The optimal model of employment and entrepreneurship models in colleges and universities based on probability theory and statistics

The paper relies on the practice process of entrepreneurship education in colleges and universities to carry out research. It summarizes the optimal models suitable for students’ employment and entrepreneurship based on statistical analysis using the probability theory. We built a pyramid structured model of college students’ entrepreneurial ability based on this model. The thesis uses statistical methods to carry out a factor analysis of various abilities. It provides a basis for the adjustment and implementation of employment-oriented entrepreneurship education models in colleges and universities.

Cost-benefit evaluation of management strategies for an invasive amphibian with a stage-structured model

Management strategies for invasive populations should be designed to maximise efficacy and efficiency, i.e. to accomplish their goals while operating with the least resource consumption. This optimisation is often difficult to achieve in stage-structured populations, because costs, benefits and feasibility of removing individuals may vary with stage. We use a spatially-explicit stage-structured model to assess efficacy of past, present and alternative control strategies for invasive guttural toads, Sclerophrys gutturalis, in Cape Town. The strategies involve removal of variable proportions of individuals at different life-history stages and spatial scales. We also quantify the time necessary to implement each strategy as a proxy of financial resources and we correct strategy outcomes by implementation of time to estimate efficiency. We found that the strategy initially pursued in Cape Town, which did not target any specific stage, was less efficient than the present strategy, which prioritises adult removal. The initial strategy was particularly inefficient because it did not reduce the population size despite allocating consistent resources to remove eggs and tadpoles. We also found that such removal might be detrimental when applied at high levels. This counter-intuitive outcome is due to the ‘hydra effect’: an undesired increase in population size caused by removing individuals before overcompensatory density dependence. Strategies that exclusively remove adults ensure much greater management efficiency than those that also remove eggs and tadpoles. Available management resources should rather be allocated to increase the proportion of adult guttural toads that are removed or the spatial extent at which this removal is pursued.

Possible future waves of SARS-CoV-2 infection generated by variants of concern with a range of characteristics

Viral reproduction of SARS-CoV-2 provides opportunities for the acquisition of advantageous mutations, altering viral transmissibility, disease severity, and/or allowing escape from natural or vaccine-derived immunity. We use three mathematical models: a parsimonious deterministic model with homogeneous mixing; an age-structured model; and a stochastic importation model to investigate the effect of potential variants of concern (VOCs). Calibrating to the situation in England in May 2021, we find epidemiological trajectories for putative VOCs are wide-ranging and dependent on their transmissibility, immune escape capability, and the introduction timing of a postulated VOC-targeted vaccine. We demonstrate that a VOC with a substantial transmission advantage over resident variants, or with immune escape properties, can generate a wave of infections and hospitalisations comparable to the winter 2020-2021 wave. Moreover, a variant that is less transmissible, but shows partial immune-escape could provoke a wave of infection that would not be revealed until control measures are further relaxed.

Students’ Perception of English Pronunciation Application in Pronouncing Ending –s

Using English Pronunciation in understanding ending –s is one technique to increase the students’ competence, focusing in pronunciation, like in pronouncing ending –s. In digital era, using English Pronunciation in understanding ending –s is the common technique since the students are actively getting involved in gadget. The researchers need in evaluating students’ perception on using English Pronunciation in understanding pronunciation of ending –s. The aim of this research is to investigate students’ perception about the use of English Pronunciation in understanding ending –s. The method employed in this research was qualitative, and it was explained descriptively. The third year semester students at STBA Persada Bunda that used this English Pronunciation application in understanding ending –s were the population as well as the sample of this research. There were 10 students of STBA Persada Bunda in academic year 2018/2019 involved in this study. To collect the data, all students were asked before using English Pronunciation in understanding ending –s from online application and offline one. Then, the researchers distributed six questions related to the students’ perception of using English Pronunciation in understanding ending –s by using interview with semi structured model. The result showed that, most of the third year students were pushed to use English Pronunciation in understanding ending –s in obtaining knowledge and joyful while learning process about voiced sounds, voiceless sound, and sibilant sound. In conclusion, the research about students perception is positive response by using English Pronunciation of pronouncing ending –s.

Global Stability and Hopf Bifurcation for a Stage Structured Model with Competition for Food

Considering the mature condition of any individual to have eaten a specific amount of food during the entire period that it can spend at its immature stage, we propose a size-structured model by a first-order quasi-linear partial differential equation. The model can be firstly reduced to a single state-dependent delay differential equation and then to a constant delay differential equation. The state-dependent delay represents intra-specific competition among individuals for limited food resources. A complete analysis of the global dynamics on the positivity and boundedness of solutions, global stability for each equilibrium and Hopf bifurcation is carried out. Our results imply that the delay leads to instability that is shown by a simple example of a certain structured population model.