Deciphering the local Interstellar spectra of primary cosmic ray species with HelMod

Local interstellar spectra (LIS) of primary cosmic ray (CR) nuclei, such as helium, oxygen, and mostly primary carbon are derived for the rigidity range from 10 MV to ~200 TV using the most recent experimental results combined with the state-of-the-art models for CR propagation in the Galaxy and in the heliosphere. Two propagation packages, GALPROP and HelMod, are combined into a single framework that is used to reproduce direct measurements of CR species at different modulation levels, and at both polarities of the solar magnetic field. The developed iterative maximum-likelihood method uses GALPROP-predicted LIS as input to HelMod, which provides the modulated spectra for specific time periods of the selected experiments for model-data comparison. The interstellar and heliospheric propagation parameters derived in this study are consistent with our prior analyses using the same methodology for propagation of CR protons, helium, antiprotons, and electrons. The resulting LIS accommodate a variety of measurements made in the local interstellar space (Voyager 1) and deep inside the heliosphere at low (ACE/CRIS, HEAO-3) and high energies (PAMELA, AMS-02).Comment: 13 pages, 13 figures, 6 tables, ApJ in press. arXiv admin note: text overlap with arXiv:1704.0633

HelMod in the works: from direct observations to the local interstellar spectrum of cosmic-ray electrons

The local interstellar spectrum (LIS) of cosmic-ray (CR) electrons for the energy range 1 MeV to 1 TeV is derived using the most recent experimental results combined with the state-of-the-art models for CR propagation in the Galaxy and in the heliosphere. Two propagation packages, GALPROP and HelMod, are combined to provide a single framework that is run to reproduce direct measurements of CR species at different modulation levels, and at both polarities of the solar magnetic field. An iterative maximum-likelihood method is developed that uses GALPROP-predicted LIS as input to HelMod, which provides the modulated spectra for specific time periods of the selected experiments for model-data comparison. The optimized HelMod parameters are then used to adjust GALPROP parameters to predict a refined LIS with the procedure repeated subject to a convergence criterion. The parameter optimization uses an extensive data set of proton spectra from 1997-2015. The proposed CR electron LIS accommodates both the low-energy interstellar spectra measured by Voyager 1 as well as the high-energy observations by PAMELA and AMS-02 that are made deep in the heliosphere; it also accounts for Ulysses counting rate features measured out of the ecliptic plane. The interstellar and heliospheric propagation parameters derived in this study agree well with our earlier results for CR protons, helium nuclei, and anti-protons propagation and LIS obtained in the same framework.Comment: 11 pages, 14 figures, 4 tables; ApJ, in pres

¿Es capaz “ChatGPT” de aprobar el examen MIR de 2022? Implicaciones de la inteligencia artificial en la educación médica en España

Artificial intelligence and natural language processing models have made an entrance into the field of medical education. Among them, the ChatGPT model has been used to try to solve different international medical exams. However, there is no literature which addresses this phenomenon in Europe or other Spanish-speaking countries. The present paper aims at evaluating the ability to answer questions of the ChatGPT model in the 2022 MIR, which grants access to the Spanish postgraduate training system. To this end, a cross-sectional descriptive analysis has been carried out in which all the questions of the 2022 MIR exam have been solved by this technology. ChatGPT was able to answer 51.4% of the questions correctly, which is approximately 69 net answers on said exam. According to estimates for this year, it would have obtained a 7688 position, which would be slightly below the population’s median, but would allow it to pass the cut-off score and choose a large number of specialties. These results are similar to those obtained in the existing literature, slightly worse to those obtained  by this tool in the American USMLE exams. The development of AI is  an opportunity for medical students and residents to learn, but it is also a risk in many ways. It is essential to train future specialists in the new reality of artificial intelligence so that they are able to use them and obtain benefits in a reasoned and safe manner.La inteligencia artificial y los modelos de procesamiento de lenguaje natural han irrumpido con fuerza en el ámbito de la educación médica. Entre ellos, el modelo ChatGPT ha sido utilizado para intentar resolver distintos exámenes de medicina a nivel internacional. Sin embargo, prácticamente no existe literatura en Europa ni países de habla hispana. El presente trabajo pretende evaluar la capacidad de responder preguntas del modelo ChatGPT en el examen MIR 2022. Para ello, se ha llevado a cabo un análisis transversal y descriptivo en el que se han introducido la totalidad de las preguntas del examen MIR 2022 en dicho modelo. ChatGPT ha sido capaz de responder de manera acertada un 51,4% de las preguntas, lo que supone aproximadamente 69 netas en el examen MIR. Según estimaciones para este año, obtendría un 7688, lo que estaría ligeramente por debajo de la mediana de la población presentada, pero que le permitiría pasar la nota de corte y escoger un gran número de especialidades. El resultado es similar a los obtenidos en la bibliografía previa, ligeramente por debajo de los resultados obtenidos por dicha herramienta en los exámenes americanos USMLE. Este tipo de modelos suponen una oportunidad para el aprendizaje de los estudiantes de medicina y los residentes, pero también supone un riesgo en muchos sentidos. Es fundamental formar a los futuros especialistas en la nueva realidad de la inteligencia artificial para que sean capaces de utilizarlas y obtener beneficios de manera razonada y segura

Shareholder Theory/Shareholder Value

Shareholder theory states that the primary objective of management is to maximize shareholder value. This objective ranks in front of the interests of other corporate stakeholders, such as employees, suppliers, customers, and society.Shareholder theory argues that shareholders are the ultimate owners of a corporate’s assets, and thus, the priority for managers and boards is to protect and grow these assets for the benefit of shareholders. Shareholder theory assumes that shareholders value corporate assets with two measurable metrics, dividends and share price. There-fore, management should make decisions that maximize the combined value of dividends and share price increases. However, shareholder theory fails to consider that shareholders and corporates may have other objectives that are not based on financial performance. For example, as early as1932, Berle and Means argued that corporations have a variety of purposes and interests including encouraging entrepreneurship, innovation, and building communities. This wider view is gaining more traction in recent decades as evidenced by an increased interest in ethical investment funds.This suggests that shareholders and potential shareholders are not only interested in financial gains but are also interested in corporates being socially responsible (Kyriakou2018). Therefore shareholder value creation is important; however,it needs to be balanced with other stakeholders’ interests. This is referred to as an enlightened approach to shareholder value maximization

Clustering dynamics of Lagrangian tracers in free-surface flows

We study the formation of clusters of passive Lagrangian tracers in a non-smooth turbulent flow in a flat free-slip surface as a model for particle dynamics on free surfaces. Single particle and pair dispersion show different behavior for short and large times: on short times particles cluster exponentially rapidly until patches of the size of the divergence correlation length are depleted; on larger times the pair dispersion is dominated by almost ballistic hopping between clusters. We also find that the distribution of particle density is close to algebraic and can trace this back to the exponential distribution of the divergence field of the surface flow.Comment: 5 pages, 5 Postscript figure

Competing biosecurity and risk rationalities in the Chittagong poultry commodity chain, Bangladesh

This paper anthropologically explores how key actors in the Chittagong live bird trading network perceive biosecurity and risk in relation to avian influenza between production sites, market maker scenes and outlets. They pay attention to the past and the present, rather than the future, downplaying the need for strict risk management, as outbreaks have not been reported frequently for a number of years. This is analysed as ‘temporalities of risk perception regarding biosecurity’, through Black Swan theory, the idea that unexpected events with major effects are often inappropriately rationalized (Taleb in The Black Swan. The impact of the highly improbable, Random House, New York, 2007). This incorporates a sociocultural perspective on risk, emphasizing the contexts in which risk is understood, lived, embodied and experienced. Their risk calculation is explained in terms of social consent, practical intelligibility and convergence of constraints and motivation. The pragmatic and practical orientation towards risk stands in contrast to how risk is calculated in the avian influenza preparedness paradigm. It is argued that disease risk on the ground has become a normalized part of everyday business, as implied in Black Swan theory. Risk which is calculated retrospectively is unlikely to encourage investment in biosecurity and, thereby, points to the danger of unpredictable outlier events

Pentoxifylline, tocopherol, and sequestrectomy are effective for the management of advanced osteoradionecrosis of the jaws—a case series

Background: The aim of the present study was to evaluate the efficacy of pentoxifylline and tocopherol for the management of osteoradionecrosis of the jaws. / Methods: Twenty-five patients diagnosed with osteoradionecrosis of the jaws treated with pentoxifylline 400 mg + tocopherol 400 mg three times daily (tid) were evaluated. Clinical records and image tests were reviewed. All patients were previously submitted to head and neck radiation therapy and presented with a clinical and radiographic diagnosis of osteoradionecrosis of the jaws. / Results: Following therapy with pentoxifylline and tocopherol, 76% (19/25) of the patients showed complete mucosal healing, in which 47.3% (9/19) did not undergo sequestrectomy. From this particular group, 77.7% (7/9) were in stage I and 33.3% (3/9) used the protocol for up to 3 months. Among those who underwent to sequestrectomy, complete mucosal healing was observed in 52.7% (10/19). Among these, 60% (6/10) were in stage I and 100% of the patients were using the protocol for more than 3 months. In all other patients, partial healing of the mucosa was observed since they presented advanced disease. These represented 24% of the sample (6/25), 66.6% (4/6) were in stage III, and 60% (4/6) used the protocol for over 6 months. / Conclusion: Pentoxifylline and tocopherol may provide effective management of osteoradionecrosis of the jaws, and the association with sequestrectomy may avoid major surgical procedures