•We tackle distributed detection of a target via a Wireless Sensor Network.•Both target average emitted power and position are unknown.•GLRT, Bayesian and hybrid approaches are ...considered.•Generalizations of Locally-Optimum Detection are obtained.•All the proposed rules are compared in terms of performance and complexity.
In this paper we tackle distributed detection of a non-cooperative target with a Wireless Sensor Network (WSN). When the target is present, sensors observe an unknown random signal with amplitude attenuation depending on the distance between the sensor and the target (unknown) positions, embedded in white Gaussian noise. The Fusion Center (FC) receives sensors decisions through error-prone Binary Symmetric Channels (BSCs) and is in charge of performing a (potentially) more-accurate global decision. The resulting problem is a one-sided testing with nuisance parameters present only under the target-present hypothesis. We first focus on fusion rules based on Generalized Likelihood Ratio Test (GLRT), Bayesian and hybrid approaches. Then, aimed at reducing the computational complexity, we develop fusion rules based on generalizations of the well-known Locally-Optimum Detection (LOD) framework. Finally, all the proposed rules are compared in terms of performance and complexity.
Strong light-matter interactions in both the single-emitter and collective strong coupling regimes attract significant attention due to emerging applications in quantum and nonlinear optics as well ...as opportunities for modifying material-related properties. Exploration of these phenomena is theoretically demanding, as polaritons exist at the intersection between quantum optics, solid state physics, and quantum chemistry. Fortunately, nanoscale polaritons can be realized in small plasmon-molecule systems, enabling treatment with ab initio methods. Here, we show that time-dependent density-functional theory calculations access the physics of nanoscale plasmon-molecule hybrids and predict vacuum Rabi splitting. By considering a system comprising a few-hundred-atom aluminum nanoparticle interacting with benzene molecules, we show that cavity quantum electrodynamics holds down to resonators of a few cubic nanometers in size, yielding a single-molecule coupling strength exceeding 200 meV due to a massive vacuum field of 4.5 V · nm
. In a broader perspective, ab initio methods enable parameter-free in-depth studies of polaritonic systems for emerging applications.
Cryptococcus neoformans is a facultative intracellular pathogen and its interaction with macrophages is a key event determining the outcome of infection. Urease is a major virulence factor in C. ...neoformans but its role during macrophage interaction has not been characterized. Consequently, we analyzed the effect of urease on fungal-macrophage interaction using wild-type, urease-deficient and urease-complemented strains of C. neoformans. The frequency of non-lytic exocytosis events was reduced in the absence of urease. Urease-positive C. neoformans manifested reduced and delayed intracellular replication with fewer macrophages displaying phagolysosomal membrane permeabilization. The production of urease was associated with increased phagolysosomal pH, which in turn reduced growth of urease-positive C. neoformans inside macrophages. Interestingly, the ure1 mutant strain grew slower in fungal growth medium which was buffered to neutral pH (pH 7.4). Mice inoculated with macrophages carrying urease-deficient C. neoformans had lower fungal burden in the brain than mice infected with macrophages carrying wild-type strain. In contrast, the absence of urease did not affect survival of yeast when interacting with amoebae. Because of the inability of the urease deletion mutant to grow on urea as a sole nitrogen source, we hypothesize urease plays a nutritional role involved in nitrogen acquisition in the environment. Taken together, our data demonstrate that urease affects fitness within the mammalian phagosome, promoting non-lytic exocytosis while delaying intracellular replication and thus reducing phagolysosomal membrane damage, events that could facilitate cryptococcal dissemination when transported inside macrophages. This system provides an example where an enzyme involved in nutrient acquisition modulates virulence during mammalian infection.
Xylosandrus crassiusculus
is an invasive ambrosia beetle comprising two differentiated genetic lineages, named cluster 1 and cluster 2. These lineages invaded different parts of the world at ...different periods of time. We tested whether they exhibited different climatic niches using Schoener’s D and Hellinger’s I indices and modeled their current potential geographical ranges using the Maxent algorithm. The resulting models were projected according to future and recent past climate datasets for Europe and the Mediterranean region. The future projections were performed for the periods 2041–2070 and 2071–2100 using 3 SSPs and 5 GCMs. The genetic lineages exhibited different climate niches. Parts of Europe, the Americas, Sub-Saharan Africa, Asia, and Oceania were evaluated as suitable for cluster 1. Parts of Europe, South America, Central and South Africa, Asia, and Oceania were considered as suitable for cluster 2. Models projection under future climate scenarios indicated a decrease in climate suitability in Southern Europe and an increase in North Eastern Europe in 2071–2100. Most of Southern and Western Europe was evaluated as already suitable for both clusters in the early twentieth century. Our results show that large climatically suitable regions still remain uncolonized and that climate change will affect the geographical distribution of climatically suitable areas. Climate conditions in Europe were favorable in the twentieth century, suggesting that the recent colonization of Europe is rather due to an increase in propagule pressure via international trade than to recent environmental changes.
•The DYB is proposed as a brace member to obtain an improved steel CBF.•The benefits of the mechanical features of DYB on the frame response is studied.•A method for the design of the components of ...the new CBF is formulated.•The design method is consistent with the architecture of EC8.•The behaviour factor is calibrated to fulfil the performance requirements of EC8.
The steel Concentric Braced Frame (CBF) is a popular structural type for buildings in seismic areas. In fact, it can conveniently provide the building with large strength and stiffness. Furthermore, the simplicity of fabrication that derives from the use of shear connections between beams and columns appeals to structural designers. Unfortunately, the dissipation capacity of steel braces is limited and the structural type is low redundant and thus prone to storey collapse mechanisms. To improve the seismic performance of the CBF double-stage BRBs (DYBs) could be used instead of conventional steel braces. The DYB exhibits high dissipative and stable cyclic response and, if inserted into a steel frame, promote the spread of damage owing to the shape of its hysteresis loop. Despite its qualities, in literature there are no design methods that allow its use. Hence, in this paper, a design method for steel frames with DYBs is formulated in compliance with the principles of the European seismic code. The behaviour factor q is calibrated to meet the performance objectives of Eurocode 8. The calibration is performed by nonlinear dynamic analysis conducted with OpenSees on 75 frames with different features. The numerical model is calibrated on the results of the experimental tests performed by Pan and his co-workers at Tsinghua University in Beijing (China). The deduced results confirm the effectiveness of the frame with DYBs, which can be designed with q values greater than those used for traditional steel braced frames.
ABSTRACT
We carry out a linear stability analysis of a magnetized relativistic rotating cylindrical jet flow using the approximation of zero thermal pressure. We identify several modes of instability ...in the jet: Kelvin–Helmholtz, current-driven and two kinds of centrifugal-buoyancy modes – toroidal and poloidal. The Kelvin–Helmholtz mode is found at low magnetization and its growth rate depends very weakly on the pitch parameter of the background magnetic field and on rotation. The current-driven mode is found at high magnetization, the values of its growth rate and the wavenumber, corresponding to the maximum growth, increase as we decrease the pitch parameter of the background magnetic field. This mode is stabilized by rotation, especially, at high magnetization. The centrifugal-buoyancy modes, arising due to rotation, tend also to be more stable when magnetization is increased. Overall, relativistic jet flows appear to be more stable with respect to their non-relativistic counterpart.
We tackle distributed detection of a non-cooperative (i.e., whose emitted power is unknown) target with a wireless sensor network. When the target is present, sensors observe an (unknown) randomly ...fluctuating signal with attenuation depending on the distance between the sensor and the (unknown) target positions, embedded in Gaussian noise. The fusion center receives (only) sensor decisions through error-prone binary symmetric channels and is in charge of performing a more-accurate global inference. The resulting test is one-sided with nuisance parameters (i.e., the target position) present only under the hypothesis <inline-formula> <tex-math notation="LaTeX">\pmb {\mathcal {H}}_{{1}} </tex-math></inline-formula>. To reduce the complexity of generalized likelihood ratio test, a generalized locally optimum detection test (based on Davies' framework) is investigated and a corresponding sensor threshold optimization (based on a semi-theoretical criterion) is developed and verified through simulations.
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