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"At-risk" concept
(2005)
Die vorliegende Festschrift wird Frau Prof. Gabrielle Saupe anlässlich ihrer Verabschiedung aus dem Institut für Geographie der Universität Potsdam gewidmet. Bewegende Räume - damit sind emotionale, materielle und strukturelle Bewegungen in einem räumlichen Kontext gemeint. Die Vieldeutigkeit des Titels impliziert die Vielfalt der wissenschaftlichen Auseinandersetzung mit dem Raum. Ein illustres Autorenkollektiv deutscher Raumwissenschaftler verdeutlicht anhand von verschiedenen zum Teil essayartigen Artikeln sein Verständnis von Raum. Die interdisziplinäre Konzeption des Heftes soll das ständige Bemühen von Frau Saupe verdeutlichen, verschiedene Perspektiven, Herangehensweisen und Fachdisziplinen zur Bewältigung der Forschungsaufgaben zusammenzuführen. Hierbei sind die wichtigsten Forschungsprojekte von Frau Saupe ebenso vertreten wie einige der von ihr betreuten Qualifikationsarbeiten. Die Beiträge reichen von der Landschafts- bzw. Geoökologie bis zum Fußball und der Musik. Sie spannen einen Bogen von der Geographie als Regionalwissenschaft zu modernen stadtsoziologischen Fragestellungen, stellen Ergebnisse neuerer Forschungsprojekte vor und widmen sich der Entwicklung von nahen und fernen Räumen aus verschiedenen Perspektiven.
"Der schlafende Riese"
(2005)
"Make a Run for the Border": Chicano Performance Art and the Search for a Space of/for Difference
(2005)
Despite the difficult situation in Iraq, US President Bush easily won a second term, but his room for manoeuvre is now significantly smaller than it was four years ago. He has at least three conflicts on his plate: the first and most critical one in Iraq, the second the continuing war on terror and the third the struggle to consolidate Afghanistan. Conscious of the growing risk of US overstretch, Bush is now reaching out to the European allies. However, most observers anticipate a change in style rather than any real change in substance.
"Partager le crime"
(2005)
The five Potsdam "Studientage zum Englischen Mittelalter (SEM)" (1999-2003) served a number of purposes. These are fully discussed in this article. The first and foremost idea was to provide a yearly forum for young scholars in English medieval studies to present their research to other scholars in the field and to test their market value ("Nachwuchsfoerderung"). After Potsdam, the SEM meetings are circulating between those universities in the German speaking countries, which feature a Medieval Studies Programme in their departments of English and American Studies. This programme serves to boost their academic profile and etablish centres of excellency for English medieval Studies on the Continent. Networking is another prime objective of the SEMs. See http://www.uni-potsdam.de/u/sem/sem.htm etc.
„Menschen benötigen Platz zum Leben.“ In dieser Erkenntnis liegt noch nichts Besonderes oder gar Aufregendes. Erst die Tatsache, dass die menschliche Bevölkerung seit jeher zunimmt, aber der zur Verfügung stehende Platz konstant bleibt bzw. die Ressourcen in ihrem Bestand sogar abnehmen, macht dieses Thema wesentlich gehaltvoller. Offensichtlich ist außerdem: „Population growth seems to affect everything but is seldom held responsible for anything.“ (McKee 2003: 10) Dies ist der Hauptgrund dafür, dass gerade die Thematik der Bevölkerungsentwicklung internationale Beachtung und Aufmerksamkeit verdient.
"Woher kommt eigentlich ...?" : Sprachberatung und Sprachgeschichte an der Universität Potsdam
(2005)
Dieses Material soll es dem Lehrer ermöglichen, schnell und mit wenig Arbeitsaufwand eine oder mehrere Unterrichtsstunden zum Thema "Söldnertum" vorzubereiten, aber auch zur Arbeit mit Bildquellen anregen, die in der Schule oftmals recht stiefmütterlich behandelt werden. Zu diesem Zweck wird in aller Kürze in die Entstehung des Soldkriegswesens als Form staatlich organisierter Gewaltsamkeit eingeführt. Ausgehend von der Spätantike werden die militärischen, wirtschaftlichen und demographischen Faktoren, die zur "Renaissance des Fußvolkes" geführt haben, beschrieben, und auf entsprechende Fachpublikationen verwiesen. Organisation, Struktur und Rechtsformen der Söldnerheere werden vorgestellt und immer anhand von Bildquellen des 15. und 16. Jahrhunderts verdeutlicht. Der zweite Teil dieses Materials besteht aus einer Einführung in die Historische Bildkunde, so dass die Schüler den Umgang mit dieser Quellengattung zügig erlernen können. Um die komplexe Symbolik der Bildmaterialien der Frühen Neuzeit entschlüsseln zu können, wurde als Hilfe für Lehrer und Schüler ein Symbolschlüssel angefertigt. Die Quellen liegen in digitaler Form, in zwei Ausführungen (einer mit Markierungen der wichtigsten Symbole für den Lehrer, einer ohne diese Markierungen als Arbeitsmaterial für die Schüler) der Arbeit bei. Das Material ist modular aufgebaut, so dass man bei Bedarf nur einen Aspekt des Soldkriegswesens (beispielsweise das Trossvolk oder die Verrechtlichung innerhalb der Söldnerheere) von den Schülern bearbeiten lassen kann. Abschließend werden Vorschläge für Tafelbilder und Übersichten, sowie für Aufgabenstellungen, die sich sowohl zur Einzel- als auch zur Gruppen- oder Projektarbeit eignen, unterbreitet.
1945 und die Polen
(2005)
The current series of anniversaries concerning World War II raise the question of how Poland is coming to terms with its past. The article summarises the ongoing Polish debate about the Warsaw Uprising and the changing perspectives on Polish history in society and political circles. The discussion about Poland’s view on its own past has great influence on recent foreign political relations, e.g. with Germany, the Ukraine, or Russia.
Tagungsbericht: Meyer, Gunda ; Warnke, Marcus ; Wolff, Sascha: 5. Berliner Symposium zum Flüchtlingsschutz: Menschenrechte und internationaler Schutz, Die Bedeutung der Menschenrechte für den Schutz von Flüchtlingen <2005, Berlin> / veranst. vom Büro Berlin des UNHCR, dem Deutschen Institut für Menschenrechte und der Evangelischen Akademie zu Berlin am 20. und 21. Juni 2005.
7a-O-methyldeguelol, a modified rotenoid with an open ring-C, from the roots of Derris trifoloata
(2005)
From the acetone extract of the roots of Derris trifoliata an isollavonoid derivative, named 7a-O- methyldeguelol, a modified rotenoid with an open ring-C, representing a new sub-class of isollavonoids (the sub-class is here named as rotenoloid), was isolated and characterised. In addition, the known rotenoids, rotenone, deguelin and alpha-toxicarol, were identified. The structures were determined on the basis of spectroscopic evidence. Rotenone and deguelin were identified as the larvicidal principles of the acetone extract of the roots of Derris trifoliata. (c) 2005 Elsevier Ltd. All rights reserved
The uptake of resources from the environment is a vital process for all organisms. Many experimental studies have revealed that the rate at which this process occurs depends critically on the resource concentration, a relationship called "functional response." However, whether the concentration of the consumer normally affects the functional response has been the subject of a long-standing, predominantly theoretical, debate in ecology. Here we present an experimental test between the alternative hypotheses that food uptake depends either only on the resource concentration or on both the resource and the consumer concentrations. In short-term laboratory experiments, we measured the uptake of radioactively labeled, unicellular green algae (Monoraphidium minutum, resource) by the rotifer Brachionus calyciflorus (a consumer) for varying combinations of resource and consumer concentrations. We found that the food uptake by Brachionus depended on the algal concentration with the relationship best described by a Holling type 3 functional response. We detected significant consumer effects on the functional response only at an extraordinarily high Brachionus density (similar to 125 rotifers/mL), which by far exceeds concentrations normally encountered in the field. We conclude that con sumer-dependent food uptake by planktonic rotifers is a phenomenon that can occur under extreme conditions, but probably plays a minor role in natural environments
Background Soy protein is effective in lowering plasma cholesterol, LDL cholesterol and triglyceride concentrations. It has not been conclusively answered, whether and to what extent other soy constituents may also contribute to this effect. Objective To investigate the change in blood lipid levels after application of two soy-based supplements containing soy protein either without (SuproSoy(R)) or with (Abacor(R)) soy fiber and phospholipids in a randomized placebo-controlled triple-armed study. Methods 121 hypercholesterolemic adults ( 66 females, 55 males) were recruited and randomly assigned to one of three treatments. Over 8 weeks they received daily either 25 g soy protein ( as a component of the supplements Abacor(R) or SuproSoy(R)) or 25 g milk protein ( as a component of placebo). Serum lipids were measured at baseline and after 4, 6 and 8 weeks. Results After 8 weeks of supplementation total cholesterol levels were reduced by 8.0 +/- 9.6% (Abacor(R)) and 3.4 +/- 8.3% (SuproSoy(R)); LDL cholesterol levels by 9.7 +/- 11.7% ( Abacor(R)) and 5.4 +/- 11.6% ( SuproSoy(R)); and Apolipoprotein B levels by 6.9 +/- 14.6% (Abacor(R)) and 4.0 +/- 12.4 % (SuproSoy(R)). Serum levels of HDL cholesterol and triglycerides remained unchanged. Conclusions A preparation combining isolated soy protein with soy fibers and phospholipids showed twice the lipid-lowering effect of a preparation containing isolated soy protein alone. Therefore, such soy-based supplements can be useful in reducing the cardiovascular risk
An unconventional but easily accessible precursor route involving the thermal treatment of hybrid precursors containing an ampholytic polymer matrix is developed to prepare multimetallic oxides of catalytic interest such as transition metal molybdates. A copolymer of diallyldimethylammonium chloride and a functionalized maleamic acid bearing an amine group suited for cation complexation was designed, synthesized and used as a matrix to stabilize inorganic species generated in solution from Ni(NO3)(2)center dot 6H(2)O, Co(NO3)(2)center dot 6H(2)O and/or Mn(NO3)(2)center dot 4H(2)O together with (NH4)(6)Mo(7)O(24)center dot 4H(2)O. UV-vis-NIR as well as C-13-NMR studies suggest that the interactions between the cations and the polymer in solution are mainly electrostatic. Only minor complexation interactions take place under certain conditions. Homogeneous hybrid blends were prepared from these solutions. The presence of a complexing amine group in addition to the charged betaine moieties in the polymer permits stabilization of more than stoichiometric amounts of the metal species in the blends. XRD measurements suggest that the homogeneity in the solid state can be kept up to about 1.5 mol of each metal that is incorporated ( anionic as well as cationic) per mol of repeat units of the copolymer. The blends were calcined under air at 600 degrees C to produce the simple as well as mixed nickel, cobalt and manganese molybdates. Characterization of the final phases by XRD and Raman spectroscopy indicates that the alpha- as well as the beta-molybdate phases can be prepared, and that the mixed structures are solid solutions of the simple NiMoO4, MnMoO4 and CoMoO4. If the precursors engaged are homogeneous, the pH of the precursor solution, the amount of metal that is incorporated in the matrix, and the nature of the polymer matrix seem to exert only a minor influence on the nature of the final phase, which demonstrates the versatility and facile applicability of the method
Parallel File Systems like PVFS2 are a necessary compo nent for high-performance computing. The design of ef ;cient communication layers for these systems is still of great research interest. This paper presents a low- latency messaging method for PVFS2 dedicated for Gigabit Ether net networks and discusses relevant design issues. In con trast to other approaches, we argue that zero-copying can be achieved also for big messages without use of a rendez vous protocol. Further, ef;ciency within the communica tion layer like a small call stack plays an important role.
1 Secondary seed dispersal by wind, the wind-driven movement of seeds along the ground surface, is an important dispersal mechanism for plant species in a range of environments. 2 We formulate a mechanistic model that describes how secondary dispersal by wind is affected by seed traits, wind conditions and obstacles to seed movement. The model simulates the movement paths of individual seeds and can be fully specified using independently measured parameters. 3 We develop an explicit version of the model that uses a spatially explicit representation of obstacle patterns, and also an aggregated version that uses probability distributions to model seed retention at obstacles and seed movement between obstacles. The aggregated version is computationally efficient and therefore suited to large-scale simulations. It provides a very good approximation of the explicit version (R-2 > 0.99) if initial seed positions vary randomly relative to the obstacle pattern. 4 To validate the model, we conducted a field experiment in which we released seeds of seven South African Proteaceae species that differ in seed size and morphology into an arena in which we systematically varied obstacle patterns. When parameterized with maximum likelihood estimates obtained from independent measurements, the explicit model version explained 70-77% of the observed variation in the proportion of seeds dispersed over 25 m and 67- 69% of the observed variation in the direction of seed dispersal. 5 The model tended to underestimate dispersal rates, possibly due to the omission of turbulence from the model, although this could also be explained by imprecise estimation of one model parameter (the aerodynamic roughness length). 6 Our analysis of the aggregated model predicts a unimodal relationship between the distance of secondary dispersal by wind and seed size. The model can also be used to identify species with the potential for long-distance seed transport by secondary wind dispersal. 7 The validated model expands the domain of mechanistic dispersal models, contributes to a functional understanding of seed dispersal, and provides a tool for predicting the distances that seeds move
An improved method for spectral subband decomposition based on simultaneous fitting of the initial spectrum and a set of its derivatives is introduced. Additionally, it procedure for finding an optimal smoothing filter to obtain undistorted derivatives IS Suggested. The proposed method is demonstrated with a model spectrum as well its with experimental absorption spectra of the photosynthetic antenna complexes, peridinin-chlorophyll a-protein (PCP) and the main light-harvesting complex of higher plants (LHC II). (c) 2005 Elsevier B.V. All rights reserved
We analyse a generic bottom-up nutrient phytoplankton model to help understand the dynamics of seasonally recurring algae blooms. The deterministic model displays a wide spectrum of dynamical behaviours, from simple cyclical blooms which trigger annually, to irregular chaotic blooms in which both the time between outbreaks and their magnitudes are erratic. Unusually, despite the persistent seasonal forcing, it is extremely difficult to generate blooms that are both annually recurring and also chaotic or irregular (i.e. in amplitude) even though this characterizes many real time series. Instead the model has a tendency to `skip' with outbreaks often being suppressed from one year to the next. This behaviour is studied in detail and we develop an analytical expression to describe the model's flow in phase space, yielding insights into the mechanism of the bloom recurrence. We also discuss how modifications to the equations through the inclusion of appropriate functional forms can generate more realistic dynamics.
Myofibrillar myopathy (MFM) is a human disease that is characterized by focal myofibrillar destruction and pathological cytoplasmic protein aggregations. In an extended German pedigree with a novel form of MFM characterized by clinical features of a limb-girdle myopathy and morphological features of MFM, we identified a cosegregating, heterozygous nonsense mutation (8130G -> A; W2710X) in the filamin c gene ( FLNC) on chromosome 7q32.1. The mutation is the first found in FLNC and is localized in the dimerization domain of filamin c. Functional studies showed that, in the truncated mutant protein, this domain has a disturbed secondary structure that leads to the inability to dimerize properly. As a consequence of this malfunction, the muscle fibers of our patients display massive cytoplasmic aggregates containing filamin c and several Z-disk-associated and sarcolemmal proteins
Quantified Boolean formulas (QBFs) play an important role in theoretical computer science. QBF extends propositional logic in such a way that many advanced forms of reasoning can be easily formulated and evaluated. In this dissertation we present our ZQSAT, which is an algorithm for evaluating quantified Boolean formulas. ZQSAT is based on ZBDD: Zero-Suppressed Binary Decision Diagram , which is a variant of BDD, and an adopted version of the DPLL algorithm. It has been implemented in C using the CUDD: Colorado University Decision Diagram package. The capability of ZBDDs in storing sets of subsets efficiently enabled us to store the clauses of a QBF very compactly and let us to embed the notion of memoization to the DPLL algorithm. These points led us to implement the search algorithm in such a way that we could store and reuse the results of all previously solved subformulas with a little overheads. ZQSAT can solve some sets of standard QBF benchmark problems (known to be hard for DPLL based algorithms) faster than the best existing solvers. In addition to prenex-CNF, ZQSAT accepts prenex-NNF formulas. We show and prove how this capability can be exponentially beneficial.
A new condensation principle
(2005)
We generalize del(A), which was introduced in [Schinfinity], to larger cardinals. For a regular cardinal kappa>N-0 we denote by del(kappa)(A) the statement that Asubset of or equal tokappa and for all regular theta>kappa(o), {X is an element of[L-theta[A]](<) : X &AND; &ISIN; &AND; otp (X &AND; Ord) &ISIN; Card (L[A&AND;X&AND;])} is stationary in [L-[A]](<). It was shown in [Sch&INFIN;] that &DEL;(N1) (A) can hold in a set-generic extension of L. We here prove that &DEL;(N2) (A) can hold in a set-generic extension of L as well. In both cases we in fact get equiconsistency theorems. This strengthens results of [Ra00] and [Ran01]. &DEL;(N3) () is equivalent with the existence of 0#
In C-13 NMR spectroscopy, there are many empirical methods for fast and exact computation of C-13 chemical shifts; comparable procedures for Si-29 NMR chemical shifts are not existing or are older than 20 years. On basis of the largest database of Si-29 chemical shifts available, along this paper a relatively simple procedure for the similarly exact calculation of the Si-29 chemical shifts of disilanes (average margin of error ca. 3.7 ppm) is given. (c) 2005 Elsevier B.V. All rights reserved
A package of programs written using the symbolic mathematics program, Mathematicatrademark, has been developed. Its principal usage is in teaching the LIMM method to students and demonstrating data analysis by means of the Polynomial Regularization Method (PRM). A large number of variables can be changed in the program and their effects can be shown graphically. Students at the University of Potsdam and Monash University have used the program successfully
Early Ilerdian (Early Eocene, Shallow Benthic Zones 5 and 6) carbonate systems of the Pyrenees shelf were deposited after a time of severe climatic ('Paleocene-Eocene Thermal Maximum, PETM') and phylogenetic ('Larger Foraminifer Turnover') changes. They reflect the radiation of nummulitid, alveolinid, and orbitolitid larger foraminifera after remarkable biotic changes at the end of the Paleocene, and announce their subsequent flourishing in the Middle Eocene. A paleoenvironmental model for tropical carbonate environments of this particular time interval is provided herein. During the Early Ilerdian, the inner and middle ramp deposits from Minerve, Campo and Serraduy revealed the end-member of a tropical carbonate factory with carbonate production dominated by the end-members of biotically (photo-autotrophic skeletal) controlled and biotically induced carbonate precipitation. Inner platform environments are dominated by alveolinids and in part by orbitolitids, middle platform environments are dominated by nummulitids. Corals are present, but they do not form reefs, which is a typical feature for the Eocene. Nummulite shoal complexes, which are well-known from the Middle Eocene are also absent during the studied Early Ilerdian interval, which may reflect the early evolutionary stage of this group
A Procedural Model for the Production of reusable and standard-compliant E-Learning Offerings
(2005)
Cost-efficient production of high-quality learning contents is an important success factor for a sustainable and economic realisation of E-Learning. This necessitates the design of sustainable production processes, which create reusable Learning Objects and require minimal resources. In such a context, this contribution introduces a practical and business-process oriented Procedural Model for the Production of reusable and standard-compliant E-Learning Offerings. It has been developed and applied in a project that produces learning contents for a Master program of an international virtual university. After the introduction of a reengineering method, a special analysis instrument for E-Learning has been designed to analyse the existing production processes and to improve them in terms of efficiency, costs, standard- compliance, and process automation. The method introduced is hence not focussing on individual technical solutions but on the efficiency of the whole E-Learning production and value chain. It gives an orientation for establishing and maintaining sustainable and competitive E-Learning production processes with appropriate effort.
We report on a receiver function study of the crust and upper mantle within DESERT, a multidisciplinary geophysical project to study the lithosphere across the Dead Sea Transform (DST). A temporary seismic network was operated on both sides of the DST between 2000 April and 2001 June. The depth of the Moho increases smoothly from about 30 to 34-38 km towards the east across the DST, with significant north-south variations east of the DST. These Moho depth estimates from receiver functions are consistent with results from steep-and wide-angle controlled-source techniques. Steep-angle reflections and receiver functions reveal an additional discontinuity in the lower crust, but only east of the DST. This leads to the conclusion that the internal crustal structure east and west of the DST is different. The P to S converted phases from both discontinuities at 410 and 660 km are delayed by 2 s with respect to the IASP91 global reference model. This would indicate that the transition zone is consistent with the global average, but the upper mantle above 410 km is 3-4 per cent slower than the standard earth model
Inositol polyphosphates, such as inositol trisphosphate, are pivotal intracellular signaling molecules in eukaryotic cells. In higher plants the mechanism for the regulation of the type and the level of these signaling molecules is poorly understood. In this study we investigate the physiological function of an Arabidopsis (Arabidopsis thaliana) gene encoding inositol polyphosphate kinase (AtIPK2alpha), which phosphorylates inositol 1,4,5-trisphosphate successively at the D-6 and D-3 positions, and inositol 1,3,4,5-tetrakisphosphate at D-6, resulting in the generation of inositol 1,3,4,5,6-pentakisphosphate. Semiquantitative reverse transcription-PCR and promoter-beta-glucuronidase reporter gene analyses showed that AtIPK2alpha is expressed in various tissues, including roots and root hairs, stem, leaf, pollen grains, pollen tubes, the flower stigma, and siliques. Transgenic Arabidopsis plants expressing the AtIPK2alpha antisense gene under its own promoter were generated. Analysis of several independent transformants exhibiting strong reduction in AtIPK2alpha transcript levels showed that both pollen germination and pollen tube growth were enhanced in the antisense lines compared to wild-type plants, especially in the presence of nonoptimal low Ca2+ concentrations in the culture medium. Furthermore, root growth and root hair development were also stimulated in the antisense lines, in the presence of elevated external Ca2+ concentration or upon the addition of EGTA. In addition, seed germination and early seedling growth was stimulated in the antisense lines. These observations suggest a general and important role of AtIPK2alpha, and hence inositol polyphosphate metabolism, in the regulation of plant growth most likely through the regulation of calcium signaling, consistent with the well-known function of inositol trisphosphate in the mobilization of intracellular calcium stores
Functional groups with diverse responses to environmental factors sum to produce communities with less temporal variability in their biomass than those lacking this diversity. The detection of these compensatory dynamics can be complicated by a spatio-temporal alternation in the environmental factors limiting growth (both abiotic and biotic), which restricts the occurrence of compensatory dynamics to certain periods or locations. Hence, resolving the spatio- temporal scale may uncover important spatial and/or temporal components in community variability. Using long-term data from Lake Constance (Bodensee), we find that a reduction in grazing pressure and relaxed competition for nutrients during winter and spring generates coherent dynamics among edible and less edible phytoplankton. During summer and fall, when both grazing pressure and nutrient limitation are present, edible and less edible phytoplankton exhibit compensatory dynamics. This study supports recent work suggesting that both abiotic and biotic interactions promote compensatory dynamics and to our knowledge, this is the first example of a system where compensatory and coherent dynamics seasonally alternate.
1 Two isoforms of the rat prostaglandin E-2 receptor, rEP3 alpha-R and rEP3 beta-R, differ only in their C- terminal domain. To analyze the function of the rEP3-R C-terminal domain in agonist induced desensitization, a cluster of Ser/Thr residues in the C-terminal domain of the rEP3 alpha-R was mutated to Ala and both isoforms and the receptor mutant (rEP3 alpha-ST341-349A-R) were stably expressed in HEK293 cells. 2 All rEP3-R receptors showed a similar ligand- binding profile. They were functionally coupled to Gi and reduced forskolin-induced cAMP-formation. 3 Repeated exposure of cells expressing the rEP3 alpha-R isoform to PGE(2) reduced the agonist induced inhibition of forskolin-stimulated cAMP-formation by 50% and led to internalization of the receptor to intracellular endocytotic vesicles. By contrast, Gi- response as well as plasma membrane localization of the rEP3 beta-R and the rEP3 alpha-ST341-349A-R were not affected by prior agonist-stimulation. 4 Agonist-stimulation of HEK293-rEP3 alpha-R cells induced a time- and dose-dependent phosphorylation of the receptor most likely by G protein-coupled receptor kinases and not by protein kinase A or protein kinase C. By contrast, upon agonist-stimulation the rEP3 beta-R was not phosphorylated and the rEP3 alpha-ST341-349A-R was phosphorylated only weakly. 5 These results led to the hypothesis that agonist-induced desensitization of the rEP3 alpha-R isoform is mediated most likely by a GRK-dependent phosphorylation of Ser/Thr residues 341 - 349. Phosphorylation then initiates uncoupling of the receptor from Gi protein and receptor internalization
We present a simple scheme for implementing an atomic phase gate using two degrees of freedom for each atom and discuss its realization with cold rubidium atoms on atom chips. We investigate the performance of this collisional phase gate and show that gate operations with high fidelity can be realized in magnetic traps that are currently available on atom chips
As meta-analyses demonstrate feedback effects on performance, our study examined possible mediators. Based on our cognitive-motivational model [Vollmeyer, R., & Rhemberg, F. (1998). Motivationale Einflusse auf Erwerb und Anwendung von Wissen in einem computersimulierten System [Motivational influences on the acquisition and application of knowledge in a simulated system]. Zeitschrift fur Padagogische Psychologie, 12, 11-23] we examined how feedback changed (1) strategies, and (2) motivation during learning, and by doing so improved (3) final performance. Students (N = 211) learned how a dynamic system works and how to reach given goal states for the system. One group received feedback (i.e., knowledge of performance) the other one did not. We expected learners to improve after they received the first feedback. However, we found that learners expecting feedback used better strategies right from the start. Thus, they acquired more knowledge over fewer trials. Although we had also expected effects of feedback on motivation during learning, we could not support this hypothesis. (c) 2005 Elsevier Ltd. All rights reserved
Mitochondrial diseases may be caused by numerous mutations that alter proteins of the respiratory chain and of other metabolic pathways in the mitochondrium. For clinicians this disease group poses a considerable diagnostic challenge due to ambiguous genotype-phenotype relationships. Until now, only 30 % of the mitochondriopathies can be diagnosed at the molecular level. We therefore need a new diagnostic tool that offers a wide view on the mitochondrial proteins. Here, we present a method to generate a high-resolution, large-gel two-dimensional gel electrophoretic (2-DE) map of a purified fraction of mitochondrial proteins from Epstein-Barr virus-immortalized lymphoblastoid cell line (LCL). LCLs can be easily obtained from patients and control subjects in a routine clinical setting. They often express the biochemical phenotype and can be cultured to high cell numbers, sufficient to gain enough purified material for 2- DE. In total we identified 166 mitochondrial proteins. Thirteen proteins were earlier not known to be of mitochondrial origin. Thirty-nine proteins were associated with human diseases ranging from respiratory chain enzyme deficiencies to disorders of P-oxidation and amino acid metabolism. This 2-DE map is intended to be the first step to diagnose mitochondrial diseases at the proteomic level
Among all voltage-gated K+ channels from the model plant Arabidopsis thaliana, the weakly rectifying K+ channel (K-weak channel) AKT2 displays unique gating properties. AKT2 is exceptionally regulated by phosphorylation: when nonphosphorylated AKT2 behaves as an inward-rectifying potassium channel; phosphorylation of AKT2 abolishes inward rectification by shifting its activation threshold far positive (>200 mV) so that it closes only at voltages positive of + 100 mV. In its phosphorylated form, AKT2 is thus locked in the open state in the entire physiological voltage range. To understand the molecular grounds of this unique gating behavior, we generated chimeras between AKT2 and the conventional inward-rectifying channel KAT1. The transfer of the pore from KAT1 to AKT2 altered the permeation properties of the channel. However, the gating properties were unaffected, suggesting that the pore region of AKT2 is not responsible for the unique K-weak gating. Instead, a lysine residue in S4, highly conserved among all K-weak channels but absent from other plant K+ channels, was pinpointed in a site-directed mutagenesis approach. Substitution of the lysine by serine or aspartate abolished the "open-lock" characteristic and converted AKT2 into an inward- rectifying channel. Interestingly, phosphoregulation of the mutant AKT2-K197S appeared to be similar to that of the K-in channel KAT1: as suggested by mimicking the phosphorylated and dephosphorylated states, phosphorylation induced a shift of the activation threshold of AKT2-K197S by about +50 mV. We conclude that the lysine residue K197 sensitizes AKT2 to phosphoregulation. The phosphorylation-induced reduction of the activation energy in AKT2 is similar to 6 kT larger than in the K197S mutant. It is discussed that this hypersensitive response of AKT2 to phosphorylation equips a cell with the versatility to establish a potassium gradient and to make efficient use of it
Equilibria between the Z (tau(1) = 0 degrees) and E (tau(1) = 180 degrees) conformers of p-substituted phenyl acetates 4 and trifluoroacetates 5 (X = OMe, Me, H, Cl, CN, NO2) were studied by ab initio calculations at the HF/6-31G* and MP2/6-31G* levels of theory. The preference for the Z conformer, Delta E(HF), was calculated to be 5.36 kcal mol(-1) and 7.50 kcal mot(-1) for phenyl acetate and phenyl trifluoroacetate (i.e., with X = H), respectively. The increasing electron-withdrawing ability of the phenyl substituent X increases the preference of the Z conformer. An excellent correlation with a negative slope was observed for both series between Delta E of the E-Z equilibrium and the Hammett sigma constant. By using an appropriate isodesmic reaction, it was shown that electron-withdrawing substituents decrease the stability of both conformers, but the effect is higher with the E conformer. Electron-withdrawing phenyl substituents decrease the delocalization of the lone pair of the ether oxygen to the C=O antibonding orbital (n(O) -> pi*(C=O)) in both the E and Z forms and in both series studied; this effect is higher in the E conformer than in the Z conformer. The n(O) -> pi*(C=O) electron donation has a minimum value with tau(1) = 90 degrees and a maximum value with tau(1) = 90 degrees (the Z conformer), the value with tau(1) = 180 degrees (the E conformer) being between these two values, obviously due to steric hindrance. The effects of the phenyl substituents on the reactivity of the esters studied are discussed in terms of molecular orbital interactions. ED/EW substituents adjust the availability of the pi*(C=O) antibonding orbital to interact with the lone pair orbital of the attacking nucleophile and therefore affect the reactivity: EW substituents increase and ED substituents decrease it. Excellent correlations were observed between the rate coefficients of nucleophilic acyl substitutions and pi*(C=O) occupancies of the ester series 4 and
Aber bitte mit Sahne ...
(2005)
Wandlungsfähigkeit von Informationssystemen ist zu einem wesentlichen Wettbewerbsfaktor geworden. Die derzeit unzureichende methodische Unterstützung zur Umsetzung von Wandlungsfähigkeit führt in Unternehmen häufig zu ungenutzten Potentialen einer leistungsfähigen Struktur durch die eingesetzte Informationstechnologie. Ziel des Forschungsprojektes CHANGE ist es, Methoden und Vorgehensmodelle zu entwickeln, die eine dauerhafte Wandlungsfähigkeit von Informationssystemen unterstützen. Dazu wird im Rahmen dieses Beitrages ein Verfahren vorgestellt, welches der Forderung zur Ermittlung der notwendigen Wandlungsfähigkeit unter Einbeziehung des Unternehmensumfeldes nachkommt. Als wesentliches Ergebnis wird ein Kennzahlensystem entwickelt, das zum einen die Umweltsituation als Indikator für den Wandlungsdruck eines Unternehmens beschreibt. Im nächsten Schritt werden Kriterien zur Ermittlung des Wandlungspotentials der eingesetzten IT herangezogen. Abschließend werden beide Dimensionen zusammengeführt und in ihrer Bedeutung für die IT Strategie eines Unternehmens interpretiert.
The interplay between topography and Indian summer monsoon circulation profoundly controls precipitation distribution, sediment transport, and river discharge along the Southern Himalayan Mountain Front (SHF). The Higher Himalayas form a major orographic barrier that separates humid sectors to the south and and regions to the north. During the Indian summer monsoon, vortices transport moisture from the Bay of Bengal, swirl along the SHF to the northwest, and cause heavy rainfall when colliding with the mountain front. In the eastern and central parts of the Himalaya, precipitation measurements derived from passive microwave analysis (SSM/I) show a strong gradient, with high values at medium elevations and extensive penetration of moisture along major river valleys into the orogen. The end of the monsoonal conveyer belt is near the Sutlej Valley in the NW Himalaya, where precipitation is lower and rainfall maxima move to lower elevations. This region thus comprises a climatic transition zone that is very sensitive to changes in Indian summer monsoon strength. To constrain magnitude, temporal, and spatial distribution of precipitation, we analyzed high-resolution passive microwave data from the last decade and identified an abnormal monsoon year (AMY) in 2002. During the 2002 AMY, violent rainstorms conquered orographic barriers and penetrated far into otherwise and regions in the northwest Himalaya at elevations in excess of 3 km asl. While precipitation in these regions was significantly increased and triggered extensive erosional processes (i.e., debris flows) on sparsely vegetated, steep hillslopes, mean rainfall along the low to medium elevations was not significantly greater in magnitude. This shift may thus play an important role in the overall sediment flux toward the Himalayan foreland. Using extended precipitation and sediment flux records for the last century, we show that these events have a decadal recurrence interval during the present-day monsoon circulation. Hence, episodically occurring AMYs control geomorphic processes primarily in the high-elevation and sectors of the orogen, while annual recurring monsoonal rainfall distribution dominates erosion in the low- to medium- elevation parts along the SHF. (C) 2004 Elsevier B.V. All rights reserved
A set of d(2) vectors in a Hilbert space of dimension d is called equiangular if each pair of vectors encloses the same angle. The projection operators onto these vectors define a POVM which is distinguished by its high degree of symmetry. Measures of this kind are called symmetric informationally complete, or SIC POVMs for short, and could be applied for quantum state tomography. Despite its simple geometrical description, the problem of constructing SIC POVMs or even proving their existence seems to be very hard. It is our purpose to introduce two applications of discrete Wigner functions to the analysis of the problem at hand. First, we will present a method for identifying symmetries of SIC POVMs under Clifford operations. This constitutes an alternative approach to a structure described before by Zauner and Appleby. Further, a simple and geometrically motivated construction for an SIC POVM in dimensions two and three is given (which, unfortunately, allows no generalization). Even though no new structures are found, we hope that the re- formulation of the problem may prove useful for future inquiries
The spectrum of the quasar PHL 1226 is known to have a strong Mg II and sub-damped Lymanalpha (sub-DLA) absorption line system with N(H I) = (5 +/- 2) x 10(19) cm(-2) at z = 0.1602. Using integral field spectra from the Potsdam Multi Aperture Spectrophotometer (PMAS) we investigate a galaxy at an impact parameter of 6".4 which is most probably responsible for the absorption lines. A fainter galaxy at a similar redshift and a slightly larger distance from the QSO is known to exist, but we assume that the absorption is caused by the more nearby galaxy. From optical Balmer lines we estimate an intrinsic reddening consistent with 0, and a moderate star formation rate of 0.5 M-circle dot yr(-1) is inferred from the Ha luminosity. Using nebular emission line ratios we find a solar oxygen abundance 12 + log (O/H) = 8.7 +/- 0.1 and a solar nitrogen to oxygen abundance ratio log (N/O) = -1.0 +/- 0.2. This abundance is larger than those of all known sub-DLA systems derived from analyses of metal absorption lines in quasar spectra. On the other hand, the properties are compatible with the most metal rich galaxies responsible for strong Mg II absorption systems. These two categories can be reconciled if we assume an abundance gradient similar to local galaxies. Under that assumption we predict abundances 12 + log (O/H) = 7.1 and log (N/O) = -1.9 for the sub-DLA cloud, which is similar to high redshift DLA and sub-DLA systems. We find evidence for a rotational velocity of similar to200 km s(-1) over a length of similar to7 kpc. From the geometry and kinematics of the galaxy we estimate that the absorbing cloud does not belong to a rotating disk, but could originate in a rotating halo
Accumulation of retinol in the liver after prolonged hyporetinolemia in the vitamin A-sufficient rat
(2005)
We assessed the effects of prolonged reduction of plasma retinol concentrations (hyporetinolemia) on the distribution of tissue vitamin A (VA) and of its active compounds using a model of continuous recombinant human interleukin-6 (rhIL-6) infusion via osmotic minipumps in VA-sufficient male rats. Plasma retinol and retinol-binding protein (RBP) concentrations remained decreased and lower in rhIL-6- treated rats compared with controls from 7.5 h throughout 7 days of infusion (P < 0.001). This reduction was accompanied by a 68% increase in hepatic retinol concentration by 7 days (P < 0.05). Hepatic and renal retinyl palmitate and retinoic acid concentrations did not change, and renal megalin content remained unchanged; hepatic RBP concentrations were 41% lower in rhIL-6-treated rats compared with controls (P < 0.05). These results indicate that instead of being lost, retinol accumulated in the liver during inflammation and that hyporetinolemia was attributable to a decrease in the availability of hepatic RBP. A plausible consequence of the effect of rhIL-6-induced hyporetinolemia is that by 7 days tissues that are dependent on plasma retinol may become deprived of VA. These results have important implications in understanding the mechanism by which measles infection induces hyporetinolemia and VA deficiency of extrahepatic tissues
Action!
(2005)
We present a flashlamp-pumped Nd: YAG laser simultaneously emitting pulse structures on microsecond, nanosecond and picosecond time scales. Within a microsecond flashlamp pump pulse a nonlinear reflector based on stimulated Brillouin scattering (SBS) generates several Q-switch pulses. The phase-conjugating effect of the SBS reflector provides a compensation of phase distortions generated inside the laser rod, resulting in transverse fundamental mode operation. Additional acousto-optic loss modulation inside the resonator leads to mode locking. As a result, each Q-switch pulse is subdivided into several picosecond pulses. Energies of up to 2 mJ for the mode-locked pulses with durations between 220 and 800 ps are demonstrated. The wide variability of the laser's temporal output parameters as well as its high beam quality make it a splendid tool for fundamental research in laser materials processing
We present a nonparametric way to retrieve an additive system of differential equations in embedding space from a single time series. These equations can be treated with dynamical systems theory and allow for long-term predictions. We apply our method to a modified chaotic Chua oscillator in order to demonstrate its potential
We study multi-dimensional gravitational models with scalar curvature nonlinearities of types R-1 and R-4. It is assumed that the corresponding higher dimensional spacetime manifolds undergo a spontaneous compactification to manifolds with a warped product structure. Special attention has been paid to the stability of the extra-dimensional factor spaces. It is shown that for certain parameter regions the systems allow for a freezing stabilization of these spaces. In particular, we find for the R-1 model that configurations with stabilized extra dimensions do not provide a late-time Acceleration (they are AdS), whereas the solution branch which allows. for accelerated expansion (the dS branch) is incompatible with stabilized factor spaces. In the case of the R-4 model, we obtain that the stability region in parameter space depends on the total dimension D = dim(M) of the higher dimensional spacetime M. Tor D > 8 the stability region consists of a single (absolutely stable) sector which is shielded from a conformal singularity (and an antigravity sector beyond it) by a potential barrier of infinite height and width. This sector is smoothly connected with the stability region of a curvature-linear model. For D < 8 an additional (metastable) sector exists Which is separated from the conformal singularity by a potential barrier of finite height and width so that systems in this sector are prone to collapse into the conformal singularity. This second sector is not smoothly connected with the first (absolutely stable) one. Several limiting cases and the possibility of inflation are discussed for the R-4 model
Affinity interaction betwen phenylboronic acid-carrying self-assembled monolayers and FAD or HRP
(2005)
A method is provided for the recognition of glycated molecules based on their binding affinities to boronate- carrying monolayers. The affinity interaction of flavin adenine dinucleotide (FAD) and horseradish peroxidase (HRP) with phenylboronic acid monolayers on gold was investigated by using voltammetric and microgravimetric methods. Conjugates of 3-aminopherrylboronic acid and 3,3'-dithiodipropionic acid di(N-hydroxysuccinimide ester) or 11-mercaptoundecanoic acid were prepared and self-assembled on gold surfaces to generate monolayers. FAD is bound to this modified sur-face and recognized by a pair of redox peaks with a formal potential of -0.433 V in a 0.1 m phosphate buffer solution, pH 6.5. Upon addition of a sugar to the buffer, the bound FAD could be replaced, indicating that the binding is reversible. Voltammetric, mass measurements, and photometric activity assays show that the HRP can also be bound to the interface. This binding is reversible, and HRP can be replaced by sorbitol or removed in acidic solution. The effects of pH, incubation time, and concentration of H2O2 were studied by comparing the catalytic reduction of H2O2 in the presence of the electron-donor thionine. The catalytic current of the HRP-loaded electrode was proportional to HRP concentrations in the incubation solution in the range between 5 mu g mL(-1) and 0.4 mg mL(-1) with a linear slope of 3.34 mu A mL mg(-1) and a correlation coefficient of 0.9945
We show that realistic aftershock sequences with space-time characteristics compatible with observations are generated by a model consisting of brittle fault segments separated by creeping zones. The dynamics of the brittle regions is governed by static/kinetic friction, 3D elastic stress transfer and small creep deformation. The creeping parts are characterized by high ongoing creep velocities. These regions store stress during earthquake failures and then release it in the interseismic periods. The resulting postseismic deformation leads to aftershock sequences following the modified Omori law. The ratio of creep coefficients in the brittle and creeping sections determines the duration of the postseismic transients and the exponent p of the modified Omori law
rezensiertes Werk: Eser, Albin ; Rabenstein, Christiane (Hrsg.): Strafjustiz im Spannungsfeld von Effizienz und Fairness. Konvergente und divergente Entwicklungen im Strafprozeßrecht (Strafrechtliche Forschungsberichte, Schriftenreihe des Max-Planck-Instituts für ausländisches und internationales Strafrecht, Band S 101). - Berlin : Duncker&Humblot, 2004. - 437 S. ISBN 3-428-11760-3
rezensiertes Werk: Eser, Albin ; Sieber, Ulrich ; Kreicker, Helmut (Hrsg.): Nationale Strafverfolgung völkerrechtlicher Verbrechen ; National Prosecution of International Crimes. - Teilband 3: Kroatien, Österreich, Serbien und Montenegro, Slowenien (Strafrechtliche Forschungsberichte, Schriftenreihe des Max-Planck-Instituts für ausländisches und internationales Strafrecht ; Bd. S 95.3). - Berlin : Duncker&Humblot, 2004. 437 S. ISBN 3-482-11774-3
Alexander von Humboldt
(2005)
En este artículo se presenta un proyecto de digitalización de las obras de Alexander von Humboldt, que se está realizando en colaboración con la Fundación Ignacio de Larramendi de Madrid. Como otros proyectos de este tipo, tiene como objetivo poner una parte del gran legado de Humboldt, con los medios de la tecnología moderna, a disposición tanto de los investigadores como de los meros lectores, para así facilitar el estudio y la lectura de sus obras. El enfoque de este proyecto de digitalización está en las traducciones de sus escritos al español que se han realizado a lo largo del tiempo. Por lo tanto, se encuentran incorporadas las obras de Humboldt en versión original, sea francés o alemán, y su respectiva traducción al español. Se acompañará este DVD con una amplia introducción dedicada al historial de las traducciones españolas y la repercusión que las mismas han tenido en España, así como a los personajes que se han ocupado de la labor de traducirlas y difundirlas en este país.
Alexander von Humboldt im Netz" ist ein Projekt des Instituts für Romanistik der Universität Potsdam, unter der wissenschaftlichen Leitung von Prof. Dr. Ottmar Ette. Die Website verfolgt den Zweck - die weltweiten Aktivitäten zu dem großen Forscher und Gelehrten vorzustellen und zu bündeln - mehr Menschen mit dem Denken Alexander von Humboldts vertraut zu machen - einen Überblick über verschiedene Institutionen, Veranstaltungen, Tagungen, Ausstellungen, Projekte, Bibliotheken und vieles mehr zu geben.
Este artículo tiene dos objetivos principales. Ambos están motivados por el hallazgo del diario humboldtiano sobre Cuba en 1804, hasta ahora desconocido (en la Biblioteka Jagiellonska Kraków por Ulrike Leitner). Primero, el artículo pretende exponer la génesis tanto discontinuada como coherente de la enemistad humboldtiana con la esclavitud (que culmina en cierto grado en este “nuevo” diario y que configura in nuce el “Ensayo sobre Cuba” del propio Humboldt). Segundo, el artículo presenta la – a nivel de la historia de las sciencias – sensación, que Humboldt empezó a aplicar sistemáticamente métodos de comparación scientífica a las condiciones sociales, históricas y socio-económicas de la esclavitud, cuando en 1804 supo en Veracruz o La Habana de la proclamación del estado “Haity”. Estos dos reconocimientos del artículo presente cambian profundamente nuestros conocimientos de la relación política de Humboldt en cuanto a dos grupos mayores de la población (partes de la élite criolla que planificó fundar “una república blanca” a manera de la revolución francesa de 1789 y el grupo o la “casta” de los llamados “pardos”) en “el umbral de la revolución de Independencia”.
The article provides historical background for Alexander von Humboldt’s expedition into Russia in 1829. It includes information on Humboldt’s works and publications in Russia over the course of his lifetime, as well as an explanation of the Russian scientific community’s response to those works. Humboldt’s ideas on the existence of an active volcano in Central Asia attracted the attention of two prominent Russian geographers, P. Semenov and P. Kropotkin, whose views on the nature of volcanism were quite different. P. Semenov personally met Humboldt in Berlin. P. Kropotkin made one of the most important geological discoveries of the 19th Century: he found the fresh volcanic cones near Lake Baikal.
Soon after Humboldt’s Russian expedition, and partly as a result of it, an important mineral was found in the Ilmen mountains – samarskite, which later gave its name to the chemical element Samarium, developed in 1879. At the beginning of the 20th Century, the Russian scientist V. Vernadskiy pointed out that samarskite was the first uranium-rich mineral found in Russia.