Change of the Most Probable Escape Path in a Fast-Slow Insect Outbreak System Under Different Noise Amplitude Ratios

In the present paper, noise-induced escape from the domain of attraction of a stable fixed point of a fast-slow insect outbreak system is investigated. According to Dannenberg's theory(Dannenberg PH, Neu JC, 2014)[1], different noise amplitude ratios μ lead to the change of the Most Probable Escape Path(MPEP). Therefore, the research emphasis of this paper is to extend their study and discuss the changes of the MPEPs in more detail. Firstly, the case for μ=1, wherein the MPEP almost traces out the critical manifold, is considered. Via projecting the full system onto the critical manifold, a reduced system is obtained and the quasi-potential of the full system can be partly evaluated by that of this reduced system. In order to test the accuracy of the computed MPEP, a new relaxation method is then presented. Then, as μ converges to zero, an improved analytical method is given, through which a better approximation for the MPEP at the turning point is obtained. And then, in the case that the value of μ is moderate, wherein the MPEP will peel off the critical manifold, to determine the changing point of the MPEP on the critical manifold, an effective numerical algorithm is given. In brief, in this paper, a complete investigation on the structural changes of the MPEPs of a fast-slow insect outbreak system under different values of μ is given, and the results of the numerical simulations match well with the analytical ones.

Simultaneous Joint Lower and Upper record values Probability Laws for Absolutely Continuous or Discrete Data

This paper investigates the probability density function (pdf) of the \((2n-1)\)-vector \((n\geq 1)\) of both lower and upper record values for a sequence of independent random variables with common \textit{pdf} \(f\) defined on the same probability space, provided that the lower and upper record times are finite up to \(n\). A lot is known about the lower or the upper record values when they are studied separately. When put together, the challenges are far complicated. The rare results in the literature still present some flaws. This paper begins a new and complete investigation with a few number of records: (n=2\) and \(n=3\). Lessons from these simple cases will allow addressing the general formulation of simultaneous joint lower-upper records.

Enhancing the Magnetization, Dielectric Loss and Photocatalytic Activity of Co-cu Ferrite Nanoparticles Via the Substitution of Rare Earth Ions

This study reports the impact of lanthanum substituted Co-Cu ferrite nanoparticles on the RhB dye disposal. Moreover, a complete investigation for the structural, magnetic and optical properties for Co0.5Cu0.5LaxFe2-xO4 (CCL) nanoferrites was executed. These nanocrystals synthesized via a combustion approach with a peculiar lattice parameter behavior; which discussed through three hypotheses. STEM-EDX micrographs of some selective samples confirm the nanocrystalline nature with presence of all constituents’ chemical elements CCL nanoferrites. The saturation magnetization of CCL nanoferrites was tuned with La3+ ions substitution. Contrary to the expected results, anisotropy constant introduced a decrement behavior with La/Fe substitution process. The microwave frequency (ωM) values for all CCL nanoparticles are in the range 11.87 GHz–9.46 GHz. The band gap has a peculiar behavior; a red shift and followed by a blue one. Through photodegradation testing, we explicate the RhB degradation mechanisms over our CCL nanoferrites. The nanoferrite Co0.5Cu0.5La0.15Fe1.85O4 has a moderate saturation magnetization, highest coercivity, and lowest loss which is a suitable candidate for data recording applications, furthermore can be utilized as a photocatalyst for RhB effluents removal with degradation efficiency 94.50% at 180 min solar radiation.

The curious case of a massive right heart thrombosis: a case report

Background Intraventricular masses are a relatively rare condition ranging from asymptomatic to potentially life-threatening situations. Case summary Herein, we report a case of a 49-year-old woman under investigation for a massive right ventricular (RV) mass who underwent complete investigation for possible differential diagnosis, in the suspect of RV tumour. Multimodality imaging with cardiac computed tomography and magnetic resonance imaging showed the presence of a massive thrombus partially obliterating the right ventricle. Surgical removal of the mass showed a large area of stratified thrombosis with an underlying area of endocardial fibrosis. The patient has been then discharged in good clinical condition and with lifetime oral anticoagulation. Discussion Massive RV thrombosis is a rare yet potentially fatal condition. Invasive management is preferable and lifetime anticoagulation is required to reduce possible downstream thrombotic complications.

Optimization of a Gate Distribution Layout to Compensate the Current Imbalance Generated by the 3D Geometry of a Railway Inverter

The impact of the stray inductances originated from interconnects in power electronics becomes crucial with the next generation of SiC devices. This paper shows that the existing layout of a railway inverter, operating with Si IGBTs already exhibits a dynamic current imbalance between paralleled modules. This will not allow using this geometry with SiC MOSFETs. A complete investigation of the electromagnetic origin of this issue has been performed. A generic circuit model has been proposed to establish a cabling rule to design a Gate Distribution Printed Circuit Board (PCB) in such a way that it compensates the power dissymmetry. An optimization strategy has been used to obtain a new geometry of this PCB, which has been validated with a time domain simulation.

Note on dark energy and cosmic transit in a scale-invariance cosmology

In general, the laws of physics are not invariant under a change of scale. To find out whether the “scale-invariance hypothesis” corresponds to nature or not, a careful examination to its implications is required. As a consequence, the scale-invariance cosmological models need to be carefully checked with many tests in order to confirm or disconfirm them. In this paper, three different toy models have been introduced in the framework of a scale-invariance cosmology to examine dark energy and cosmic transit. Although cosmic transit exists in the three models, the pressure stays always negative during cosmic evolution. In addition, there is always a singularity in the evolution of the equation of state parameter which is not suitable for a complete investigation of dark energy evolution. The undesirable features of the parameters have been discussed, and a comparison with other cosmological contexts has been done.

Hyperhomocysteinemia and Dementia Associated With Severe Cortical Atrophy, but No Amyloid Burden

We report a case of a 77 years old patient who was admitted to our memory clinic because of progressive gait impairment and amnestic cognitive decline associated with extrapyramidal symptoms and behavioral changes. The clinical picture was consistent with a possible diagnosis of Alzheimer’s Disease associated with parkinsonian symptoms or with a Parkinson Plus syndrome. After a complete investigation, she was found to have a high plasma level of homocysteine due to homozygous methylene-tetrahydrofolate reductase (MTHFR) gene C665 T polymorphism, cognitive and motor impairment were associated with a severe cortical atrophy and mild subcortical vascular disease. PET neuroimaging excluded a significant amyloid load. Clinically, she showed improvement of the movement disorder and functional status after folate integration plus levodopa and memantine administration. We concluded for a primary degenerative dementia with movement impairment associated with persistent hyperhomocysteinemia. We hypothesized that neurodegeneration is driven by mechanisms linked to homocysteine metabolism possibly associated with tauopathy.

MEMORY FORENSIC: ACQUISITION AND ANALYSIS OF MEMORY AND ITS TOOLS COMPARISON

The enhancement of technology has led to a considerable amount of growth in number of cases pertaining to cyber-crime and has raised an enormous challenge to tackle it effectively. There are various cyber forensic techniques and tools used to recover data from the devices to tackle cyber-crime. Present research paper focuses on performing memory forensic and analyzes the memory which contains many pieces of information relevant to forensic investigation, such as username, password, cryptographic keys, deleted files, deleted logs, running processes; that can be helpful to investigate the cyber-crime pining down the accused. The three main steps followed in memory forensic are acquiring, analyzing and recovering. Recovery of the evidences of crime from the volatile memory can be possible with the knowledge of different tools and techniques used in memory forensic. However, it is always tough to analyze volatile memory as it stays for a very short period. Not all tools can be used for memory forensic in every situation and therefore, it is important to have the knowledge of tools before applying to solve a particular cyber-crime. It is yet to establish on using a single tool for complete investigation, however, most of the tools used are successful in providing reasonable evidences. The present research paper provides an insight on analyzing the memory that stores relevant data, collection of evidences from the device(s), extraction of essential data using different memory forensic tools, tools useful for various purposes and the best suited tool for a particular situation.

Dynamics of a Prey–Predator System with Foraging Facilitation in Predators

The dynamics of a prey–predator system with foraging facilitation among predators are investigated. The analysis involves the computation of many semi-algebraic systems of large degrees. We apply the pseudo-division reduction, real-root isolation technique and complete discrimination system of polynomial to obtain the parameter conditions for the exact number of equilibria and their qualitative properties as well as do a complete investigation of bifurcations including saddle-node, transcritical, pitchfork, Hopf and Bogdanov–Takens bifurcations. Moreover, numerical simulations are presented to support our theoretical results.

A Complete Investigation of the Effect of External Force on a 3D Megastable Oscillator

Multistability is an essential topic in nonlinear dynamics. Recently, two critical subsets of multistable systems have been introduced: systems with extreme multistability and systems with megastability. In this paper, based on a newly introduced megastable system, a megastable forced oscillator is introduced. The effect of adding a forcing term and its parameters on the dynamical behavior of the designed system is investigated. By the help of bifurcation diagram and Lyapunov exponents, it is shown that the modified oscillator can show a variety of dynamical solutions including limit cycle, torus, and strange attractor.