Paenibacillus larvae Bacteremia in Injection Drug Users

Paenibacillus larvae causes American foulbrood in honey bees. We describe P. larvae bacteremia in 5 injection drug users who had self-injected honey-prepared methadone proven to contain P. larvae spores. That such preparations may be contaminated with spores of this organism is not well known among pharmacists, physicians, and addicts

Screening for Mutations Related to Atovaquone/ Proguanil Resistance in Treatment Failures and Other Imported Isolates of Plasmodium falciparum in Europe

Background. Two single-point mutations of the Plasmodium falciparum cytochrome b gene (Tyr268Asn and Tyr268Ser) were recently reported in cases of atovaquone/proguanil (Malarone) treatment failure. However, little is known about the prevalence of codon-268 mutations and their quantitative association with treatment failure. Methods. We set out to assess the prevalence of codon-268 mutations in P. falciparum isolates imported into Europe and to quantify their association with atovaquone/proguanil treatment failure. Isolates of P. falciparum collected by the European Network on Imported Infectious Disease Surveillance between April 2000 and August 2003 were analyzed for codon-268 mutations, by use of polymerase chain reaction-restriction fragment-length polymorphism. Results. We successfully screened 504 samples for the presence of either Tyr268Ser or Tyr268Asn. One case of Ser268 and no cases of Asn268 were detected. Therefore, we can be 95% confident that the prevalence of Ser268 in the European patient pool does not exceed 0.96% and that Asn268 is less frequent than 0.77%. In 58 patients treated with atovaquone/proguanil, Tyr268Ser was present in 1 of 5 patients with treatment failure but in 0 of 53 successfully treated patients. Conclusions. Tyr268Ser seems to be a sufficient, but not a necessary, cause for atovaquone/proguanil treatment failure. The prevalence of both codon-268 mutations is currently unlikely to be >1% in the European patient poo

Molecular surveillance of drug resistance through imported isolates of Plasmodium falciparum in Europe

BACKGROUND: Results from numerous studies point convincingly to correlations between mutations at selected genes and phenotypic resistance to antimalarials in Plasmodium falciparum isolates. In order to move molecular assays for point mutations on resistance-related genes into the realm of applied tools for surveillance, we investigated a selection of P. falciparum isolates that were imported during the year 2001 into Europe to study the prevalence of resistance-associated point mutations at relevant codons. In particular, we tested for parasites which were developing resistance to antifolates and chloroquine. The screening results were used to map the prevalence of mutations and, thus, levels of potential drug resistance in endemic areas world-wide. RESULTS: 337 isolates have been tested so far. Prevalence of mutations that are associated with resistance to chloroquine on the pfcrt and pfmdr genes of P. falciparum was demonstrated at high levels. However, the prevalence of mutations associated with resistance to antifolates at the DHFR and DHPS genes was unexpectedly low, rarely exceeding 60% in endemic areas. CONCLUSIONS: Constant screening of imported isolates will enable TropNetEurop to establish a screening tool for emerging resistance in endemic areas

Agriculture in the Face of Changing Markets, Institutions and Policies: Challenges and Strategies

Since the late 1980s, agriculture in Central and Eastern European Countries (CEECs) has been under considerable adjustment pressure due to changing political, economic and institutional environments. These changes have been linked to the transition process, as well as the ongoing integration into the European Union and the world market. Reduced subsidies, increased environmental and food quality demands, as well as structural changes in the supply, processing and food retailing sector call for major structural adjustments and the improvement of farmersâ managerial abilities. Though such changes always carry significant threats to farms, they also offer new opportunities for the farms' entrepreneurial engagement. Upcoming changes in the agricultural environment and their possible consequences for farm structures across Europe are thus still timely subjects. The objective of the IAMO Forum 2006 is to contribute to the success of agriculture in the CEECs, as well as their neighboring countries, in todayâs increasingly competitive environment. Concrete questions the conference focuses on are: What are the most suitable farm organizations, cooperative arrangements and contractual forms? How to improve efficiency and productivity? Where do market niches lie and what are the new product demands? This book contains 33 invited and selected contributions. These papers will be presented at the IAMO Forum 2006 in order to offer a platform for scientists, practitioners and policy-makers to discuss challenges and potential strategies at the farm, value chain, rural society and policy levels in order to cope with the upcoming challenges. IAMO Forum 2006, as well as this book, would not have been possible without the engagement of many people and institutions. We thank the authors of the submitted abstracts and papers, as well as the referees, for their evaluation of the abstracts from which the papers were selected. In particular, we would like to express our thanks to OLIVER JUNGKLAUS, GABRIELE MEWES, KLAUS REINSBERG and ANGELA SCHOLZ, who significantly contributed to the organization of the Forum. Furthermore, our thanks goes to SILKE SCHARF for her work on the layout and editing support of this book, and to JIM CURTISS, JAMIE BULLOCH, and DÃNALL Ã MEARÃIN for their English proof-reading. As experience from previous years documents, the course of the IAMO Forum continues to profit from the support and engagement of the IAMO administration, which we gratefully acknowledge. Last but not least, we are very grateful to the Robert Bosch Foundation, the Federal Ministry of Nutrition, Agriculture and Consumer Protection (BMELV), the German Research Foundation (DFG), the Haniel Foundation and the Leibniz Institute of Agricultural Development in Central and Eastern Europe (IAMO) for their respective financial support.Agribusiness, Community/Rural/Urban Development, Farm Management, Industrial Organization, International Development, Labor and Human Capital, Land Economics/Use, Productivity Analysis,

Phylogenetic Dependency Networks: Inferring Patterns of CTL Escape and Codon Covariation in HIV-1 Gag

HIV avoids elimination by cytotoxic T-lymphocytes (CTLs) through the evolution of escape mutations. Although there is mounting evidence that these escape pathways are broadly consistent among individuals with similar human leukocyte antigen (HLA) class I alleles, previous population-based studies have been limited by the inability to simultaneously account for HIV codon covariation, linkage disequilibrium among HLA alleles, and the confounding effects of HIV phylogeny when attempting to identify HLA-associated viral evolution. We have developed a statistical model of evolution, called a phylogenetic dependency network, that accounts for these three sources of confounding and identifies the primary sources of selection pressure acting on each HIV codon. Using synthetic data, we demonstrate the utility of this approach for identifying sites of HLA-mediated selection pressure and codon evolution as well as the deleterious effects of failing to account for all three sources of confounding. We then apply our approach to a large, clinically-derived dataset of Gag p17 and p24 sequences from a multicenter cohort of 1144 HIV-infected individuals from British Columbia, Canada (predominantly HIV-1 clade B) and Durban, South Africa (predominantly HIV-1 clade C). The resulting phylogenetic dependency network is dense, containing 149 associations between HLA alleles and HIV codons and 1386 associations among HIV codons. These associations include the complete reconstruction of several recently defined escape and compensatory mutation pathways and agree with emerging data on patterns of epitope targeting. The phylogenetic dependency network adds to the growing body of literature suggesting that sites of escape, order of escape, and compensatory mutations are largely consistent even across different clades, although we also identify several differences between clades. As recent case studies have demonstrated, understanding both the complexity and the consistency of immune escape has important implications for CTL-based vaccine design. Phylogenetic dependency networks represent a major step toward systematically expanding our understanding of CTL escape to diverse populations and whole viral genes

The interplay between mineral metabolism, vascular calcification and inflammation in Chronic Kidney Disease (CKD): challenging old concepts with new facts

Chronic kidney disease (CKD) is one of the most powerful predictors of premature cardiovascular disease (CVD), with heightened susceptibility to vascular intimal and medial calcification associated with a high cardiovascular mortality. Abnormal mineral metabolism of calcium (Ca) and phosphate (P) and underlying (dys)regulated hormonal control in CKD-mineral and bone disorder (MBD) is often accompanied by bone loss and increased vascular calcification (VC). While VC is known to be a multifactorial process and a major risk factor for CVD, the view of primary triggers and molecular mechanisms complexity has been shifting with novel scientific knowledge over the last years. In this review we highlight the importance of calcium-phosphate (CaP) mineral crystals in VC with an integrated view over the complexity of CKD, while discuss past and recent literature aiming to highlight novel horizons on this major health burden. Exacerbated VC in CKD patients might result from several interconnected mechanisms involving abnormal mineral metabolism, dysregulation of endogenous calcification inhibitors and inflammatory pathways, which function in a feedback loop driving disease progression and cardiovascular outcomes. We propose that novel approaches targeting simultaneously VC and inflammation might represent valuable new prognostic tools and targets for therapeutics and management of cardiovascular risk in the CKD population.Portuguese Foundation for Science and Technology (UID/Multi/04326/2019); Portuguese Society of Nephrology (SPN)info:eu-repo/semantics/publishedVersio

Fracture mechanical and stereoscopic characterization of cement bonded interfaces

Abweichender Titel laut Übersetzung der Verfasserin/des VerfassersZsfassung in engl. SpracheDie vorliegende Arbeit beschäftigt sich mit der experimentellen Ermittlung des Zusammenwirkens der Oberflächenausbildung mit den Verbundeigenschaften von zementgebundenen Interfaces. Dabei wurde grundsätzlich der Fragestellung nachgegangen, wie Beton-Beton-Verbundbaustoffe herzustellen sind, um das Verbundverhalten zwischen den beiden Baustoffen bestmöglich zu optimieren. Diese Frage entstand primär daraus, dass die herkömmlich angewandten Methoden zur Charakterisierung der Oberflächenrauheit sowie zur Ermittlung der Verbundeigenschaften oft nur ungenügende Aussa-gen über Zusammenhänge zwischen Oberflächenausbildung und Verbundfestigkeit des Interfaces liefern. Um diese Problemstellung besser beleuchten zu können, erfolgte die Erfassung der Oberflä-cheneigenschaften neben dem gängigen Verfahren der Rautiefenbestimmung nach N. Kaufmann [KAUF 71] mit einem Verfahren zur Erstellung von dreidimensionalen Oberflächenmodellen. Die Ver-bundeigenschaften in Abhängigkeit einer Oberflächenprofilierung wurden durch Prüfung der Haftzug-festigkeit sowie durch Bestimmung der bruchmechanischen Kennwerte mit der Keilspaltmethode nach E. K. Tschegg [TSCH 86] ermittelt. Die theoretischen Grundlagen geben einen Literaturüberblick über den derzeit aktuellen Wissensstand wodurch eine Basis für die zu untersuchenden Fragestellungen geschaffen wird. Dabei wird vorerst im ersten Kapitel die generelle Materialstruktur von Beton beleuchtet, um das Werkstoffverhalten dieses Baustoffes besser verstehen zu können. Das darauf folgende Kapitel stellt die bruchmechanische Materialcharakterisierung mit speziellem Fokus auf Beton dar. Diese Zusammenstellung liefert die Grundlagen zu der im Rahmen dieser Arbeit durchgeführten Charakterisierung der Verbundeigen-schaften mit der Keilspaltmethode nach E. K. Tschegg. Ein weiteres Kapitel beschreibt die Oberflä-chencharakterisierung von Werkstoffen. Diese im Bauwesen noch wenig verbreitete Disziplin liefert die Basis zur exakten mathematischen Erfassung von Oberflächenkenngrößen sowie einen Überblick über mögliche Bestimmungsmethoden. Das letzte Kapitel des Literaturüberblicks beleuchtet den bisherigen Wissensstand des Zusammenwirkens von Oberflächenausbildung auf die Verbundeigenschaften von Beton-Verbundkonstruktionen. Dabei werden Mechanismen des Tragverhaltens, der Einfluss von Kontaktzonen sowie Zusammenhänge zwischen Oberflächenausbildung und Verbundfestigkeit verschiedenster Beton-Verbundbaustoffe dargelegt. Im Rahmen der experimentellen Untersuchungen wurden grundsätzlich mehrere Anwendungsfälle von Betonverstärkungsmaßnahmen betrachtet. Der erste Themenblock behandelt das Zusammenwirken von Beton mit hochelastischen Spritzabdichtungen für Brückentragwerke. Diese an unterschiedlichen Abdichtungssystemen durchgeführten Untersuchungen zeigten, dass durch die alleinige Prüfung der Haftzugfestigkeit keine qualifizierten Aussagen zum Verbundverhalten dieser Systeme getroffen werden konnten. Erst die bruchmechanischen Untersuchungen mit der Keilspaltmethode nach E. K. Tschegg konnten darlegen, dass das Materialverhalten der untersuchten Systeme sehr unterschied-lich, jedoch für das Verbundverhalten die Ausbildung der Betonrandzone in Interfacenähe entschei-dend ist. Der zweite Themenblock widmet sich dem Verbundverhalten von zwei zu unterschiedlichen Zeitpunk-ten hergestellten Betonschichten. Bei diesen im Rahmen von Instandsetzungsmaßnahmen aber auch im Neubau ausgeführten Verbundbauweisen wird auf eine bestehende Betonschicht eine weitere auf-gebracht. Bei diesen Untersuchungen wurde der Fokus speziell auf den Einfluss unterschiedlicher Oberflächenausbildung auf das Zusammenwirken von zwei Betonschichten gelegt. Da die herkömm-lich eingesetzte Bestimmungsmethode der Rautiefenbestimmung mit dem Sandflächenverfahren nach N. Kaufmann keine fundierte Interpretation der Oberflächenbeschaffenheit zulässt, erfolgte darüber hinaus die Erfassung der Oberflächeneigenschaften mit einem stereoskopischen Verfahren zur Erstel-lung eines dreidimensionalen Oberflächenmodells. Im Rahmen dieser Untersuchungen konnten zwar Korrelationen zwischen der Rautiefe nach N.Kaufmann und den bruchmechanischen Kennwerten hergestellt werden, eindeutig bessere Aussagen lieferte jedoch die Gegenüberstellung der Kerb-Spaltzugfestigkeit und der spezifischen Bruchenergie mit den Oberflächenparametern aus dem drei-dimensionalen Oberflächenmodell. Es konnte dargelegt werden, dass Zusammenhänge zwischen ausgewählten Oberflächenparametern des Oberflächenmodells und den bruchmechanischen Kenn-werten existieren. Der dritte abschließende Themenblock behandelt Versuche zum Einfluss von mit unterschiedlichen Intensitäten hochdruckwassergestrahlten Oberflächen auf das Verbundverhalten. Diese Untersuchungen konnten darlegen, dass nicht nur die Oberflächenausbildung an sich sondern auch die Festigkeitseigenschaften der an das Interface angrenzenden Betonflächen für das Bruchver-halten der Verbundfuge wesentlich sind.This thesis deals with the experimental determination of the interaction of the surface characteristics between interface properties of cement-bonded interfaces. Basically the question was addressed on how to establish concrete-concrete-connection material in order to make the best possible improve-ment of bonding property between both these construction materials. This question arose primarily from the fact that the conventionally used methods for the characterization of the surface roughness as well as for the determination of the compound characteristics were inconclusive. They often only provide insufficient statements about the relationships between surface formation and bond strength of the interface. To examine this problem more effectively, the acquisition of the surface characteristics, beside the common procedure of determination of the surface roughness according to N. Kaufmann [KAUF 71], took place with a method for creating three-dimensional elevation models. The interface properties in dependence of surface profiling were determined by examination of adhesive tensile strength as well as by determination of fracture mechanical properties with the wedge splitting method according to E. K. Tschegg [TSCH 86]. The theoretical bases give a bibliographical overview of the current knowledge, whereby a basis for the examined questions will be covered.In the first chapter, the general material structure of concrete is illustrated in order to be able to understand the material behaviour of this construction material bet-ter. The chapter following on it presents the fracture mechanical material characterization with special focus on concrete. This compilation supplies the basics in context with this thesis to put into effect the characterization of the interface properties with the wedge splitting method according to E. K. Tschegg. A further chapter describes the surface characterization of materials.This style of civil engi-neering is still rarely used; it supplies the basis for the accurate mathematical measurement of surface characteristics as well as an overview of possible methods of determination. The last chapter of this overview illuminates the current state of knowledge of the cooperation of the surface formation on the interface properties of concrete composite structure. Mechanisms of structural behaviour, the influ-ence of contact zones as well as the connections between surface formation and bond strength of various concrete-connection materials are presented. Generally, in context of experimental investigations, several applications of concrete reinforcement have been considered. The first section deals with the interaction of concrete with high elastic spray-on waterproofing for bridge support structure. These investigations, accomplished at different sealing systems, showed that by the exclusive examination of adhesive tensile strength no qualified state-ments could be made for the bond property of these systems. Only the fracture mechanical investiga-tions with the wedge splitting method according to E. K. Tschegg could demonstrate that the material behaviour of the examined systems is very different. However, it is decisive for the formation of the bond property of the concrete edge zone next to the interface. The second section gives special attention to the bonding property of two produced concrete layers at different times. Within this context of maintenance measure, but also of new building implemented composite construction, a further layer is applied to the existing concrete layer.In these investigations the focus was particularly on the influence of different surface characteristics on the interaction of two concrete layers. As the conventionally used method of determination of the surface roughness with the sand surface method according to N. Kaufmann, does not permit a founded interpretation of the surface property, beyond that of the acquisition of the surface characteristics with a stereoscopic method for creating a three-dimensional elevation model. In context, these investigations correlations between roughness depth according to N. Kaufmann and fracture mechanical properties could be established, however, clearly better statements could be provided by the comparison of the notch-splitting tensile strength and the specific fracture energy with surface parameters from the three-dimensional elevation model. It could be stated that connections between selected surface parameters of the elevation model and fracture mechanical properties exist. The third concluding section deals with experiments covering the influence of with different intensities of high pressure water sprayed surfaces on the bond property. These investigations could demonstrate that not only the surface formation per se but also the mechanical properties of the concrete surfaces that adjoin the interface are essential for the fracture behaviour of the composite joint.15

Creep and cracking of concrete hinges: insight from centric and eccentric compression experiments

Existing design guidelines for concrete hinges consider bending-induced tensile cracking, but the structural behavior is oversimplified to be time-independent. This is the motivation to study creep and bending-induced tensile cracking of initially monolithic concrete hinges systematically. Material tests on plain concrete specimens and structural tests on marginally reinforced concrete hinges are performed. The experiments characterize material and structural creep under centric compression as well as bending-induced tensile cracking and the interaction between creep and cracking of concrete hinges. As for the latter two aims, three nominally identical concrete hinges are subjected to short-term and to longer-term eccentric compression tests. Obtained material and structural creep functions referring to centric compression are found to be very similar. The structural creep activity under eccentric compression is significantly larger because of the interaction between creep and cracking, i.e. bending-induced cracks progressively open and propagate under sustained eccentric loading. As for concrete hinges in frame-like integral bridge construction, it is concluded (i) that realistic simulation of variable loads requires consideration of the here-studied time-dependent behavior and (ii) that permanent compressive normal forces shall be limited by 45% of the ultimate load carrying capacity, in order to avoid damage of concrete hinges under sustained loading.Austrian Ministry forTransport and Technology (bmvit)Austrian Research PromotionAgency (FFG)ÖBB-Infrastruktur AGASFINAG Bau Management Gmb

Concrete Curing Performance Assessment Based on Gas Permeability Testing in the Lab and on Site

Durability is an essential aspect of the lifetime performance of concrete components. The adequate surface quality and thus the service life of concrete can be achieved, among other things, by appropriate curing during hydration. To measure and control the curing quality, appropriate procedures are required. Gas permeability allows conclusions to be drawn about the porosity of concrete, which has a significant impact on durability. In this contribution, the effect of different curing methods on gas permeability is presented with the help of laboratory and on-site tests, showing that inadequate curing leads to increased permeability in the near-surface area of concrete. The measurement results of concrete samples and components with the same composition but varying curing treatment are compared and evaluated. Influences such as concrete composition and environmental factors on the quality of concrete are observed, and recommendations are made for a reliable assessment of the surface quality as a result of the investigated curing measures