Sequence of protein expression of bone sialoprotein and osteopontin at the developing interface between repair cementum and dentin in human deciduous teeth

Experimental periodontal regeneration studies have revealed the weak binding of repair cementum to the root surface, whereas attachment of cementum to dentin preconditioned by odontoclasts appears to be superior. The aim of this study has been, therefore, to analyze the structural and partial biochemical nature of the interface that develops between resorbed dentin and repair cementum by using human deciduous teeth as a model. Aldehyde-fixed and decalcified tooth samples were embedded in acrylic or epoxy resins and sectioned for light and transmission electron microscopy. Antibodies against bone sialoprotein (BSP) and osteopontin (OPN), two noncollagenous proteins accumulating at hard tissue interfaces in bone and teeth, were used for protein A-gold immunocytochemistry. Light microscopy revealed a gradually increasing staining intensity of the external dentin matrix starting after the withdrawal of the odontoclast. Labeling for both BSP and OPN was first detected among the exposed collagen fibrils and in the intratubular dentin matrix when odontoclasts had withdrawn but mesenchymal cells were present. Subsequently, collagen fibrils of the repair cementum were deposited concomitantly with the appearance of labeling for BSP and OPN over the intratubular, intertubular, and peritubular dentin matrix. Labeled mineralization foci indicated the advancing mineralization front, and the collagenous repair matrix became integrated in an electron-dense organic material that showed labeling for BSP and OPN. Thus, no distinct planar interfacial matrix layer lies between the resorbed dentin and the repair cementum. The results suggest that odontoclasts precondition the dentin matrix such that the repair cementum becomes firmly attache

Changes in Arctic Benthos

The shift towards a seasonally ice-free Arctic Ocean raises many questions related to the future of productivity and function of Arctic ecosystems. The highly productive marginal ice zone is dragged closer towards the center of the Arctic, and the ongoing thinning of sea ice and increased light penetration to the surface ocean may change spatio-temporal patterns of under- ice productivity. As under-ice processes are hard to monitor we study the dynamics on (and in) the Arctic seafloor, particularly the macrobenthos, as a proxy for pelagic change. We use biological trait analysis (BTA) to study the benthic functions and responses as this method links species, environment and ecosystem processes (Bremner 2005). Although benthos data from the Arctic and especially from the Arctic deep sea are scarce, international cooperation enables us to compile a dataset ranging over the past twenty years up to today. Based on this dataset we show that benthic functional traits like secondary production are correlated to Arctic sea ice and its associated dynamics. We give a regional example where benthic community functions have changed already over the last twenty years and highlight the areas of the Arctic Ocean that are most prone to these effects. Finally we want to stress the importance of international cooperation in the process of integrating existing data and knowledge to build up a spatially explicit Arctic trait database. Such a database would provide the scientific base to classify the Arctic into clearly defined “eco-function” regions. This functional atlas can then be used by the scientific community to correlate observed environmental trends and predict upcoming changes in ecosystem functioning accordingly

The Role of Herbivore-induced Plant Volatiles in Trophic Interactions: The Swiss Connection

It is increasingly evident that plants actively respond to the threats and challenges that they come to face while growing. This is particularly manifested in the dynamic responses to insect herbivory, especially in terms of the volatile compounds that the attacked plants emit. Indeed, many plants respond to insect-inflicted damage with the synthesis and release of volatile organic compounds. These emissions, commonly referred to as herbivore-induced plant volatiles (HIPVs), play important roles in the interactions between the emitting plants and their biotic environment. The odorous signal can be picked up and exploited by various organisms: neighbouring plants, herbivores and their natural enemies, such as predators and parasitoid wasps. Coincidence or not, scientists currently working in Switzerland have made numerous key contributions to the work in this field. By highlighting their work, we attempt to give a somewhat historic overview of this field of research

Women Inmates: An Exploration of Misconduct and Victimization Behind Bars

Experimental periodontal regeneration studies have revealed the weak binding of repair cementum to the root surface, whereas attachment of cementum to dentin preconditioned by odontoclasts appears to be superior. The aim of this study has been, therefore, to analyze the structural and partial biochemical nature of the interface that develops between resorbed dentin and repair cementum by using human deciduous teeth as a model. Aldehyde-fixed and decalcified tooth samples were embedded in acrylic or epoxy resins and sectioned for light and transmission electron microscopy. Antibodies against bone sialoprotein (BSP) and osteopontin (OPN), two noncollagenous proteins accumulating at hard tissue interfaces in bone and teeth, were used for protein A-gold immunocytochemistry. Light microscopy revealed a gradually increasing staining intensity of the external dentin matrix starting after the withdrawal of the odontoclast. Labeling for both BSP and OPN was first detected among the exposed collagen fibrils and in the intratubular dentin matrix when odontoclasts had withdrawn but mesenchymal cells were present. Subsequently, collagen fibrils of the repair cementum were deposited concomitantly with the appearance of labeling for BSP and OPN over the intratubular, intertubular, and peritubular dentin matrix. Labeled mineralization foci indicated the advancing mineralization front, and the collagenous repair matrix became integrated in an electron-dense organic material that showed labeling for BSP and OPN. Thus, no distinct planar interfacial matrix layer lies between the resorbed dentin and the repair cementum. The results suggest that odontoclasts precondition the dentin matrix such that the repair cementum becomes firmly attached. © Springer-Verlag 2005.link_to_subscribed_fulltex

Evaluating the Induced-Odour Emission of a Bt Maize and its Attractiveness to Parasitic Wasps

The current discussion on the safety of transgenic crops includes their effects on beneficial insects, such as parasitoids and predators of pest insects. One important plant trait to consider in this context is the emission of volatiles in response to herbivory. Natural enemies use the odours that result from these emissions as cues to locate their herbivorous prey and any significant change in these plant-provided signals may disrupt their search efficiency. There is a need for practical and reliable methods to evaluate transgenic crops for this and other important plant traits. Moreover, it is imperative that such evaluations are done in the context of variability for these traits among conventional genotypes of a crop. For maize and the induction of volatile emissions by caterpillar feeding this variability is known and realistic comparisons can therefore be made. Here we used a six-arm olfactometer that permits the simultaneous collection of volatiles emitted by multiple plants and testing of their attractiveness to insects. With this apparatus we measured the induced odour emissions of Bt maize (Bt11, N4640Bt) and its near-isogenic line (N4640) and the attractiveness of these odours to Cotesia marginiventris and Microplitis rufiventris, two important larval parasitoids of common lepidopteran pests. Both parasitoid species were strongly attracted to induced maize odour and neither wasp distinguished between the odours of the transgenic and the isogenic line. Also wasps that had previously experienced one of the odours during a successful oviposition divided their choices equally between the two odours. However, chemical analyses of collected odours revealed significant quantitative differences. The same 11 compounds dominated the blends of both genotypes, but the isogenic line released a larger amount of most of these. These differences may be due to altered resource allocation in the transgenic line, but it had no measurable effect on the wasps' behaviour. All compounds identified here had been previously reported for maize and the differential quantities in which they were released fall well within the range of variability observed for other maize genotype

Assembly of Micro Systems with the High Precision Robot Parvus

In recent years, the development of micro systems has been widely discussed in research articles concerning a decrease in size, an increase of complexity and the variety of materials used. In contrast, manufacturing and especially assembly processes of millimetre-sized products with high complexity did not play a significant role. Conventional precision robots that provide adequate accuracies for micro assembly are relatively large and expensive. These machines have to be operated in clean rooms, which results in high costs of maintenance. These days, the assembly technology of electronic production and conventional assembly robots is often no longer suitable for the assembly of hybrid micro systems. The increasing gap between millimetre-sized products and the production machines has lead to a high proportion of manual assembly in the manufacturing process of microproducts. Assembly costs that sometimes account for up to 80 % of the costs of micro systems retard the commercialisation and bulk production of these products. [1] Especially for small and medium-sized businesses, new concepts for flexible and lower-cost micro assembly have to be found

Using Business Intelligence Tools to Support Medical Validation of Laboratory Tests

Modern clinical laboratories have to confirm that the procedures used for specific tests are reliable and valid. There are several sources of errors and interferences that can invalidate the results. Medical validation refers to the plausibility check of the test results. Implausible results indicate that something might went wrong with a sample retrieved from the patient, e.g., the blood sample got contaminated with another fluid, which requires re-examination. Here, we describe how an integrated R-based business intelligence (BI) tool can be developed that increase the efficiency of the medical validation at the Institute of Clinical Chemistry (ICC) of the University Hospital Zurich. A BI software environment allowed us to digitalize steps in the validation process that were manually done in Excel worksheets, e.g., importing the data, calculating percentiles, and producing graphical outputs

Struktur und Metamorphose im Norden des Fjällfjäll-Fensters in den Skandinavischen Kaledoniden (Västerbotten, Schweden)

Die Entstehung der Skandinavischen Kaledoniden resultiert aus der Kollision Baltikas mit Laurentia. Hierbei kam es zur Ausbildung eines Orogenen Keils, der auf den Baltischen Schild aufgeschoben wurde. Dieser Keil entstand durch die Stapelung verschiedener lithologischer Decken, dem Unteren, Mittleren, Oberen und Obersten Allochthon. Das Mittlere Allochthon diente dabei als Basis und Überschiebungsbahn der mächtigen Deckenkomplexe des Oberen und Obersten Allochthons. In den zentralen Kaledoniden in Västerbotten sind tiefergelegene allochthone Einheiten in tektonischen Fenstern aufgeschlossen. Das Arbeitsgebiet befindet sich innerhalb einer solchen Struktur, dem nördlichen Fjällfjäll-Fenster. Hier sind die Decken des Mittleren und des Oberen Allochthons in einer antiformen Struktur, einem Duplex, aufgeschlossen. Das Obere Allochthon kann in zwei Sub-Decken, die Seve- und Köli-Decke, unterteilt werden, wobei der Kern des Duplexes durch eine Stapelung aller drei Einheiten (Mittleres Allochthon, Seve- und Köli-Decke) aufgebaut ist. Die Umrandung des Fensters besteht ausschließlich aus Gesteinen der Köli-Decke. Alle Einheiten sind regionalmetamorph überprägt. Lithologisch besteht das Mittlere Allochthon hauptsächlich aus Meta-Arkosen, die im Kontaktbereich zum Oberen Allochthon stark mylonitisiert sind. Die Mineralparagenesen dieser Einheit zeigen grünschieferfazielle Druck- und Temperaturbedingungen von bis zu 460°C und 4,2 kbar. Eine jüngere, niedriggradige grünschieferfazielle Überprägung konnte ebenfalls beobachtet werden. Die Seve-Decke des Oberen Allochthons besteht aus granatführenden Meta-Grauwacken. Die Mineralparagenesen deuten auf eine mittlere bis hochgradige amphibolitfazielle Überprägung hin. Die metamorphen Bedingungen werden mit 650°C und 6 kbar angenommen. Vereinzelt zeigen Dünnschliffe aus der Seve- Decke granulitfazielle Relikte, welche auf deutlich höhere metamorphe Bedingungen von über 700°C und 6,5 kbar schließen lassen. Die Köli-Decke ist hauptsächlich aus unterschiedlichen Phylliten aufgebaut. Hier konnten Druck- und Temperaturbedingungen einer oberen Grünschiefer- bis unteren Amphibolitfazies von 550°C und 5 kbar nachgewiesen werden. Beide, die Seve- und Köli- Decke, zeigen ebenso wie das Mittlere Allochthon eine zweite, jüngere grünschieferfazielle Überprägung. Die unterschiedlichen metamorphen Bedingungen erlauben so eine genaue Abgrenzung der Deckenkomplexe und zeigen den Stapelbau der allochthonen Einheiten im Fjällfjäll-Fenster. Während der Aufstapelung der unterschiedlichen Decken bildete sich ein in Richtung Hinterland einfallender Duplex aus, wobei das Mittlere Allochthon mit den Einheiten der Seve- und Köli-Decke intensiv miteinander verschuppt wurden. Dabei wurde die überfahrende Decke, das Obere Allochthon, über die gesamte Aufdomung geschoben („passive roof folding“). Während der Anlage der antiformen Struktur kam es zu duplextypischen Einengungsstrukturen. So konnte im Zentrum des Arbeitsgebietes eine „pop-up structure“ konstruiert werden. Da diese unterhalb des Mittleren Allochthons angelegt ist, wird postuliert, dass die im Westen des Arbeitsgebietes auskartierte deckeninterne Duplex-Struktur des Mittleren Allochthons sich erst nach der „pop-up structure“ ausbildete. Des Weiteren wurde im nördlichen Teil des Fjällfjäll-Fensters eine Rücküberschiebung („out of sequence back thrust“) nachgewiesen, die als letzte, deckenübergreifende Einengung interpretiert wird. Zusammenfassend zeigte sich im Gelände durch eine deutliche Verschuppung der oben genannten Decken der tektonische Stapelbau, der den Kern des nördlichen Fjällfjäll-Duplex repräsentiert. Weiterhin konnte eine inverse Abfolge von niedriggradig metamorphen Einheiten an der Basis zu höhergradig metamorphen Folgen im Top des gesamten Komplexes nachgewiesen werden, was die Entwicklung des paläozoischen Orogenen Keils verdeutlicht