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In this note we revisit the channelling effect of deep ocean acoustic wave propagation. To model propagation phenomena ray theory is used, where particular attention is payed to ray chaos. The effect of transitions between two archetypal sound speed versus depth profiles (Munk and double duct profiles) is studied. To do this the novel concept of launching basin is introduced. Its use in identifying the launching parameters of rays which remain stable is indicated, something which is highly desirable for understanding sonar system performance.

The role of topology in the statistical mechanics of surfaces in the lattice is considered. The possibility that a phase transition driven by the number of boundary components occurs is investigated. Bounds on the limiting free energy is derived and conditions for the existence of a critical point in the phase diagram are presented.

The low-lying positive and negative parity states of even–even ${}^{144-154}$Nd isotopes are studied using the interacting boson model (IBM). The negative parity states are involved within the IBM model by adding a single angular momentum ($L=3$) boson with intrinsic negative parity $f$-boson to $s$ and $d$-bosons model space. For these nuclei, the potential energy surfaces $V(\beta ,\gamma )$, transition probability $B(E1)$, $B(E2)$ and $B(E3)$ are calculated. Phase transition from the $U(5)$ limit to the $SU(3)$ limit is observed in the chain and the critical point has been determined for ${}^{150}$Nd isotope. It is found that the calculated positive and negative parity energy spectra of Nd-isotopes agree well with the experimental data.

The negative- and positive-parity states and electromagnetic transitions for ${}^{201-209}$Rn and ${}^{203-211}$Fr nuclei have been studied by using the Interacting Boson–Fermion Approximation (IBFM-1). Based on our calculations, the spin assignments for some states with uncertain spin have been done. Energy spectra, electromagnetic transition probabilities and branching ratios in these isotopes are calculated and compared with available experimental data. The wave functions are analyzed to understand the nuclear structure. In addition, some predictions of levels that have no experimental data are presented such as spin and electromagnetic transitions. Good results were obtained with a decrease in the collectivity properties, especially for the most neutron-deficient isotopes.

We study dynamics of active Brownian particles in two dimensions under the influence of external fields of forces. Several generic fields are considered, including symmetric linear attraction to a center, asymmetric linear attraction and a field described by a double well potential. We show the formation of limit cycles, which reflect collective rotational motion of the particles and study the influence of asymmetry on collective motion. In the case of the double well potential we study the transition rates between potential wells and show their crucial dependence on a parameter which determines activeness of the particles.

We describe a simple model of the dynamics of adoption of agri-environmental measures by farmers in Europe. Farmers choices are based on their evaluation of the economic advantages of taking environmental premiums in exchange for environment friendly practices, plus imitation terms taking into account the information that they get from neighbours which have already made their own choice. We show that under a large set of social network topologies and hypotheses on distribution of farmers characteristics, the outcome of the social processes, namely premium uptake rate, depends upon local characteristics of farmers and their network. It is not directly related to average characteristics. Some conclusions and recommendations about policy implementation can then be driven.

We claim that the apparently enhanced CpG transversions in the form CpG to CpC/GpG or to ApG/CpT are caused by the hypermutable CpG to CpA/TpG transition. The nucleotide replacement counts obtained from the human/chimpanzee/gorilla/orangutan sequence alignments representing the replacements due to the evolutionary species divergence and the results of 1000 genomes project that provide us with the differences due to the intraspecies diversification were analyzed to estimate the ratio of CpG versus non-CpG transversion probabilities. The trinucleotide replacement counts were extracted from the regions that are free of functional constraints. The CpG transversion probabilities based upon the genomic comparisons were found to exceed more than twice the non-CpG transversions. The diversity data emerging from 14 population groups were partitioned in five classes as a function of the parameter quantifying the spread of the polymorphic allele among the group of individuals. The results based upon the human polymorphism exhibit a trend where CpG over non-CpG transversion probability ratio is less and less exceeding unity as the values of the derived allele frequency (DAF) of snps are diminishing. A computer simulation of a simplified model indicates that the phenomenon of the apparent enhancement of CpG transversions can have its source in the interference of the entropic effects with the maximum likelihood methodologies.

Locomotor state transitions are challenging for transfemoral (TF) amputees due to the lack of active knee control even in the current powered prosthetic devices. Myoelectric activation has been used successfully to classify steady-state locomotion states, but classification of transitions between locomotion states remains a challenge, especially for TF amputees. The purpose of this study was to determine if lower-extremity muscle activation differences between pre-transition and transition gait cycles occur in the involved or uninvolved limb of TF amputees during locomotion state transitions. Surface electromyography (EMG) was collected from residual muscles on the involved limb and from the uninvolved limb from five TF amputees as they transitioned between different locomotion states (level ground, ramp ascent/descent, stair ascent/descent). Statistical parametric mapping (SPM) was used to assess differences in activation. When analyzed as a group, the only significant differences were observed in the vastus lateralis of the uninvolved limb. High inter-subject variation reduced the significance of other pattern differences. Further inspection revealed that the individual subjects expressed three different recruitment patterns. These recruitment patterns may indicate compensatory strategies adopted by the subjects over the years since amputation. Furthermore, the separate recruitment patterns suggest the need for individualized locomotion transition classification algorithms rather than a general classification scheme.

We describe a simple model of the dynamics of adoption of agri-environmental measures by farmers in Europe. Farmers choices are based on their evaluation of the economic advantages of taking environmental premiums in exchange for environment friendly practices, plus imitation terms taking into account the information that they get from neighbors which have already made their own choice. We show that under a large set of social network topologies and hypotheses on distribution of farmers characteristics, the outcome of the social processes, namely premium uptaken rate, depends upon local characteristics of farmers and their network. It is not directly related to average characteristics. Some conclusions and recommendations about policy implementation can then be driven.

The role of topology in the statistical mechanics of surfaces in the lattice Ƶ^d is considered. The possibility that a phase transition driven by the number of boundary components occurs is investigated. Bounds on the limiting free energy is derived and conditions for the existence of a critical point in the phase diagram are presented.

High spins states in ⁸⁶Sr were populated by the reaction ⁸²Se (⁹Be, 5n) ⁸⁶Sr. γ - γ coincidence measurements along with investigation of directional correlation ratios(DCO) were utilized to establish the extended level scheme of ⁸⁶Sr from 13ħ up to 20ħ. Twenty-nine new transitions were found in ⁸⁶Sr. The configurations of ⁸⁶Sr were generally specified tentatively by comparing neighboring nuclei systematically.

Thulium-doped potassium lanthanum gallate glasses (K₂O-La₂O₃-Ga₂O₃ or KLG) which are suitable to use in amplifiers has been fabricated and characterized. The density, the refractive indexes, the absorption and luminescence spectra were measured and analyzed. By using the Judd–Ofelt theory, the experimental oscillator strengths, the Judd–Ofelt intensity parameters Ω_t were determined, and some important radiative properties were calculated. Using a least-squares fitting approach, the Judd–Ofelt intensity parameters Ω_t were found to be Ω₂=7.26×10^-20cm², Ω₄=1.69×10^-20cm², and Ω₆=0.66×10^-20cm². The bandwidth of the ³H₄→³F₄ transition around 1.47μm in Tm³⁺-doped KLG glasses is ~92nm which is smaller than Tm³⁺-doped KBG glasses at ~120nm.