Evolutionary tendencies in flowers of Marantaceae with special reference to the style movement mechanism

One of the quickest plant movements ever known is made by the ´explosive´ style in Marantaceae in the service of secondary pollen presentation – herewith showing a striking apomorphy to the sister Cannaceae that might be of high evolutionary consequence. Though known already since the beginning of the 19th century the underlying mechanism of the movement has hitherto not been clarified. The present study reports about the biomechanics of the style-staminode complex and the hydraulic principles of the movement. For the first time it is shown by experiment that in Maranta noctiflora through longitudinal growth of the maturing style in the ´straitjacket´ of the hooded staminode both the hold of the style prior to its release and its tensioning for the movement are brought about. The longer the style grows in relation to the enclosing hooded staminode the more does its capacity for curling up for pollen transfer increase. Hereby I distinguish between the ´basic tension´ that a growing style builds up anyway, even when the hooded staminode is removed beforehand, and the ´induced tension´ which comes about only under the pressure of a ´too short´ hooded staminode and which enables the movement. The results of these investigations are discussed in view of previous interpretations ranging from possible biomechanical to electrophysiological mechanisms. To understand furthermore by which means the style gives way to the strong bending movement without suffering outwardly visible damage I examined its anatomical structure in several genera for its mechanical and hydraulic properties and for the determination of the entire curvature after release. The actual bending part contains tubulate cells whose walls are extraordinarily porous and large longitudinal intercellular spaces. SEM indicates the starting points of cell-wall loosening in primary walls and lysis of middle lamellae - probably through an intense pectinase activity in the maturing style. Fluorescence pictures of macerated and living style-tissue confirm cell-wall perforations that do apparently connect neighbouring cells, which leads to an extremely permeable parenchyma. The ´water-body´ can be shifted from central to dorsal cell layers to support the bending. The geometrical form of the curvature is determined by the vascular bundles. I conclude that the style in Marantaceae contains no ´antagonistic´ motile tissues as in Mimosa or Dionaea. Instead, through self-maceration it develops to a ´hydraulic tissue´ which carries out an irreversible movement through a sudden reshaping. To ascertain the evolutionary consequence of this apomorphic pollination mechanism the diversity and systematic value of hooded staminodes are examined. For this hooded staminodes of 24 genera are sorted according to a minimalistic selection of shape characters and eight morphological types are abstracted from the resulting groups. These types are mapped onto an already available maximally parsimonious tree comprising five major clades. An amazing correspondence is found between the morphological types and the clades; several sister-relationships are confirmed and in cases of uncertain position possible evolutionary pathways, such as convergence, dispersal or re-migration, are discussed, as well as the great evolutionary tendencies for the entire family in which – at least as regards the shape of hooded staminodes – there is obviously a tendency from complicated to strongly simplified forms. It suggests itself that such simplifying derivations may very likely have taken place as adaptations to pollinating animals about which at present too little is known. The value of morphological characters in relation to modern phylogenetic analysis is discussed and conditions for the selection of morphological characters valuable for a systematic grouping are proposed. Altogether, in view of the evolutionary success of Marantaceae compared with Cannaceae the movement mechanism of the style-staminode complex can safely be considered a key innovation within the order Zingiberales.

Kriterien effizienter Informationsverarbeitung als Prädiktoren des Karriereerfolgs

Die vorliegende Arbeit beschäftigt sich mit Kriterien effizienter und flexibler Informationsverarbeitung und deren Auswirkungen auf den Karriereerfolg. Die Kriterien Interferenz, Interferenz unter der negativen Priming-Bedingung und die Spontanflexibilität wurden in drei aufeinander aufbauenden Studien untersucht. Die Interferenzindices wurden mit einer modifizierten Form des Stroop-Tests erhoben, und das Konstrukt der Spontanflexibilität wurde mit der Gauß-Aufgabe, der Wasserumschüttaufgabe, dem Wortgruppentest und der Anagramm-Aufgabe operationalisiert. Bei diesen Aufgaben wurde eine Lösungsstrategie vorgegeben, aber es gab zusätzlich eine effizientere Lösungsstrategie, die während der Bearbeitung der Einzelaufgaben immer offensichtlicher wurde. Da die einzelnen Aufgaben nicht signifikant miteinander korrelierten, wurde im Rahmen einer Nachuntersuchung die Reliabilität über Parallelaufgaben geprüft. Für die Diagnose von Gruppenunterschieden erwiesen sich die Indikatoren der Spontanflexibilität als hinreichend reliabel. Die Wortdarbietungszeiten der Interferenzindices waren hochreliabel. Zwischen den Interferenzindices zeigte sich ein starker positiver Zusammenhang. Zur Validierung der Aufgaben wurden Beurteilungen über die berufliche Leistung der Versuchsteilnehmer herangezogen. Zwischen den einzelnen Beurteilungskriterien zeigten sich hohe Zusammenhänge. Die Gauß-Aufgabe korrelierte mit einem Beurteilungskriterium, dessen Verhaltensbeschreibungen sehr gut mit der Definition der Spontanflexibilität übereinstimmten. Die Wasserumschüttaufgabe korrelierte mit einem Beurteilungskriterium, welches eher eine durch die Situation herausgeforderte Flexibilität widerspiegelt. Die Interferenzindikatoren korrelierten mit Beurteilungskriterien, die zum einen die Fähigkeit zum Aufbauen von professionellen Beziehungen und zum anderen die Effizienz und den Qualitätsstandard eines Mitarbeiters bewerteten. Aufgrund der replizierten Zusammenhänge kann davon ausgegangen werden, dass die Interferenz, die Interferenz unter der negativen Priming-Bedingung, die Spontanflexibilität und die herausgeforderte Flexibilität Einfluss auf den Karriereerfolg eines Mitarbeiters nehmen. Aus diesem Grund bieten sich im Bereich der Arbeits- und Organisationspsychologie vielversprechende Einsatzmöglichkeiten für die in dieser Untersuchung entwickelten Tests an.

Entwicklung und Anwendung molekularbiologischer Methoden zur Art- und Stamm-Identifizierung pro- und eukaryotischer Organismen

Das Wachstum von Milchsäurebakterien-Arten der Gattungen Lactobacillus, Pediococcus und Leuconostoc während der Weinfermentation kann durch die Bildung verschiedener Stoffwechselprodukte zu Weinfehlern führen. Um rechtzeitig Gegenmaßnahmen ergreifen zu können und einem Weinverderb vorzubeugen, bedarf es geeigneter Identifizierungsmethoden. Klassische mikrobiologische Methoden reichen oft nicht aus, um Mikroorganismen auf Art- und Stammniveau gezielt zu identifizieren. Wegen ihrer schnellen Durchführbarkeit und Zuverlässigkeit sind molekularbiologische Identifizierungsmethoden zur Kontrolle der mikrobiellen Flora während der Lebensmittelfermentierung in der heutigen Zeit unabdingbar. In der vorliegenden Forschungsarbeit wurden die 23S rRNA-Gensequenzen von neun Pediococcus-Typstämmen sequenziert, analysiert und phylogenetische Analysen durchgeführt. Zur Art-Identifizierung der Pediokokken wurden PCR-Primer generiert und ein Multiplex PCR System entwickelt, mit dem alle typischen Arten simultan in einer Reaktion nachgewiesen werden konnten. Die Ergebnisse der Multiplex PCR-Identifizierung von 62 Pediococcus-Stämmen aus Kulturensammlungen und 47 neu isolierten Stämmen aus Wein zeigten, dass einige Stämme unter falschen Artnamen hinterlegt waren, und dass P. parvulus im Weinanbaugebiet Rheinhessen weit verbreitet war. Die Fähigkeit der Pediococcus-Stämme zur Exopolysaccharid-Synthese wurde durch den Nachweis zweier Gene überprüft. Auf Basis der 23S rDNA-Sequenzen wurden rRNA-Sekundärstrukturen mit der neu entwickelten Software Structure Star generiert, die zum Auffinden von Zielbereichen für fluoreszenzmarkierte DNA-Sonden geeignet waren. Die Sequenzunterschiede zwischen den Pediococcus-Arten reichten aus, um zwei Gruppen durch Fluoreszenz in situ Hybridisierung differenzieren zu können. Die Verwendung unmarkierter Helfer-sonden verbesserte die Zugänglichkeit der Sonden an die rRNA, wodurch das Fluoreszenz-Signal verstärkt wurde. Um Milchsäurebakterien durch Denaturierende Gradienten Gel Elektrophorese differenzieren zu können, wurden Primer entwickelt, mit denen ein hochvariabler 23S rDNA-Bereich amplifiziert werden konnte. Die Nested Specifically Amplified Polymorphic DNA (nSAPD)-PCR wurde in der vorliegenden Arbeit zur Art- und Stamm-Differenzierung pro- und eukaryotischer Organismen angewandt. Es wurden vor allem weinrelevante Milchsäurebakterien der Gattungen Oenococcus, Lactobacillus, Pediococcus und Leuconostoc und Hefen der Gattungen Dekkera / Brettanomyces und Saccharomyces untersucht. Die Cluster-Analyse der Pediococcus-Typstämme führte zu einer unterschiedlichen Baum-Topologie im Vergleich zum phylogenetischen 23S rDNA-Stammbaum. Die Verwandtschaftsverhältnisse der untersuchten O. oeni-Stämme aus Starterkulturen konnten in Bezug auf eine frühere Cluster-Analyse reproduziert werden. Die Untersuchung von 40 B. bruxellensis-Stämmen aus rheinhessischen Weinproben zeigte eine Gruppierung der Stämme gemäß dem Ort der Probennahme. Beim Vergleich der Verwandtschaftsverhältnisse von Stämmen der Arten P. parvulus und B. bruxellensis, die aus denselben Weinproben isoliert wurden, konnte eine hohe Übereinstimmung der beiden Baum-Topologien beobachtet werden. Anhand der SAPD-PCR Untersuchung von Sekthefen aus Starterkulturen konnten alle Stämme der Art S. cerevisiae zugeordnet werden. Die nSAPD-PCR war darüber hinaus geeignet, um höhere Eukaryoten wie Weinreben zu differenzieren und es konnten die Verwandtschaftsverhältnisse von Mäusen und menschlichen Individuen durch Cluster-Analysen nachvollzogen werden. Mit Hilfe der Sequence Characterized Amplified Region (SCAR)-Technik wurden (n)SAPD-Marker in SCAR-Marker konvertiert. Die neu generierten SCAR-Primer konnten zur simultanen Art-Identifizierung von sieben weinschädlichen Milchsäurebakterien in einer Multiplex PCR erfolgreich eingesetzt werden. Die in dieser Arbeit entwickelten molekularbiologischen Identifizierungsmethoden können zum Beispiel in der mikrobiologischen Qualitätskontrolle Anwendung finden.

Phylogenomische Analysen bei Metazoen - Zur Stellung der Xenoturbellida und Syndermata

Im Rahmen der vorliegenden Dissertation wurde die phylogenetischen Stellungen der Xenoturbellida (Deuterostomia) und der Syndermata (Protostomia) mit phylogenomischen Techniken untersucht. Auf methodischer Ebene konnte gezeigt werden, dass ribosomale Proteine aufgrund ihres mittleren bis hohen Konservierungsgrades, ihrer Häufigkeit in kleineren EST-Projekten, damit verbunden ihrer Häufigkeit in Datenbanken und ihres phylogenetischen Informationsgehalts nützliche Werkzeuge für phylogenetische Fragestellungen sind. Es konnte durch phylogenetische Rekonstruktionen und Hypothesentests auf Basis eines 11.912 Aminosäuren langen Datensatzes gezeigt werden, dass die Xenoturbellida innerhalb der Deuterostomia eine Schwestergruppenbeziehung zu den Ambulacraria eingehen. Diese Arbeit zeigt im Vergleich aller bisher durchgeführten Arbeiten die beste statistische Unterstützung für diese Topologie. Weiterhin konnte untermauert werden, dass die Urochordata vermutlich anstelle der Cephalochordata die Schwestergruppe der Vertebrata sind. Der Vergleich der publizierten Xenoturbella EST-Datensätze mit dem eigenen Datensatz ließ den Rückschluß zu, dass ESTs offenbar klar weniger anfällig gegen Kontaminationen mit Erbmaterial (DNA+RNA) anderer Spezies sind als PCR-Amplifikate genomischer oder mitochondrialer Gene. Allerdings bestimmt anscheinend der physiologische Zustand der Tiere die Repräsentation von Transkriptklassen wie Stressproteine und mitochondriale Transkripte. Die bakteriellen Transkripte in einem der EST-Datensätze stammen vermutlich von Chlamydien, die möglicherweise symbiontisch in Xenoturbella bocki leben. Im Bereich der Protostomia wurden drei EST-Projekte für Vertreter der Syndermata durchgeführt. Basierend auf drei verschiedenen Proteinalignment-Datensätzen von ca. 11.000 Aminosäuren Länge konnte gezeigt werden, dass die Syndermata innerhalb der Spiralia einzugruppieren sind und dass sie mit den Gnathostomulida das monophyletische Supertaxon Gnathifera bilden. Die genaue phylogenetische Position der Syndermata innerhalb der Spiralia konnte hingegen noch nicht eindeutig geklärt werden, ebenso wie kein kongruenter Beweis für die Existenz des Supertaxons Platyzoa gefunden werden konnte. Im Rahmen der Untersuchung der internen Phylogenie der Syndermata konnten drei der fünf konkurrierenden Hypothesen aufgrund der Paraphylie der Eurotatoria ausgeschlossen werden. Da keine Daten der Seisonidea in den Analysen implementiert waren, bleibt die Frage der internen Phylogenie der Syndermata letztlich offen. Klar ist jedoch, dass die Eurotatoria nicht wie bislang angenommen monophyletisch sind, da die räderorgantragenden Bdelloidea keinesfalls den morphologisch diesbezüglich ähnlichen Monogononta ähnlich sind, sondern den räderorganlosen Acanthocephala näher stehen. Die Abbildung der molekularen Phylogenie auf die morphologischen Verhältnisse zeigt, dass das Räderorgan (partiell oder komplett) offenbar kurz nach der Aufspaltung der Syndermata in Monogononta und Acanthocephala + Bdelloidea in der Acanthocephala + Bdelloidea-Linie reduziert wurde. Die Entstehung des einziehbaren hinteren Körperteils (Rostrum bei Bdelloidea bzw. Proboscis bei Acanthocephala) in der Acanthocephala + Bdelloidea-Linie könnte das Schlüsselereignis zur Entstehung des Endoparasitismus der Acanthocephala gewesen sein.

Anatomic study of the feline bronchial and vascular structures with a 64 detector-row computed tomography

Multidetector row computed tomography over the last decade is commonly used in veterinary medicine. This new technology has an increased spatial and temporal resolution, could evaluate wider scanning range in shorter scanning time, providing an advanced imaging modality. Computed tomography angiographic studies are commonly used in veterinary medicine in order to evaluate vascular structures of the abdomen and the thorax. Pulmonary pathology in feline patients is a very common condition and usually is further evaluating with computed tomography. Up to date few references of the normal computed tomographic aspects of the feline thorax are reported. In this study a computed tomographic pulmonary angiography (CTPA) protocol is reported in normal cats and is compared with the up to date anatomical references. A CTPA protocol using a 64 MDCT in our study achieved high resolution images of the pulmonary arteries, pulmonary veins and bronchial lumen till the level of minor segmental branches. Feline pulmonary bronchial parenchyma demonstrates an architecture of mixed type with a monopedial model observed in the most anatomical parts and the dichotomic aspect is seen at the accessory lobe. The arterial and venous architecture is similar to the bronchial. Statistical analysis demonstrates the linear correlation of tracheal diameter to the felines weight. Vascular variations were noticed. The pulmonary venous system enters into the left atrium through three ostia (left cranial ostia: consisted of the anastomosis of the cranial and caudal portion of the left cranial pulmonary vein; right ostia: consisted of the anastomosis of the right cranial and middle pulmonary vein; and the caudal ostia: consisted of the anastomosis of the right and left caudal pulmonary vein). In conclusion CTPA is applicable in feline patients and provides an excellent imaging of the pulmonary arterial, venous and bronchial system till the level of minor segmental branches.

Novel isolates of Cydia pomonella granulovirus (CpGV): deciphering the molecular mechanism for overcoming CpGV resistance in codling moth (Cydia pomonella)

During the last twenty years, Cydia pomonolla granulovirus (CpGV, Baculoviridae) has become the most important biological control agent for the codling moth (CM) in organic and integrated apple production. All registered products in Europe are based on the isolate CpGV-M, which was discovered 1964 in Mexico. A serious threat to future application of CpGV is the occurrence of CM field populations resistant to CpGV. Since 2003, populations with up to 10,000-fold reduced susceptibility were reported from orchards in Germany, France, Italy, Switzerland, Austria and the Netherlands. A putative alternative to CpGV-M are novel CpGV isolates which are able to overcome CM resistance. This thesis focuses on the identification and characterisation of resistance overcoming CpGV isolates and the analysis of their molecular difference to CpGV-M.rnSixteen CpGV isolates were tested against CM lab strains in bioassays. Hereby, five isolates were identified which were able to completely overcome resistance. The genomes of these isolates were compared to CpGV-M by restriction fragment length polymorphism (RFLP) analysis. To identify the molecular factor responsible for improved virulence of some CpGV isolates, major genomic differences were sequenced and analysed. A 0.7 kb insertion was found in CpGV-I01, -I12 and -E2, but not in other resistance overcoming isolates. Analysis of the insertions sequence revealed that it might be due to a transposition event, but not involved in overcoming resistance. rnFor unequivocal identification of CpGV isolates, a new method based on molecular analysis was established. Partial sequencing of the conserved polyhedrin/granulin (polh/gran), late expression factor-8 (lef-8) and late expression factor-9 (lef-9) genes revealed single nucleotide polymorphisms (SNPs). SNP analysis correlated with the grouping obtained by RFLP analysis. A phylogenetic classification due to different genome types A-E is proposed. Phylogenetic analysis suggested that CpGV-M was the phylogenetically youngest of the tested CpGV isolates.rnWhole genome sequencing of two resistance overcoming isolates CpGV-I12 (type D genome) and -S (type E genome) and CpGV-M (type A genome) was performed. Comparison of the three genomes revealed a high sequence identity. Several insertions and deletions ranging from 1-700 nucleotides (nt) were found. Comparison on open reading frame (ORF) level revealed that CpGV-I12 and -S shared only one protein alteration when compared to CpGV-M: a stretch of 24 nt present in ORF cp24 was not found in any of the resistance overcoming isolates. Cp24 codes for the early gene pe38. Combined with the results of phylogenetic analysis, it is proposed that these 24 nt are a recent insertion into the CpGV-M genome. The role of pe38 in overcoming resistance was investigated by knocking out pe38 of a CpGV-M based bacmid and swapping of CpGV-I12 pe38 of into the k.o. bacmid. When pe38 of CpGV-I12 was inserted into the k.o. bacmid, the infectivity could not be rescued, suggesting that the genomic portion of pe38 might play a role in its function.rnIt can be concluded that the recently observed CpGV resistance in CM is only related to type A genomes. RFLP and SNP analysis provide tools for identifying and characterising different CpGV isolates reliably, a pre-condition for a future registration of CpGV products based on novel CpGV isolates.rnrnrn

Studio e applicazione di tecniche di riduzione di dimensionalita a modelli geometrici di percezione visiva

La tesi affronta il tema della neuromatematica della visione, in particolare l’integrazione di modelli geometrici di percezione visiva con tecniche di riduzione di dimensionalità. Dall’inizio del secolo scorso, la corrente ideologica della Gestalt iniziò a definire delle regole secondo le quali stimoli visivi distinti tra loro possono essere percepiti come un’unica unità percettiva, come ad esempio i principi di prossimità, somiglianza o buona continuazione. Nel tentativo di quantificare ciò che gli psicologi avevano definito in maniera qualitativa, Field, Hayes e Hess hanno descritto, attraverso esperimenti psicofisiologici, dei campi di associazione per stimoli orientati, che definiscono quali caratteristiche due segmenti dovrebbero avere per poter essere associati allo stesso gruppo percettivo. Grazie alle moderne tecniche di neuroimaging che consentono una mappatura funzionale dettagliata della corteccia visiva, è possibile giustificare su basi neurofisiologiche questi fenomeni percettivi. Ad esempio è stato osservato come neuroni sensibili ad una determinata orientazione siano preferenzialmente connessi con neuroni aventi selettività in posizione e orientazione coerenti con le regole di prossimità e buona continuazione. Partendo dal modello di campi di associazione nello spazio R^2xS^1 introdotto da Citti e Sarti, che introduce una giustificazione del completamento percettivo sulla base della funzionalità della corteccia visiva primaria (V1), è stato possibile modellare la connettività cellulare risolvendo un sistema di equazioni differenziali stocastiche. In questo modo si sono ottenute delle densità di probabilità che sono state interpretate come probabilità di connessione tra cellule semplici in V1. A queste densità di probabilità è possibile collegare direttamente il concetto di affinità tra stimoli visivi, e proprio sulla costruzione di determinate matrici di affinità si sono basati diversi metodi di riduzione di dimensionalità. La fenomenologia del grouping visivo descritta poco sopra è, di fatto, il risultato di un procedimento di riduzione di dimensionalità. I risultati ottenuti da questa analisi e gli esempi applicativi sviluppati si sono rivelati utili per comprendere più nel dettaglio la possibilità di poter riprodurre, attraverso l’analisi spettrale di matrici di affinità calcolate utilizzando i modelli geometrici di Citti-Sarti, il fenomeno percettivo di grouping nello spazio R^2xS^1.

Genetic and morphological variation and differentiation of Raja clavata populations in the European seas: marker development and preliminary data

In this study the population structure and connectivity of the Mediterranean and Atlantic Raja clavata (L., 1758) were investigated by analyzing the genetic variation of six population samples (N = 144) at seven nuclear microsatellite loci. The genetic dataset was generated by selecting population samples available in the tissue databases of the GenoDREAM laboratory (University of Bologna) and of the Department of Life Sciences and Environment (University of Cagliari), all collected during past scientific surveys (MEDITS, GRUND) from different geographical locations in the Mediterranean basin and North-east Atlantic sea, as North Sea, Sardinian coasts, Tuscany coasts and Cyprus Island. This thesis deals with to estimate the genetic diversity and differentiation among 6 geographical samples, in particular, to assess the presence of any barrier (geographic, hydrogeological or biological) to gene flow evaluating both the genetic diversity (nucleotide diversity, observed and expected heterozygosity, Hardy- Weinberg equilibrium analysis) and population differentiation (Fst estimates, population structure analysis). In addition to molecular analysis, quantitative representation and statistical analysis of morphological individuals shape are performed using geometric morphometrics methods and statistical tests. Geometric coordinates call landmarks are fixed in 158 individuals belonging to two population samples of Raja clavata and in population samples of closely related species, Raja straeleni (cryptic sibling) and Raja asterias, to assess significant morphological differences at multiple taxonomic levels. The results obtained from the analysis of the microsatellite dataset suggested a geographic and genetic separation between populations from Central-Western and Eastern Mediterranean basins. Furthermore, the analysis also showed that there was no separation between geographic samples from North Atlantic Ocean and central-Western Mediterranean, grouping them to a panmictic population. The Landmark-based geometric morphometry method results showed significant differences of body shape able to discriminate taxa at tested levels (from species to populations).

PET/CT-guided biopsies of metabolically active bone lesions: applications and clinical impact

In a minority of cases a definite diagnosis and stage grouping in cancer patients is not possible based on the imaging information of PET/CT. We report our experience with percutaneous PET/CT-guided bone biopsies to histologically verify the aetiology of hypermetabolic bone lesions.

Tissue fusion, a new opportunity for sutureless bypass surgery

Microsurgical suturing is the standard for cerebral bypass surgery, a technique where temporary occlusion is usually necessary. Non-occlusive techniques such as excimer laser-assisted non-occlusive anastomosis (ELANA) have certainly widened the spectrum of treatment of complex cerebrovascular situations, such as giant cerebral aneurysms, that were otherwise non-treatable. Nevertheless, the reduction of surgical risks while widening the spectrum of indications, such as a prophylactic cerebral bypass, is still a main aim, that we would like to pursue with our sutureless tissue fusion research. The primary concern in sutureless tissue fusion- and especially in tissue fusion of cerebral vessels- is the lack of reproducibility, often caused by variations in the thermal damage of the vessel. This has prevented this novel fusion technique from being applicable in daily surgical use. In this overview, we present three ways to further improve the laser tissue soldering technique.In the first section entitled "Laser Tissue Soldering Using a Biodegradable Polymer," a porous polymer scaffold doped with albumin (BSA) and indocyanine green (ICG) is presented, leading to strong and reproducible tensile strengths in tissue soldering. Histologies and future developments are discussed.In the section "Numerical Simulation for Improvement of Laser Tissue Soldering," a powerful theoretical simulation model is used to calculate temperature distribution during soldering. The goal of this research is to have a tool in hand that allows us to determine laser irradiation parameters that guarantee strong vessel fusion without thermally damaging the inner structures such as the intima and endothelium.In a third section, "Nanoparticles in Laser Tissue Soldering," we demonstrate that nanoparticles can be used to produce a stable and well-defined spatial absorption profile in the scaffold, which is an important step towards increasing the reproducibility. The risks of implanting nanoparticles into a biodegradable scaffold are discussed.Step by step, these developments in sutureless tissue fusion have improved the tensile strength and the reproducibility, and are constantly evolving towards a clinically applicable anastomosis technique.

Musical Expertise and Melodic Structure in Memory for Musical Notation

Two experiments plus a pilot investigated the role of melodic structure on short-term memory for musical notation by musicians and nonmusicians. In the pilot experiment, visually similar melodies that had been rated as either "good" or "bad" were presented briefly, followed by a 15-sec retention interval and then recall. Musicians remembered good melodies better than they remembered bad ones: nonmusicians did not distinguish between them. In the second experiment, good, bad, and random melodies were briefly presented, followed by immediate recall. The advantage of musicians over nonmusicians decreased as the melody type progressed from good to bad to random. In the third experiment, musicians and nonmusicians divided the stimulus melodies into groups. For each melody, the consistency of grouping was correlated with memory performance in the first two experiments. Evidence was found for use of musical groupings by musicians and for use of a simple visual strategy by nonmusicians. The nature of these musical groupings and how they may be learned are considered. The relation of this work to other studies of comprehension of symbolic diagrams is also discussed.

[Blood flow assessment with magnetic resonance imaging after 1.9 μm diode laser assisted arterial micronastomoses]

The most important factor for successful free-flap transfer and replantations is a well-executed anastomosis. The aim of this study is to assess blood flow after laser assisted arterial microanastomosis (LAMA) using a 1.9 μm diode laser.

[Historical review and future orientations of the conventional vascular microanastomoses]

Microvascular surgery has become an important method for reconstructing surgical defects due to trauma, tumors or after burn. The most important factor for successful free flap transfer is a well-executed anastomosis. The time needed to perform the anastomosis and the failure rate are not negligible despite the high level of operator's experience. During the history, many alternatives were tried to help the microsurgeon and to reduce the complications. A Medline literature search was performed to find articles dealing with non-suture methods of microvascular anastomosis. Many historical books were also included. The non-suture techniques can be divided into four groups based on the used mechanism of sutures: double intubation including tubes and stents, intubation-eversion including simple rings, double eversion including staples and double rings, and wall adjustement with adhesives or laser. All these techniques were able to produce a faster and easier microvascular anastomosis. Nevertheless, disadvantages of the suturless techniques include toxicity, high cost, leakage or aneurysm formation. More refinement is needed before their widespread adoption. Thus, laser-assisted microvascular anastomosis using 1,9 μm diode laser appeared to be a safe and reliable help for the microsurgeon and may be further developed in the near future.

Inferences regarding the diet of extinct hominins: structural and functional trends in dental and mandibular morphology within the hominin clade

This contribution investigates the evolution of diet in the Pan – Homo and hominin clades. It does this by focusing on 12 variables (nine dental and three mandibular) for which data are available about extant chimpanzees, modern humans and most extinct hominins. Previous analyses of this type have approached the interpretation of dental and gnathic function by focusing on the identification of the food consumed (i.e. fruits, leaves, etc.) rather than on the physical properties (i.e. hardness, toughness, etc.) of those foods, and they have not specifically addressed the role that the physical properties of foods play in determining dental adaptations. We take the available evidence for the 12 variables, and set out what the expression of each of those variables is in extant chimpanzees, the earliest hominins, archaic hominins, megadont archaic hominins, and an inclusive grouping made up of transitional hominins and pre-modern Homo . We then present hypotheses about what the states of these variables would be in the last common ancestor of the Pan – Homo clade and in the stem hominin. We review the physical properties of food and suggest how these physical properties can be used to investigate the functional morphology of the dentition. We show what aspects of anterior tooth morphology are critical for food preparation (e.g. peeling fruit) prior to its ingestion, which features of the postcanine dentition (e.g. overall and relative size of the crowns) are related to the reduction in the particle size of food, and how information about the macrostructure (e.g. enamel thickness) and microstructure (e.g. extent and location of enamel prism decussation) of the enamel cap might be used to make predictions about the types of foods consumed by extinct hominins. Specifically, we show how thick enamel can protect against the generation and propagation of cracks in the enamel that begin at the enamel– dentine junction and move towards the outer enamel surface.

[Acute lower gastrointestinal bleeding--an evidence-based algorithm for diagnosis and treatment]

Novel means to locate and treat lower gastrointestinal bleeding (lGB) allow to reduce the rate of required surgical interventions and help to limit the extend of resection. The risk stratification of patients with lGB is the primary step of our recommended treatment algorithm. Accordingly, risk stratifying instruments, which are only partly validated up to now, are gaining significance in lGB. Whereas, gastro-duodenoscopy and colonoscopy prior to angiography or scintigraphy are established diagnostic tools, capsule enteroscopy offers a novel approach to hemodynamic stable patients with lGB that are difficult to localize. With its every increasing sensitivity, Angio-Computer Tomography is likely to replace scintigraphy and diagnostic angiography in the very near future. In addition, recent advances in superselective microembolisation have been shown to have the potential rendering surgical interventions in a majority of patients with acute lGB unnecessary. The extend of required surgical resection is largely dependent on the success to localize the bleeding source of prior diagnostics. Only if the source is identified, a limited segmental resection should be performed. Should surgery be required, we suggest to maintain the effort to localize the bleeding, either by prior laparoscopy and/or by intraoperative entero-colonoscopy. Eventually, if the source of bleeding remains unclear total colectomy with ileorectal anastomosis represents the procedure of choice in patients with acute lGB.