Unimodal and crossmodal processing of visual and kinesthetic stimuli in working memory

The processing of (object) information in working memory has been intensively investigated in the visual modality (i.e. D’Esposito, 2007; Ranganath, 2006). In comparison, research on kinesthetic/haptic or crossmodal processing in working memory is still sparse. During recognition and comparison of object information across modalities, representations built from one sensory modality have to be matched with representations obtained from other senses. In the present thesis, the questions how object information is represented in unimodal and crossmodal working memory, which processes enable unimodal and crossmodal comparisons, and which neuronal correlates are associated with these processes were addressed. In particular, unimodal and crossmodal processing of visually and kinesthetically perceived object features were systematically investigated in distinct working memory phases of encoding, maintenance, and recognition. At this, the kinesthetic modality refers to the sensory perception of movement direction and spatial position, e.g. of one’s own hand, and is part of the haptic sense. Overall, the results of the present thesis suggest that modality-specific representations and modality-specific processes play a role during unimodal and crossmodal processing of object features in working memory

Widespread occurrence of apple proliferation disease in low-intensity orchards of Basilicata

Visual symptom assessment and PCR amplification were used to survey the occurrence of apple proliferation (AP) disease in low-intensity orchards in the Agri valley, a major cultivation area of Basilicata (southern Italy). The apple trees examined, whose cultivars were not determined as they consisted mostly of local types, were more than 20-year-old. Therefore, these plants had been exposed to insect vectors for a long time. The survey revealed that a high percentage of trees were infected reaching more than 50% in some locations. The symptoms of diseased trees were generally mild and consisted of enlarged stipules, rosettes, witches’-brooms as well as subterraneous witches’-broom-like growth arising from large roots. However, the incidence and severity of symptoms in the aerial parts of affected trees were more pronounced in trees which had been heavily pruned in the previous dormant season. Specificity of the primers used and RFLP analysis of PCR-amplified 16S rDNA sequences employing SspI and BsaAI restriction endonucleases showed that the trees testing positive by PCR were infected by the AP agent ‘Candidatus Phytoplasma mali’. The high incidence of AP infections in low-intensity orchards of the Agri valley is likely due to inappropriate vector control. The trees examined were not or rarely treated with insecticides. Although a few AP-affected apple trees grown in a low-intensity orchard in the Agri valley had previously been observed, our survey shows that the distribution of AP disease in Europe extends further south than previously thought and that the climatic conditions of southern Italy are not unsuitable for this quarantine disease

Comparison of European stone fruit yellows phytoplasma strains differing in virulence by multi-gene sequence analyses

Twenty strains of the ESFY phytoplasma, which on the basis of graft-inoculation experiments greatly differ in aggressiveness, were examined by sequence analyses of several PCR-amplified non-ribosomal genes in order to identify molecular markers linked to virulence. These strains, which were maintained in P. insititia rootstock St. Julien GF 655/2 were indistinguishable with techniques for routine phytoplasma differentiation and characterization such as sequence and RFLP analyses of PCR-amplified rDNA. Also, the virulent ESFY strains maintained in periwinkle, namely GSFY1, GSFY2 and ESFY1, as well as an avirulent strain of the same phytoplasma, maintained in apricot, which was identified in recovered apricot trees in France and used there as a cross protecting agent, were included in the work for comparison. For PCR amplification, primers were designed from a number of genes distributed over the chromosome of the closely related apple proliferation phytoplasma strain AT. Visible PCR products were only obtained with primer pairs derived from the tuf gene which encodes the elongation factor Tu (EF-Tu), rpsC (rps3) gene encoding the ribosomal protein S3, tlyC gene which encodes a hemolysin known as a membrane-damaging agent and important virulence factor of many bacteria, the imp and fol genes encoding an immunodominant membrane protein and an enzyme involved in the folate biosynthesis, respectively. Nucleotide sequence comparisons revealed that the highest genomic variability occurred within the imp gene sequence with dissimilarity values ranging from 0.2 to 4.6%. For the remaining genes, the strains examined proved to be identical or nearly identical. Within the tuf gene, an extra TaqI site known to occur in strain GSFY1 was not identified in other strains. The genetic differences observed among the strains examined are neither suitable markers for strain differentiation nor linked to pathological traits.Keywords: European stone fruit yellows, strain virulence, 16SrX group, tlyC gene, Prunus spp

K-Ras-Mutationen in ovariellen und extraovariellen Herden von serösen LMP-Tumoren (Borderline-Tumoren) des Ovars

K-RAS-Mutationen sind die häufigsten genetischen Veränderungen bei serösen Borderline-Tumoren des Ovars. Nach wie vor ist die Pathogenese der assoziierten ovariellen und extraovariellen Läsionen, die ein Spektrum von Müller-Inklusionszysten (Endosalpingiose) über Implantate bis hin zu kontralateralen LMP-Tumoren umfassen, ungeklärt. Um eine multifokale Entstehung dieser Herde von metastasenartiger Streuung zu unterscheiden, wurden diese Läsionen auf eine Mutation im K-RAS Onkogen hin untersucht. Acht Fälle mit bekannter K-RAS-Mutation und zwei RAS-negative Fälle ohne RAS-Mutation wurden zum Vergleich analysiert. Insgesamt wurde DNA aus 58 in Paraffin eingebetteten und laser-mikrodissezierten ovariellen und extraovariellen Herden extrahiert (10 SBOT, 8 kontralaterale Tumoren, 25 Implantate, 15 Inklusionszysten, insgesamt 97 Proben). Es wurde das Codon 12 des Exon 1 des K-RAS-Onkogens auf Mutationen mit einer DGGE voruntersucht und die genaue Art der Mutation durch direkte Sequenzierung bestimmt. In 12 von 14 SBOT und in 2 von 2 extraovariellen Implantaten konnte die K-RAS Mutation in verschiedenen Bereichen der gleichen Läsion gefunden werden. Sämtliche RAS-positive ovariellen Borderline-Tumoren, die mit einem kontralateralen Tumor assoziiert waren, wiesen in beiden Tumoren die identische Mutation auf (in einem Fall enthielt die oberflächliche Komponente des Borderline-Tumors eine zusätzliche zweite Punktmutation). In 4 von 5 RAS-positiven SBOT mit extraovariellen Läsionen wurden RAS-Mutationen auch in Implantaten (15/21 Implantate 71%) gefunden und seltener in Inklusionszysten (3/12 Läsionen, 25%). Alle extraovariellen Mutationen waren mit der des Ovars identisch (18/18 Läsionen, 100%). Bei den RAS-negativen Kontroll-Fällen ließ sich nur bei einem einzelnen Implantat eine RAS-Mutation nachweisen. Die Tatsache, daß sich K-RAS-Mutationen in Müller-Inklusionszysten und Implantaten von SBOT nachweisen lassen, weisen daraufhin, daß es sich dabei um einen sehr frühen Schritt in der neoplastischen Transformation von ovariellem und extraovariellem serösem Epithel handelt. Die Ergebnisse dieser Studie legen die Vermutung nahe, daß die zwei postulierten pathogenetischen Mechanismen, die zur Entwicklung von Implantaten und Inklusionszysten führen sollen, nebeneinander koexistieren

On Information Asymmetry as a Source of Value: Intermediation, Auctions and Information

Why are there market makers, where a bargainer has limited information about the reservation prices of other buyers and sellers? What are the conditions such that a bargainer prefers the market maker over direct bilateral or multilateral trade, even if full information about his peers’ reservation prices may be available in direct negotiations? Within Mr. Seemüller’s work, these questions are addressed. He analyses how bargainers determine prices on different platforms, where buyers and sellers reveal their respective offers for a good or a service to each other. A special focus lies upon the distribution of information between the bargaining parties and their inability of precise valuation. Each platform’s efficiency is analysed in detail. Additionally, he introduces market maker’s markets, where bid and ask prices for a good or service are quoted. Despite a bid or an ask price, no more information is revealed to a seller or a buyer. Mr. Seemüller compares the efficiency of the market maker and the platform market and develops conditions when the market maker is preferred by the bargainers. When these conditions are satisfied, then a market with limited information is Pareto efficient over a market design where full information may be available. A bargainer’s inability of precise valuation is an important ingredient to Mr. Seemüller’s work. While a buyer (or a seller) can arrive at an individual reservation price, that buyer can not determine whether that price is high or low compared to some unknown average valuation and how his reservation price compares to the other bargainers’ reservation prices. This statement is valid until the bargainers reveal their reservation prices or full information is available. Assuming a buyer with a certain valuation of a good, that buyer can only determine or estimate his valuation imprecision with some effort

Is the efficacy of psychopharmacological drugs comparable to the efficacy of general medicine medication?

There is an ongoing debate concerning the risk benefit ratio of psychopharmacologic compounds. With respect to the benefit, recent reports and meta-analyses note only small effect sizes with comparably high placebo response rates in the psychiatric field. These reports together with others lead to a wider, general critique on psychotropic drugs in the scientific community and in the lay press. In a recently published article, Leucht and his colleagues compare the efficacy of psychotropic drugs with the efficacy of common general medicine drugs in different indications according to results from reviewed meta-analyses. The authors conclude that, overall, the psychiatric drugs were generally not less effective than most other medical drugs. This article will highlight some of the results of this systematic review and discuss the limitations and the impact of this important approach on the above mentioned debate

Dissecting the assembly pathway of the 20S proteasome

AbstractProteasomes reach their mature active state via a complex cascade of folding, assembly and processing events. The Rhodococcus proteasome offers a means to dissect the assembly pathway and to characterize intermediates; its four subunits (α1, α2, β1, β2) assemble efficiently in vitro with any combination of α and β. Assembly studies with wild-type and N-terminally truncated β-subunits in conjunction with refolding studies allowed to define the role of the propeptide which is two-fold: It supports the initial folding of the β-subunits and it promotes the maturation of the holoproteasomes

Evaluation of Powder Metallurgical Processing Routes for Multi-Component Niobium Silicide-Based High-Temperature Alloys

Niobium silicide-based composites are potential candidates to replace nickel-base superalloys for turbine applications. The goal of this work was to evaluate the feasibility and differences in ensuing properties of various powder metallurgical processing techniques that are capable of manufacturing net-shape turbine components. Two routes for powder production, mechanical alloying and gas atomization were combined with compaction via hot isostatic pressing and powder injection molding