1,167 research outputs found
Intruder States and their Local Effect on Spectral Statistics
The effect on spectral statistics and on the revival probability of intruder
states in a random background is analysed numerically and with perturbative
methods. For random coupling the intruder does not affect the GOE spectral
statistics of the background significantly, while a constant coupling causes
very strong correlations at short range with a fourth power dependence of the
spectral two-point function at the origin.The revival probability is
significantly depressed for constant coupling as compared to random coupling.Comment: 18 pages, 10 Postscript figure
Data-driven estimation of the instantaneous reproduction number and growth rates for the 2022 monkeypox outbreak in Europe
Objective: To estimate the instantaneous reproduction number and the epidemic growth rates for the 2022 monkeypox outbreaks in the European region.
Methods: We gathered daily laboratory-confirmed monkeypox cases in the most affected European countries from the beginning of the outbreak to September 23, 2022. A data-driven estimation of the instantaneous reproduction number is obtained using a novel filtering type Bayesian inference. A phenomenological growth model coupled with a Bayesian sequential approach to update forecasts over time is used to obtain time-dependent growth rates in several countries.
Results: The instantaneous reproduction number for the laboratory-confirmed monkeypox cases in Spain, France, Germany, the UK, the Netherlands, Portugal, and Italy. At the early phase of the outbreak, our estimation for , which can be used as a proxy for the basic reproduction number , was ( CI ) for Spain, ( CI ) for France, ( CI ) for Germany, ( CI ) for the UK, ( CI ) for the Netherlands, ( CI ) for Portugal, ( CI ) for Italy. Cumulative cases for these countries present subexponential rather than exponential growth dynamics.
Conclusions: Our findings suggest that the current monkeypox outbreaks present limited transmission chains of human-to-human secondary infection so the possibility of a huge pandemic is very low. Confirmed monkeypox cases are decreasing significantly in the European region, the decline might be attributed to public health interventions and behavioral changes in the population due to increased risk perception. Nevertheless, further strategies toward elimination are essential to avoid the subsequent evolution of the monkeypox virus that can result in new outbreaks.Non
The erosion of nongambling spheres by smartphone gambling: a qualitative study on workplace and domestic disordered gambling
The potential dangers of internet-based gambling as compared with more traditional land-based gambling have been increasingly investigated over the past decade. The general consensus appears to be that although internet gambling might not be a more dangerous medium for gambling per se, the 24/7 availability it generates for problem gamblers, however, is. Because smartphones have become the most used way of gambling online, internet gambling must, therefore, be further subcategorized according to the device by which it is accessed. This study examines the issue by exploring the views of smartphone gamblers undergoing treatment for gambling disorder in focus group settings (N=35). Utilizing thematic analysis, the paper shows that smartphone gambling has colonized spaces previously regarded as nongambling spheres. The workplace, especially in male-dominated contexts, emerged as an accommodator and stimulator of gambling behavior, raising issues of productivity rather than criminality. Domestic gambling was mostly characterized by an invasion of bathroom and bedtime spheres of intimacy. The study examines the implications of prevention and treatment, focusing on the minimization of exposure to gambling stimuli, the erosion of intimacy that recovering gamblers must endure, and the necessity of embracing a broader definition of gambling-related harm
Strategic Teaching Plan For The Training of Students Towards. The Creation and Management of Family Businesses in Barcelona, Spain
Family businesses are one of the main drivers of the economy, hence the relevance of studying them. There are several contributions from national specialists on the subject of family businesses, but the studies and tools developed with the purpose of to professionalize to this type of companies are insufficient. Therefore, the main objective of this research is to design a strategic teaching plan with interdisciplinary characteristics for the training of students towards the creation and management of family businesses in Barcelona, Spain, responding to the needs and demands of society. The methodology used is of a quantitative nature, with a scope according to the level of knowledge obtained with said research: exploratory-descriptive. It also required a non-experimental descriptive transactional type, all in order to investigate the incidence and provide a vision of the study community. The unit of analysis used was the teaching staff of the area of Organization of companies. Based on the proposed strategic teaching plan, it is intended that teachers first acquire the same skills that students are required to manage and lead family businesses. Key words: strategic plan, family businesses, teaching competencies JEL Classification: M13, M19, M53, M5
Optimal vaccine allocation for the control of sexually transmitted infections
The burden of sexually transmitted infections (STIs) poses a challenge due to its
large negative impact on sexual and reproductive health worldwide. Besides simple
prevention measures and available treatment efforts, prophylactic vaccination is a
powerful tool for controlling some viral STIs and their associated diseases. Here, we
investigate how prophylactic vaccines are best distributed to prevent and control STIs.
We consider sex-specific differences in susceptibility to infection, as well as disease
severity outcomes. Different vaccination strategies are compared assuming distinct
budget constraints that mimic a scarce vaccine stockpile. Vaccination strategies are
obtained as solutions to an optimal control problem subject to a two-sex Kermack–
McKendrick-type model, where the control variables are the daily vaccination rates
for females and males. One important aspect of our approach relies on conceptualizing
a limited but specific vaccine stockpile via an isoperimetric constraint. We solve the
optimal control problem via Pontryagin’sMaximum Principle and obtain a numerical
approximation for the solution using a modified version of the forward–backward
sweep method that handles the isoperimetric budget constraint in our formulation. The
results suggest that for a limited vaccine supply (20%–30%vaccination coverage), onesex
vaccination, prioritizing females, appears to be more beneficial than the inclusion
of both sexes into the vaccination program.Whereas, if the vaccine supply is relatively
large (enough to reach at least 40% coverage), vaccinating both sexes, with a slightly
higher rate for females, is optimal and provides an effective and faster approach to
reducing the prevalence of the infection
Modeling spillover dynamics: understanding emerging pathogens of public health concern
The emergence of infectious diseases with pandemic potential is a major public health threat worldwide. The World Health Organization reports that about 60% of emerging infectious diseases are zoonoses, originating from spillover events. Although the mechanisms behind spillover events remain unclear, mathematical modeling offers a way to understand the intricate interactions among pathogens, wildlife, humans, and their shared environment. Aiming at gaining insights into the dynamics of spillover events and the outcome of an eventual disease outbreak in a population, we propose a continuous time stochastic modeling framework. This framework links the dynamics of animal reservoirs and human hosts to simulate cross-species disease transmission. We conduct a thorough analysis of the model followed by numerical experiments that explore various spillover scenarios. The results suggest that although most epidemic outbreaks caused by novel zoonotic pathogens do not persist in the human population, the rising number of spillover events can avoid long-lasting extinction and lead to unexpected large outbreaks. Hence, global efforts to reduce the impacts of emerging diseases should not only address post-emergence outbreak control but also need to prevent pandemics before they are established
Optimal vaccination strategies for a heterogenous population using multiple objectives: The case of L1 and L2-formulations
The choice of the objective functional in optimization problems coming from biomedical and epidemiological applications plays a key role in optimal control outcomes. In this study, we investigate the role of the objective functional on the structure of the optimal control solution for an epidemic model for sexually transmitted infections that includes a core group with higher sexual activity levels than the rest of the population. An optimal control problem is formulated to find a targeted vaccination program able to control the spread of the infection with minimum vaccine deployment. Both and objectives are considered as an attempt to explore the trade-offs between control dynamics and the functional form characterizing optimality. The results show that the optimal vaccination policies for both the and the formulation share one important qualitative property, that is, immunization of the core group should be prioritized by policymakers to achieve a fast reduction of the epidemic. However, quantitative aspects of this result can be significantly affected depending on the choice of the control weights between formulations. Overall, the results suggest that with appropriate weight constants, the optimal control outcomes are reasonably robust with respect to the or formulation. This is particularly true when the monetary cost of the control policy is substantially lower than the cost associated with the disease burden. Under these conditions, even if the formulation is more realistic from a modeling perspective, the formulation can be used as an approximation and yield qualitatively comparable outcomes
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