Biološke i ekološke karakteristike crnke umbra krameri kao osnov za in-situ i ex-situ zaštitu

The analysis of ecological characteristics and morphological-genetic differentiation of populations of the European mudminnow (Umbra krameri Walbaum, 1792) from the localities Lugomir and Bakreni Batar in Serbia and the locality Gromiželj in Bosnia and Herzegovina provides a basis for future activities related to in situ and ex situ conservation of one of the most endangered species in the region. Physical and chemical habitat parameters, aquatic plant and fish species composition, as well as invertebrate assemblages from mud and submerged vegetation at all investigated localities are consistent with the literature data which indicates that European mudminnow lives in typical habitats within its range. Population structure was analysed with regard to measured body lengths and weights, sex ratio and the age of the sampled individuals. The results show that the mean lengths and weights of the most frequent age classes (1+ and 2+) are rather uniform at all investigated localities. Younger (0+) and older (3+ and 4+) individuals were recorded in Gromiželj; males outnumber females in samples from Lugomir and Bakreni Batar, while females outnumber males in samples from Gromiželj. Individuals from Gromiželj show the highest absolute and relative growth. The growth of this species varies and depends on several factors, such as physical and chemical environmental parameters, food availability, population density, presence of predators, etc. Qualitative and quantitative composition of European mudminnow diet was determined on the basis of its gastrointestinal contents. The obtained results indicate that the European mudminnow is a zoophagous species and an opportunistic predator. The morphological variability (body size and shape) was analyzed using the methods of geometric morphometrics, while the genetic diversity of the analyzed populations was determined by applying the molecular-genetic methods (microsatellites and mitochondrial DNA). These analyses indicate high level of compatibility between the morphological variability and the genetic diversity. Namely, the Danube River population from Lugomir differs from the Sava River populations from Bakreni Batar and Gromiželj, the latter two having a significantly higher level of similarities and relatedness. All obtained results are extremely important for implementing the adequate measures of active protection, conservation, and improvement of recent populations, most notably repopulation, reintroduction, and aquaculture of the European mudminnow in ex situ conditions and at controlled natural spawning sites within their habitats.Na osnovu analize ekoloških karakteristika i morfološko-genetičke diferencijacije populacija crnke (Umbra krameri Walbaum, 1792) sa lokaliteta Lugomir i Bakreni Batar u Srbiji kao i sa lokaliteta Gromiželj u Bosni i Hercegovini, dat je osnov za buduće aktivnosti na in-situ i ex-situ zaštiti jedne od najugroženijih vrsta riba na ovim prostorima. Analiza fizičko-hemijskih parametara vode i kvalitativnog sastava zajednice biljaka, riba, akvatičnih beskičmenjaka iz mulja i submerzne vegetacije pokazala je da su na svim istraživanim lokalitetima rezultati u skladu sa literaturnim podacima koji ukazuju na to da crnka naseljava tipična staništa u okviru svog areala. U odnosu na dužinu i težinu, pol i uzrast uzorkovanih jedinki, analizirana je struktura populacija, koja je pokazala da su na svim istraživanim lokalitetima srednje vrednosti dužinskih i težinskih parametara kod najfrekventnijih uzrasnih klasa (1+ i 2+) prilično ujednačene, da su na Gromiželju evidentirane i mlađe (0+) i starije (3+ i 4+) jedinke, kao i da mužjaci dominiraju u uzorcima iz Lugomira i Bakrenog Batara, a ženke u uzorku iz Gromiželja. Analizom dužinskog i težinskog rasta, najveći apsolutni i relativni priraštaj ustanovljen je kod jedinki sa lokaliteta Gromiželj, a konstatovano je i da rast crnke varira i zavisi od više faktora, kao što su fizičko-hemijski parametri sredine, dostupnost hrane, gustina populacija, prisutni predatori itd. Na osnovu želudačno-crevnog sadržaja utvrđen je kvalitativno-kvantitativni sastav ishrane crnke, koji ukazuje na to da crnka predstavlja zoofagnu vrstu i oportunističkog predatora. Metodama geometrijske morfometrije analizirana je varijabilnost spoljašnje morfologije, odnosno varijabilnost veličine i oblika tela istraživanih populacija, a upotrebom molekularno-genetičkih metoda (mikrosateliti i mitohondrijalna DNK), utvrđena je i genetička raznovrsnost analiziranih populacija. Uz visok stepen podudarnosti dobijenih rezultata korišćenjem navedenih metoda, utvrđeno je jasno razdvajanje dunavske populacije sa lokaliteta Lugomir u odnosu na savske populacije sa lokaliteta Bakreni Batar i Gromiželj, koje pokazuju znatno veći stepen međusobne sličnosti i srodnosti. Svi dobijeni rezultati ovih istraživanja od izuzetne su važnosti za preduzimanje odgovarajućih mera aktivne zaštite, očuvanja i unapređenja stanja recentnih populacija, od kojih su najznačajniji repopulacija, reintrodukcija i akvakultura crnke u ex situ uslovima i u kontrolisanim prirodnim plodištima na samim staništima

31st Annual Meeting and Associated Programs of the Society for Immunotherapy of Cancer (SITC 2016) : part two

Background The immunological escape of tumors represents one of the main ob- stacles to the treatment of malignancies. The blockade of PD-1 or CTLA-4 receptors represented a milestone in the history of immunotherapy. However, immune checkpoint inhibitors seem to be effective in specific cohorts of patients. It has been proposed that their efficacy relies on the presence of an immunological response. Thus, we hypothesized that disruption of the PD-L1/PD-1 axis would synergize with our oncolytic vaccine platform PeptiCRAd. Methods We used murine B16OVA in vivo tumor models and flow cytometry analysis to investigate the immunological background. Results First, we found that high-burden B16OVA tumors were refractory to combination immunotherapy. However, with a more aggressive schedule, tumors with a lower burden were more susceptible to the combination of PeptiCRAd and PD-L1 blockade. The therapy signifi- cantly increased the median survival of mice (Fig. 7). Interestingly, the reduced growth of contralaterally injected B16F10 cells sug- gested the presence of a long lasting immunological memory also against non-targeted antigens. Concerning the functional state of tumor infiltrating lymphocytes (TILs), we found that all the immune therapies would enhance the percentage of activated (PD-1pos TIM- 3neg) T lymphocytes and reduce the amount of exhausted (PD-1pos TIM-3pos) cells compared to placebo. As expected, we found that PeptiCRAd monotherapy could increase the number of antigen spe- cific CD8+ T cells compared to other treatments. However, only the combination with PD-L1 blockade could significantly increase the ra- tio between activated and exhausted pentamer positive cells (p= 0.0058), suggesting that by disrupting the PD-1/PD-L1 axis we could decrease the amount of dysfunctional antigen specific T cells. We ob- served that the anatomical location deeply influenced the state of CD4+ and CD8+ T lymphocytes. In fact, TIM-3 expression was in- creased by 2 fold on TILs compared to splenic and lymphoid T cells. In the CD8+ compartment, the expression of PD-1 on the surface seemed to be restricted to the tumor micro-environment, while CD4 + T cells had a high expression of PD-1 also in lymphoid organs. Interestingly, we found that the levels of PD-1 were significantly higher on CD8+ T cells than on CD4+ T cells into the tumor micro- environment (p < 0.0001). Conclusions In conclusion, we demonstrated that the efficacy of immune check- point inhibitors might be strongly enhanced by their combination with cancer vaccines. PeptiCRAd was able to increase the number of antigen-specific T cells and PD-L1 blockade prevented their exhaus- tion, resulting in long-lasting immunological memory and increased median survival

Mitigation of primary user emulation attacks using belief propagation

Theoretical thesis.Bibliography: pages 71-74.1. Introduction -- 2. Cognitive Radio technology -- Cognitive Radio security -- 4. PUEA mitigation algorithms -- 5. A new belief propagation based PUEA mitigation algorithm -- 6. Conclusion.Cognitive Radio (CR) is a promising technology that has the potential torevolutionize spectrum utilization by enabling unlicensed users (secondary users) to seek opportunities for transmission by taking advantage of the idle periods of licensed users (primary users) [1]. However, participants in the CR network can comprise of malicious adversaries who adopt dishonest and non-cooperative strategies to attack the network. An attack called the Primary user emulation attack has been identified as the most serious threat to cognitive radio security. In primary user emulation attacks a malicious user emulates the characteristics of a primary user and transmits on available frequency spectrum channels. As a result, secondary users are tricked into believing that the channel is occupied and avoid it, which allows the malicious user to occupy the entire frequency spectrum band uncontested. This report proposes a new technique based on belief propagation to combat primary user emulation attacks in cognitive radio networks. We introduce a method that dramatically reduces the computational complexity and run time of the existing techniques, while also improving the performance.Mode of access: World wide web1 online resource (xi, 74 pages) diagrams, graph

The development of novel physical layer security algorithms to mitigate cognitive radio attacks

Empirical thesis.Bibliography: pages 145-154.1. Introduction -- 2. Cognitive radio networks -- 3. Security threats for a new generation of networks -- 4. Mitigation of primary user emulation attacks -- 5. Single iteration belief propagation -- 6. Compressive sensing belief propagation hybrid -- 7. Mitigation of spectrum sensing data falsification attacks -- 8. SSDFA, reputation mining and reset attacks -- 9. Discussion and conclusion -- Bibliography.Since the implementation of the first public-access networks, attackers have looked to take advantage of vulnerabilities in network security to gain an unfair advantage. In recent times, wireless networks have increasingly been integrated in our everyday lives. Science-fiction style automated homes and societies have increasingly become a reality. Today's wireless devices possess high cognitive ability, they dynamically adjust according to their environment and user preferences to ensure maximum comfort for their users. As a result, a global network of interconnected wireless devices has been growing exponentially for the past few decades. Previous radio-frequency spectrum allocation has failed to predict this growth, which has resulted in extreme congestion in some bands and low utilisation of others. Cognitive Radio, a collection of intelligent methods, is seen as the most promising solution. To increase effciency they allow secondary users (users that do not have a regulatory right to use a frequency channel) to utilise allocated frequency bands when they are not being utilised by paying users (primary users). However, cognitive radio implementation has been delayed several times because of its susceptibility to a number of security attacks, specifically in the physical layer. As such, a taxonomy of new attacks has been identfied, which could not be mitigated by standard security algorithms that were developed for conventional wireless networks. The primary aim of this thesis is to mitigate the effects of physical layer attacks in Cognitive Radio Networks (CRN). In particular, two attacks have been identified as the most serious threats to cognitive radio security. These are a Primary User Emulation Attack (PUEA), which involves an attacker emulating the properties of primary users in order to gain an unfair advantage over other secondary users and a Spectrum Sensing Data Falsification Attack (SSDFA), during which an attacker intentionally manipulates messages containing spectrum sensing information in order to trick secondary users into miss-diagnosing the status of a primary user. In this thesis, we present a number of algorithms to combat the vast array of attacks within the physical layer. In particular we present a number of novel, highly effective, low computational complexity algorithms that can be implemented to completely eradicate these attacks and render them ineffective. Since many of the devices that make up a cognitive radio network have battery and computational complexity constrains, our objective was to develop mitigation algorithms that they are lightweight and can be implemented effectively.Mode of access: World wide web1 online resource (xvi, 154 pages) graph

Mitigation of primary user emulation attacks in Cognitive Radio Networks using belief propagation

In this paper, we introduce a belief propagation based technique to combat the effects of primary user emulation attacks (PUEA) in Cognitive Radio (CR) Networks. Primary user emulation attacks have been identified as the most serious threat to CR security. In a PUEA, a malicious user emulates the characteristics of a primary user and transmits over idle channels. As a result, secondary users that want to use the channels are tricked into believing that they are occupied and avoid transmitting on those channels. This allows the malicious user to use the channels uncontested. To moderate the effects of PUEA, we propose a defence strategy based on belief propagation. In our solution, each secondary user examines the incoming signal and calculates the probability that it was transmitted from a primary user. These probabilities are known as beliefs. The beliefs at secondary users are reconciled to an agreed decision by comparison to a predefined threshold. The decision is made by a secondary user on whether it is believed that received transmission on a channel originated from a legitimate primary user or from a primary user emulation attacker.14 page(s

A Single iteration belief propagation algorithm to minimize the effects of primary user emulation attacks

This paper presents a method to alleviate the effects of primary user emulation attacks in cognitive radio (CR) networks. The proposed method uses a simplified belief propagation (BP) algorithm that is able to identify whether a transmitter is a legitimate primary user or an attacker. In a primary user emulation attack (PUEA) a transmitter impersonates a primary user (PU) in order to deceive secondary users (SU) into believing that a channel is occupied. As a result, secondary users must vacate the channel immediately. This paper presents a simplified belief propagation method as a defence strategy against primary user emulation attacks. In our method each secondary user examines an incoming signal from a transmitter and determines with a certain probability whether the transmitter is a legitimate user or not. This probability is known as the belief. The beliefs at each secondary user are reconciled and a final belief is compared to a predefined threshold. If the final belief is below the threshold, the user is identified as an attacker. If it is above the threshold, the user is deemed a primary user. This result is then propagated throughout the network so that all users on the network are aware of the attacker. In this paper, we present a method based on the belief propagation framework. The proposed method converges in a single iteration; this is the result of a redefined messaging protocol and a simplified belief equation. As a result, the computational complexity of the method is reduced significantly, while still maintaining a high level of accuracy.6 page(s

New data on sterlet (Acipenser ruthenus L.) genetic diversity in the middle and lower Danube sections, based on mitochondrial DNA analyses

Poor regulated fishery, pollution, fragmentation and loss of habitat are most important factors influencing decline of sterlet population worldwide. In Middle and Lower Danube region, this species still have significant economic importance since wilde populations are commercially exploited, while Upper Danube populations are dependent on stocking efforts in order to maintain their presence in open waters. Aim of present study is to analyze genetic diversity of sterlet populations from the Middle and Lower Danube and Lower Tisza rivers, as a prerequisite for their effective conservation and management. Analysis of a highly variable D-loop fragment of mitochondrial DNA detected five new haplotypes, while the eight previously identified haplotypes had extended their previous range. Genetic variability could be attributed almost entirely to individuals, with observed lack of population structure. Negative values of neutrality test indicate recent expansion on some sampling locations. Adittionaly, gene flow analysis between Lower and Middle Danube region showed intensive exchange of speciemens. At the same time analysis showed some influence of Tisza dam on gene flow between samples from Tisza and Middle Danube section. Our study indicated the need for a careful planning of sterlet stocking programmes and inclusion of demographic data or catch time-series.Ministry of Education, Science and Technological Development of the Republic Serbia {[}173045

Genetic architecture of trout from Albania as revealed by mtDNA control region variation

International audienceTo determine the genetic architecture of trout in Albania, 87 individuals were collected from 19 riverine and lacustrine sites in Albania, FYROM and Greece. All individuals were analyzed for sequence variation in the mtDNA control region. Among fourteen haplotypes detected, four previously unpublished haplotypes, bearing a close relationship to haplotypes of the Adriatic and marmoratus lineages of Salmo trutta, were revealed. Ten previously described haplotypes, characteristic of S. ohridanus, S. letnica and the Adriatic and Mediterranean lineages of S. trutta, were also detected. Haplotypes detected in this study were placed in a well supported branch of S. ohridanus, and a cluster of Mediterranean-Adriatic-marmoratus haplotypes, which were further delimited into three subdivisions of Mediterranean, marmoratus, and a previously non-described formation of four Adriatic haplotypes (Balkan cluster). Haplotypes of the Balkan cluster and the other Adriatic haplotypes, do not represent a contiguous haplotype lineage and appear not to be closely related, indicating independent arrivals into the Adriatic drainage and suggesting successive colonization events. Despite the presence of marmoratus haplotypes in Albania, no marbled phenotype was found, confirming previously reported findings that there is no association between this phenotype and marmoratus haplotypes

Genetic diversity and phylogenetic origin of brown trout Salmo trutta populations in eastern Balkans

WOS: 000325811700034The study focuses on the phylogenetic origin and genetic diversity of brown trout in the eastern part of the Balkan Peninsula. It further aims to reveal the impact of human-mediated transfers and stocking with non-indigenous trout on the populations in this area. For these purposes, mtDNA control region and microsatellite variation of 204 individuals from 16 populations were analysed. The results indicate that mtDNA haplotypes from the lower Danube basin and southern Black Sea basins differ substantially from a subclade of the Danubian lineage consisting of haplotypes found so far in the most of the Danube basin and in the Caspian and Aral Sea basins. Considering also the results of demographic analyses, this study evidences a complex evolutionary history of brown trout in the southern and western parts of the Black Sea basin. In the Aegean Sea basin, a high frequency of the central haplotype of Adriatic mtDNA lineage has been found. The other Adriatic lineage haplotypes found in this basin differ from the central haplotype by one mutational step only, indicating a recent evolution of the Adriatic lineage in the Aegean Sea basin. Substantial genetic differentiation among populations and basins was revealed. The hybridization with Atlantic brown trout was indicated in both sea basins, but especially in the Danube basin. Compared to other European regions, it can be inferred that the introgression of exogenous brown trout in the eastern Balkan populations is rather low.Grant Agency of the University of South Bohemia [58/2007/P-VURH]; Academy of Sciences of the Czech RepublicCzech Academy of Sciences [1QS500450513]; Ministry of Science and Technological Development of the Republic of Serbia [173045]We are thankful to T. Nalbant, Z. Lajbner, R. Sanda and L. Choleva for their help with obtaining samples. Earlier versions of the manuscript increased due to the comments of J. Bohlen, P. Rab and Z. Lajbner. The study was supported by the Grant Agency of the University of South Bohemia (grant No. 58/2007/P-VURH), the Academy of Sciences of the Czech Republic (project No. 1QS500450513) and the Ministry of Science and Technological Development of the Republic of Serbia (Grant No. 173045)