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Connectivity is a fundamental issue in research on wireless sensor networks. However, unreliable and asymmetric links have a great impact on the global quality of connectivity (QoC). By assuming the deployment of nodes a homogeneous Poisson point process and eliminating the border effect, this paper derives an explicit expression of node non-isolation probability as the upper bound of one-connectivity, based on an analytical link model which incorporates important parameters such as path loss exponent, shadowing variance of channel, modulation, encoding method etc. The derivation has built a bridge over the local link property and the global network connectivity, which makes it clear to see how various parameter impact the QoC. Numerical results obtained further confirm the analysis and can be used as reference for practical design and simulation of wireless ad hoc and sensor networks. Besides, we find giant component size a good relaxed measure of connectivity in some applications that do not require full connectivity.

This paper aims to propose a framework for optimizing performance in cluster-based wireless sensor networks (WSNs) with constrains of energy consumption, delay and connectivity. For the limitation of energy storage being discussed a lot, many researches try to find more solutions to improve it. But, the other index of wireless sensor networks may be deteriorated by many routings which are dedicated to optimizing energy consumption. Thereby, multi-objectives optimization is one of significant issues in WSNs. The model of isolation nodes probability for connectivity in the clusterbased networks is adopted for the issue. Not only will the performance of Leach and existing multiobjectives optimization methods be compared under the proposed framework, but also will the performance of networks in different size of scenarios be analyzed. Simulation results show that the proposed framework combining NSGA can provide an effective sensing in terms of energy consumption, delay and connectivity in the cluster-based networks.

Background The WHO recently recommended the new Xpert MTB/RIF Ultra assay (Ultra) instead of the Xpert MTB/RIF assay because Ultra has improved sensitivity. We report the diagnostic accuracy of Ultra for tuberculous adenitis in a tuberculosis and HIV endemic setting. Methods We obtained fine-needle aspirates (FNA) and lymph node tissue by core-needle biopsy in adult patients with peripheral lymphadenopathy of >20 mm. Ultra and mycobacterial culture were performed on FNA and tissue specimens, with histological examination of tissue specimens. We assessed the diagnostic accuracy of Ultra against a composite reference standard of ‘definite tuberculosis’ (microbiological criteria) or ‘probable tuberculosis’ (histological and clinical criteria). Results We prospectively evaluated 99 participants of whom 50 were HIV positive: 21 had ‘definite tuberculosis’, 15 ‘probable tuberculosis’ and 63 did not have tuberculosis (of whom 38% had lymphoma and 19% disseminated malignancy). Using the composite reference standard the Ultra sensitivity on FNA was 70% (95% CI 51–85; 21 of 30), and on tissue was 67% (45–84; 16/24) these were far superior to the detection of acid-fast bacilli on an FNA (26%; 7/27); AFB on tissue (33%; 8/24); or tissue culture (39%; 9/23). The detection of granulomas on histology had high senstivity (83%) but the lowest specficity. When compared with culture the Ultra on FNA had a sensitvity of 78% (40-97; 7/9) and tissue 90% (55-100; 9/10). Conclusions Ultra performed on FNA or tissue of a lymph node had good sensitivity and high specificity. Ultra had a higher yield than culture and has the advantage of being a rapid test. Ultra on FNA would be an appropriate initial investigation for lymphadenopathy in tuberculosis endemic areas followed by a core biopsy for histopathology with a repeat Ultra on tissue if granulomas are present.

Network survivability is the ability of a network to stay connected under failures and attacks, which is a fundamental issue to the design and performance evaluation of wireless ad hoc networks. In this paper, we focus on the analysis of network survivability in the presence of node misbehaviors and failures. First, we propose a novel semi-Markov process model to characterize the evolution of node behaviors. As an immediate application of the proposed model, we investigate the problem of node isolation where the effects of denial-of-service (DoS) attacks are considered. Then, we present the derivation of network survivability and obtain the lower and upper bounds on the topological survivability for k-connected networks. We find that the network survivability degrades very quickly with the increasing likelihood of node misbehaviors, depending on the requirements of disjoint outgoing paths or network connectivity. Moreover, DoS attacks have a significant impact on the network survivability, especially in dense networks. Finally, we validate the proposed model and analytical result by simulations and numerical analysis, showing the effects of node misbehaviors on both topological survivability and network performance.

To construct an evolutionary hypothesis for the genus Frankia, gyr B (encoding gyrase B), nif H (encoding nitrogenase reductase) and gln II (encoding glutamine synthetase II) gene sequences were considered for 38 strains. The overall clustering pattern among Frankia strains based on the three analyzed sequences varied among themselves and with the previously established 16S rRNA gene phylogeny and they did not reliably reflect clear evolution of the four discerned Frankia clusters (1, 2, 3 and 4). Based on concatenated gyr B, nif H and gln II, robust phylogenetic trees were observed with the three treeing methods (Maximum Likelihood, Parsimony and Neighbor-Joining) and supported by strong bootstrap and posterior probability values (>75%) for overall branching. Cluster 4 (non-infective and/or non-nitrogen-fixing Frankia ) was positioned at a deeper branch followed by cluster 3 (Rhamnaceae and Elaeagnaceae infective Frankia ), while cluster 2 represents uncultured Frankia microsymbionts of the Coriariaceae, Datiscaceae, Rosaceae and of Ceanothus sp. (Rhamnaceae); Cluster 1 (Betulaceae, Myricaceae and Casuarinaceae infective Frankia ) appears to have diverged more recently. The present study demonstrates the utility of phylogenetic analyses based upon concatenated gyr B, nif H and gln II sequences to help resolve previously unresolved or poorly resolved nodes and will aid in describing species among the genus Frankia .

Mycobacterium spp. and Rhodococcus equi are generally regarded as the main causes of lymphadenitis in pigs and wild boars. In Poland, mycobacterial submandibular lymphadenitis was first diagnosed in a wild boar in 2012 but Mycobacterium spp. infections are also present in the Polish population of European bison ( Bison bonasus ). The prevalence of lymphadenitis in Polish wild boars has been found to 8.4% (95% CI 6.2–11.3%) and it has been proved that R. equi is not an important cause of purulent lesions in these animals. The current study was carried out to assess the prevalence of mycobacterial lymphadenitis in the Polish wild boar population. Submandibular lymph nodes with purulent lesions collected from 38 wild boars in 2010/2011 and negative for R. equi were included. Calculations based on the hypergeometric approximation were used to determine the probability that at least one positive individual would be detected if the infection had been present at a prevalence greater than or equal to the design prevalence. All 38 samples were negative for Mycobacterium spp. [0% (95% CI 0, 9.2%)]. Epidemiological analysis showed that the true prevalence was 95% likely to be lower than 10%. In conclusion, mycobacterial lymphadenitis seems to occur rarely in wild boars in Poland. Due to the presence of Mycobacterium spp. infections in other wildlife, the surveillance of mycobacterial infections in wild animals in Poland remains an important issue.

Microwave links are the obvious mobile backhauling solution for many mobile operators. Multi-hops are likely to be necessary in order to ensure connectivity for mobile backhaul solutions. The subject of the present paper is the evaluation of the connectivity of wireless multi-hop backhaul networks assuming high frequency transmissions among the relays. A novel analytical physical propagation and engineering model is presented for the calculation of the connectivity of wireless multi-hop networks that appropriate for operating frequencies above 10 GHz. Assuming equal power transmissions from every node and a random spatial node distribution following the homogeneous Poisson process, we calculate the node isolation probability. Furthermore, we calculate the minimum required node density in order to keep the backhaul network almost connected. The sensitivity of the isolation probability and of the minimum node density on frequency of operation, transmission power and climatic conditions is also investigated. Some useful conclusions are drawn.