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Organisationer är utsatta för ständiga säkerhetshot på internet och penetrationstester uppdagar hur sårbara nätverken är när mjuk- och hårdvara inte är uppdaterade. Uppdateringar i IT-sammanhang kallas ”patchar” och brukar generellt förbättra antingen funktioner eller säkerhet. Det finns en arbetsprocess inom IT kallad patch management, som ansvarar för hur mjukvara och annan utrustning uppdateras för att göra nätverket säkrare. Idag finns stora utmaningar i arbetsprocessen och denna studie undersöker hur arbetet kan effektiviseras. Ett problem historiskt sett har varit att det släppts för många patchar, vilket gjort det svårare för organisationer att hålla sig uppdaterade. Enligt rekommendationer från standardiseringsorgan ska patchar helst testas innan de implementeras, för att undvika eventuella följdproblem som kan uppstå. Genom intervjuer med personer som har ansvar för patch management, visades att det finns framgångsrika metoder för att hålla systemen uppdaterade, men delvis genom att bortse från vissa rekommenderade arbetsmetoder. Automatiserade verktyg underlättar processen till stor del men det finns delprocesser som ännu inte har blivit fullgott automatiserade. Test av patchar har närmast helt förbigåtts i organisationer vars nätverk är anslutna mot internet, därför att testprocessen i dagsläget tar för mycket tid. Slutsatsen som dragits är att det är att säkrare att snabbt lösa eventuella problem som uppstår på grund av en dålig patch, hellre än att testa patchar under långa perioder, eftersom nätverket är sårbart så länge ett känt säkerhetshål inte har täppts igen. / Organizations are exposed to constant security threats from the internet and penetration tests reveal just how vulnerable networks are when software and hardware patching aren’t up to date. Updates, known in IT as “patches”, usually enhances functions or security. Patch Management is the field in which anything related to patching of software and other various equipment falls under. As of today, Patch Management faces great challenges and the purpose of this study is to understand how the process can be made more efficient. Historically, a common issue has been the number of patch releases, which has made it cumbersome for organizations to stay up to date. Standardization bodies, such as IEC and NIST recommend that patches are tested in test environments before being installed to the production environment, to make sure no unintended consequences arise from faulty patches. Through interviews with professionals working in Patch Management, it became clear that there are ways to stay up to date, but partly through disregarding recommended best practice. Automated tools ease the Patch Management process to great extents but there are still areas that remain non-automated. The testing process has been largely ignored by organizations whose networks are connected to the internet, because said process is much too inefficient. Their answer to the problem of staying up to date is to solve problems quickly that arise through faulty patching, rather than test patches over longer periods of time. Their reasoning being that leaving known vulnerabilities unpatched is more damaging to the network.

Les bourgeons du goût contiennent 50 à 100 cellules gustatives. Parmi elles, on distingue les cellules de type 2 et 3, capables d’émettre des potentiels d’action. Les cellules réceptrices (type 2), qui détectent les stimulus sapides dans la salive, ne possèdent pas de synapse. Les cellules présynaptiques (type 3), équipées d’une synapse, transmettent l’information aux neurones gustatifs. Nous avons réalisé des enregistrements électrophysiologiques (patch-clamp) de cellules de bourgeons du goût de papilles fongiformes in situ, dans un épithélium lingual isolé de souris.L’analyse des courants d’action en configuration cellule-attachée, permet de distinguer des impulsions courtes et longues. Dans ce dernier cas, la phase initiale rapide de dépolarisation est suivie d’une dépolarisation maintenue et d’une repolarisation lente. Ceci dénote l’activation de canaux dépolarisants autres que ceux réglant habituellement le décours temporel du potentiel d’action.Les enregistrements en patch-perforé gramicidine, qui n’altèrent pas le milieu intracellulaire, ont permis de perfuser l’intérieur de la cellule avec du césium, bloqueur des canaux potassiques. Le césium permet de distinguer les cellules de type 2 des cellules de type 3 par la présence d’un courant césium-résistant qui correspondrait, selon la littérature, à un courant résultant de l’ouverture d’hémicanaux permettant la sortie d’ATP. Nos observations sont globalement en accord avec les données de la littérature, mais ne supportent pas totalement la classification proposée actuellement en trois types cellulaires bien définis.Les hémicanaux joueraient donc un rôle central dans la communication intercellulaire au sein du bourgeon du goût. Nous avons, à notre connaissance pour la première fois, enregistré des canaux à grande conductance dans les cellules gustatives, en absence d’ion divalents dans la pipette d’enregistrement. Ces canaux, non spécifiques, présentent un fonctionnement complexe avec, outre l’état fermé et l’état de plus haute conductance (700pS), de nombreux états d’ouvertures intermédiaires et un état de conductance résiduel proche du niveau fermé.Au bilan, nos résultats confortent l’hypothèse de l’ouverture de canaux dont la grande conductance laisserait passer l’ATP dans les cellules réceptrices. / Taste buds contain 50 to 100 taste cells. Among those cells, type 2 and type 3 cells are able to produce action potentials. Receptor cells (type 2) detect sapid stimulus in the saliva, but do not possess synapses. Presynaptic cells (type 3) with synapse deliver information to the taste neurons. We performed electrophysiological (patch-clamp) recordings of fungiform taste bud cells in situ, from a mouse isolated lingual epithelium.Analysis of action currents in cell-attached configuration allows discrimination of short and long impulses. In the long ones, the rapid initial depolarizing phase is followed by a slow and a maintained repolarization. This suggests the activation of depolarizing channels other than the ones implied in usual action potential time decay. Gramicidin perforated-patch recordings, which do not alter the inside of the cell, allowed cells perfusion with cesium, a potassic channel blocker. Cesium allows to distinguish type 2 from type 3 cells by the presence of a cesium-resistant current, that may correspond, according to the literature, to the current flowing through hemichannels responsible for ATP release. Our observations mostly agree with data from the literature, but do not fully support the actual classification in only three defined cell types.Hemichannels have a key role in intercellular communication within the taste bud. Thus, and to our knowledge for the very first time, we recorded large conductance channels from taste cells, using a divalent-free pipet. Those non-specific channels have a complex opening mechanism, which, besides closed and upper conductance states (700pS), present many intermediate opening levels and residual states close to the closed state. Our results support the hypothesis that large conductance channels responsible for ATP release open in receptor cells.

D-Aspartate (D-Asp) is an endogenous compound found in the central nervous system (CNS) of a variety of organisms. Despite its prevalence, however, relatively little understood of its physiological role. The prevailing theory is that D-Asp is an alternate agonist of N-methyl-D-aspartate receptor (NMDAR) channels. The goal of this work was to characterize the currents activated by D-Asp in neurons Aplysia californica, focusing on cells of the buccal S cluster (BSC). First, a general electrophysiological characterization was carried out, examining ion permeability, agonist dose-response, and the kinetics of activation, inactivation, and desensitization. D-Asp activated non-specific cation currents characterized by permeability to Na+ and K+. D-Asp-induced currents shared similar current-voltage relationships and time courses of activation and inactivation with L-glutamate (L-Glu)-induced currents. D-Asp currents, however, were subject to prolonged desensitization. Additionally, D-Asp activated currents independently of L-Glu, the known agonist of NMDAR channels, suggesting a non-NMDAR-dependent role of D-Asp. Next, select antagonists were used in an effort to pharmacologically characterize D-Asp receptor channels. These experiments suggested that D-Asp whole cell currents may be characterized by activation of multiple receptor sites, including NMDARS, excitatory amino acid transporters (EAATs), and a putative non-L-Glu D-Asp receptor. Furthermore, bath-applied D-Asp attenuated L-Glu-activated currents. Finally, D-Asp currents were compared to those evoked by acetylcholine (ACh) and serotonin (5-HT) in BSC cells. Results suggested that D-Asp activated receptor channels independently of ACh and 5-HT. Ten minute bath application of 5-HT was found to potentiate D-Asp current responses, likely through activation of a protein kinase C (PKC)-dependent mechanism, suggesting that D-Asp induced currents may be subject to synaptic plasticity associated with learning. While the identity of the putative D-Asp receptor remains elusive, the current work has advanced our understanding of the role D-Asp may play in the nervous system. These results should provide the groundwork for future studies aimed at identifying this unknown receptor channel, as well as investigation of the potential relationship of D-Asp receptor modulation to learning and memory in Aplysia, which may have relevance in higher organisms.

Various compact and packaging-adaptive antennas have been designed for practical wireless communications systems such as global system of mobile communications (GSM), Bluetooth Industrial-Scientific-Medical (ISM) devices, IEEE802.11a WLAN, and Local Multipoint Distribution Systems (LMDS) applications. First, compact stacked patch antennas using LTCC multilayer technology have been presented. A set of design rules is established for the purpose of designing optimized bandwidth compact antennas on LTCC multilayer substrates. To verify its effectiveness, the proposed design rules are applied to three emerging wireless bands. The return loss and the impedance bandwidth are optimized for all three bands. A maximum bandwidth of 7% can be achieved for an antenna operating in the LMDS band. Furthermore, folded shorted patch antennas (SPAs) are designed to significantly reduce the resonant frequency of a standard patch antenna. The design methodology of this structure starts with a conventional half-wave and through a series of procedures, evolves into a smaller, lambda/8 wavelength resonant length structure. Upon varying the height of the lower patch, the resonant length can be reduced to lambda/16. A comparison between a folded SPA and a standard SPA validates the folding technique proposed in this document. The folded SPA is applied to the 2.4 GHz ISM band. The measured results are in good agreement with simulated results. This antenna can be implemented into 3D packages using multilayer laminates such as LTCC or LCP.

Novel designs of three-dimensional patch antennas for beamdwidth enhancement and broadband operation have been proposed in this dissertation. For the beamwidth enhancement, the patch antenna with an inverted V-shaped patch has been proposed, and the antenna¡¦s radiation beamwidths have been broadened. Another beamwidth enhancement design using a three-dimensional square ground structure has also been demonstrated, and the 3-dB beamwidth of the CP radiation can reach more than 110¢X. In addition to the designs of beamwidth enhancement, the broadband patch antennas with a V-shaped patch, a W-shaped ground plane and a short probe-pin have been proposed. These novel structures can have significantly reduced probe-pin length and obtain a good impedance matching over a wide frequency range. Finally, a 1 ¡Ñ 2 broadband patch antenna array, suitable for base-station antenna applications for mobile communications systems, has also been studied

The purpose of this study was to examine the time course and kinetics of L-type Ca2+ current (ICa,L) from pituitary GH3 cells in response to various action potential (AP) waveforms using the whole-cell configuration of the patch-clamp technique. The major findings in this study are: 1. ICa,L evoked during the AP waveform exhibited an early and a late component. The early component of ICa,L occurred on the rising phase of the AP, whereas the late component coincided with the falling phase. 2. A prolongation of the falling phase of APs led to an increase in Ca2+ charge carried by ICa,L, although the amplitude of the late ICa,L was reduced. 3. When the peak voltage of AP waveforms was prolonged without changing the rising and falling phases, the amplitude of the late components was significantly increased. 4. ICa,L was also found to inactivate during a train of AP waveforms. When Ba2+ ions were used as the charge carriers, current inactivation during a train of APs was decreased. 5. The amplitude of ICa,L evoked by the AP templates with irregular bursting pattern was inactivated. 6. When spontaneous APs with the depolarizing potentials were replayed to GH3 cells, Ca2+ entry was not only spread over the entire AP, but also occurred during the interspike voltage trajectory. 7. When cells were exposed to thyrotropin releasing hormone (TRH; 10

Multibeam system is a rather new technique for generating huge digital terrain model quickly. If the primitive data does not perform quality control and the calibration process, inconsistency among the axes of transducer, motion sensor and gyrocompass may results in unreasonable underwater topography. The problem in the hydrographic surveying in the practice is not easy to seek for the suitable seabed or underwater feature for patch test at present. This research attempts to use fewer horizontal cross section of an underwater feature to compute roll, pitch and yaw deviation angle that differs from traditional vertical profile computing approach for patch test. And using different survey line combination and different underwater topography condition to achieve independent solution of angle deviation . We also design the new processing order for patch test. It hopes to utilize this concept to carry out patch test by the common underwater feature or recycling man-made object for resolving this problem in the future. The experimental results show that new calibration can get the same achievement as the traditional calibration by the CARIS HIPS software, and the calibration results applied in the cross check lines can pass through IHO special standard. It shows that the calibration results not only suit for calibration survey lines, but also good for rest of the area. It proves the proposed new patch test is feasible.

Diversity in the expression of ion channel proteins among neurons allows a wide range of excitability, growth and functional regulation. Ether-a-go-go (EAG), a member of the voltage-gated K+ channels, was characterized by spontaneous firing in nerve terminals and enhanced neurotransmitter release. In situ whole-cell patch-clamp recordings performed from the somata of Drosophila larval thoracic aCC motoneurons revealed spontaneous spike-like events in eag mutants. Spontaneous events were absent in wild type motoneurons. Spikes evoked by somatic current injection in to the cell body were not altered and comparable to wild type. Spontaneous spike-like events could be due to increased synaptic drive or altered intrinsic excitability of the motoneuron. Reduction of EAG function with selective expression of eag double stranded RNAi transgene in motoneurons only did not cause spontaneous spike-like events or alter evoked firing. This suggests increased synaptic drive contributes to spontaneous events.Both transient and sustained voltage-activated K+ currents, each with Ca++-sensitive (IA(Ca) and IK(Ca)) and Ca++ -insensitive components (IA and IK), were isolated in thoracic aCC motoneurons. In wild type motoneurons, IA was larger than IA(Ca). Conversely, IK(Ca) was larger than IK. Both eag mutants and eag RNAi expression resulted in a decrease in IA , IK and a slow sustained K+ current. Further, EAG and Shal demonstrate a potential functional interaction and contribute to IA. The voltage sensitivity for inactivation was reduced in Shal only and EAG-Shal double knock down compared to controls and EAG only knock down. In addition, a Ca++ sensitive EAG dependent K+ current was blocked by cAMP. Thus, both voltage-dependent and modulatory functions of EAG influence excitability in motoneurons.Firing properties and K+ currents distinguish aCC motoneurons in thoracic segments, T1 and T3. T3aCC had a shorter delay to spike, higher input resistance and were more easily recruited than T1aCC. T1aCC had a larger IA than T3aCC, but comparable IA(Ca). IK(Ca) was larger in T3aCC compared to T1aCC. These differences reflect cell-specific ion channel distribution that could contribute to patterned segmental motor output.

Zugl.: Giessen, Universiẗat, Diss., 2007.