Atypical status of bovine spongiform encephalopathy in Poland: a molecular typing study

The aim of this study was to analyze molecular features of protease-resistant prion protein (PrPres) in Western blots of BSE cases diagnosed in Poland with respect to a possible atypical status. Confirmed cases were analyzed by Western blotting with several monoclonal antibodies directed at N-terminal and core epitopes of prion protein (PrP). Most cases showed the classical glycoprofile characterized by the dominance of the di- over the monoglycosylated PrPres band, yielding di-/mono- ratios well above 2 and by reactivity with antibodies having their epitopes in bovine PrP region 110-242 (C-type cases). Surprisingly, seven cases of BSE were atypical. Six were classified as L-type based on a slightly lower molecular mass (M-r) of the non- glycosylated band with respect to C-types and a conspicuously low di-/mono- ratio of glycosylated PrPres bands approaching unity. One case was classified as H-type because of a higher M-r of PrPres bands on the blot when compared with C-type cases. A characteristic epitope of H-type PrPres occurred in the 101-110 region of PrP for which only antibody 12B2 had a sufficient affinity. The occurrence of atypical cases only in animals 9 years of age and older raises questions about the mechanisms of prion diseases and the origin of BSE

Seroprevalence of bovine herpesvirus 1 related alphaherpesvirus infections in free-living and captive cervids in Poland.

To determine the occurrence of bovine herpesvirus 1 (BoHV-1) related alphaherpesvirus infections in cervids, 1194 serum samples of wild ruminants originating from 59 forest districts of Poland were tested with IBR gB ELISA and virus neutralization test (VNT) against BoHV-1 and cervid herpesvirus 1 (CvHV-1). The seroprevalence differed significantly between free-living and captive cervids (P<0.001) with a total of 89 out of 498 (17.9%) and 268 out of 696 (38.5%) seropositive animals in each type of population. In free-ranging cervids, the highest seroprevalence was found among red deer (25.6%) and in fallow deer (23.1%), while it was the lowest in roe deer (1.7%). The seroprevalence varied at the district level between 0 and 100% with the mean value of 17.4% (95% CI:10.1-24.0). Additionally, seroprevalence was associated with afforestation (chi(2)=7.5; P=0.006) and to some degree with the mean of cattle density in province (chi(2)=7.0; P=0.08). The mean antibody titre against CvHV-1 in VNT (161.8; 95%CI: 146.0-177.6) has been significantly higher (P<0.0001) than the mean titre of BoHV-1 antibodies (10.1; 95%CI: 8.9-11.4). The results showed that BoHV-1 related alphaherpesvirus infections are present in population of free-ranging and farmed cervids in Poland. Based on the VNT results and considering the low susceptibility of red deer to BoHV-1, it seems that the dominant alphaherpesvirus circulating in wild ruminants is most likely CvHV-1 and therefore it is rather unlikely that deer in Poland could play any role as a reservoir of BoHV-1 for cattle

Inhibition of caspase-1 prolongs survival of mice infected with rabies virus

Rabies virus infects almost all mammals resulting in lethal disease. To date there is no treatment available for symptomatic rabies and there is an urgent need to develop treatment strategies that would prolong survival, thereby providing a window of opportunity for the host to mount a protective immune response. We hypothesized that both virus and excessive immune response contribute to disease and that interfering with both is necessary to prevent lethal disease. Here, we have inhibited the pro-inflammatory response associated with pyroptosis and showed that inhibition of CASP-1 had a beneficial effect on survival time. Our results confirm that some inflammatory responses may be involved in the pathogenesis of severe disease and the results suggest that effective intervention includes inhibition of virus and host response

Digital Watermarking for Verification of Perception-based Integrity of Audio Data

In certain application fields digital audio recordings contain sensitive content. Examples are historical archival material in public archives that preserve our cultural heritage, or digital evidence in the context of law enforcement and civil proceedings. Because of the powerful capabilities of modern editing tools for multimedia such material is vulnerable to doctoring of the content and forgery of its origin with malicious intent. Also inadvertent data modification and mistaken origin can be caused by human error. Hence, the credibility and provenience in terms of an unadulterated and genuine state of such audio content and the confidence about its origin are critical factors. To address this issue, this PhD thesis proposes a mechanism for verifying the integrity and authenticity of digital sound recordings. It is designed and implemented to be insensitive to common post-processing operations of the audio data that influence the subjective acoustic perception only marginally (if at all). Examples of such operations include lossy compression that maintains a high sound quality of the audio media, or lossless format conversions. It is the objective to avoid de facto false alarms that would be expectedly observable in standard crypto-based authentication protocols in the presence of these legitimate post-processing. For achieving this, a feasible combination of the techniques of digital watermarking and audio-specific hashing is investigated. At first, a suitable secret-key dependent audio hashing algorithm is developed. It incorporates and enhances so-called audio fingerprinting technology from the state of the art in contentbased audio identification. The presented algorithm (denoted as ”rMAC” message authentication code) allows ”perception-based” verification of integrity. This means classifying integrity breaches as such not before they become audible. As another objective, this rMAC is embedded and stored silently inside the audio media by means of audio watermarking technology. This approach allows maintaining the authentication code across the above-mentioned admissible post-processing operations and making it available for integrity verification at a later date. For this, an existent secret-key ependent audio watermarking algorithm is used and enhanced in this thesis work. To some extent, the dependency of the rMAC and of the watermarking processing from a secret key also allows authenticating the origin of a protected audio. To elaborate on this security aspect, this work also estimates the brute-force efforts of an adversary attacking this combined rMAC-watermarking approach. The experimental results show that the proposed method provides a good distinction and classification performance of authentic versus doctored audio content. It also allows the temporal localization of audible data modification within a protected audio file. The experimental evaluation finally provides recommendations about technical configuration settings of the combined watermarking-hashing approach. Beyond the main topic of perception-based data integrity and data authenticity for audio, this PhD work provides new general findings in the fields of audio fingerprinting and digital watermarking. The main contributions of this PhD were published and presented mainly at conferences about multimedia security. These publications were cited by a number of other authors and hence had some impact on their works

Natural regeneration of black spruce (Picea mariana (Mill) B.S.P.) on lowland clearcut strips near Shebandowan, Ontario

Growing conditions for black spruce natural regeneration on clearcut strips were studied near Shebandowan, Ontario. These conditions were significantly different from those present in the mature, residual forest in the study area. Furthermore, growing conditions changed with increased age of the clearcut strips. The most favourable seedbed (sphagnum) and limited hardwood competition were present only for few years following harvesting. The succession of less favourable seedbeds (sedges, hardwood litter) and severe hardwood competition had a negative impact on density and stocking of spruce regeneration. Height growth based on stem analysis data of regenerated and residual trees were expressed by a Weibull function. Half of the natural regeneration consisted of advance growth. The growth progressions for both advanced growth and new regeneration closely fit the growth models for the GOOD site disregarding early suppression. This study demonstrates that utilizing narrow, progressive clearcut strips and control of competition will produce a well stocked new forest as productive as the old forest on lowland, conifer site types

Watermark-Based Authentication and Key Exchange in Teleconferencing Systems

Abstract. In this paper we propose an architecture which combines watermarking with traditional cryptographic key agreement protocols to establish an authenticated or encrypted channel in teleconferencing systems. Technically the proposed method embeds messages of the key agreement protocol within an audio or video stream and is based on the assumption that the human communication partners can recognize each other easily; the watermark establishes a close coupling between the cryptographic key exchange messages and the media stream. We argue that the security of the scheme is based on a yet unexplored security property of digital watermarks; furthermore we present preliminary research results that suggest that this property holds in standard watermarking schemes

Welcome to the (urban) jungle: notes on new science, biological evolution in cities

The city – a modern jungle, where not cellulose and photosynthesis but concrete and combustion reign supreme. The question now being asked by urban planners, governments, and scientists is if it may stay like that and if it can stay like that or if it has to stay like that. Social, economic, cultural, historical, and legal factors are determinants in the ecology of urban ecosystems. Even well-managed cities are usually hostile toward non-human inhabitants. Furthermore, as with any complex system, the equilibrium is fragile, even if it exists. This publication outlines the co-evolution and ecology of humans and other species in the cities, their importance, and perspectives

Theoretical Study of the Spurious-Free Dynamic Range of a Tunable Delay Line based on Slow Light in SOA

We developed a predictive model describing harmonic generation and intermodulation distortions in semiconductor optical amplifiers (SOAs). This model takes into account the variations of the saturation parameters along the propagation axis inside the SOA, and uses a rigorous expression of the gain oscillations harmonics. We derived the spurious-free dynamic range (SFDR) of a slow light delay line based on coherent population oscillation (CPO) effects, in a frequency range covering radar applications (from 40kHz up to 30GHz), and for a large range of injected currents. The influence of the high order distortions in the input microwave spectrum is discussed, and in particular, an interpretation of the SFDR improvement of a Mach-Zehnder modulator by CPOs effects in a SOA is given.Comment: 12 pages, 5 figures (8 attached figures