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We introduce efficient $(1+\varepsilon)$-approximation algorithms for the binary matrix factorization (BMF) problem, where the inputs are a matrix $\mathbf{A}\in\{0,1\}^{n\times d}$, a rank parameter $k>0$, as well as an accuracy parameter $\varepsilon>0$, and the goal is to approximate $\mathbf{A}$ as a product of low-rank factors $\mathbf{U}\in\{0,1\}^{n\times k}$ and $\mathbf{V}\in\{0,1\}^{k\times d}$. Equivalently, we want to find $\mathbf{U}$ and $\mathbf{V}$ that minimize the Frobenius loss $\|\mathbf{U}\mathbf{V} - \mathbf{A}\|_F^2$. Before this work, the state-of-the-art for this problem was the approximation algorithm of Kumar et. al. [ICML 2019], which achieves a $C$-approximation for some constant $C\ge 576$. We give the first $(1+\varepsilon)$-approximation algorithm using running time singly exponential in $k$, where $k$ is typically a small integer. Our techniques generalize to other common variants of the BMF problem, admitting bicriteria $(1+\varepsilon)$-approximation algorithms for $L_p$ loss functions and the setting where matrix operations are performed in $\mathbb{F}_2$. Our approach can be implemented in standard big data models, such as the streaming or distributed models., ICML 2023

Nach zwei Corona Pandemie bedingten Absagen in den Jahren 2020/21 fand die Tagung des AÖPM am 8. April 2022 in Gratkorn statt. Am Vorabend trafen sich die Teilnehmer im Gasthof Thomahan in Friesach zu einem gemütlichen Erfahrungsaustausch.

Three-dimensional (3D)-printed vascular models for cardiovascular surgery planning and endovascular procedure simulations often lack realistic biological tissues mim¬icking material properties, including flexibility or transparency, or both. Transparent silicone or silicone-like vascular models were not available for end-user 3D printers and had to be fabricated using complex and cost-intensive workarounds. This limita¬tion has now been overcome by novel liquid resins with biological tissue properties. These new materials enable simple and low-cost fabrication of transparent and flexi¬ble vascular models using end-user stereolithography 3D printers and are promising technological advances toward more realistic patient-specific, radiation-free proce¬dure simulations and planning in cardiovascular surgery and interventional radiol¬ogy. This paper presents our patient-specific manufacturing process of fabricating transparent and flexible vascular models using freely available open-source software for segmentation and 3D post-processing, aiming to facilitate the integration of 3D printing into clinical care.

Motivated by fairness requirements in communication networks, we introduce a natural variant of the online paging problem, called \textit{min-max} paging, where the objective is to minimize the maximum number of faults on any page. While the classical paging problem, whose objective is to minimize the total number of faults, admits $k$-competitive deterministic and $O(\log k)$-competitive randomized algorithms, we show that min-max paging does not admit a $c(k)$-competitive algorithm for any function $c$. Specifically, we prove that the randomized competitive ratio of min-max paging is $\Omega(\log(n))$ and its deterministic competitive ratio is $\Omega(k\log(n)/\log(k))$, where $n$ is the total number of pages ever requested. We design a fractional algorithm for paging with a more general objective -- minimize the value of an $n$-variate differentiable convex function applied to the vector of the number of faults on each page. This gives an $O(\log(n)\log(k))$-competitive fractional algorithm for min-max paging. We show how to round such a fractional algorithm with at most a $k$ factor loss in the competitive ratio, resulting in a deterministic $O(k\log(n)\log(k))$-competitive algorithm for min-max paging. This matches our lower bound modulo a $\mathrm{poly}(\log(k))$ factor. We also give a randomized rounding algorithm that results in a $O(\log^2 n \log k)$-competitive algorithm., Comment: 25 pages, 1 figure, to appear in SODA 2023

Background This study sought to evaluate the incidence of and identify risk factors for distal stent graft–induced new entries (dSINEs) after the frozen elephant trunk (FET) procedure. Methods Patient characteristics and radiographic and follow-up data on 126 patients treated for aortic dissections with the Thoraflex (Vascutek Ltd, Inchinnan, United Kingdom) FET device in 2 centers between November 2013 and December 2018 were evaluated. Stress-strain behavior and load-displacement curves of the Thoraflex and the E-Vita Open (Jotec Inc, Hechingen, Germany) FET prosthesis were evaluated by applying axial load to the most distal ring of the prostheses. Results dSINEs were diagnosed in 16 patients (13%). There was no difference in the underlying disease, aortic features, or FET stent graft dimension between patients with and without dSINEs. No predictors for dSINE occurrence in patients treated with the Thoraflex device were identified. The risk for dSINE development was 14% (95% confidence interval [CI], 0% to 22%), 16% (95% CI, 0% to 24%), and 25% (95% CI, 0% to 45%) after 12, 24, and 36 months, respectively. When prostheses were loaded axially to 2-mm maximal displacement, the Thoraflex prosthesis exhibited strongly nonlinear behavior with maximal stiffness for minimal displacements, whereas the E-Vita prosthesis showed nearly constant stiffness. In addition, the Thoraflex prosthesis showed an increase in stiffness when confined. Conclusions dSINEs may develop at any time after the FET procedure, and the risk for dSINE development is high. No clinical or patient-specific risk factors were identified in this study. The design of the Thoraflex graft with a stiff distal ring may be a potential reason for the occurrence of dSINEs.

Der Erste Weltkrieg spielt eine zentrale Rolle im kulturellen Gedächtnis Großbritanniens. Wie alle historischen Ereignisse unterliegt dieser Konflikt vereinfachenden Darstellungen. Fortwährende Bilder, wie beispielsweise die Schützengräben der Westfront samt Stacheldrahtzaun und dem Niemandsland, wurden nicht zuletzt von der kanonischen Literatur gefestigt und trugen zu dem gängigen Verständnis eines zwecklosen Krieges bei, der die Moderne in der Kunst einläutete. Bei näherer Betrachtung lässt sich außerhalb des Kanons ein differenzierteres Bild des Krieges und seiner Bedeutung in der Gesellschaft feststellen. Die Untersuchung der Kurzgeschichte des Ersten Weltkrieges – einer vernachlässigten Gattung in diesem Kontext – erweist sich dabei als äußerst fruchtbar, um die Fülle an unterschiedlichsten literarischen Interpretationen erkennbar zu machen. Nach der Einordung der Kurzgeschichte in den Kontext des Krieges wird die Theorie des kulturellen Gedächtnisses als Rahmenkonzept herangezogen. Weiters erlaubt ein diverses Korpus an Kurzgeschichten, welches nach Erscheinungsjahr in die Kategorien Kriegs-, Zwischenkriegs, und Nachkriegszeit unterteilt wird, eine kritische Begutachtung der verschiedenen und koexistenten Ideologien. Um ein breiteres Abbild der Kriegserfahrungen zu gewährleisten, werden außerdem die verschiedenen Rollen der Frau in der Fiktion, welche von konservativen bis hin zu modernen Konzeptualisierungen reichen, beleuchtet. Anschließend erhält die intrinsisch polyvokale Briefform Aufmerksamkeit als narrativer Vermittler zentraler Themen wie Trauer, Schuld und Gedenken. Zuletzt widmet sich die vorliegende Arbeit der Relevanz von Raumdarstellungen in Bezug auf ihre ideologischen Implikationen und erforscht obskure und vernachlässigte Kriegsschauplätze. The First World War occupies a central position in British cultural memory. Like all historical events, the conflict has been streamlined into a simplified master narrative. Persistent iconography, such as the trenches of the Western Front, the barbed wire and no man’s land, has been consolidated by canonical literature and contributed to the conceptualisation of the war as a futile undertaking and a watershed event, ushering in modern art. A closer look beyond the literary canon of the Great War, however, allows for a more comprehensive (re)assessment of what the war meant and has come to mean. The investigation of short fiction of the First World War – a neglected genre in this context – proves to be an eminently suitable way of accessing the great variety and multi-perspectivity of literary interpretations. Upon putting the short story in the context of the First World War, this thesis will utilise cultural memory theory to provide a theoretical framework. Subsequently, a closer inspection of a diverse corpus of short stories grouped according to their date of publication allows for a critical assessment of the various ideological implications and trends which co-existed during the war years, the inter-war period and the post-war climate. In order to provide a more inclusive picture of the war experience, the varying roles of female characters in short fiction, ranging from conservative to modern conceptualisations, will be analysed. Furthermore, the epistolary form with its intrinsic polyvocality will be investigated according to its effects on mediating central themes, such as grief, guilt and commemoration. Lastly, this thesis will determine the relevance of the spatial setting with regards to its ideological undercurrents and explore obscure and neglected locales. Arbeit an der Bibliothek noch nicht eingelangt - Daten nicht geprüft Abweichender Titel laut Übersetzung des Verfassers/der Verfasserin Masterarbeit Karl-Franzens-Universität Graz 2022

Der Beitrag untersucht die didaktischen und sozialen Dimensionen des kooperativen Lernens in Breakout-Rooms. Letztere werden als soziale Arrangements definiert, deren Interaktionsprozesse unter bestimmten Bedingungen lernforderliche Wirkung erzielen können. Im Rahmen eines Mixed-Methods-Ansatzes werden Studierende eines berufspädagogischen Masterstudiengangs befragt, wobei in einer quantitativen Erhebung zunächst ihre Einschätzungen in Bezug auf Rahmenbedingungen und Merkmale von Breakout-Rooms untersucht werden. In der anschließenden qualitativen Erhebung werden diese Befunde vertieft und die Studierenden danach gefragt, was die Qualität der Zusammenarbeit ausmacht. Die Ergebnisse unterstreichen den Einfluss, den Faktoren wie Zeit, Gruppengröße und Gruppenzusammensetzung auf die Zusammenarbeit in Breakout-Rooms haben. Folglich verlangen virtuelle Räume einen reflektierten Einsatz von Methoden und klar strukturierte Arbeitsaufträge. Die Lehrperson tritt dabei nur scheinbar in den Hintergrund, denn ihre Rolle bleibt für die Vorbereitung und Moderation des Lernprozesses ebenso entscheidend wie für dessen Ergebnissicherung. Einige dieser Implikationen bringen wir abschließend in Vorschlägen für den Praxistransfer auf den Punkt. (DIPF/Orig.)

We report the draft genomes of two Listeria monocytogenes strains that were isolated from the invasive alien snail species Arion vulgaris in Austria in 2019.

purpose: The paper discusses the tension between vocational and scientific knowledge, which often presents itself as a question of theory-practice transfer. The context of the study are VET programs in the initial teacher training in Tyrol, Austria. One dimension of the research question focuses on the students’ perspective: How do they perceive and evaluate the different forms of knowledge? A second dimension concerns the integration of learning experiences into the process of professionalization. methods: Using a mix of quantitative and qualitative methods, the paper analyses material from different sources (questionnaires, focus groups transcripts, observation protocols), in which a total of 21-29 students from three VET programs were consulted over a period of four years. findings: The findings display the students’ expectations as well as their assessment of the relevance of theory. While the evaluation of scientific knowledge depends on the students (professional) background, the importance of reflection is being emphasized for the development of teacher professionalization. The connection to prior professional experience is expressed less through vocational knowledge or skills, but rather through social competencies. conclusions: While the integration of learning experiences into the process of professionalization can be explained through reflective competence, the tension between vocational and scientific knowledge remains ambiguous at several levels of the VET programs. The results provide insights into the potentials that can be activated by the VET programs for creating transitions to past or future learning pathways. While many in-service students already are part of a "community of practice" in their professional field, they now become immersed into a new one without completely uncoupling from the old.

OBJECTIVES The aim of this study was to evaluate the impact of concomitant ascending aortic replacement on operative morbidity and mortality in patients undergoing aortic valve replacement (AVR). METHODS We retrospectively analysed our institutional database for all patients undergoing elective isolated AVR and AVR with concomitant replacement of the ascending aorta between January 2009 and May 2020. Patients undergoing surgery for infective endocarditis or requiring hypothermic circulatory arrest were excluded. A 3:1 propensity matching was performed for 688 patients to compare isolated AVR (120 patients) with AVR + ascending aortic replacement (40 patients). RESULTS There were significant differences in median cardiopulmonary bypass (CPB) time [92.5 (75–114) vs 118.5 (104–131) min; P CONCLUSIONS Concomitant replacement of the ascending aorta significantly prolongs CPB and aortic clamp times but does not increase operative morbidity and mortality. Therefore, replacement of a dilated ascending aorta appears to be the most durable and safest treatment option in patients undergoing AVR with an aneurysmatic ascending aorta.

Streptococcus suis is a common pathogen colonising the respiratory tract of pigs. It can cause meningitis, sepsis and pneumonia leading to economic losses in the pig industry worldwide. Cyclooxygenase-2 (COX-2) and its metabolites play an important regulatory role in different biological processes like inflammation modulation and immune activation. In this report we analysed the induction of COX-2 and the production of its metabolite prostaglandin E2 (PGE2) in a porcine precision-cut lung slice (PCLS) model. Using Western blot analysis, we found a time-dependent induction of COX-2 in the infected tissue resulting in increased PGE2 levels. Immunohistological analysis revealed a strong COX-2 expression in the proximity of the bronchioles between the ciliated epithelial cells and the adjacent alveolar tissue. The morphology, location and vimentin staining suggested that these cells are subepithelial bronchial fibroblasts. Furthermore, we showed that COX-2 expression as well as PGE2 production was detected following infection with two prevalent S. suis serotypes and that the pore-forming toxin suilysin played an important role in this process. Therefore, this study provides new insights in the response of porcine lung cells to S. suis infections and serves as a basis for further studies to define the role of COX-2 and its metabolites in the inflammatory response in porcine lung tissue during infections with S. suis.

The Klebsiella pneumoniae complex comprises several closely related entities, which are ubiquitous in the natural environment, including in plants, animals, and humans. K. pneumoniae is the major species within this complex. K. pneumoniae strains are opportunistic pathogens and a common cause of healthcare-associated infections. K. pneumoniae can colonize the human gastrointestinal tract, which may become a reservoir for infection. The aim of this study was to investigate the fecal K. pneumoniae carriage in six healthy individuals during a 1 year period. Stool samples were obtained once a week. Using direct and pre-enriched cultures streaked on ampicillin-supplemented agar plates, up to eight individual colonies per positive sample were selected for further characterization. Whole genome sequencing (WGS) was performed for strain characterization. Sequence type (ST), core genome complex type (CT), K and O serotypes, virulence traits, antibiotic resistance profiles, and plasmids were extracted from WGS data. In total, 80 K. pneumoniae isolates were obtained from 48 positive cultures of 278 stool samples from five of the six test subjects. The samples of the five colonized volunteers yielded at most two, three, four (two persons), and five different strains, respectively. These 80 K. pneumoniae isolates belonged to 60 STs, including nine new STs; they were of 70 CTs, yielded 48 K serotypes, 11 O serotypes, and 39 wzc and 51 wzi alleles. Four of the five subjects harbored serotypes K20 and K47, as well as STs ST37, ST101, ST1265, and ST20, which had previously been linked to high-risk K. pneumoniae clones. In total, 25 genes conferring antibiotic resistance and 42 virulence genes were detected among all 80 isolates. Plasmids of 15 different types were found among 65 of the isolates. Fecal carriage of individual strains was of short duration: 70 strains were found on a single sampling day only, and 5 strains were isolated in samples collected over two consecutive weeks. Two of the five colonized individuals—working colleagues having meals together—shared identical K. pneumoniae types four times during the study period. Our findings point toward the potential role of food as a reservoir for K. pneumoniae in humans.

Streptococcus suisis a common pathogen colonising the respiratory tract of pigs. It can cause meningitis, sepsis and pneumonia leading to economic losses in the pig industry worldwide. Cyclooxygenase-2 (COX-2) and its metabolites play an important regulatory role in different biological processes like modulation of inflammation and immune activation. In this report we analysed the induction of COX-2 and the production of its metabolite prostaglandin E2(PGE2) in a porcine precision-cut lung slice (PCLS) model. Using Western blot analysis, we found a time-dependent induction of COX-2 in the infected tissue resulting in increased PGE2levels. Immunohistological analysis revealed a strong COX-2 expression in the proximity of the bronchioles between the ciliated epithelial cells and the adjacent alveolar tissue. The morphology, location and vimentin staining suggested that these cells are subepithelial bronchial fibroblasts. Furthermore, we showed that COX-2 expression as well as PGE2production was detected following infection with two prevalentS. suisserotypes and that the pore-forming toxin suilysin played an important role in this process. Therefore, this study provides new insights in the response of porcine lung cells toS. suisinfections and serves as a basis for further studies to define the role of COX-2 and its metabolites in the inflammatory response in porcine lung tissue during infection withS. suis.

OBJECTIVES Our goal was to evaluate the use of the frozen elephant trunk (FET) technique for the treatment of penetrating aortic ulcers involving the aortic arch. METHODS Between January 2008 and January 2020, a total of 34 patients had the FET technique at 3 aortic centres. The indication for the FET technique was unsuitability for thoracic endovascular aortic repair due to the lack of a sufficient proximal landing zone even after supra-aortic rerouting (subclavian transposition, double transposition), ectasia of the ascending aorta/aortic arch (>40 mm) and/or a shaggy proximal thoracic aorta. RESULTS Additional cardiac procedures were performed in 14 patients (41%), and the beating heart technique was used in 7 patients (21%). Perioperative mortality was 18% (n = 6); 3 of these patients had a major stroke (9%). No case of spinal cord ischaemia was observed, and 2 patients (6%) developed a non-disabling stroke. After a median follow-up of 7 (first quartile: 1; third quartile 29) months, 2 patients (6%) died (1 of malignant disease and 1 of an unclear cause); 10 additional aortic interventions in all aortic segments (29%; endovascular: n = 8 [24%] and conventional surgical: n = 2 [6%]) were performed in 8 patients. CONCLUSIONS The FET technique is a good treatment option for patients with penetrating aortic ulcers involving the aortic arch unsuitable for thoracic endovascular aortic repair. However, the high obliterative atherosclerotic load in these patients is accompanied by an un-neglectable risk of perioperative neurological injury. Concomitant cardiac surgical procedures are frequently needed. Patients commonly require secondary aortic procedures in all aortic segments, emphasizing the need for thorough primary conceptual planning and stringent follow-up.

Das Thema dieser Arbeit sind kofinitäre Gruppen, eine spezielle Klasse an Untergruppen der unendlichen Permutationsgruppen. Wir beginnen mit einer Übersicht der algebraischen Resultate für diese Gruppen. Die wichtigsten Resultate in diesem Kapitel sind strukturelle Einschränkungen der Kardinalität von kofinitären Gruppen durch ihre Orbitstruktur. In weiterer Folge betrachten wir Konstruktionen von kofinitären Gruppen mittels projektiver Limits und Automorphismen von Boolschen Algebren. Der Rest der Thesis befasst sich mit maximalen kofinitären Gruppen, wobei wir zuerst die möglichen Größen, sowie die kombinatorische Charakteristik a_g betrachten. In Kapitel 4 werden wir Forcing verwenden, um zu jedem Tupel (n, m) in N>0 x N eine maximale kofinitäre Gruppe zu finden welche n unendliche und m endliche Orbits aufweist, wodurch wir unendlich viele nicht isomorphe Gruppen konstruieren können. In Kapitel 5 konstruieren wir mittels Forcing eine maximale kofinitäre Gruppe in welche wir alle abzählbar unendlichen Gruppen einbetten können. Im letzten Kapitel zeigen wir eine Konstruktion, welche uns die möglichen Größen von maximalen kofinitären Gruppen in unserem Modell steuern lässt., The topic of this thesis is cofinitary groups, which are special subgroups of the infinite permutation group. We will begin by giving an overview of the algebraic properties of cofinitary groups. We will survey the algebraic properties of cofinitary groups, where the main results give us bounds on the size of cofinitary groups based on their orbit structure. We will then examine how to construct cofinitary groups using inverse limits and automorphisms of Boolean algebras. We then begin looking at maximal cofinitary groups and their possible sizes as well as the combinatorial characteristic a_g. In chapter 4 we will use forcing to show that there are infinitely many, non-isomorphic, maximal cofinitary groups, by constructing a group with n infinite and m finite orbits, for any tuple (n, m) in N>0 x N. In chapter 5, we use forcing constructions to show the existence of a maximal cofinitary group into which every countable group embeds. Finally, we show that we can tightly control the possible sizes of cofinitary groups in a model by adapting a novel proof from the theory of maximal almost disjoint families.

Bordetella (B.) bronchiseptica and Streptococcus (S.) suis are major pathogens in pigs, which are frequently isolated from co-infections in the respiratory tract and contribute to the porcine respiratory disease complex (PRDC). Despite the high impact of co-infections on respiratory diseases of swine (and other hosts), very little is known about pathogen-pathogen-host interactions and the mechanisms of pathogenesis. In the present study, we established a porcine precision-cut lung slice (PCLS) model to analyze the effects of B. bronchiseptica infection on adherence, colonization, and cytotoxic effects of S. suis. We hypothesized that induction of ciliostasis by a clinical isolate of B. bronchiseptica may promote subsequent infection with a virulent S. suis serotype 2 strain. To investigate this theory, we monitored the ciliary activity by light microscopy, measured the release of lactate dehydrogenase, and calculated the number of PCLS-associated bacteria. To study the role of the pore-forming toxin suilysin (SLY) in S. suis-induced cytotoxicity, we included a SLY-negative isogenic mutant and the complemented mutant strain. Furthermore, we analyzed infected PCLS by histopathology, immunofluorescence microscopy, and field emission scanning electron microscopy. Our results showed that pre-infection with B. bronchiseptica promoted adherence, colonization, and, as a consequence of the increased colonization, the cytotoxic effects of S. suis, probably by reduction of the ciliary activity. Moreover, cytotoxicity induced by S. suis is strictly dependent on the presence of SLY. Though the underlying molecular mechanisms remain to be fully clarified, our results clearly support the hypothesis that B. bronchiseptica paves the way for S. suis infection.

Streptococcus (S.) suis is a major cause of economic losses in the pig industry worldwide and is an emerging zoonotic pathogen. One important virulence-associated factor is suilysin (SLY), a toxin that belongs to the family of cholesterol-dependent pore-forming cytolysins (CDC). However, the precise role of SLY in host&ndash, pathogen interactions is still unclear. Here, we investigated the susceptibility of different respiratory epithelial cells to SLY, including immortalized cell lines (HEp-2 and NPTr cells), which are frequently used in in vitro studies on S. suis virulence mechanisms, as well as primary porcine respiratory cells, which represent the first line of barrier during S. suis infections. SLY-induced cell damage was determined by measuring the release of lactate dehydrogenase after infection with a virulent S. suis serotype 2 strain, its isogenic SLY-deficient mutant strain, or treatment with the recombinant protein. HEp-2 cells were most susceptible, whereas primary epithelial cells were hardly affected by the toxin. This prompted us to study possible explanations for these differences. We first investigated the binding capacity of SLY using flow cytometry analysis. Since binding and pore-formation of CDC is dependent on the membrane composition, we also determined the cellular cholesterol content of the different cell types using TLC and HPLC. Finally, we examined the ability of those cells to reseal SLY-induced pores using flow cytometry analysis. Our results indicated that the amount of membrane-bound SLY, the cholesterol content of the cells, as well as their resealing capacity all affect the susceptibility of the different cells regarding the effects of SLY. These findings underline the differences of in vitro pathogenicity models and may further help to dissect the biological role of SLY during S. suis infections.

Streptococcus suis is an important zoonotic pathogen which can infect humans and pigs worldwide, posing a potential risk to global public health. Suilysin, a pore-forming cholesterol-dependent cytolysin, is considered to play an important role in the pathogenesis of S. suis infections. It is known that infection with influenza A viruses may favor susceptibility to secondary bacterial infection, resulting in more severe disease and increased mortality. However, the molecular mechanisms underlying these coinfections are incompletely understood. Applying highly differentiated primary porcine respiratory epithelial cells grown under air-liquid interface (ALI) conditions, we analyzed the contribution of swine influenza viruses (SIV) to the virulence of S. suis, with a special focus on its cytolytic toxin, suilysin. We found that during secondary bacterial infection, suilysin of S. suis contributed to the damage of well-differentiated respiratory epithelial cells in the early stage of infection, whereas the cytotoxic effects induced by SIV became prominent at later stages of infection. Prior infection by SIV enhanced the adherence to and colonization of porcine airway epithelial cells by a wild-type (wt) S. suis strain and a suilysin-negative S. suis mutant in a sialic acid-dependent manner. A striking difference was observed with respect to bacterial invasion. After bacterial monoinfection, only the wt S. suis strain showed an invasive phenotype, whereas the mutant remained adherent. When the epithelial cells were preinfected with SIV, the suilysin-negative mutant also showed an invasion capacity. Therefore, we propose that coinfection with SIV may compensate for the lack of suilysin in the adherence and invasion process of suilysin-negative S. suis.

Streptococcus suis is a swine pathogen and zoonotic agent responsible for meningitis and septic shock. Although several putative virulence factors have been described, the initial steps of the S. suis pathogenesis remain poorly understood. While controversial results have been reported for a S. suis serotype 2 zinc metalloprotease (Zmp) regarding its IgA protease activity, recent phylogenetic analyses suggested that this protein is homologous to the ZmpC of Streptococcus pneumoniae, which is not an IgA protease. Based on the previously described functions of metalloproteases (including IgA protease and ZmpC), different experiments were carried out to study the activities of that of S. suis serotype 2. First, results showed that S. suis, as well as the recombinant Zmp, were unable to cleave human IgA1, confirming lack of IgA protease activity. Similarly, S. suis was unable to cleave P-selectin glycoprotein ligand-1 and to activate matrix metalloprotease 9, at least under the conditions tested. However, S. suis was able to partially cleave mucin 16 and syndecan-1 ectodomains. Experiments carried out with an isogenic Δzmp mutant showed that the Zmp protein was partially involved in such activities. The absence of a functional Zmp protein did not affect the ability of S. suis to adhere to porcine bronchial epithelial cells in vitro, or to colonize the upper respiratory tract of pigs in vivo. Taken together, our results show that S. suis serotype 2 Zmp is not a critical virulence factor and highlight the importance of independently confirming results on S. suis virulence by different teams. Electronic supplementary material The online version of this article (10.1186/s13567-018-0606-y) contains supplementary material, which is available to authorized users.

Streptococcus (S.) suis is a frequent early colonizer of the upper respiratory tract of pigs. In fact, it is difficult to find S. suis-free animals under natural conditions, showing the successful adaptation of this pathogen to its porcine reservoir host. On the other hand, S. suis can cause life-threatening diseases and represents the most important bacterial cause of meningitis in pigs worldwide. Notably, S. suis can also cause zoonotic infections, such as meningitis, septicemia, endocarditis, and other diseases in humans. In Asia, it is classified as an emerging zoonotic pathogen and currently considered as one of the most important causes of bacterial meningitis in adults. The “two faces” of S. suis, one of a colonizing microbe and the other of a highly invasive pathogen, have raised many questions concerning the interpretation of diagnostic detection and the definition of virulence. Thus, one major research challenge is the identification of virulence-markers which allow differentiation of commensal and virulent strains. This is complicated by the high phenotypic and genotypic diversity of S. suis, as reflected by the occurrence of (at least) 33 capsular serotypes. In this review, we present current knowledge in the context of S. suis as a highly diverse pathobiont in the porcine respiratory tract that can exploit disrupted host homeostasis to flourish and promote inflammatory processes and invasive diseases in pigs and humans.

Until now, to our knowledge no case of bioprosthetic valvular thrombosis after implantation of the sutureless Sorin Perceval valve has been reported. Although sutureless aortic valve replacement has become a powerful tool in our daily practice, recent guidelines from the European Society of Cardiology, the European Association for Cardio-Thoracic Surgery, the American College of Cardiology, and the American Heart Association do not give specific recommendations on postoperative anticoagulation therapy. We report the first case of valve dysfunction resulting from thrombosis 12 months after implantation with a possible link to postoperative cortisole therapy.

BACKGROUND: The constantly increasing life-expectancy has led to a high incidence of severe heart diseases in elderly people. The aim of this study was to compare the 30-day morbidity and mortality of octogenarians (group I) with a cohort younger than 60 years (group II). METHODS: Both groups (July 2008 and July 2011) were extracted from the Cardiac database. Demographic data, risk factors, surgical procedures and complications were double-checked. To compare the proportions of patients, Fisher's exact test was performed. RESULTS: In group I (n = 348 patients, 82.6±2.6 years) elective cases (35.3% valvular procedures) were performed in 77.6% and in 67.9% in group II (n = 656 patients, 50±2.4 years). The ICU-stay was 86±108 h (10–1040 h) (median: 51 h) in group I versus 94±256 h (3–4700 h) (median: 46 h). Postoperative renal failure occured in 2.9% in group I. After 17.9 h (1–760 h) (median 4.5 h) patients in group I could be weaned from ventiulation (group II: 26.4 h [1–1230 h] [median 4 h]). The need for blood transfusion was 1.7 units (0–10) in group I (1 unit (0–28) in group II). The 30-day mortality was 5.5% (n = 19) in group I versus 4.7 (n = 31) in group II and was in both groups lower than the expected EuroScore mortality of 16.1 and 6.25%. CONCLUSIONS: It must be argued that the surgical outcome of elderly patients is much better than the individual feeling in the daily routine. We proved that octogenarians should not be excluded from possible benefits of cardiac surgery. As a result of comparing postoperative data of the two different groups we cannot attribute higher costs for our elderly patients.

The influence of SrO–WO3 additive on the piezoelectric properties and electric conductivity of lead zirconate–titanate (PZT) near the morphotropic phase boundary was investigated. Starting from the composition 0.995 Pb(Zr0.525Ti0.475)O3 + 0.015 SrO + 0.005 WO3 (corresponding to 0.5 mol% of Sr3WO6) the fraction of WO3 was increased until Sr:W = 1:1. These samples were compared to a set of samples of PZT with WO3 addition but without SrO. Sr3WO6 has pseudocubic K2NaAlF6 structure with part of the strontium being octahedrally coordinated. In a solid solution with PZT this opens the possibility of realizing Sr on a B-site adjacent to a B-site occupied by W. Piezoelectric properties were measured on sintered disc samples under high field conditions. Impedance spectroscopy was used to investigate the conductivity and dielectric properties of the ceramics at various temperatures. The combined addition of SrO and WO3 increases the piezoelectric strain compared to samples of PZT with WO3 addition only. The results in polarization and conductivity indicate that the donor effect of WO3 is counteracted by the addition of SrO.

BACKGROUND: Garden sage (Salvia officinalis L., Lamiaceae) has gained importance during the last decade as a natural antioxidant, mainly owing to the antioxidant secondary plant metabolites rosmarinic acid (RA) and diterpenes such as carnosic acid. The aim of this work was to study the biomass production, the concentrations of total phenolics and RA and the essential oil of garden sage in response to phosphorus (P) supply. The treatments included P fertilisation and inoculation with arbuscular mycorrhizal fungi (AMF), since AMF are the most efficient biotic factor promoting the P uptake of plants. RESULTS: The P concentration in the plant was highest in P-fertilised plants, intermediate in AMF-inoculated plants and lowest in non-inoculated/non-P-supplied plants. The leaf biomass increased only in P-fertilised plants. AMF-inoculated plants, in contrast, did not show an increased leaf biomass, but their root biomass was enhanced. The total phenolic and RA concentrations were affected differently in leaves and roots, with the highest concentration and yield being found in leaves of P-fertilised plants. In none of the treatments were the essential oil concentration and composition affected. CONCLUSION: Optimal P fertilisation improves the antioxidant potential of garden sage and increases its biomass yield, thus optimising agronomic production of this plant for antioxidant use. c � 2009 Society of Chemical Industry

Design of attachment devices in insects varies enormously in relation to different functional loads. Many systems, located on different parts of the body, involve surfaces with particular frictional properties. Such systems evolved to attach parts of the body to each other, or to attach an insect to the substratum by providing fast and reversible attachment/detachment. Among these systems, there are some that deal with predefined surfaces, and others, in which one surface remains unpredictable. The first type of system occurs, for example, in wing-locking devices and head-arresting systems and is called probabilistic fasteners. The second type is mainly represented by insect attachment pads of two alternative designs: hairy and smooth. The relationship between surface patterns and/or mechanical properties of materials of contact pairs results in two main working principles of the frictional devices: mechanical interlocking, or maximization of the contact area. We give an overview of the functional design of two main groups of friction-based attachment devices in insects: probabilistic fasteners and attachment pads.

This study is the first attempt to characterise the chemical composition of the secretion of the smooth pads of the locust Locusta migratoria and to relate this to the composition of the cuticle coverage of the pads and the wings. Gas-chromatography and mass-spectrometry (GC-MS) were the principal techniques used for the characterization of these materials. Secretion droplets were visualised and quantified with the aid of diverse microscopic techniques. The chemical composition of prints is shown to differ from the cuticle coverage, in particular, with respect to the fatty acid distribution: in the secretion, saturated and unsaturated fatty acids with chain lengths between C 16 and C 20 in both the free form and as glycerides predominate, whereas cuticle coverage contains waxes of long-chained fatty-acids bound to long-chain primary alcohols. The second important difference is the significant amount of glucose and other saccharides found in methanolyzates of the pad fluid. A considerable amount of the amino acids (up to 53%) was detected in the non-volatile portion of the fluid. Data obtained from the shock-freezing, carbon-platinum coating and replica preparation show that the secretory droplets contain nano-droplets on their surfaces. The results lead us to suggest that the pad secretion is an emulsion consisting of lipidic nano-droplets dispersed in an aqueous liquid. According to the chemical composition of the secretion, a high-viscosity of the fluid may be suggested. Presumably, the fluid is a kind of a coupling agent, promoting and strengthening adhesion between otherwise incompatible materials by providing the proximity of contact for intermolecular forces.

Was denken die Menschen uber die Welt, in der sie handeln? Aus der Rekonstruktion der konkreten Lebenswelten soll erfasst werden, welche Bedeutung die Akteure der p.m.k ihrem Tun beimessen. Erst dann lasst sich sinnvoll daruber sprechen, was sie unter frei entfaltetem Handeln verstehen und wo sie Handlungsfreiraume verorten. Einleitend stellen wir das Handlungskollektiv als Teil eines gesellschaftlichen Gefuges dar und untersuchen, welche Kraftlinien und Fluchtlinien seine Praxis pragen. Diese historische Entfaltung zeigt, aus welchen Kontexten und Diskursstrangen das Kollektiv hervorgegangen ist (5.1). Anschliesend versuchen wir, die konkreten Lebenswelten der Akteure nachzuvollziehen. Wir fragen, was die Menschen uber die Welt denken, in der sie handeln und welche Bedeutung sie ihrem Tun beimessen. Dadurch wird nachvollziehbar, warum sie sich wofur engagieren und welches Selbstverstandnis sie dabei von sich und ihrer Praxis entwickeln (5.2). Dieser phanomenologischen Dimension folgt eine deskriptive Dimension, in der wir beschreiben, wie die Menschen ihr Handeln organisieren.

Die deskriptive Analyse der Freiheitspraktiken erfolgt auf Basis der durchgefuhrten Fallstudie. Zunachst stellen wir die „Plattform Mobile Kulturinitiativen“ (p.m.k) anhand auserlicher Eckpunkte dar. Wir beschreiben, wer die Akteure sind und wie die Plattform strukturiert ist (4.1); sodann, aus welchem soziokulturellen Kontext deren Praxis hervorgegangen ist und wie sie sich darin entfaltet hat (4.2); schlieslich, welche Funktionen und Aufgaben die Plattform als Ort des kulturellen Schaffens zu erfullen beansprucht (4.3). Das Portrat endet mit einer kleinen Phanomenologie des Namens (p.m.k), den sich das Kollektiv gegeben hat (4.4). Auserlich bleibt diese Beschreibung, weil damit im Wesentlichen eine Sicht von Ausen eingenommen wird, die zeigen soll, um was es geht und damit die p.m.k wie eine klar erfassbare Organisation erscheinen lasst. Cooper & Law sehen das Charakteristikum einer solchen von Ausen betrachteten Organisation darin, dass sie wie ein definierbares System mit starken Grenzen auftritt.

Wie wird das Handeln der Menschen organisiert? In diesem letzten Abschnitt analysieren wir jene Dynamiken und Prozesse, Interaktionen und Relationen, die sich aus dem kollektiven Handlungszusammenhang der p.m.k ergeben. Dies sind zum einen die Machtverhaltnisse unter den Akteuren, wie sie sich in der Arbeitsteilung, den Fuhrungstechniken und den Praxisausrichtungen materialisieren (6.1). Zum zweiten thematisieren wir die Konstitutionsbedingungen der Multitude, jenes kollektiven Subjekts, in dem die Vielheit als Vielheit fortbesteht (6.2). Zum dritten fragen wir auch nach den Bedingungen, unter denen von einer Strategie des Kollektivs gesprochen werden kann (6.3). In all diesen Dimensionen tun sich Moglichkeiten fur individuelle wie kollektive Handlungsfreiraume auf. Die Praxis der Akteure ist eingebettet in einen offenen Entfaltungszusammenhang, dessen Ambivalenz gleichwohl darin liegt, dass die Bewegungen der Formgebung und Gestaltwerdung stets oszillieren zwischen den Ebenen der Komposition und Ordnung.

Freiheit ist eine omniprasente Kategorie. Implizit oder explizit, vieldeutig oder klar umgrenzt, stellt sie einen zentralen Begriff der gegenwartigen Zeitlaufte dar. Egal ob in politischen, okonomischen oder kulturellen Kontexten – kaum eine Frage, kaum ein Problem, kaum ein Gesetz, das nicht mit dem Thema der Freiheit verknupft ware. Dabei wird Freiheit politisch wie sozial haufig zu einem der elementarsten Werte unserer gesellschaftlichen Verfassung erhoben, sie steht im Brennpunkt der Debatten um eine Ausweitung oder Einengung des okonomischen Marktprinzips und ist vor dem Hintergrund zunehmender globaler Bedrohungspotentiale wie Terrorismus oder Weltklima zu einem der am heisesten umkampften Terrains offentlicher Diskurse geworden. Doch all das ist nur die eine Seite der Medaille: Freiheit als Ideal, Freiheit als normative Vorgabe, Freiheit als Phrase, Vorwand und Ziel. Nicht selten verkommt Freiheit dabei zum rhetorischen Allgemeinplatz, der inhaltlichen Beliebigkeit preisgegeben, denn mit der Offenheit eines normativen Begriffes steht immer auch seine Glaubwurdigkeit auf dem Spiel.

Mein wissenschaftlicher Ansatz und das Selbstverstandnis als Forscher folgen einem konstruktivistischen Grundverstandnis, das sich von traditionellen positivistischen Annahmen klar abgrenzt. Damit sind im Wesentlichen Annahmen uber die Natur der Welt, der Wissenschaft, des Forschers sowie dessen Moglichkeiten angesprochen. Aus einer positivistischen Perspektive ist die Welt erkennbar, vorhersehbar und anhand einer Wahrheit erklarbar. Ziel und Zweck der Wissenschaft ist es, diese Einsichten bestandig voranzutreiben. Wissenschaftler sind dabei objektiv und neutral, ihre Methoden reproduzierbar, beweisbar, verlasslich, generalisierbar sowie, empirisch betrachtet, statistisch signifikant. Die wissenschaftstheoretische Kritik an diesen Grundannahmen hat zu einer Reihe unterschiedlicher –ismen gefuhrt: Konstruktivismus, Postmodernismus, Poststrukturalismus, interpretative und ethnographische Ansatze – um nur einige zu nennen. O’Leary (2004: 6) folgend, subsumiere ich diese Perspektiven unter die Kategorie Post-Positivismus, um die Abstosbewegung ihrer epistemologischen und ontologischen Kritik zu verdeutlichen.

Wurde man ein Lexikon des beginnenden 21. Jahrhunderts verfassen, dann ware Kreativitat bestimmt unter den popularsten Begriffen gelistet. „Das Attribut ‚kreativ‘ adelt noch die banalsten Tatigkeiten“, schreibt Ulrich Brockling im Glossar der Gegenwart (Brockling 2004: 141). Weit uber einen engen kunstlerischen Bezugsrahmen hinaus wird der Begriff gegenwartig in okonomischen, politischen, sozialen, kulturellen und padagogischen Zusammenhangen kontextualisiert. Es ist vielleicht nicht ubertrieben zu sagen, dass „Kreativitat“ zu einem, wenn nicht zu dem „,Heilswort‘ der Gegenwart“ (Brockling 2007: 152) aufgestiegen ist und den Charakter eines „moralischen Imperativs“ (Osborne 2003) angenommen hat, dem man sich nur schwer widersetzen kann. Eine besonders einschneidende Nuancierung hat Kreativitat in der Wortschopfung der Creative Industries erhalten. Ausgehend von Grosbritannien Ende der 1990er Jahre wurde dieses Label zur Benennung heterogener Bereiche verwendet, in denen individueller Kreativitat eine besondere Rolle als Erfolgs- und Wirtschaftsfaktor zugeschrieben wird. Als einem eigenen Wirtschaftszweig wird den Creative Industries inzwischen in vielen Landern und Regionen eine grose Bedeutung zugesprochen. Dem Bestsellerautor Richard Florida gilt Kreativitat gar als die „ultimative okonomische Ressource“ (Florida 2002: XIII), aus der eine neue Klasse, die Creative Class, als Vorreiter okonomischer und gesellschaftlicher Entwicklung hervorgeht.

eingereicht von Marlies Vötsch Zsfassung in engl. Sprache Wien, Univ. für Bodenkultur, Dipl.-Arb., 2008

An unsuspected attachment mechanism may help these huge spiders to avoid catastrophic falls. Spiders spin silk from specialized structures known as abdominal spinnerets--a defining feature of the creatures--and this is deployed to capture prey, protect themselves, reproduce and disperse. Here we show that zebra tarantulas (Aphonopelma seemanni) from Costa Rica also secrete silk from their feet to provide adhesion during locomotion, enabling these spiders to cling to smooth vertical surfaces. Our discovery that silk is produced by the feet provides a new perspective on the origin and diversification of spider silk.

Four hours after surgery for aortic valve stenosis and tricuspid valve regurgitation, an unknown foreign body was present on the routine chest X-ray. We performed re-sternotomy in order to retrieve this foreign body. The foreign body was easy to move on fluoroscopy but we could not extract it. We concluded that the foreign body was in a subdiaphragmatic location. As a consequence, we performed gastroscopy. A white, frothy mass (similar to an undissolved effervescent tablet) within an ulcerated lesion was seen and partially extracted.

Using the known mapping position the gene encoding a beta-1, 4-N-acetylglucosaminidase needed for the degradation of muropeptides could be identified. nagZ encodes a cytosolic enzyme active on N-actylglucosamyl-beta-1,4-(1,6)-anhydromuramic acid containing muropeptides. These degradation products of the peptidoglycan are formed during the enlargement of the murein sacculus as a consequence of a growth mechanism, which couples the controlled degradation of the cell wall polymer with the insertion of new material. NagZ is needed for the formation of monosaccharides from the released disaccharides during the cytosolic steps of the muropeptide-recycling pathway. The formation of intracellular 1, 6-anhydro-N-acetylmuramyl-peptides is important for the expression control of the inducible beta-lactamases of the AmpC type. A mutant lacking active NagZ cannot establish AmpC mediated beta-lactam resistance. The biochemical characterization of the enzyme showed its activity on different muropeptides and inhibitors of enzyme activity could be identified. This observation might be important for designing inhibitors of NagZ that could prevent the establishment of beta-lactam resistance of Enterobacteria possessing inducible beta-lactamases.