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Solifuges (Solifugae, Arachnida) are an important element of the fauna especially in arid and desert environments. Unfortunately, this animal group has only been extremely poorly studied not only in terms of morphology, but also ecology, physiology, systematics and phylogeny. The present study aimed to provide a detailed overview of their anatomy and ultrastructure. Representatives of these peculiar animals were investigated by means of light and electron microscopy in order to gain new insights in their functional morphology and also to evaluate potential characters for their systematic and future phylogenetic studies. The histology and ultrastructure of the following organ systems have been investigated: tarsal structures, sensory structures and nervous system, coxal glands, alimentary system, respiratory system, circulatory system and reproductive systems. Additionally, a camel spider in Baltic amber was described, representing the second known specimen of fossil Solifugae in Baltic amber. Further on, the entire mitochondrial genome of Nothopuga sp. was sequenced for comparison with other solifuges and chelicerates in order to reveal changes in their gene order.
Infrared laser absorption spectroscopy (IRLAS) employing both tuneable diode and quantum cascade lasers (TDLs, QCLs) has been applied with both high sensitivity and high time resolution to plasma diagnostics and trace gas measurements.
TDLAS combined with a conventional White type multiple pass cell was used to detect up to 13 constituent molecular species in low pressure Ar/H2/N2/O2 and Ar/CH4/N2/O2 microwave discharges, among them the main products such as H2O, NH3, NO and CO, HCN respectively. The hydroxyl radical has been measured in the mid infrared (MIR) spectral range in-situ in both plasmas yielding number densities of between 1011 ... 1012 cm-3. Strong indications of surface dominated formation of either NH3 or N2O and NO were found in the H2-N2-O2 system. In methane containing plasmas a transition between deposition and etching conditions and generally an incomplete oxidation of the precursor were observed.
The application of QCLs for IRLAS under low pressure conditions employing the most common tuning approaches has been investigated in detail. A new method of analysing absorption features quantitatively when the rapid passage effect is present is proposed. If power saturation is negligible, integrating the undisturbed half of the line profile yields accurate number densities without calibrating the system. By means of a time resolved analysis of individual chirped QCL pulses the main reasons for increased effective laser line widths could be identified. Apart from the well-known frequency down chirp non-linear absorption phenomena and bandwidth limitations of the detection system may significantly degrade the performance and accuracy of inter pulse spectrometers. The minimum analogue bandwidth of the entire system should normally not fall below 250 MHz.
QCLAS using pulsed lasers has been used for highly time resolved measurements in reactive plasmas for the first time enabling a time resolution down to about 100 ns to be achieved. A temperature increase of typically less than 50 K has been established for pulsed DC discharges containing Ar/N2 and traces of NO. The main NO production and depletion reactions have been identified from a comparison of model calculations and time resolved measurements in plasma pulses of up to 100 ms. Considerable NO struction is observed after 5 ... 10 ms due to the impact of N atoms.
Finally, thermoelectrically cooled pulsed and continuous wave (cw) QCLs have been employed for high finesse cavity absorption spectroscopy in the MIR. Cavity ring down spectroscopy (CRDS) has been performed with pulsed QCLs and was found to be limited by the intrinsic frequency chirp of the laser suppressing an efficient intensity build-up inside the cavity. Consequently the accuracy and advantage of an absolute internal absorption calibration is not achievable. A room temperature cw QCL was used in a complementary cavity enhanced absorption spectroscopy (CEAS) configuration which was equipped with different cavities of up to ~ 1.3 m length. This spectrometer yielded path lengths of up to 4 km and a noise equivalent absorption down to 4 x 10-8 cm-1Hz-1/2. The corresponding molecular concentration detection limit (e.g. for CH4, N2O and C2H2 at 1303 cm-1/7.66 μm) was generally below 1 x 1010 cm-3 for 1 s integration times and one order of magnitude less for 30 s integration times. The main limiting factor for achieving even higher sensitivity is the residual mode noise of the cavity. Employing a ~ 0.5 m long cavity the achieved sensitivity was good enough for the selective measurement of trace atmospheric constituents at 2.2 mbar.
(A paperback version is published by Logos under ISBN 978-3-8325-2345-9.)
Alcohol-related somatic disorders are highly prevalent among general hospital inpatients. Alcohol problem drinking can be differentiated into alcohol use disorders (alcohol dependence and alcohol abuse) and three subtypes of drinking above recommended levels (at-risk drinking only [AR], heavy episodic drinking only [HE], at-risk and heavy episodic drinking [ARHE]). The aims of this study were threefold. First, proportions of alcohol problem drinking among general hospital inpatients in a region of north-eastern Germany were estimated (study 1). Second, among individuals with alcohol problem drinking the association between beverage preference and alcohol-related diseases was tested (study 2). Third, subtype differences regarding demographics, alcohol-related variables, motivation to change drinking behaviors, and the risk to develop short-term alcohol dependence among the three subtypes of drinking above recommended levels were analyzed (study 3). The data presented in this dissertation are based on the randomized controlled trial “Early Intervention at General Hospitals”, which is part of the Research Collaboration Early Substance Use Intervention (EARLINT). Study 1 includes a sample of consecutively admitted general hospital inpatients between 18 and 64 years old (n = 14,332). The study adopted a two-stage-sampling approach: (a) screening and (b) ascertainment of alcohol problem drinking. Those who were identified with alcohol problem drinking were asked for written consent for further study participation. This included further baseline assessment, the consent to use routine treatment diagnoses and participation in a follow-up interview 12 months after hospitalization. For study 2, routine treatment diagnoses were provided by hospital physicians for a total of 1,011 men with problem drinking. These diagnoses were classified into three categories according to their alcohol-attributable fractions (AAF): diseases totally attributable to alcohol by definition (AAF=1), diseases partially attributable to alcohol (AAF<1) and diseases with no empirical relationship to alcohol or with a possibly protective effect associated with alcohol (AAF=0). Study 3 was restricted to study participants with drinking above recommended levels (n=425). Study 1: Among all general hospital inpatients, 8.9% were identified with current problem drinking in the following descending order: 5.3% exhibited alcohol use disorders and 3.6% drinking above recommended levels. Higher proportions of problem drinking were found at rural sites compared to urban sites (13.7 vs. 7.5%, p<.001). Study 2: Because of the low proportion of women with alcohol problem drinking the following analyses were restricted to males. Multinomial regression analyses revealed different risks for alcohol-related diseases in relation to beverage preference while controlling for alcohol-associated and demographic confounders. Compared to all other groups, spirits only drinkers had the highest risk for having a disease with AAF>0; e.g., beer only drinkers had lower odds of having a disease with AAF<1 (odds ratio, OR=0.50, 95% confidence interval, CI: 0.27-0.92). Study 3: Men with alcohol use disorder were excluded from the following analysis. At baseline, multinomial logistic regression revealed differences between individuals with AR, HE and ARHE while controlling for age. ARHE was associated with higher odds of having a more severe alcohol problem (OR=2.06, CI: 1.23-3.45), using formal help (OR=2.21, CI: 1.02-4.79), and having a disease with AAF=1 (OR=3.43, CI: 1.58-7.43), compared with AR. In addition, individuals with ARHE had higher odds of taking action to change drinking behaviors (i.e., beginning to implement change) than individuals with HE (OR=2.29, CI: 1.21-4.34) or AR (OR=2.11, CI: 1.15-3.86). At follow-up, individuals with ARHE had higher odds of having alcohol dependence according to the DSM-IV (OR=4.73, CI: 1.01–22.20) compared to individuals with AR. In addition to alcohol use disorders, drinking above recommended levels is a common problem among general hospital inpatients. Thus, the implementation of systematic alcohol screening and brief interventions should be considered. These data suggest an association between beverage preference and alcohol-related diseases. Among hospitalized problem drinkers, spirits only drinkers had the greatest risk of having diseases with AAF>0. Of the three subtypes of drinking above recommended levels, ARHE seems to be particularly problematic because there appears to be an indication of a subclinical diagnosis. To provide adequate intervention, clinical practice should distinguish between the three groups of drinking above recommended levels. Brief alcohol intervention should be tailored to the individual’s motivation to change and to the type of alcohol problem drinking. The effectiveness of such a procedure remains to be evaluated in further studies.
Turbulence is a state of a physical system characterized by a high degree of spatiotemporal disorder. Turbulent processes are driven by instabilities exhibiting complex nonlinear dynamics, which span over several spatial as well as temporal scales. Apart from fluids and gases, turbulence is observed in plasmas. While turbulent mixing of a system is sometimes a desired effect, often turbulence is an undesired state. In hot, magnetically confined plasmas, envisaged for energy generation by thermonuclear fusion, plasma turbulence is clearly a problem, since the magnetic confinement time is drastically deteriorated by turbulent transport. Hence, a control mechanism to influence and to suppress turbulence is of significance for future fusion power devices. An important area of plasma turbulence is drift wave turbulence. Drift waves are characterized by currents parallel to the ambient magnetic field, that are tightly coupled to a coherent mode structure rotating in the perpendicular plane. In the present work, the control of drift waves and drift wave turbulence is experimentally investigated in the linear magnetized helicon experiment VINETA. Two different open-loop control systems - electrostatic and electromagnetic - are used to drive dynamically parallel currents. It is observed that the dynamics of the drift waves can be significantly influenced by both control schemes. If the imposed mode number as well as the rotation direction match those of the drift waves, classical synchronization effects like, e.g., frequency locking, frequency pulling, and Arnold tongues are observed. These confirm the nonlinear interaction between the control signal and the drift wave dynamics. Finally, the broadband drift wave turbulence, and thereby turbulent transport, is considerably reduced if the applied control signal is sufficiently large in amplitude.
The experimental determination of the electron energy distribution of a low pressure glow discharge in neon from emission spectroscopic data has been demonstrated. The method extends an approach by Fischer and Dose [5]. The spectral data were obtained with a simple overview spectrometer and analyzed using a strict probabilistic, Bayesian data analysis. It is this Integrated Data Analysis (IDA) approach, which allows the significant extraction of non-thermal properties of the electron energy distribution function (EEDF). The results bear potential as a non-invasive alternative to probe measurements. This allows the investigation of spatially inhomogeneous plasmas (gradient length smaller than typical probe sheath dimensions) and plasmas with reactive constituents. The diagnostic of reactive plasmas is an important practical application, needed e.g. for the monitoring and control of process plasmas. Moreover, the experimental validation of probe theories for magnetized plasmas as a long-standing topic in plasma diagnostics could be addressed by the spectroscopic method.
Therapeutic Sealing of Proximal Tooth Surfaces: Two-Year Clinical and Radiographic Evaluation
(2009)
The diagnosis, prevention and treatment of proximal carious lesions comprise a constant problem in clinical dentistry. The purpose of this investigation was to test the safety and clinical effect of a new treatment for proximal caries. In 50 patients with two proximal initial lesions (D1-3 without cavitation, bitewing X-ray), orthodontic rubber rings were applied to gain access to the interproximal space. One of the lesions was sealed with a thin polyurethane-dimethacrylate foil using a bonding agent (Heliobond®, Vivadent, Schaan/Liechtenstein); the other lesion received oral home-care with dental floss and fluoridated toothpaste and was left as control. In clinical follow-ups after 6 and 12 months and X-ray evaluation after two years, clinical retention of proximal tape and the underlying sealant, marginal adaptation, discoloration, tooth vitality, proximal plaque and gingivitis were checked. In addition, caries was assessed clinically and radiographically. The sealants showed good retention, marginal adaptation and colour. After two years, vitality of all teeth was still positive and no relevant differences in plaque accumulation or gingival status were found between sealed and control teeth. Two sealed surface had to be filled due to caries progression (D3 with cavitation). 9 sealed lesions showed caries regression. In contrast, only 4 control lesions regressed and also two showed progression. The loss of tape had no significant influence on the lesion progression indicating the effect of the underlying bond. All other sealants and control lesions were stable indicating an arrest of the lesion. In conclusion, sealing initial proximal lesions showed no clinical problems and mostly arrest of initial carious lesions on bitewing X-rays.
Age-related brain injuries including stroke, are a major cause of physical and mental disabilities. Therefore studying the basic mechanism underlying functional recovery after brain stroke in middle aged subjected it is of considerable clinical interest. Data from our lab and elsewhere indicate that, behaviorally, middle aged rats were more severely impaired by stroke than were young rats, and they also showed diminished functional recovery. Infarct volume did not differ significantly in young and middle aged animals, but critical differences were apparent in the cytological response to stroke, most notably an age-related acceleration of the establishment of the glial scar. The early infarct in older rats is associated with a premature accumulation of BrdU-positive microglia and astrocytes, persistence of activated oligodendrocytes, a high incidence of neuronal degeneration, and accelerated apoptosis. In middle aged rats, neuroepithelial-positive cells were rapidly incorporated into the glial scar, but these neuroepithelial-like cells did not make a significant contribution to neurogenesis in the infarcted cortex in young or middle aged animals. Stroke is accompanied by a strong inflammatory reaction in the brain. We hypothesized that a mild systemic inflammatory reaction as caused by periodontal disease prior to stroke onset, may exert a neuroprotective effect in a rat model of focal ischemia. To test this hypothesis, marginal periodontitis was induced in BB/LL Wistar rats for 3 weeks. Two weeks after periodontitis initiation, focal cerebral ischemia was produced by reversible occlusion of the right middle cerebral artery. After a survival time of 7 days after ischemia, rat brains were analyzed. In addition, markers of systemic inflammation were determined in a different group of laboratory animals at 14 days after the onset of periodontitis. We found that rats with a mild systemic inflammation had a significantly reduced infarct volume and a significant reduction in the number of brain macrophages in the infarcted area. Conclusions: The available evidence indicates that the middle aged brain has the capability to mount a cytoproliferative response to injury, but the timing of the cellular and genetic response to cerebral insult is deregulated in middle aged animals, thereby further compromising functional recovery. In addition we found that that mild systemic inflammation elicited prior to stroke onset may have a neuroprotective effect in rats by reducing the infarct volume and tissue destruction by brain macrophages.
The Caribbean is a geologically complex region with several different plate boundary interactions. Geodynamic reconstructions of the northwestern Caribbean region have been particularly controversial in terms of the number of arcs, subduction polarity, and timing of collision. This thesis develops a refined tectonic reconstruction for the northwestern Caribbean based on a review of geological data of Cuba and a regional analysis within the northwestern Caribbean context. With regard to plausibility, significant emphasis was put on the degree and qualitiy of visualization. Three crustal sections across key areas in western, central, and eastern Cuba have been constructed in order to conduct an evolutionary interpretation in three dimensions. Western and central Cuba constitute an orogenic belt resulting from the collision of a mid- to Late Cretaceous volcanic arc - the "Great Caribbean Arc" - with the southern paleomargin of North America. The collision process apparently started in the Campanian, but major north- to northeast-directed thrusting processes at the southern Bahamas margin culminated during the Paleocene. A continous southwest-dipping polarity of the "Great Caribbean Arc", at least from the Aptian-Albian, can be infered from (1) its Late Cretaceous approach towards the North American margin, (2) the magnitude of top to the north directed tectonic transport in the Cuba orogenic belt, and (3) the internal structures of the metamorphic fore-arc assemblages and their evolution on the north side of the arc. An Early Cretaceous southwest-dipping origin of the "Great Caribbean Arc" along the northern fringe of the Chortís Block appears to be in all probability. This concept provides a link between (1) middle Late Cretaceous collision processes along the Matagua suture zone, (2) the Turonian termination of "Great Caribbean Arc"-activity on Jamaica, and (3) the late Campanian onset of collision in the Cuba orogenic belt. The collision of the "Great Caribbean Arc" with the Bahamas margin hampered relative northward motion of the Caribbean Plate from the late Campanian onward. Continued northward push finally resulted in the commencement of north-dipping subduction. Late Cretaceous commencement of north-dipping subduction was accompanied by superposition of oceanic crust and large-scale north-directed gravity sliding on the upper plate, as documented by ophiolitic slide-masses and Maastrichtian olistostromes in eastern Cuba (Nipe - Cristal and Moa Baracoa ophiolite massifs) as well as on Jamaica (ophiolites of the Bath-Dunrobin Complex) and the southern peninsula of Hispaniola. Progress of north-dipping subduction was responsible for the emergence of a Paleocene to Middle Eocene volcanic arc which spanned the northwestern Caribbean along the southern boundary of the Yucatán Basin while the Chortís Block and the Nicaragua Rise were still in a paleoposition to the south of the Maya Block. North-dipping subduction and the associated volcanic arc isolated the Yucatán Basin from its original affiliation to the Caribbean Plate. Relative northward motion of the Caribbean Plate and activity of the Paleogene volcanic arc stopped after the Eocene arrival of thickened oceanic crust of the Caribbean Large Igneous Province at the north-dipping subduction zone. After the late Early Eocene commencement of spreading at the Mid-Cayman Rise, North America - Caribbean relative motion was taken up along the sinistral Oriente Fault with estimated amounts of 800 to 1000 km offset since the Middle Eocene. This transform margin dissmembered the northwestern Caribbean extend of the Paleocene to Middle Eocene volcanic arc. Its eastern bend was uncoupled in the course of this process and may be represented by the Aves Ridge. South-central Hispaniola can be restored to a Middle Eocene position to the south of eastern Cuba, which accounts for an approximate Cenozoic displacement of 200 to 300 km. Therefore, most of the western prolongation of the Oriente Fault must be accommodated at the northern bounding-faults of the southern peninsula of Hispaniola. The proposed synthesis is in clear accordance with the paradigm of plate tectonics, corroborating its capability to incorporate even a complex region like the Caribbean.
In 1992, the international regime 'Agenda 21' was agreed upon. Accordingly, countries worldwide have been undergoing reforms in their water management into Integrated Water Resources Management (IWRM). The implementation is promoted by international actors. The main institutional aspects of IWRM are the river basin approach, clear property rights allocation, and application of economical instruments. In former centrally planned economies, the process of IWRM implementation has been coincided with transformation for the market economy. The implementation of institutional aspects of IWRM in countries under transition is connected with high transaction costs. Against this background, the comparative empirical study was initialised in order to analyse institutional change of water management towards IWRM in Vietnam and in Poland. Two models of river basin organisations were examined. Consequently, pros and cons of decentralised polycentric and hierarchical unicentric river basin organisations have been evaluated. Formal institutions were studied with the use of an in-depth review of legislation in Vietnam and in Poland. The EU Water Frame Directive (EU WFD) and other international policies were also examined. For the empirical study in Vietnam and in Poland, actors were interviewed as experts. The results of the study on both countries were discussed separately, and conclusions were drawn in a comparative manner. Water management reforms towards IWRM in Vietnam and in Poland have been generating multi-level governance processes including international, national and sub-national levels. The implementation of IWRM in Vietnam is supported by international donor agencies. In Poland, the implementation of the EU WFD is coordinated by the European Commission in a hierarchical manner. In comparison to international joint-development projects in Vietnam, the European Commission enforces international IWRM policy more effectively. Since the resumption of ODA in early 1990s, water resources management has been institutionalised in Vietnam by international support. In 1998, a Water Law was established in Vietnam. The intended separation of water resources management from water service provisions caused fragmentation between the Ministry of Natural Resources and Environment, and the Ministry of Agriculture and Rural Development, respectively. This ‘silo-effect’ has been intensified by the competition for international ODA. The power struggles affect even agencies within ministries. Polycentric river basin committees have been established as entities subordinated to the Ministry of Agriculture and Rural Development, as well as the Ministry of Natural Resources and Environment. However, because of weak property rights allocation and the absence of administrative powers, the river basin organisations work ineffectively. The river basin has not yet been established as a sub-national area of political action. Decisions sustained to be made at central level and are affected by the information problem due to largely centralised organisations of Vietnamese water management. The sub-national level is characterised by very low planning and management capacities. In Poland, unicentric river basin organisations were established in 1991. They are aligned with hydrological borders. Water resources planning and management are carried out according to river basins and water regions in order to implement the EU WFD. The river basin has been established as a new area of decision-making. Conflicts between local-governments have been resolved after the reforms. Nevertheless, spatial management planning, environmental protection planning, water service delivery, etc., are further carried out by local self-governments. To integrate water resources planning and management with these services, horizontal coordination is of critical importance. However, this is hampered by problems of ‘spatial fit’. Moreover, a high degree of horizontal cross-border communication increases information problems in hierarchical organisations. Thus, features of polycentric governance models become increasingly important in order to fully implement the EU WFD in Poland.
Asymmetrical capacitively coupled RF discharges in oxygen, argon and hydrogen have been experimentally investigated with the innovative technique of the phase resolved optical emission spectroscopy. This diagnostic tool allows to measure spatio-temporally resolved emission intensities of electronically excited species with a high resolution. The spatial (axial) resolution was better than 1 mm and a temporal resolution of about 1.5 ns has been achieved. Therefore the plasma induced optical emission within the RF cycle (TRF = 73.75 ns) from the RF sheath region with a typical mean sheath thickness of about 5mm has been studied. Spatio-temporally resolved optical emission patterns of the following optical transitions have been measured for a total gas pressure in the range of 20 to 100 Pa and self-bias voltages between -50 and -550 V: Oxygen plasma Emission at 777.4 nm and 844.6 nm (atomic oxygen) Argon plasma Emission at about 751 nm and 841 nm (argon) Hydrogen plasma Emission at 656.3nm (atomic hydrogen, H alpha-line) These transitions are the most prominent ones of the investigated excited species in these plasmas as could be shown from overview spectra of the plasma induced optical emission in the range from 350 to 850 nm. For the first time such extensive PROES measurements in oxygen CCRF plasmas are presented in this work. The additional investigations of argon and hydrogen plasmas serve as a reference and for a direct comparison with results from the literature. The temporal behavior of the emission intensity is influenced by the effective lifetime of the emitting states which is on the order of the nanosecond time scale of the RF cycle. Therefore, it does not represent the real temporal behavior of the excitation. A simple method has been applied to calculate relative excitation rates from the measured emission intensities to distinguish different excitation mechanisms and their correct relative temporal behavior. In a close collaboration within the framework of the Sonderforschungsbereich Transregio 24 'Fundamentals of Complex Plasmas' a newly 1d3v PIC-MCC code for simulations of capacitive RF discharges in oxygen has been developed by Matyash et al. The very close coupling of experiment and modeling allowed a really detailed and microscopic understanding of the processes and dynamics from the sheath to the bulk plasma in CCRF discharges. The spatio-temporally resolved excitation rate profiles show four different excitation structures (I-IV). Excitation processes due to the following mechanisms in CCPs could be identified and characterized: I Electrons expelled from growing sheath II Electrons detached from negative ions (collisions with neutrals) + secondary electrons from the electrode surface (ion bombardment) III Field-reversal effect, reduced mobility of electrons (electron-neutral collisions) IV Heavy-particle collisions These excitation mechanisms are characterized by different temporal and spatial behaviors of the excitation rate within the RF cycle. Additionally it has been shown that the excitation by electron impact in the investigated oxygen plasmas results mainly from dissociative electron impact excitation (O2 + e -> O + O* + e) and not from direct electron impact excitation (O + e -> O* + e). Actinometry measurements show that the results are not really credible. Thus actinometry is not applicable on the investigated oxygen RF plasma. A challenge in interpretation is the observed excitation pattern IV. Pattern IV has to be caused in connection with heavy particle collisions nearby the electrode surface and could be observed in all the three plasmas oxygen, argon and hydrogen. It is located directly in front of the powered electrode and appears during almost the whole RF cycle. The temporal modulation is nearly sinusoidal and weak in comparison to the first three patterns. This is due to the weak RF modulation of the ion flux towards the electrode surface which has been proven by a PIC simulation. It could be shown that the modulation degree of pattern IV depends on the transition time of the corresponding positive ions through the RF sheath which is influenced by the ion mass. In oxygen as well as in argon CCRF plasmas pattern IV is less modulated than in hydrogen CCRF plasmas due to the heavier ions in oxygen and argon. Additionally the modulation degree increases with increasing pressure due to the more confined plasma at higher pressures which is yielding in a stronger modulated ion current towards the powered electrode.