Realistic, Extensible DNS and mDNS Models for INET/OMNeT++

The domain name system (DNS) is one of the core services in today's network structures. In local and ad-hoc networks DNS is often enhanced or replaced by mDNS. As of yet, no simulation models for DNS and mDNS have been developed for INET/OMNeT++. We introduce DNS and mDNS simulation models for OMNeT++, which allow researchers to easily prototype and evaluate extensions for these protocols. In addition, we present models for our own experimental extensions, namely Stateless DNS and Privacy-Enhanced mDNS, that are based on the aforementioned models. Using our models we were able to further improve the efficiency of our protocol extensions.Comment: Published in: A. F\"orster, C. Minkenberg, G. R. Herrera, M. Kirsche (Eds.), Proc. of the 2nd OMNeT++ Community Summit, IBM Research - Zurich, Switzerland, September 3-4, 201

The role of B- and T-cell immunity in toltrazuril-treated C57BL/6 WT, µMT and nude mice experimentally infected with Neospora caninum

Neospora caninum is a protozoan parasite predominantly known for causing abortion in cattle and neuromuscular disease in dogs. So far, no efficient metaphylactic chemotherapy has been developed. In preliminary studies, toltrazuril had been successfully used against experimental neosporosis in mice and calves. In the present study, we used immunocompetent and immunodeficient mouse strains to address the role of immunity in supporting the chemotherapy of experimental N. caninum infection. WT, µMT and athymic nude mice were intraperitoneally inoculated with 1×106 Nc-1 tachyzoites. The drug was administered in the drinking water for 6 consecutive days so as to obtain a daily dose of approximately 20mg toltrazuril/kg body weight. The course of infection was monitored by clinical, histological and immunohistochemical means, as well as by the search for parasite DNA using PCR-analyses of various organs. In immunocompetent WT mice, treatment proved to be of high efficacy by abrogation of any lesion formation or PCR-positivity in medicated C57BL/6 mice and a significant reduction of lesion formation or PCR-positivity in BALB/c animals. Similarly, treated µMT mice exhibited a significant reduction in cerebral lesion formation as well as in parasite DNA detectability by PCR when compared to untreated animals. Athymic nude mice, however, did not respond to treatment in that only a delay of the parasite dissemination was achieved, and nude mice still showed the neosporosis disease symptoms, although later than untreated animals. We conclude that treatment with toltrazuril appears to act parasitostatically rather than parasitocidically. This is supported by the fact that: (1) although the lack of B-cells did not impair the effect of toltrazuril, (2) the lack of T-cells did not allow for a full efficacy of treatment. Therefore, chemotherapy with toltrazuril against experimental infections with N. caninum requires the support of T-cell immunity in order to be successfu

Ökonomische Analyse europäischer Bankenregulierung: Verbriefung und Interbankenmarkt im Fokus

Die Bankenneuregulierung der Europäische Kommission sieht eine Beschränkung der Kreditvergabe im Interbankenmarkt auf 25 % des Eigenkapitals sowie einen Selbsteinbehalt des Originators in Höhe von 5 % am gesamten zu verbriefenden Forderungsportfolio vor. Eine starre Regulierung führt aber nicht zwingend zu einer dauerhaften Krisenprävention, wie die vorliegende Arbeit modelltheoretisch belegt. Eine starre Kreditvergabebeschränkung erreicht zwar eine Mindestdiversifikation und Eigenkapitalaufstockung im Bankensektor, wodurch das systemische Risiko gesenkt wird. Allerdings geht dies mit steigenden Transaktionskosten einher. Anhand eines Modells von Fender und Mitchell werden die Auswirkungen auf die Screening-Anstrengungen bei Verbriefungen mit komplettem Portfolioselbsteinbehalt, Einbehalt der Equity Tranche und Einbehalt eines vertikalen Anteils durch den Originator untersucht. Aus dem Modell wird ersichtlich, dass ein vertikaler Einbehalt kleiner 100 % des Forderungspools, wie er von der Europäischen Kommission vorgesehen ist, in keiner Situation zu einem optimalen Screening-Einsatz führt, sondern sogar teilweise eine Verschlechterung im Vergleich zum Einbehalt der Equity Tranche darstellt. Eine pauschale Regulierung ist deshalb abzulehnen und eine qualitative, dynamische Regulierung, die mehr Transparenz schafft, zu befürworten. -- The new regulation for banks by the European Commission contains a restriction to 25 % of the equity for credit allocation on the interbank market and an enduring participation of the originator in the whole receivables portfolio of 5 %. But an inflexible regulation does not permanently prevent the market from further financial crisis, which is theoretically analysed in the presented paper. Indeed an inflexible restriction of the equity for credit allocation achieves a minimum diversification and an equity increase on the banking sector, which reduces the systemic risk. Admittedly, this can only occur by acceptance of increasing transaction costs. By applying a model from Fender and Mitchell the impact of the screening efforts for securitizations with complete retention of the portfolio, the retention of the equity tranche and the retention of the vertical fraction by the originator is analysed. The model shows that a vertical retention smaller than 100 % of the pool of receivables, as proposed by the European Commission, does not lead to an optimal level of screening in any situation and might even cause a worsening in comparison to the retention of the equity tranche. Considering the complexity of the financial system, a sweeping regulation must be rejected and a qualitative, dynamic regulation that establishes a higher level of transparency is recommended.Bankenregulierung,Verbriefung,Selbstbehalt,Interbankenmarkt

Distributed Systems Group Utilizing Cloud Storages for iSCSI: Is Security really expensive?

Cloud storage promises unlimited, flexible and cheap storages, including alltime availability and accessibility with the help of various technologies. Free-ofcharge offers for endusers allure customers the same way as professional, payas-you-go storages do. The delocalization of the data provokes security concerns especially regarding the confidentiality of the data. Even though encryption offers a straight-forward solution to this problem, the performance questions its applicability when it comes to the utilization of professional storage-approaches like iSCSI. In this white-paper, we propose a utilization of NoSQL-based cloudstorages like Amazon S3 or Microsoft Azure for iSCSI. We evaluate the costs of a direct, bucket-based encryption and show, that in complex systems like iSCSI, the distance to the cloud represents the bottleneck instead of the encryption. Performance-boosting techniques like prefetching and caching improve the access and result in no practical overhead within such an utilization. Based on our own developed fully Java-based iSCSI target (jSCSI) and jClouds, our prototype represents, to the best of our knowledge, the first, free available, cloud-deployable iSCSI

Effect of Cyclosporin A and Zidovudine on Immune Abnormalities Observed in the Murine Acquired Immunodeficiency Syndrome

Two therapeutic modalities, zidovudine (targeting retroviral replication) and cyclosporin A (targeting immunopathologic consequences of retroviral expression) were evaluated in a murine model of AIDS. In previous studies, cyclosporin A treatment (40 or 60 mg/kg/day) before and after infection with LP-BM5 murine leukemia viruses protected against the development of immunodeficiency disease. The present study extends these findings. First, a low dose of cyclosporin A (20 mg/kg/day) was ineffective, and treatment initiated 5 days after infection did not protect against virus-induced lymphoproliferation and hypergammaglobulinemia. Second, zidovudine added to drinking water (0.1 mg initiated 5 days after infection and continued for 8 weeks) was more effective than 0.2 mg/ml, given day 5-12 after infection. This treatment reduced lymph node size, disease severity as determined histologically, retrovirus-induced gp70 expression, and IgE (but not IgM and IgG) levels. Third, combined treatment had an additive, protective effect on lymphocyte proliferative capacity. This successful dual therapeutic strategy in a mouse model has potential applicability for similar approaches in treating human immunodeficiency virus infectio

An ADAMTS3 Missense Variant is Associated with Norwich Terrier Upper Airway Syndrome

In flat-faced dog breeds, air resistance caused by skull conformation is believed to be a major determinant of Brachycephalic Obstructive Airway Syndrome (BOAS). The clinical presentation of BOAS is heterogeneous, suggesting determinants independent of skull conformation contribute to airway disease. Norwich Terriers, a mesocephalic breed, are predisposed to Upper Airway Syndrome (UAS), a disease whose pathological features overlap with BOAS. Our health screening clinic examined and scored the airways of 401 Norwich terriers by laryngoscopy. Genome-wide association analyses of UAS-related pathologies revealed a genetic association on canine chromosome 13 (rs9043975, p = 7.79x10-16). Whole genome resequencing was used to identify causal variant(s) within a 414 kb critical interval. This approach highlighted an error in the CanFam3.1 dog assembly, which when resolved, led to the discovery of a c.2786G>A missense variant in exon 20 of the positional candidate gene, ADAM metallopeptidase with thrombospondin type 1 motif 3 (ADAMTS3). In addition to segregating with UAS amongst Norwich Terriers, the ADAMTS3 c.2786G>A risk allele frequency was enriched among the BOAS-susceptible French and (English) Bulldogs. Previous studies indicate that ADAMTS3 loss of function results in lymphoedema. Our results suggest a new paradigm in the understanding of canine upper airway disease aetiology: airway oedema caused by disruption of ADAMTS3 predisposes dogs to respiratory obstruction. These findings will enhance breeding practices and could refine the prognostics of surgical interventions that are often used to treat airway obstruction

Auswirkung vom Einsatz einer Klauenwaschanlage auf infektiöse Klauenerkrankungen, sowie ökonomischer Vergleich von Klauenwaschanlage und Klauenbad

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