| 15491. |
- Merseburger, Axel S., et al.
(author)
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Renal cell carcinoma
- 2016
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In: World journal of urology. - : Springer Science and Business Media LLC. - 0724-4983 .- 1433-8726. ; 34:8, s. 1051-1052
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Journal article (other academic/artistic)
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| 15492. |
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| 15493. |
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| 15494. |
- Messinger, Johannes, et al.
(author)
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Mastering sustainable energy : Light-Induced Water-Splitting in Nature. Electronic Structure of the Manganese Cluster in Photosystem II
- 2009
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In: The Treasures of EUREKA. Volume 1. Electron Paramagnetic Resonance.. - : AXAS Publishing Ltd. - 9781877524011 ; , s. 164-165
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Book chapter (other academic/artistic)abstract
- Beautifully presented, this publication reveals the knowledge in several layers appealing to a wide audience. Parts of the publication are so easy to read and so well illustrated that every reader will be able to get a glimpse of how key inventions from the past feed science and technology today and what they will bring us in the future. Business people and professionals will be able to discover opportunities revealed through innovative scientific research. Students will get a wider perspective on what science is about and finally scientists themselves will discover how seemingly unrelated discoveries may have a profound impact on their own research.Now it's your turn to discover "The Treasures of Eureka" created to entertain and challenge people from different walks of life, including you.The Treasures of Eureka" series starts from the publication devoted to a recent invention, which in just a short 70 years became one of the key methods of matter research and diagnostic and is widely used from control of food processing to medical treatment, from discovery of new superconductors to building elements of quantum computers.It might not be common knowledge that all these are referring to the discovery of the Electron Paramagnetic Resonance in 1944 by E.K. Zavoisky in Kazan, Tatarstan, Russia. An international Zavoisky Award has been established in 1991 to commemorate the significance of EPR theoretical and practical applications. Since 1991 the Zavoisky Award is awarded in Kazan, Russia, to recognize outstanding applications or developments of electron paramagnetic resonance in any field of science.This publication is a celebration of the EPR discovery, scientists working in this area, Zavoisky Awardees and technology applications which enhance quality of everyday living for every human on the planet today.Over 100 of the world's leading EPR experts contributed articles to introduce the marvels of EPR theoretical research and its practical applications to a wider audience. The expertise of authors is matched by high quality design, which makes this publication a milestone in EPR history. This beautifully crafted, fully illustrated hard-cover edition is a true celebration of the significant role of EPR spectroscopy in various aspects of modern life.Completed with a biography of Eugenii Zavoisky and an original overview of EPR written by the book's editor Prof. Kev Salikhov, it introduces 23 awardees of the Zavoisky Award as individuals and scientists; giving readers a unique insight into the scientific community, which is working on the forefront of modern technology that is shaping the life of humankind. There are also over 37 short articles demonstrating latest research and applications of EPR.Recognizing a trend of inter-disciplinary research this publication contributes to the introduction of EPR spectroscopy methods and technologies to a world wide scientific community. This publication is bound to become an invaluable resource to all life and material scientists, students and the general public interested in modern science.Without a doubt this publication is s must for scientific, tertiary and general libraries,. It makes a great gift for natural scientists and science enthusiasts. Business and technology experts will fdiscover how ;atest scientific advances can add value in real life. It is especially valuable for everyone involveddin quality control. Multi-level presentation of information makes it an enjoyable read for many.
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| 15495. |
- Messinger, Johannes
(author)
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Water Oxidation in Photosystem II : Structure and Function of Nature’s Mn4CaO5 Cluster
- 2011
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Conference paper (other academic/artistic)abstract
- Photosynthesis is Nature‟s way of utilizing solar energy. Photosystem II (PSII) is the unique pigment-protein complex of photosynthesis that is able to perform visible light-driven oxidation of water into O2, protons and energized electrons. The catalytic site of water-oxidation in PSII is referred to as the water-oxidizing complex (WOC) and contains a Mn4CaO5 cluster that accumulates in a cyclic reaction four oxidizing equivalents before water-oxidation occurs. Since it is possible to combine protons and electrons in a subsequent step to H2, PSII is frequently viewed as blueprint for developing man-made catalysts for storing solar energy in the chemical bonds of H2 and O2.1 This talk will report on recent dramatic improvements regarding the understanding of the geometric and electronic structures of the WOC and especially of its Mn4CaO5 cluster. These improvements are based on X-ray crystallographic data by Zouni et al.2 and Shen and coworkers3, but crucial information also comes from EXAFS4-11 and EPR/ENDOR studies12-16 and from theoretical calculations17-20. Furthermore the energetic of the O2 release step21 will be discussed and the mode of substrate water binding22. Possible mechanism for photosynthetic water-oxidation23-25 and activity measurements of synthetic Mn4CaO5 complexes will be briefly covered26-28.
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| 15496. |
- Messner, Torbjörn, 1947-
(author)
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Ischemic heart disease in Kiruna : risk factors and sequelae
- 1996
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Doctoral thesis (other academic/artistic)abstract
- Kiruna, a Swedish community situated 300 km north of the Arctic Circle, has a very high mortality in ischemic heart disease (IHD). Acase-control study was undertaken to find out if the risk factors for IHD or their impact differed from those in other populations. The survey methods comprised questionnaires, physical examinations, laboratory tests, a food diary, ecological studies, and a register study. The study group consisted of 219 men who had suffered an acute myocardial infarction (cases) and 438 men without known ischemic heart disease (controls).The main risk factors were: a family history of IHD, hypertension, hyperlipidemia, diabetes mellitus, and smoking. Also psycho-social risk factors like lack of job support constituted a risk factor.Cholesterol ester and adipose tissue triglyceride fatty acids have a slower turn-over rate than other routinely analysed lipids and lipoproteins and thus reflect dietary habits over a longer period of time. They were measured in a subset of our cohort, showing that the cases, judged from lipid and fatty acid composition, lived on a diet comparable to that of the controls. A prospective diet diary showed few differences between cases and controls and between the whole cohort and a reference cohort in Uppsala in the central part of Sweden. Most notable differences were a low level of y-tocopherol, a low proportion of linoleic acid, and a high proportion of palmitic acid in serum cholesterol esters and adipose tissue triglycerides in the Kiruna cohort.The expected reduced morbidity in ischemic heart disease related to alcohol consumption was not seen in our material. This finding was further examined in an ecological study on a national Swedish level, longitudinally, cross-sectionally, and with time-series methodology. There was an inverse correlation between wine consumption and mortality in IHD for women but no correlation between the consumption of beer and distilled spirits, and mortality in IHD.Heart failure, a common sequela of IHD, has an increasing incidence in a hospital-based population. In spite of improved treatments the prognosis has not improved during the last seven years and is still as bad as or worse than that of many malignant diseases. Male sex and high age implied a worse prognosis.Consumption of acetylsalicylic acid (ASA) for pain relief resulted in a greater risk of developing an acute myocardial infarction in our cohort. This was further examined in an ecological study on anational Swedish level also showing a correlation between ASA consumption and mortality in IHD both in the geographical and the longitudinal analysis for the surveyed years, but not in the time series analysis.
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| 15497. |
- Mettin, Uwe, 1979-
(author)
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Applications of the Virtual Holonomic Constraints Approach : Analysis of Human Motor Patterns and Passive Walking Gaits
- 2008
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Licentiate thesis (other academic/artistic)abstract
- In the field of robotics there is a great interest in developing strategies and algorithms to reproduce human-like behavior. One can think of human-like machines that may replace humans in hazardous working areas, perform enduring assembly tasks, serve the elderly and handicapped, etc. The main challenges in the development of such robots are, first, to construct sophisticated electro-mechanical humanoids and, second, to plan and control human-like motor patterns.A promising idea for motion planning and control is to reparameterize any somewhat coordinated motion in terms of virtual holonomic constraints, i.e. trajectories of all degrees of freedom of the mechanical system are described by geometric relations among the generalized coordinates. Imposing such virtual holonomic constraints on the system dynamics allows to generate synchronized motor patterns by feedback control. In fact, there exist consistent geometric relations in ordinary human movements that can be used advantageously. In this thesis the virtual constraints approach is extended to a wider and rigorous use for analyzing, planning and reproducing human-like motions based on mathematical tools previously utilized for very particular control problems.It is often the case that some desired motions cannot be achieved by the robot due to limitations in available actuation power. This constraint rises the question of how to modify the mechanical design in order to achieve better performance. An underactuated planar two-link robot is used to demonstrate that springs can complement the actuation in parallel to an ordinary motor. Motion planning is carried out for the original robot dynamics while the springs are treated as part of the control action with a torque profile suited to the preplanned trajectory.Another issue discussed in this thesis is to find stable and unstable (hybrid) limit cycles for passive dynamic walking robots without integrating the full set of differential equations. Such procedure is demonstrated for the compass-gait biped by means of optimization with a reduced number of initial conditions and parameters to search. The properties of virtual constraints and reduced dynamics are exploited to solve this problem.
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| 15498. |
- Mettin, Uwe, 1979-
(author)
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Principles for planning and analyzing motions of underactuated mechanical systems and redundant manipulators
- 2009
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Doctoral thesis (other academic/artistic)abstract
- Motion planning and control synthesis are challenging problems for underactuated mechanical systems due to the presence of passive (non-actuated) degrees of freedom. For those systems that are additionally not feedback linearizable and with unstable internal dynamics there are no generic methods for planning trajectories and their feedback stabilization. For fully actuated mechanical systems, on the other hand, there are standard tools that provide a tractable solution. Still, the problem of generating efficient and optimal trajectories is nontrivial due to actuator limitations and motion-dependent velocity and acceleration constraints that are typically present. It is especially challenging for manipulators with kinematic redundancy. A generic approach for solving the above-mentioned problems is described in this work. We explicitly use the geometry of the state space of the mechanical system so that a synchronization of the generalized coordinates can be found in terms of geometric relations along the target motion with respect to a path coordinate. Hence, the time evolution of the state variables that corresponds to the target motion is determined by the system dynamics constrained to these geometrical relations, known as virtual holonomic constraints. Following such a reduction for underactuated mechanical systems, we arrive at integrable second-order dynamics associated with the passive degrees of freedom. Solutions of this reduced dynamics, together with the geometric relations, can be interpreted as a motion generator for the full system. For fully actuated mechanical systems the virtually constrained dynamics provides a tractable way of shaping admissible trajectories. Once a feasible target motion is found and the corresponding virtual holonomic constraints are known, we can describe dynamics transversal to the orbit in the state space and analytically compute a transverse linearization. This results in a linear time-varying control system that allows us to use linear control theory for achieving orbital stabilization of the nonlinear mechanical system as well as to conduct system analysis in the vicinity of the motion. The approach is applicable to continuous-time and impulsive mechanical systems irrespective of the degree of underactuation. The main contributions of this thesis are analysis of human movement regarding a nominal behavior for repetitive tasks, gait synthesis and stabilization for dynamic walking robots, and description of a numerical procedure for generating and stabilizing efficient trajectories for kinematically redundant manipulators.
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| 15499. |
- Meurle-Hallberg, Kina
(author)
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Relationships between bodily characteristics and mental attitudes: Bodily examined and self assessed raitings of ill health
- 2005
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Licentiate thesis (other academic/artistic)abstract
- The present thesis investigates the psychometric properties and clinical relevance of the Resource Oriented Body Examination and its capacity to provide a useful assessment tool in patients whose symptoms appear to contain associations between psychological and physical problems.Our aims were to find out if an early version of the Resource Oriented BodyExamination, ROBE I, could be reduced into a shorter version, labelled ROBE II. We also wanted to know if ROBE II would treat the variation of items in the different subscales in a way that provided for discrimination between groups of patients with psychosomatic, musculoskeletal and schizophrenic disorders compared to a group of non-patients. A total of 198 subjects were body examined with a ROBE I protocol. The sample data were entered into a separate factor analysis for each domain. Principal components with varimaxrotations were used, and the first two factors for each domain were extracted. The original 254 variables were reduced to 144, constituting an instrument for body examination, ROBE II, with 10 subscales. All subscales showed satisfactory internal consistency. Within all but one of the domains the subscales showed acceptable intercorrelation. All subscales disclosed information of body patterns relevant for tracing psychosomatic symptoms inaccordance with the Norwegian Psycho Motor Physiotherapy (NPMP). The subscales of ROBE II distinguished bodily characteristics of patients with psychosomatic, musculoskeletal and schizophrenic disorders. Another research question in this study was: how do patients with stress-related behaviorand somatoform disorders assess their symptoms and self-image compared to healthy individuals, and how are these assessments related to bodily resources, assessed with a physiotherapeutic body examination?The test group (n=31) consisted of consecutive patients referred to a treatment center specializing in psychosomatic problems. Significant differences (p≤0.01) were found between the test and comparison groups (n=22) on all but two of the ten subscales of the Resource-Oriented Body Examination (ROBE II). This was also the case for all the subscales of The Symptom Checklist-90 (SCL-90) (comparison groups n=52), and for all but three of the eight clusters of the Structural Analysis of Social Behavior (SASB) (comparison groups n=52). For the patient group, the ROBE II subscale Increased respiratory control correlated significantly with the SCL-90 subscales that measures Angerhostility,Phobic anxiety, Paranoid ideation, with the Personality Severity Index (PSI) andwith the SASB clusters Daydreaming and self-neglect, Self-indictment and oppression with r’s between 0.38 and 0.50. Body examination with ROBE II might provide a useful assessment tool in patients whose stress-related problems appear to contain associations between psychological and physical problems.
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| 15500. |
- Meyer-Jacob, Carsten, 1984-
(author)
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Infrared spectroscopy as a tool to reconstruct past lake-ecosystem changes : Method development and application in lake-sediment studies
- 2015
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Doctoral thesis (other academic/artistic)abstract
- Natural archives such as lake sediments allow us to assess contemporary ecosystem responses to climate and environmental changes in a long-term context beyond the few decades to at most few centuries covered by monitoring or historical data. To achieve a comprehensive view of the changes preserved in sediment records, multi-proxy studies – ideally in high resolution – are necessary. However, this combination of including a range of analyses and high resolution constrains the amount of material available for analyses and increases the analytical costs. Infrared spectroscopic methods are a cost-efficient alternative to conventional methods because they offer a) a simple sample pre-treatment, b) a rapid measurement time, c) the non- or minimal consumption of sample material, and d) the potential to extract quantitative and qualitative information about organic and inorganic sediment components from a single measurement.The main objective of this doctoral thesis was twofold. The first part was to further explore the potential of Fourier transform infrared (FTIR) and visible-near infrared (VNIR) spectroscopy in paleolimnological studies as a) an alternative tool to conventional methods for quantifying biogenic silica (bSi) – a common proxy of paleoproductivity in lakes – in sediments and b) as a tool to infer past lake-water total organic carbon (TOC) levels from sediments. In a methodological study, I developed an independent application of FTIR spectroscopy and PLS modeling for determining bSi in sediments by using synthetic sediment mixtures with known bSi content. In contrast to previous models, this model is independent from conventional wet-chemical techniques, which had thus far been used as the calibration reference, and their inherent measurement uncertainties. The second part of the research was to apply these techniques as part of three multi-proxy studies aiming to a) improve our understanding of long-term element cycling in boreal and arctic landscapes in response to climatic and environmental changes, and b) to assess ongoing changes, particularly in lake-water TOC, on a centennial to millennial time scale.In the first applied study, high-resolution FTIR measurements of the 318-m long sediment record of Lake El’gygytgyn provided a detailed insight into long-term climate variability in the Siberian Arctic over the past 3.6 million years. Highest bSi accumulation occurred during the warm middle Pliocene (3.6-3.3 Ma), followed by a gradual but variable decline, which reflects the first onset of glacial periods and then the finally full establishment of glacial–interglacial cycles during the Quaternary. The second applied study investigated the sediment record of Torneträsk in subarctic northern Sweden also in relation to climate change, but only over the recent post-glacial period (~10 ka). By comparing responses to past climatic and environmental forcings that were recorded in this large-lake system with those recorded in small lakes from its catchment, I determined the significance and magnitude of larger-scale changes across the study region. Three different types of response were identified over the Holocene: i) a gradual response to the early landscape development following deglaciation (~10000-5300 cal yr BP); ii) an abrupt but delayed response following climate cooling during the late Holocene, which occurred c. 1300 cal yr BP – about 1000-2000 years later than in smaller lakes from the area; and iii) an immediate response to the ongoing climate change during the past century. The rapid, recent response in a previously rather insensitive lake-ecosystem emphasizes the unprecedented scale of ongoing climate change in northern Fennoscandia. In the third applied study, VNIR-inferred lake-water TOC concentrations from lakes across central Sweden showed that the ongoing, observed increase in surface water TOC in this region was in fact preceded by a long-term decline beginning already AD 1450-1600. These dynamics coincided with early human land use activities in the form of widespread summer forest grazing and farming that ceased over the past century. The results of this study show the strong impact of past human activities on past as well as ongoing TOC levels in surface waters, which has thus far been underestimated. The research in this thesis demonstrates that infrared spectroscopic methods can be an essential component in high-resolution, multi-proxy studies of past environmental and climate changes.
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