Recently, it was found that pathogens are trapped and killed by neutrophil extracellular traps (NETs). The role of Rac small GTPases is explored in the formation of NET using neutrophils lacking Rac1, Rac2 or both isoforms. NET formation was observed in both wild-type and Rac1-null neutrophils. In contrast, NET formation was markedly impaired in cells lacking either Rac2 or both Rac2 and Rac1. The defect in NET formation in Rac2-null cells was rescued in the presence of exogenous reactive oxygen species sources, suggesting that Rac2-mediated ROS generation is required. In addition, the role of nitric oxide in NET formation is assessed. Blocking NO production with the nitric oxide synthase inhibitor L-NAME significantly reduced NET formation. Moreover, Rac2-null cells produced significantly less NO than Rac1-null cells or their wild type counterparts. Our data suggest that Rac2 is essential for NET formation via pathways involving both ROS and NO.

This thesis reports the effects of disturbance and harbourage on the fitness of Tribolium confusum and T. castaneum, as well as the the efficacy of pheromone monitoring traps for monitoring for populations of Tribolium in laboratory and mill settings. Behavioural studies were also carried out on mill and laboratory-reared beetles and the distributions of both species in a mill were examined. Twenty-four hour sieving disturbance decreased the rates of dispersal for both species, and decreased T. castaneum fecundity. Rolling disturbance decreased T. confusum dispersal rate while shaking disturbance decreased T. castaneum dispersal rate. When undisturbed beetles were given differing amounts of flour in the presence or absence of harbourage, beetles laid more eggs in larger amounts of flour, but harbourage only affected T. castaneum at one level of flour (2 g). Throughout disturbance and harbourage experiments, T. castaneum laid more eggs than T. confusum. Pheromone monitoring traps placed in three Canadian flour mills were not useful in predicting the degree of infestation inside Simons rollstands. Pheromone monitoring traps also showed low efficacy (i.e. caught few beetles) in both mill and laboratory settings, and T. confusum was caught less often than T. castaneum in both mills and in a warehouse. Mill-strain beetles of both species were caught less often than laboratory-strain beetles in a warehouse. In one Canadian flour mill, both T. castaneum and T. confusum were found inside rollstands but the two species were spatially segregated from one another, rarely being found together in the same rollstand. In contrast to this, both species were consistently found together in samples taken from the same mill less than a year beforehand. In behavioural laboratory studies, beetles collected directly from a mill moved slower than beetles collected from a laboratory culture and this response was shown to be phenotypic. Mill-strain and laboratory-strain beetles also differed in burrowing tendencies, with T. confusum from the laboratory strain burrowing less than T. confusum from a mill and T. castaneum from different mills sometimes burrowing more and sometimes less than T. castaneum from the laboratory strain. / October 2008

At present the county and city governments universally establish the fixed speed traps on the roads for clamping down on speeding and running a red light based on the reason of the traffic safety. It causes the populace to violate the traffic regulations incidentally and have the bad impression on the county and city governments who seem to enrich their local budget through setting traps. Essentially do speed trap devices have absolute relationship with the improvements in traffic condition and safety? It still needs verification and study. The governments raise the fine quite subjectively to curb speeding; however, now the domestic lacked research and discussion on the standard reliability of the speed traps. In addition, few people have the recognition of risks and terror appeal messages, such as fine or possible traffic accidents that might happen to the speeding populace. Therefore, we have to research into the aspects of changing the driving behaviors. The study range and the questionnaire design mainly define if the establishment of speed traps in fongsan city Kaohsiung County is a terror appeal to the drivers through risk communication and cognition. To survey the intention of obeying the laws and obtain the data, we implement the questionnaire survey on the common populace. It takes the risk communication and cognition as independent variable and the intention of obeying the laws as dependent variable. Through its deduction and the empirical study, it proves that the establishment and law enforcement of speed traps have the reinforcement and altruism on the law-abiding perception and the constraint to the populace. They will behave appropriately according to the information and the establishments; the governments will also make the most proper laws, regulations and the policies according to the data; finally this will help the individuals, the organizations or the society to make the choices tending to luck and avoiding disasters.

Οι γόνοι, θαλάσσιοι ασπόνδυλοι οργανισμοί, έχουν θετική απόκριση στις φωτεινές πηγές, στη διάρκεια της νύκτας. Στην παρούσα διπλωματική εργασία σχεδιάσαμε και κατασκευάσαμε ένα σύστημα αυτοματοποιημένης λειτουργίας μιας φωτοπαγίδας για την προσέλκυση τέτοιων οργανισμών, με χρήση του μικροελεγκτή STM32F103RBT6. Στην εργασία περιλαμβάνονται 7 κεφάλαια. Πιο συγκεκριμένα στο πρώτο κεφάλαιο γίνεται αναφορά στις φωτοπαγίδες, τη λειτουργία τους, τον τρόπο κατασκευής τους καθώς και στην συμπεριφορά των ψαριών απέναντί τους. Στο δεύτερο κεφάλαιο περιγράφεται η λειτουργία των διόδων και των φωτοδιόδων. Στο τρίτο κεφάλαιο περιγράφεται η λειτουργία των LED καθώς και των LED ισχύος. Στο τέταρτο κεφάλαιο περιγράφεται η λειτουργία των τελεστικών ενισχυτών. Στο πέμπτο κεφάλαιο περιγράφεται η λειτουργία των καρτών SD και ο τρόπος προγραμματισμού τους. Στο έκτο κεφάλαιο περιγράφεται η πλακέτα που χρησιμοποιήθηκε και αναλυτικά ο επεξεργαστής STM32F103RBT6 και τα περιφερειακά του. Τέλος, δίνεται ο κώδικας του προγράμματος με κάποια σχόλια που αναφέρουν λεπτομερώς την λειτουργία του / Fish larvae, are aspondylous and they have a positive phototactic behavior, during the night time. For the current paper, we designed and built an automated system for a lighttrap device , using the microprocessor STM32F103RBT6. In this paper there are 7 chapters. The first chapter refers to lighttraps and their usage , their cnstruction and the way fish larvae respond to them. In the second chapter the operation of the lighttraps is described. In the third chapter, power LEDs and normal LEDs are described. In the fourth chapter, the operation of operational amplifiers is described. In the fifth chapter the operation of the sd cards is described, along with the proper way to program one. In the sixth chapter, the circuit used is described and the microprocessor in detail. Finaly, in the seveth chapter, there are parts of the code and the full operation of the system is descrived in detail.

Τα τελευταία χρόνια, ιδιαίτερα μετά το 2000, έχει παρατηρηθεί μια αξιοσημείωτη αύξηση στις διαδικτυακές επιθέσεις εισβολής και στις DDoS επιθέσεις, με ιδιαίτερα σημαντικές οικονομικές επιπτώσεις. Στην παρούσα διπλωματική αναλύουμε εκτενώς το πρόβλημα των DoS και DDoS επιθέσεων και μελετάμε πιθανές μεθόδους αντιμετώπισης του. Ιδιαίτερα ασχολούμαστε με μια πρωτοποριακή μέθοδο ανίχνευσης DDoS επιθέσεων η οποία χρησιμοποιεί παραπλανητικούς υπερσυνδέσμους για να εντοπίζει πιθανά προγράμματα-χρήστες. Επίσης αναλύουμε τα πειραματικά αποτελέσματα που προέκυψαν από προσομοιώσεις επιθέσεων με χρήση αυτής της μεθόδου. / In recent years, especially after the year 2000, there has been observed a sudden increase of Network-based intrusion and DDoS attacks, causing very significant financial losses. The present thesis analyses thoroughly the DoS and DDoS attack problem and studies possible means of countering such attacks. Especially an innovative method is proposed, that uses decoy hyperlinks in order to trace possible attackers. Also the experimental results that derived from the use of this method are analysed.

This thesis reports the effects of disturbance and harbourage on the fitness of Tribolium confusum and T. castaneum, as well as the the efficacy of pheromone monitoring traps for monitoring for populations of Tribolium in laboratory and mill settings. Behavioural studies were also carried out on mill and laboratory-reared beetles and the distributions of both species in a mill were examined. Twenty-four hour sieving disturbance decreased the rates of dispersal for both species, and decreased T. castaneum fecundity. Rolling disturbance decreased T. confusum dispersal rate while shaking disturbance decreased T. castaneum dispersal rate. When undisturbed beetles were given differing amounts of flour in the presence or absence of harbourage, beetles laid more eggs in larger amounts of flour, but harbourage only affected T. castaneum at one level of flour (2 g). Throughout disturbance and harbourage experiments, T. castaneum laid more eggs than T. confusum. Pheromone monitoring traps placed in three Canadian flour mills were not useful in predicting the degree of infestation inside Simons rollstands. Pheromone monitoring traps also showed low efficacy (i.e. caught few beetles) in both mill and laboratory settings, and T. confusum was caught less often than T. castaneum in both mills and in a warehouse. Mill-strain beetles of both species were caught less often than laboratory-strain beetles in a warehouse. In one Canadian flour mill, both T. castaneum and T. confusum were found inside rollstands but the two species were spatially segregated from one another, rarely being found together in the same rollstand. In contrast to this, both species were consistently found together in samples taken from the same mill less than a year beforehand. In behavioural laboratory studies, beetles collected directly from a mill moved slower than beetles collected from a laboratory culture and this response was shown to be phenotypic. Mill-strain and laboratory-strain beetles also differed in burrowing tendencies, with T. confusum from the laboratory strain burrowing less than T. confusum from a mill and T. castaneum from different mills sometimes burrowing more and sometimes less than T. castaneum from the laboratory strain.

This thesis reports the effects of disturbance and harbourage on the fitness of Tribolium confusum and T. castaneum, as well as the the efficacy of pheromone monitoring traps for monitoring for populations of Tribolium in laboratory and mill settings. Behavioural studies were also carried out on mill and laboratory-reared beetles and the distributions of both species in a mill were examined. Twenty-four hour sieving disturbance decreased the rates of dispersal for both species, and decreased T. castaneum fecundity. Rolling disturbance decreased T. confusum dispersal rate while shaking disturbance decreased T. castaneum dispersal rate. When undisturbed beetles were given differing amounts of flour in the presence or absence of harbourage, beetles laid more eggs in larger amounts of flour, but harbourage only affected T. castaneum at one level of flour (2 g). Throughout disturbance and harbourage experiments, T. castaneum laid more eggs than T. confusum. Pheromone monitoring traps placed in three Canadian flour mills were not useful in predicting the degree of infestation inside Simons rollstands. Pheromone monitoring traps also showed low efficacy (i.e. caught few beetles) in both mill and laboratory settings, and T. confusum was caught less often than T. castaneum in both mills and in a warehouse. Mill-strain beetles of both species were caught less often than laboratory-strain beetles in a warehouse. In one Canadian flour mill, both T. castaneum and T. confusum were found inside rollstands but the two species were spatially segregated from one another, rarely being found together in the same rollstand. In contrast to this, both species were consistently found together in samples taken from the same mill less than a year beforehand. In behavioural laboratory studies, beetles collected directly from a mill moved slower than beetles collected from a laboratory culture and this response was shown to be phenotypic. Mill-strain and laboratory-strain beetles also differed in burrowing tendencies, with T. confusum from the laboratory strain burrowing less than T. confusum from a mill and T. castaneum from different mills sometimes burrowing more and sometimes less than T. castaneum from the laboratory strain.

The Double-TOP trap is a new type of magnetic trap for neutral atoms, and is suitable for Bose-Einstein condensates (BECs) and evaporatively cooled atoms. It combines features from two other magnetic traps, the Time-averaged Orbiting Potential (TOP) and Ioffe-Pritchard traps, so that a potential barrier can be raised in an otherwise parabolic potential. The cigar-like cloud of atoms (in the single-well configuration) is divided halfway along its length when the barrier is lifted. A theoretical model of the trap is presented. The double-well is characterised by the barrier height and well separation, which are weakly coupled. The accessible parameter space is found by considering experimental limits such as noise, yielding well separations from 230 [mu]m up to several millimetres, and barrier heights from 65 pK to 28 [mu]K (where the energies are scaled by Boltzmann�s constant). Potential experiments for Bose-Einstein condensates in this trap are considered. A Double-TOP trap has been constructed using the 3-coil style of Ioffe-Pritchard trap. Details of the design, construction and current control for these coils are given. Experiments on splitting thermal clouds were carried out, which revealed a tilt in the potential. Two independent BECs were simultaneously created by applying evaporative cooling to a divided thermal cloud. The Double-TOP trap is used to form a linear collider, allowing direct imaging of the interference between the s and d partial waves. By jumping from a double to single-well trap configuration, two ultra-cold clouds are launched towards a collision at the trap bottom. The available collision energies are centred on a d-wave shape resonance so that interference between the s and d partial waves is pronounced. Absorption imaging allows complete scattering information to be collected, and the images show a striking change in the angular distribution of atoms post-collision. The results are compared to a theoretical model, verifying that the technique is a useful new way to study cold collisions.

Neutrophils provide a rapid first response to invading pathogens and orchestrate the immune response. They are able to employ potent antipathogenic mechanisms such as phagocytosis, reactive oxygen species (ROS) generation, protease release from granules, and formation of neutrophil extracellular traps (NETs). Despite this, certain pathogens have evolved mechanisms to benefit from neutrophil effector functions. Human cytomegalovirus (HCMV) is a clinically important pathogen that infects the majority of the human population. Monocytes are considered the main vehicle of HCMV dissemination throughout the body, but little research has been done on its interaction with neutrophils. The virus encodes a range of immunomodulatory proteins including an IL-8 homologue that acts as a powerful neutrophil chemoattractant. Viral conservation of a protein that recruits neutrophils to the site of HCMV infection suggests that the interaction between neutrophils and HCMV provides an overall advantage to the virus, but little evidence exists so far to suggest this is the case. Here I report that human peripheral blood neutrophils exposed to a clinical strain of HCMV display a profound survival phenotype, as assessed by morphology, phosphatidylserine exposure, cell permeability, and caspase-3/7 activity. This occurs in the absence of viral gene production. Neutrophils also upregulated their release of inflammatory cytokines in response to HCMV, with higher concentrations of IL-6, IL-8, and MIP-1α detected in the secretomes of infected neutrophils. These secretomes induced monocyte chemotaxis and increased monocyte permissivity to HCMV infection, as well as augmented survival in healthy, uninfected neutrophils. These experiments were confirmed with clean HCMV after the discovery of contaminating Mycoplasma spp. in the viral inocula of the initial experiments. Mycoplasma-HCMV coinfection induced an autophagic phenotype in neutrophils, as assessed by Western blotting and qPCR of autophagy-related components. Inhibition of autophagy using 3-MA reversed a profound survival effect. The unintended inclusion of Mycoplasma spp. further led to the serendipitous discovery of yet another pathogenic ability to overcome neutrophil immune functions: contaminating Mycoplasma spp. as well as Mycoplasma pneumoniae profoundly degraded NETs. These extracellular chromatin structures were stimulated using PMA or pyocyanin, and their release was dependent on the generation of ROS: severely ROS-deficient murine bone marrow neutrophils were unable to generate NETs. However, small amounts of ROS were sufficient for NETs generation, as neutrophils from acute respiratory distress syndrome patients, including many that had attenuated ROS-responses, were still capable of NETs generation. The NETs-degradative properties of mycoplasma were confirmed by fluorescence confocal and scanning electron microscopy, as well as spectrophotometry and agarose gel electrophoresis. This study demonstrates that two pervasive pathogens, HCMV and M. pneumoniae, both frequently found in coinfections in clinical contexts, are able to overcome neutrophil antipathogenic mechanisms to potentially enhance pathogen dissemination. These data provide not only a novel example of manipulation of an anti-viral response in a cell not productively infected, but also a novel example of pathogenic NETs degradation. These findings may have implications on our understanding of mycoplasma and HCMV pathogenesis and provide new targets for the generation of therapies.

Collapsing magnetic traps (CMTs) have been suggested as one of the mechanisms that could contribute to particle energisation in solar flares. The basic idea behind CMTs is that charged particles will be trapped on the magnetic field lines below the reconnection region of a flare. This thesis discusses a number of important new aspects in particle energisation processes in CMTs, based on the model by Giuliani et al. (2005). In particular, we extend previous studies of particle acceleration in this CMT model to the relativistic regime and compare our results obtained using relativistic guiding centre theory with results obtained using the non-relativistic guiding centre theory. The similarities and differences found are discussed. We then present a detailed study of the question, what leads to the trapping or escape of particle orbits from CMTs. The answer to this question is investigated by using results from the non-relativistic orbit calculations with guiding centre theory and a number of simple models for particle energy gain in CMTs. We find that there is a critical pitch angle dividing trapped particle orbits from the escaping particle orbits and that this critical pitch angle does not coincide with the initial loss cone angle. Furthermore, we also present a calculation of the time evolution of an anisotropic pressure tensor and of the plasma density under the assumptions that they evolve in line with our kinematic MHD CMT model and that the pressure tensor satisfies the double-adiabatic Chew-Goldburger-Low (CGL) theory. Finally, we make a first step to introduce Coulomb scattering by a Maxwellian background plasma into our guiding centre equations by changing them into a set of stochastic differential equations. We study the influence of a static background plasma onto selected particle orbits by pitch angle scattering and energy losses, and look at its effect on the particle energy and the trapping conditions.