47 research outputs found
Elevated faecal ovotransferrin concentrations are indicative for intestinal barrier failure in broiler chickens
Intestinal health is critically important for the welfare and performance of poultry. Enteric diseases that cause gut barrier failure result in high economic losses. Up till now there is no reliable faecal marker to measure gut barrier failure under field conditions. Therefore, the aim of the present study was to identify a faecal protein marker for diminished intestinal barrier function due to enteric diseases in broilers. To assess this, experimental necrotic enteritis and coccidiosis in broilers were used as models for gut barrier failure. Ovotransferrin was identified as a marker for gut barrier failure using a proteomics approach on samples from chickens with necrotic enteritis. These results were confirmed via ELISA on samples derived from both necrotic enteritis and coccidiosis trials, where faecal ovotransferrin levels were significantly correlated with the severity of gut barrier failure caused by either coccidiosis or necrotic enteritis. This indicates that faecal ovotransferrin quantification may represent a valuable tool to measure gut barrier failure caused by enteric pathogens
Protein truncating variants of colA in clostridium perfringens type G strains
Extracellular matrix (ECM) degrading enzymes produced by Clostridium perfringens may play an important role during the initial phases of avian necrotic enteritis by facilitating toxin entry in the intestinal mucosa and destruction of the tissue. C. perfringens is known to produce several ECM-degrading proteases, such as kappa toxin, an extracellular collagenase that is encoded by the colA gene. In this study, the colA gene sequence of a collection of 48 C. perfringens strains, including pathogenic (i.e. toxinotype G) and commensal (i.e. toxinotype A) chicken derived strains and strains originating from other host species, was analyzed. Although the colA gene showed a high level of conservation (>96% nucleotide sequence identity), several gene variants carrying different nonsense mutations in the colA gene were identified, leading to the definition of four truncated collagenase variant types (I-IV). Collagenase variant types I, III and IV have a (nearly) complete collagenase unit but lack parts of the C-terminal recruitment domains, whereas collagenase variant types II misses the N-terminal part of collagenase unit. Gene fragments encoding a truncated collagenase were mainly linked with necrotic enteritis associated C. perfringens type G strains with collagenase variant types I and II being the most prevalent types. Gelatin zymography revealed that both recombinant full-length and variant type I collagenase have active auto-cleavage products. Moreover, both recombinant fragments were capable of degrading type I as well as type IV collagen, although variant type I collagenase showed a higher relative activity against collagen type IV as compared to full-length collagenase. Consequently, these smaller truncated collagenases might be able to break down collagen type IV in the epithelial basement membrane of the intestinal villi and so contribute to the initiation of the pathological process leading to necrotic enteritis
Competition and substitution between public transport modes
The management and understanding of modal split between public transport (PT) modes is of interest for numerous reasons. It may, for example, be desirable to stimulate passengers to switch from crowded buses and over to higher capacity rail. This requires a good understanding of drivers of transit modal substitution.
The evidence put forward in this paper is based on more than 150 empirically estimated cross elasticities between PT modes from over 20 sources collected from Australia, Europe and USA. These sources include scientifically published evidence as well as grey literature.
This evidence is coded into a database from which our paper presents and analyses the available cross-PT-modal demand relations. We focus on evidence for how fares, travel time and service intervals on PT ‘mode A’ affect the demand for PT ‘mode B’.
Despite generally low levels of substitution between PT modes, passengers are particularly sensitive to in-vehicle, access/egress and waiting time in choosing PT mode and less so for fare variations. In general, rail demand is less sensitive to changes in bus than bus demand is to changes in rail. We also find that peak-hour demand more markedly switches between PT modes than off-peak demand does
Myelin insulation as a risk factor for axonal degeneration in autoimmune demyelinating disease
Axonal degeneration determines the clinical outcome of multiple sclerosis and is thought to result from exposure of denuded axons to immune-mediated damage. Therefore, myelin is widely considered to be a protective structure for axons in multiple sclerosis. Myelinated axons also depend on oligodendrocytes, which provide metabolic and structural support to the axonal compartment. Given that axonal pathology in multiple sclerosis is already visible at early disease stages, before overt demyelination, we reasoned that autoimmune inflammation may disrupt oligodendroglial support mechanisms and hence primarily affect axons insulated by myelin. Here, we studied axonal pathology as a function of myelination in human multiple sclerosis and mouse models of autoimmune encephalomyelitis with genetically altered myelination. We demonstrate that myelin ensheathment itself becomes detrimental for axonal survival and increases the risk of axons degenerating in an autoimmune environment. This challenges the view of myelin as a solely protective structure and suggests that axonal dependence on oligodendroglial support can become fatal when myelin is under inflammatory attack
Reformation als Kommunikationsprozess
Beim Hussitismus bzw. Utraquismus in Böhmen und der reformatorische Bewegung ab 1517 in Sachsen handelt es sich um zwei unterschiedliche Reformationen, jedoch mit einer Fülle von sachlichen und personalen Verbindungslinien. Diese rücken im vorliegenden Band erstmalig in einen gemeinsamen Fokus.»Wir sind alle Hussiten«, bekannte Martin Luther 1520 nach der Lektüre von Schriften des tschechischen Reformators Jan Hus, der gut einhundert Jahre zuvor als Ketzer verbrannt worden war. Die beiden Reformatoren verbinden, ebenso wie die von ihnen ausgehenden Erweckungs- und Erneuerungsbewegungen, viele Ähnlichkeiten, Übereinstimmungen und parallele Entwicklungsverläufe. Dennoch werden sie meist getrennt betrachtet. Der Sammelband analysiert Aspekte der Reformation in Böhmen und Sachsen und rückt so die beiden religiösen Brennpunkte in einen gemeinsamen Fokus. Methodisch wählen die Beiträgerinnen und Beiträger dabei einen kommunikationsgeschichtlichen Zugang
Artikler i transportøkonomi : utfordringer i modellering av transportmiddelvalg og brukernytte
The subject of this PhD thesis is transport economics. The thesis concerns the modeling and application of transport-related choice data, in particular data from choice experiments, and contributes on the field of specifying utility function in travel mode choice and estimating and applying willingness-to-pay (WTP) measures and user benefits for economic appraisal. The thesis consists of four self-contained essays and an introduction.Temaet for denne doktorgradsavhandlingen er transportøkonomi. Avhandlingen handler om modellering og anvendelse av transportrelaterte valgdata, spesielt data fra valgeksperimenter, og bidrar på feltet knytet til spesifisering av nyttefunksjon i transportmiddelvalgmodeller og estimering og anvendelse av betalingsvillighet og brukernytte i samfunnsøkonomisk analyser. Avhandlingen består av fire selvstendige artikler og en innledning
Accounting for user type and mode effects on the value of travel time savings in project appraisal: Opportunities and challenges
Differences in Value of Travel Time Savings (VTTS) between travel modes can play a decisive role in the ranking of projects that affect the travel time of different travel modes. Conceptually, between-mode differences in VTTS can be decomposed into the user type effect (UE) that accounts for differences in characteristics of user groups (e.g. income differences) and the mode effect (ME) that accounts for differences in travel modes (e.g. the comfort level). Several studies have disentangled and quantified these two effects. However, their potential use for project appraisal has not been thoroughly discussed in the literature. Two opportunities of using information about ME and UE in appraisal are discussed: (i) Removing the UE from national mode-specific VTTS in order to obtain a set of VTTS that only differs by the comfort level of the modes (ii) Provide the VTTS in travel modes taking into account user type effects of travellers that switch modes after project implementation. The former arguably improves on the equity approach in project appraisal under the normative argument of valuing individual\u27s time saving equally. The latter can improve the overall precision of user benefit representation in project appraisal compared to the standard mode-specific approach, where mode switchers are assumed to have the same VTTS in the new mode independent of which original user group they belong to
Essays in transport economics : challenges in modeling travel mode choice and user benefits
The subject of this PhD thesis is transport economics. The thesis concerns the modeling and application of transport-related choice data, in particular data from choice experiments, and contributes on the field of specifying utility function in travel mode choice and estimating and applying willingness-to-pay (WTP) measures and user benefits for economic appraisal. The thesis consists of four self-contained essays and an introduction
Curriculum for training motorcyclists
Mit dem vorliegenden Bericht wird ein neuentwickeltes Curriculum zur Ausbildung motorisierter Zweiradfahrer in Fahrschulen vorgestellt. Zunächst werden der curriculare und verkehrspädagogische Ansatz, der dem Curriculum zugrunde liegt, sowie schon bestehende Curricula in der Fahrschul- und Fahrlehrerausbildung dargelegt und die grundlegenden Schritte der Curriculumentwicklung aufgezeigt. Eine Darstellung der geänderten gesetzlichen Rahmenbedingungen und der sich daraus ergebenden didaktisch-organisatorischen Überlegungen schließen sich an. Das aus 8 Lerneinheiten für die Theorie und 16 Lerneinheiten für die Praxis bestehende Curriculum wird anhand von drei Lerneinheiten exemplarisch vorgestellt. Die Erprobung des Curriculum fand in fünf Fahrschulen mit 50 Fahrschülern statt und sollte vor allem die Praktikabilität, Handhabbarkeit, Lehrzielerreichung und die Akzeptanz der verwendeten Methoden, Medien und Materialien überprüfen. Zusätzlich wurden einige in Richtung Wirksamkeitsuntersuchung gehende Variablen erhoben und ausgewertet. Bei der anschließenden Revision des Curriculum wurden die Lerneinheiten entsprechend den Erprobungsergebnissen modifiziert. Ein Rahmenplan für die Ausbildung von Motorradfahrern und Folgerungen für die Umsetzung des Curriculum auf breiter Basis, für die Fahrlehrerausbildung und für eine summative Evaluation des Curriculum schließen den Bericht ab.This report introduces a newly developed curriculum for training motorcyclists in driving schools. First of all, the report indicates the curricular and pedagogical approach underlying the curriculum, gives an account of existing curricula in driving schools and in driving instructor courses and describes the basic steps in curriculum developments. This is followed by an account of the changes in underlying statutory conditions and by a discussion of their didactic-organizational implications. The curriculum, consisting of 8 teaching units for the theoretical and 16 units for the practical course, is presented here, taking three units as examples. The curriculum has been tested in live driving schools with 50 learners, in order to check, above all, practicability, ease of implementation, success in achieving objectives and acceptance of the methods, media and materials used. In addition, some variables associated with testing efficacy were recorded and evaluated. In the subsequent revision of the curriculum,, teaching units are modified to take account of the trial results. The report winds up with an overall plan for training motorcyclists and with conclusions for placing the curriculum an a wide basis, for the teaching of driving instructors and for an overall evaluation of the curriculum. All other theoretical and practical units. with media and materials, are available in an original volume at the BASt and can be inspected there
Die Steuerreform in der Grafschaft Mark 1791. Ein Modell für die Stein-Hardenbergschen Reformen?
Gorißen S. Die Steuerreform in der Grafschaft Mark 1791. Ein Modell für die Stein-Hardenbergschen Reformen? In: Brakensiek S, Flügel A, Freitag W, eds. Kultur und Staat in der Provinz. Perspektiven und Erträge der Regionalgeschichte. Studien zur Regionalgeschichte, 2. Bielefeld: Verl. für Regionalgeschichte; 1992: 189-212