-, 29.51, 29.95, 30.45, 30.76, (31.3), 31.65, 31.90, 32.51, 33.14, 33.41, 33.77, 34.45 (12+,14+) and 35.13 MeV. A consistent theoretical interpretation of the 28Si molecular structures has been given, taking into account the predictions of Nilsson-Strutinsky, a-cluster model and two centre shell model calculations. The present results for the 12C(24Mg,12C 12C)12C reaction agree with previous measurements. In addition, new spin assignments have been proposed for several of the breakup states in 24Mg. States have been observed at excitation energies (spins) of 20.54 (2+), 21.07 (4+), 21.88 (4+), 22.33 (4+), 22.90 (6+), 23.80 (6+,(8+)), 24.56 (8+), 25.14 (6+), 25.72, 26.41 (8+) and 27.12 MeV. Evidence for the population of many of these states via the 16O(24Mg,12C 12C)16O reaction has also been observed. However, the data gave no evidence for either the 7Li(24Mg,12C 12C)7Li or 9Be(24Mg,12C 12C)9Be reactions. The presently available information did not allow an unambiguous determination of the reaction mechanism responsible for the population of the 24Mg breakup states. The performance of the Gas-Si-Csl telescopes has been investigated. For multiplicity 2 events in the silicon strip detectors, a crosstalk has been observed between the two active strips. The energy calibration of the silicon strip detectors for penetrating particles has also been found to differ to that for stopped particles. Empirical corrections for both of these effects have been deduced allowing the simultaneous detection and identification of heavy and light ions within a single telescope. These techniques have been extended to the detection of 8Be → alpha+alpha events over a wide range of alpha-particle energies.

Murine cytomegalovirus (MCMV) encodes a non-coding RNA, m169, that inhibits the cellular miRNA, miR-27. Previous studies have shown that the overexpression of miR-27 in vitro suppresses replication of MCMV and degradation of miR-27 by m169 is important for the viral replication during the lytic stage of infection in vivo. To understand why the virus specifically targets this cellular miRNA for degradation, this thesis focuses on identification of cellular target genes of miR-27 that are involved in viral growth in the lytic infection. Microarray analysis was conducted to globally examine cellular genes differentially expressed following miR-27 overexpression or repression during MCMV infection. Data obtained from the microarray analysis were analysed in order to select potential targets of miR-27 for functional screening. Functional screening involved siRNA knockdown of individual genes followed by infection with a GFP reporter virus (GFP-MCMV) to assess the effects on viral growth. Knockdown of 5 out of 55 genes (Rpl18a, Lyar, Itga5, Mapkapk3 and Pik3r1) led to a significant reduction in GFP expression. Based on luciferase reporter assays, Mapkapk3 was validated as a direct target of miR-27 with a seed site interaction in its 3’UTR. Mutation of this site in the mRNA was shown to eliminate miR-27-mediated repression. Analysis of MAPKAPK3 protein levels upon infection demonstrates that the protein levels are higher in cells infected with wild type MCMV versus the m169 deletion virus (MCMV Δm169). This is in line with the difference in miR-27 levels in the two infections showing a decrease of miR-27 in wild type MCMV and unaltered levels in MCMV Δm169 infection. Mapkapk3 is a direct downstream target of p38 mitogen-activated protein (MAP) kinase within the p38 MAP kinase pathway, which has previously been shown to be an essential pathway for CMV replication. Expression levels of substrates of MAPKAPK3 including HSP27 and ATF1 were examined during infection to evaluate whether they are regulated by miR-27. The level of phosphorylation of HSP27 was shown to correlate with the levels of MAPKAPK3 during infection and was higher in cells infected with wild type MCMV versus MCMV Δm169. This suggests that MAPKAPK3 and its substrate, HSP27, are regulated by miR-27 during MCMV infection. This work provides an important foundation for further functional studies on the role of Mapkapk3 and its substrates in MCMV infection and its capacity to be dynamically regulated by miR-27. Based on the microarray analysis upon miR-27 overexpression, it was shown that miR-27 has an impact on the cell cycle, consistent with previous studies. Functional analysis of miR-27 in the cell cycle using miR-27 mimics and inhibitors demonstrated that the mimics cause an increase of cells in S phase at early time points (12 and 14 h), whereas the inhibition of miR-27 results in a significant reduction in the S phase population and accumulation of cells in G1 phase. Luciferase reporter assays confirmed that two genes known to be associated with the cell cycle are direct targets of miR-27: polycomb ring finger oncogene 1 (Bmi1) and caveolin 1 (Cav1). Knockdown of Bmi1 and Cav1 leads to a significant decrease in the number of cells in S phase and accumulation of cells in the G1 phase; however, this is the opposite result to that observed with the miR-27 mimics. These results suggest that the increase in cells in the S phase induced by miR-27 mimics is unlikely to be associated with targeting of Bmi1 and Cav1. Furthermore, knockdown of Bmi1 and Cav1 does not affect viral replication in vitro. Since miR-27 induces the transition of cells from the G1 to S phase, further studies are required to identify the miR-27 targets involved in this function. To identify direct targets of miR-27 through biochemical methods, one chapter of this thesis was devoted to developing CLASH datasets (cross-linking, ligation and sequencing of hybrid). This technique can directly map miRNA-mRNA interactions within the Argonaute protein (AGO). Initially, a NIH 3T3 stable cell line expressing AGO2 with a double affinity tag at the N terminus was generated. Analysis of the stable cell line revealed no significant alteration of miR-27 regulation or change in permissiveness to MCMV compared to wild type cells, making this amenable to further studies. Using the stable cell line, the CLASH protocol was carried out and preliminary data collected. In summary, this thesis identifies a direct target of miR-27, Mapkapk3, that is an important gene in MCMV replication that requires further investigation. Mapkapk3 is a substrate of p38 in the p38 MAP kinase pathway which is a signal transduction mediating numerous biological processes in response to cellular stresses including CMV infection. Furthermore, miR-27 overexpression was found to stimulate the G1/S transition of the cell cycle, and miR-27 inhibition had the opposite effect. Previous evidence has shown that MCMV and HCMV arrest the cell cycle in the G1 phase and inhibit host DNA synthesis to create an optimal condition for viral gene expression and DNA replication. Given that MCMV arrests host cells in the G1 phase, it is possible that degradation of miR-27 by MCMV contributes to this effect. Since miR-27 regulates both Mapkapk3 and the cell cycle, it seems likely that a number of targets and pathways underlie the antiviral properties of this miRNA.

Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Botany and Ecology Candidate: Tereza Olivová Supervisor: RNDr. Jitka Vytlačilová, Ph.D Title of diploma thesis: The occurrence of pharmaceuticals in the environment II. Pharmaceuticals are biologically active substances used for treatment or prevention of human and animal diseases. Some of these substances remain active even after being excreted from an organism and they can enter the environment. The residues of pharmaceuticals are present not only in rivers, but also in sea, groundwater and in soil, into which the contaminated water and manure are applied. The concentration of pharmaceuticals in water and in soil differ from place to place (it is higher e. g. in close proximity of sewage treatment plants) and from season to season (it depends on levels of precipitations and sunshine). Nowadays, thanks to sensitive analytical methods it is not a problem to detect these xenobiotics even in very small amounts, in which they usually occur in nature (usually in order of units or tens of ng/l or ng/g). However, even these low concentrations might have a negative impact on the life of non-target organisms (e. g. reproduction disorders) and therefore, the calculations, which measure the lever of risk of particular...

Visual target acquisition is performed during several daily tasks, often requmng time¬dependent behavioural responses towards stimuli. Information processing during such tasks is subject to bottom-up as well top-down influences, which results in an integrated processing mechanism. It follows that if the underlying neural mechanisms can be elucidated, behaviour towards visual stimuli will be better understood, allowing for the development of visual environments that facilitates desired behavioural response. The current study aimed to develop a systems-level approach according to which the mechanisms that underlie visual target acquisition can be understood, by interpreting psychophysical data in terms of the structural and functional organization of the visual system. Empirical work entailed psychophysical experiments and elaborated on previous studies regarding conspicuity areas around and response time towards visual targets. The rationale was that these two measures can be used as an indication of the conspicuity of a target within a specific background, which in turn can be related to the nature of information processing during a target acquisition task. Results showed that a proportional relationship exists between the size of the conspicuity area and a target's perceived conspicuity, with the most conspicuous targets being associated with the largest conspicuity areas. Response time trends showed that target detectability at different positions within the conspicuity area is equal, but that detection performance at positions outside the conspicuity area is greatly influenced by the nature of the background surrounding the target. Interpretation of the results points to the importance of visual attention during target acquisition, which in turn is supported by the structural and functional organization of the visual system. Findings from the psychophysical study presented here, along with the proposed framework of information processing, emphasise that behavioural outcome during visual target acquisition cannot be explained without considering the structural and functional organization of the visual system. / Dissertation (MSc (Human Physiology))--University of Pretoria, 2006. / Physiology / unrestricted

Target tracking using Wireless Sensor Networks (WSNs) has drawn lots of attentions after the recent advances of wireless technologies. Target tracking aims at locating one or several mobile objects and depicting their trajectories over time. The applications of Object Tracking Sensor Networks (OSTNs) include but not limited to environmental and wildlife monitoring, industrial sensing, intrusion detection, access control, traffic monitoring, patient monitoring in the health-related studies and location awareness in the battle eld. One of the most rewarding applications of target tracking is wildlife monitoring. Wildlife monitoring is used to protect the animals which are endangered to extinction. Road safety applications are another popular usage of wildlife monitoring using WSNs. In this thesis, the issues and challenges of energy-efficient wildlife monitoring and target tracking using WSNs are discussed. This study provides a survey of the proposed tracking algorithms and analyzes the advantages and disadvantages of these algorithms. Some of the tracking algorithms are proposed to increase the energy e ciency of the tracking algorithm and to prolong the network lifetime; while, other algorithms aim at improving the localization accuracy or decreasing the missing rate. Since improving the energy efficiency of the system provides more alive sensors over time to locate the target; it helps to decrease the missing rate as the network ages. Thus, this study proposes to adjust the sensing radius of the sensor nodes in real-time to decrease the sensing energy consumption and prolong the network lifetime. The proposed VAriable Radius Sensor Activation (VARSA) mechanism for target tracking using wireless sensor networks tackles the energy consumption issues due to resource constraints of the WSNs. VARSA reduces the radio covered area of each sensor node to only cover the Area of Interest (AoI) which is the location of the target in tracking applications. Thus, VARSA aims at decreasing the sensing energy consumption which leads to encreasing the network life time. In addition, VARSA decreases the missing rate over time as it provides more alive sensors to detect the target compared to previous activation algorithms as the network ages. VARSA is compared to PRediction-based Activation (PRA) and Periodic PRediction-based Activation (PPRA) algorithms which are two of the most promising algorithms proposed for sensor activation. The simulation results show that VARSA outperforms PRA and PPRA. VARSA prolongs the lifetime of the network and decreases the missing rate of the target over time.

In this thesis we present a method for detecting planar targets in real-time on power-constrained, or low-powered, hand-held devices such as mobile phones. We adopt the feature recognition (also referred to as feature matching) approach and employ fast-to-compute local feature descriptors to establish point correspondences. To obtain a satisfactory localization accuracy, most local feature descriptors seek a transformation of the input intensity patch that is invariant to various geometric and photometric deformations. Generally, such transformations are computationally intensive, hence are not ideal for real-time applications on limited hardware platforms. On the other hand, descriptors which are fast to compute are typically limited in their ability to provide invariance to a vast range of deformations. To address these shortcomings, we have developed a learning-based approach which can be applied to any local feature descriptor to increase the system’s robustness to both affine and perspective deformations. The motivation behind applying a learning-based approach is to transfer as much of the computational burden (as possible) onto an offline training phase, allowing a reduction in cost during online matching. The approach comprises of identifying keypoints which remain stable under artificially induced perspective transformations, extracting the corresponding feature vectors, and finally aggregating the feature vectors of coincident keypoints to obtain the final descriptors. We strictly focus on objects which are planar, thus allowing us to synthesize images of the object in order to capture the appearance of keypoint patches under several perspectives.

The diploma thesis deals with analysis of interbank payment systems in the Czech and in the Irish Republic. There are described basic types of payment systems that serve as background for analysis. Both observe countries are members of EU, so this work includes also brief characteristics of the law frame of EU and payment systems of EU. Farther there are characterized payment systems of both countries. In the Czech Republic operates just one interbank system of payment named CERTIS, while in Ireland operate three systems of payment. The first of them TARGET2-IE serves mainly for large value payments, while remaining two systems IRECC and IPCC serve for retail payments. Finally there is included comparison of payment systems by number of transactions and value of transactions.

Positron emission tomography (PET) is a molecular imaging technique that provides a direct and accurate evaluation of tissue function in vivo. PET of the glucose analogue 18F-fluoro-deoxy-glucose, is increasingly in use to aid in gross target volume delineation in radiotherapy treatment planning (RTP) where it shows reduced inter-observer variability. The aim of this thesis was to develop and investigate a new technique for delineating PET-GTV with sufficient accuracy for RTP. A new technique, volume and contrast adjusted thresholding (VCAT), has been developed to automatically determine the optimum threshold value that measures the true volume on PET images. The accuracy was investigated in spherical and irregular lesions in phantoms using both iterative and filtered back-projection reconstructions and different image noise levels. The accuracy of delineation for the irregular lesions was assessed by comparison with CT using the Dice Similarity Coefficient and Euclidean Distance Transformation. A preliminarily investigation of implementing the newly developed technique in patients was carried out. VCAT proved to determine volumes and delineate tumour boundaries on PET/CT well within the acceptable errors for radiotherapy treatment planning irrespective of lesion contrast, image noise level and reconstruction technique.

In this thesis, I study three aspects of sell-side analysts’ stock price forecasts, henceforth target prices: analyst teams’ target price forecast characteristics, analysts’ use of information to revise target prices, and determinants of target price disagreement between analysts.The first essay studies the target price forecast performance of team analysts in the UK and finds that teams issue timelier but not less accurate target prices. Unlike evidence from previous studies, my findings suggest that analyst teamwork may improve forecast timeliness without sacrificing forecast accuracy. However, market reactions to team target price revisions are not significantly different from those to individual analyst target price revisions, suggesting that although target prices issued by analyst teams are timelier and not less accurate than those of individual analysts, investors do not consider analyst team target prices more informative. I conjecture that analysts may work in teams to meet the demand to cover more companies while maintaining the quality of research by individual team members rather than to issue more informative reports.In the second essay, I study how analysts revise their target prices in response to new information implicit in recent market returns, stock excess returns and other analysts’ target price revisions. The results suggest that analysts’ target price revisions are significantly influenced by market returns, stock excess return and other analysts’ target price revisions. I also find that the correlation between target price revisions and stock excess returns is significantly higher when the news implicit in these returns is bad rather than good. I conjecture that analysts discover more bad news from the information in stock excess returns because firms tend to withhold bad news, disclosing it only when it becomes inevitable, while they disclose good news early. Using a new measure of bad to good news concentration, I show that the asymmetric responsiveness of target price revisions to positive and negative stock excess returns is significant for firms with the highest concentration of bad news but is insignificant for firms with the lowest concentration of bad news. I argue that firms with the highest concentration of bad news are more likely to withhold and accumulate bad news. The findings, therefore, support my hypothesis that analysts discover more bad news than good news from stock returns because firms tend to withhold bad news, disclosing it only when it is inevitable. The third essay examines the determinants of analyst target price disagreement. I find that while disagreement in short-term earnings and in long-term earnings growth forecasts are significant determinants, recent 12-month idiosyncratic return volatility has the strongest explanatory power for target price disagreement. The findings suggest that target price disagreement is driven not only by analyst disagreement about short-term earnings and long-term earnings growth, but also by differences in analysts’ opinions about the impact of recent firm-specific events on value drivers beyond short-term future earnings and long-term growth, which are eventually reflected in past idiosyncratic return volatility.