The suspicion of mediastinal alterations, always includes in its initial study, the chest radiography. The identification of mediastinal alterations in the X-ray is a priority. The knowledge of the mediastinal references and the identification of their alterations allows the suspicion of a pathology specific to each of the mediastinal spaces. When the semiology of mediastinal lesions, their location and the three most frequent pathologies are taken into account, the possibility of having an etiological diagnosis increases^[1]. This is a review article based on a detailed literature search, in which radiological mediastinal references are studied, with emphasis on the epidemiological data of each one of them.

The structure and diversity of tree species in a temperate forest in northwestern Mexico was characterized. Nine sampling sites of 50 × 50 m (2,500 m²) were established, and a census of all tree species was carried out. Each individual was measured for total height and diameter at breast height. The importance value index (IVI) was obtained, calculated from the variable abundance, dominance and frequency. The diversity and richness indices were also calculated. A total of 12 species, four genera and four families were recorded. The forest has a density of 575.11 individuals and a basal area of 23.54/m². The species of Pinus cooperi had the highest IVI (79.05%), and the Shannon index of 1.74.

Effective small and medium enterprise (SME) leadership demands creative solutions to ensure organisations survive and thrive during the turbulent times that COVID-19 continues to bring. This paper explores how SME leaders (in micro and small organisations) prioritise and access the skills and development needed to provide effective and sustainable leadership to organisations, focusing on the role of resilience and the benefits it provides. Participants were selected through purposive and snowballing sampling. Online surveys and semi-structured interviews were conducted and provided qualitative data that contributes to an understanding of the role of resilience and the view of participants as to what is needed to effectively respond to a dynamic environment. Evidence shows that SME leaders prioritise learning and development opportunities that provide demonstrable benefits throughout the organisation. Building business resilience remains a fuzzy concept; however, viewing resilience as a multi-level construct offers benefits when designing and delivering development opportunities. It has been found that networking, partnerships, and relationship building promote resilience and may offer a solution to how to embed resilience building into development opportunities that SME leaders value and wish to engage with. This article contributes by illustrating and exploring leadership development within SMEs during a period of unexpected and untested uncertainty. The pandemic caused major shock waves within business communities, and SMEs were significantly affected. The research is limited in that it is expected to be a once-in-a lifetime event, and as such conditions may not be replicable, learning opportunities for other ‘shock’ events are possible. The findings of this paper have relevance to practice in that, while the event may be one-off, shocks to the business environment are not.

The purpose of this study is to predict the frequency of mortality from urban traffic injuries for the most vulnerable road users before, during and after the confinement caused by COVID-19 in Santiago de Cali, Colombia. Descriptive statistical methods were applied to the frequency of traffic crash frequency to identify vulnerable road users. Spatial georeferencing was carried out to analyze the distribution of road crashes in the three moments, before, during, and after confinement, subsequently, the behavior of the most vulnerable road users at those three moments was predicted within the framework of the probabilistic random walk. The statistical results showed that the most vulnerable road user was the cyclist, followed by motorcyclist, motorcycle passenger, and pedestrian. Spatial georeferencing between the years 2019 and 2020 showed a change in the behavior of the crash density, while in 2021 a trend like the distribution of 2019 was observed. The predictions of the daily crash frequencies of these road users in the three moments were very close to the reported crash frequency. The predictions were strengthened by considering a descriptive analysis of a range of values that may indicate the possibility of underreporting in cases registered in the city’s official agency. These results provide new elements for policy makers to develop and implement preventive measures, allocate emergency resources, analyze the establishment of policies, plans and strategies aimed at the prevention and control of crashes due to traffic injuries in the face of extraordinary situations such as the COVID-19 pandemic or other similar events.

This paper provides a concise historical analysis of the political economy of privatization in Algeria, Morocco, and Tunisia from the 1980s to 2007, a period that witnessed the emergence of privatization as a primary policy tool to reform the public sector. The paper examines the influence of political history, macroeconomic considerations, and International Development Agencies (IDAs) on the early privatization processes in these North African countries. Despite shared developmental trajectories, internal and external factors had a significant impact on the outcomes of economic liberalization. The paper aims to answer the following key questions: What were the underlying political-economic factors driving privatization, and how successful was it in achieving the promised economic growth? Through a focused analysis of each country’s contextual factors, privatization processes, and outcomes, the paper contributes valuable insights into the nuanced dynamics shaping privatization in developing countries.

With the rapid development of modern AI painting, Chinese university fine arts education is facing numerous challenges and opportunities. This paper analyzes the impact of modern AI painting on traditional art creation and its implications for student skill development. Additionally, it explores the key areas where Chinese university fine arts education needs to transform, including curriculum, teaching methods, and teacher training, while proposing corresponding strategies.