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The aim of the paper is to assess the causes of spatial variations in labour productivity of Italian regions using the gravitational model of economic growth. The model is an extension of Robert Solow’s economic growth model. The model parameters are calibrated using historical data and numerical simulations of the long-run equilibrium states of the model are carried out. The scenarios considered in the paper vary in forecast investment rates, employment growth rates and urbanisation rates. Based on the results of numerical simulations, it is claimed that to achieve the full convergence in labour productivity, it is necessary to maintain higher investment rates in the south of the country than in Lombardy (by about 4%–11%), and to keep investment rates in central and northern Italy at a similar level as in Lombardy. The fall in investment has affected the poorest regions, Southern Italy, the most, followed by central Italy and the richest regions of the north of the country the least.

The present study explores the synthesis and bio-safety evaluation of gadolinium-doped carbon quantum dots (GCQDs) as a potential dual-contrast agent for diagnostic imaging. GCQDs exhibit both fluorescent and magnetic properties, making them suitable for UV–Vis and magnetic resonance imaging (MRI). The synthesis of GCQDs was achieved via hydrothermal treatment, incorporating gadolinium into the carbon quantum dot matrix. The magnetic properties of GCQDs were analyzed, showing significantly enhanced values compared to gadobutrol, a common MRI contrast agent. However, synthesis constraints limit the gadolinium content achievable in nanodots. To assess the safety of GCQDs, their effects on the embryonic development of zebrafish (Danio rerio) were examined. Various concentrations of GCQDs were tested, observing mortality rates, hatchability, malformations, heartbeats, spontaneous movement, and GCQDs uptake. Dialysis studies indicated that gadolinium ions are incorporated into the internal structure of the carbon nanodots. Zebrafish toxicity tests revealed that while survival rates were comparable to control groups, hatchability decreased significantly with higher gadolinium concentrations in GCQDs. Fluorescence microscopy showed no statistical differences in the fluorescence intensity between groups. These findings suggest that GCQDs could serve as an effective dual-contrast agent, combining the optical imaging capabilities of CQDs with the enhanced MRI contrast provided by gadolinium. This study underscores the need for further research on the synthesis methods and biological interactions of GCQDs to ensure their safety and efficacy in medical applications. [ABSTRACT FROM AUTHOR]

Background: The measurement of handgrip force responses is important in many aspects, for example: to complement neurological assessments, to investigate the contribution of muscle mass in predicting functional outcomes, in setting realistic treatment goals, evaluating rehabilitation strategies. Normative data about handgrip force can assist the therapist in interpreting a patient's results compared with healthy individuals of the same age and gender and can serve as key decision criteria. In this context, establishing normative values of handgrip strength is crucial. Hence, the aim of the this study is to develop a tool that could be used both in rehabilitation and in the prevention of work-related musculoskeletal disorders. This tool takes the form of population-specific predictive equations, which express maximum handgrip force as a function of age. Methodology: In order to collect data from studies measuring maximum handgrip force, three databases were searched. The search yielded 5,058 articles. Upon the removal of duplicates, the screening of abstracts and the full-text review of potentially relevant articles, 143 publications which focussed on experimental studies on various age groups were considered as fulfilling the eligibility criteria. A comprehensive literature review produced 1,276 mean values of maximum handgrip force. Results: A meta-analysis resulted in gender- and world region-specific (general population, USA, Europe and Asia) equations expressing maximum force as a function of age. The equations showed quantitative differences and trends in maximum handgrip force among age, gender and national groups. They also showed that values of maximum handgrip force are about 40% higher for males than for females and that age-induced decrease in force differs between males and females, with a proved 35% difference between the ages of 35 and 75. The difference was lowest for the 60–64 year olds and highest for the 18–25 year-olds. The equations also showed that differences due to region are smaller than those due to age or gender. Conclusions: The equations that were developed for this study can be beneficial in setting population-specific thresholds for rehabilitation programmes and workstation exposure. They can also contribute to the modification of commonly used methods for assessing musculoskeletal load and work-related risk of developing musculoskeletal disorders by scaling their limit values. [ABSTRACT FROM AUTHOR]

The paper presents the importance of electricity parameters in transient states for assessing the ability of an aircraft's power grid to self-regulate. It has been shown that the quality of electrical energy of an aircraft's power system is influenced by its operating time. Aging changes resulting from long-term operation of the power system cause deterioration of electrical energy parameters, which directly affects airworthiness and flying safety. Maintaining standard energy parameters in transient states is very important to ensure proper operation of the aircraft. The article describes the method of measuring the quality of electricity in transient states, and using the example of the DC power system of the Su 22 aircraft, the essence of its network diagnostics in transient states is presented. Also presented are sample results of research conducted by the authors regarding changes in electrical energy parameters in transient states of the Su 22 aircraft, obtained during its many years of operation. [ABSTRACT FROM AUTHOR]

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The described model of economic growth under conditions of an epidemic does not directly refer to the social and economic situation in the years 2020 and 2021, i.e. to the COVID-19 pandemic. It is aimed to identify the consequences of any epidemic leading to severe social losses (high percentages of the infected and dead, limited interpersonal contacts as a result of lockdown, a lowered level of general individual and social well-being) and economic losses (a fall in production as a result of the collapse of aggregate demand and a reduction in the supply capacity of the economy, and consequently a decreased rate of capital accumulation). The described epidemiological-economic model combines the SIR epidemiological model from 1927 (with its modification proposed in 2020 by Bärwolff) and the neoclassical growth model proposed by Solow in 1956. The authors expanded the concept by lockdown restrictions with various levels of their severity, considering specific rules for their implementation, and by guidelines for scenario analyses of changes in the value of social and economic activity index, in the value of aggregate production, in the capital stock accumulated in the economy and in social utility. The effect of an epidemic on mediumterm economic growth was also considered, for various levels of economic development (measured by the distance of input capital stock from that formed in a long-term equilibrium in the Solow model). The principal conclusions drawn from the discussion are listed below. First, the introduction of the same restrictions imposed on social and economic activity throughout the territory of a country poses a considerable risk of error in assuming a uniform spread of the epidemic. Second, a rapid introduction of lockdown measures has a stronger effect on accumulated social and economic activity than a continual process of gradual imposing and lifting restrictions on that activity. Third, a scenario of a rapidly imposed severe lockdown has the most drastic consequences for the economy, causing both the sharpest drop in production, the longest time of remaining on the path of relatively lowest growth, and the most dramatic expected accumulated decrease in production. Similar conclusions are drawn as to the changes in social utility. [ABSTRACT FROM AUTHOR]