74 research outputs found
Metabolomics in Bariatric and Metabolic Surgery Research and the Potential of Deep Learning in Bridging the Gap
No full textDuring the past several years, there has been a shift in terminology from bariatric surgery alone to bariatric and metabolic surgery (BMS). More than a change in name, this signifies a paradigm shift that incorporates the metabolic effects of operations performed for weight loss and the amelioration of related medical problems. Metabolomics is a relatively novel concept in the field of bariatrics, with some consistent changes in metabolite concentrations before and after weight loss. However, the abundance of metabolites is not easy to handle. This is where artificial intelligence, and more specifically deep learning, would aid in revealing hidden relationships and would help the clinician in the decision-making process of patient selection in an individualized way
Comment on Salazar et al. Weight Regain after Metabolic Surgery: Beyond the Surgical Failure. J. Clin. Med. 2024, 13, 1143
No full textI read the article by Salazar J. [...
Radio Wave Propagation and Channel Modeling for Earth–Space Systems. Chapter 8 - Impact of Clouds from Ka Band to Optical Frequencies
No full textThe accurate design of earth–space systems requires a comprehensive understanding of the various propagation media and phenomena that differ depending on frequencies and types of applications. The choice of the relevant channel models is crucial in the design process and constitutes a key step in performance evaluation and testing of earth–space systems. The subject of this book is built around the two characteristic cases of satellite systems: fixed satellites and mobile satellite systems.
Radio Wave Propagation and Channel Modeling for Earth–Space Systems discusses the state of the art in channel modeling and characterization of next-generation fixed multiple-antennas and mobile satellite systems, as well as propagation phenomena and fade mitigation techniques. The frequencies of interest range from 100 MHz to 100 GHz (from VHF to W band), whereas the use of optical free-space communications is envisaged.
Examining recent research advances in space-time tropospheric propagation fields and optical satellite communication channel models, the book covers land mobile multiple antennas satellite- issues and relative propagation campaigns and stratospheric channel models for various applications and frequencies. It also presents research and well-accepted satellite community results for land mobile satellite and tropospheric attenuation time-series single link and field synthesizers.
The book examines aeronautical communications channel characteristics and modeling, relative radio wave propagation campaigns, and stratospheric channel model for various applications and frequencies. Propagation effects on satellite navigation systems and the corresponding models are also covered
Concentration in Knowledge Output:A Case of Economics Journals
No full textJournals moderate knowledge activity in economics. The activity of publishing article in professional journal forms significant part of knowledge output. Output of economics articles has been growing over the time. We examine an important question: Is there any case of institutional or location concentration in knowledge production? This paper analyses concentration indicators specific to economics journals and explores link between publication process and concentration. The analysis of various concentration measures present evidence for institutional-geographic-area-author concentration in Knowledge production in Economics. High concentration levels indicate possibility of institutional lock-in. The literature provides evidence for myopic refereeing, editorial favouritism and the presence of ‘lock-in’ effect. The achievement in journal publication is influenced by factors like institutional affiliation, propitious circumstances etc. Discussion carried out in this paper hints the possibility of causal link between unfair process and unfair outcome.Knowledge,Lotka's Law,Fourier Series
Effective colonoscopy training techniques: strategies to improve patient outcomes
No full textIoannis S Papanikolaou,1 Pantelis S Karatzas,2 Lazaros T Varytimiadis,2 Athanasios Tsigaridas,2 Michail Galanopoulos,2 Nikos Viazis,2 Dimitrios G Karamanolis21Hepato-gastroenterology Unit, 2nd Department of Internal Medicine, Attikon University General Hospital, University of Athens, 2Gastroenterology Department, Evangelismos Hospital, Athens, GreeceAbstract: Colonoscopy has substantially evolved during the last 20 years and many different training techniques have been developed in order to improve the performance of endoscopists. The most known are mechanical simulators, virtual reality simulators, computer-simulating endoscopy, magnetic endoscopic imaging, and composite and explanted animal organ simulators. Current literature generally indicates that the use of simulators improves performance of endoscopists and enhances safety of patients, especially during the initial phase of training. Moreover, newer endoscopes and imaging techniques such as high-definition colonoscopes, chromocolonoscopy with dyes spraying, and third-eye retroscope have been incorporated in everyday practice, offering better visualization of the colon and detection of polyps. Despite the abundance of these different technological features, training devices are not widely used and no official guideline or specified training algorithm or technique for lower gastrointestinal endoscopy has been evolved. In this review, we present the most important training methods currently available and evaluate these using existing literature. We also try to propose a training algorithm for novice endoscopists.Keywords: endoscopy, colonoscopy, teaching techniques, simulator, endoscopists, colon, polyp
Nutrición en la actual pandemia de COVID-19. Una revisión narrativa
No full textThe pandemic of Coronavirus Disease 2019 (COVID-19) has shocked world health authorities generating a global health crisis. The present study discusses the main finding in nutrition
sciences associated with COVID-19 in the literature. We conducted a consensus critical review using
primary sources, scientific articles, and secondary bibliographic indexes, databases, and web pages.
The method was a narrative literature review of the available literature regarding nutrition interventions and nutrition-related factors during the COVID-19 pandemic. The main search engines used
in the present research were PubMed, SciELO, and Google Scholar. We found how the COVID-19
lockdown promoted unhealthy dietary changes and increases in body weight of the population,
showing obesity and low physical activity levels as increased risk factors of COVID-19 affection
and physiopathology. In addition, hospitalized COVID-19 patients presented malnutrition and
deficiencies in vitamin C, D, B12 selenium, iron, omega-3, and medium and long-chain fatty acids
highlighting the potential health effect of vitamin C and D interventions. Further investigations are
needed to show the complete role and implications of nutrition both in the prevention and in the
treatment of patients with COVID-19.La pandemia de la enfermedad del coronavirus 2019 (COVID-19) ha conmocionado a las autoridades sanitarias mundiales generando una crisis sanitaria mundial. El presente estudio analiza el principal hallazgo en nutrición
ciencias asociadas con COVID-19 en la literatura. Realizamos una revisión crítica de consenso utilizando
fuentes primarias, artículos científicos e índices bibliográficos secundarios, bases de datos y páginas web.
El método fue una revisión de la literatura narrativa de la literatura disponible con respecto a las intervenciones nutricionales y los factores relacionados con la nutrición durante la pandemia de COVID-19. Los principales motores de búsqueda utilizados
en la presente investigación fueron PubMed, SciELO y Google Scholar. Descubrimos cómo el COVID-19
el bloqueo promovió cambios dietéticos poco saludables y aumentos en el peso corporal de la población,
mostrando la obesidad y los bajos niveles de actividad física como factores de riesgo incrementados de la afección COVID-19
y fisiopatología. Además, los pacientes hospitalizados por COVID-19 presentaban desnutrición y
deficiencias de vitamina C, D, B12, selenio, hierro, omega-3 y ácidos grasos de cadena media y larga
destacando el posible efecto sobre la salud de las intervenciones con vitamina C y D. Investigaciones adicionales son
necesario para mostrar el papel completo y las implicaciones de la nutrición tanto en la prevención como en la
tratamiento de pacientes con COVID-19.Clemente-Suárez, Vicente Javier-will be generated-orcid-0000-0002-2397-2801-600Ramos-Campo, Domingo Jesús-will be generated-orcid-0000-0002-8890-4244-600Mielgo Ayuso, Juan-will be generated-orcid-0000-0002-6554-4602-600Dalamitros, Athanasios-will be generated-orcid-0000-0003-1069-2146-600Nikolaidis, Pantelis-will be generated-orcid-0000-0001-8030-7122-600Hormeno-Holgado, Alberto Joaquin-will be generated-orcid-0000-0001-7858-661X-600Tornero Aguilera, José Francisco-will be generated-orcid-0000-0002-0747-8133-60
An Analytical Prediction Model of Time Diversity Performance for Earth-Space Fade Mitigation
No full textTime diversity (TD) has recently attracted attention as a promising and cost-efficient solution
for high-frequency broadcast satellite applications. The present work proposes a general
prediction model for the application of TD by approximating the time dynamics of rain attenuation
through the use of the joint lognormal distribution. The proposed method is tested against experimental
data and its performance is investigated with respect to the basic parameters of a satellite link
Status of Body Contouring Following Metabolic Bariatric Surgery in a Tertiary Hospital of Greece—Still a Long Way to Go
No full textObesity is a disease rather than a state, and metabolic bariatric surgery (MBS) is its most effective treatment. Body contouring surgery (BCS) is an integral part of the continuum of care following MBS, provided that the body mass index (BMI) has stabilized for an adequate period. This study is an attempt to capture the current status of BCS following MBS in Greece, based on data from one of the country’s highest-volume hospitals. We recruited patients from the Bariatric and Plastic-Reconstructive Surgery registries who had undergone both MBS and BCS and invited them to answer a structured questionnaire with components on demographics, safety and effectiveness of previous operations, quality of life (QoL), body image, social activity, sexual activity, and doctor–patient communication. Twenty-four patients participated in the survey (response rate 88.1%). The mean BMI pre-MBS was 43.8 kg/m2 and that pre-BCS was 28.6 kg/m2. Based on the Bariatric sub-cohort, only 2.5% of post-bariatric patients underwent BCS. The mean interval between MBS and BCS was 2.9 years. The distribution of patients by MBS was as follows: sleeve gastrectomy 8 (33.3%), gastric band 7 (29.2%), gastric bypass 5 (20.8%), and gastric plication 2 (8.3%). The distribution of patients by BCS was as follows: abdominoplasty 23 (94.7%), breast contouring 8 (33.3%), thigh contouring 3 (12.5%), and arm contouring 5 (20.8%). Most positive components (70.6%) regarding QoL were appraised by >80% of the participants, indicating overall satisfaction after BCS. Conversely, only 12.5% of negative components were endorsed by >20% of patients. In conclusion, BCS has a low prevalence after MBS, although it is related to an improved quality of life and body image
Artificial Intelligence and Machine Learning in the Diagnosis and Management of Gastroenteropancreatic Neuroendocrine Neoplasms—A Scoping Review
No full textNeuroendocrine neoplasms (NENs) and tumors (NETs) are rare neoplasms that may affect any part of the gastrointestinal system. In this scoping review, we attempt to map existing evidence on the role of artificial intelligence, machine learning and deep learning in the diagnosis and management of NENs of the gastrointestinal system. After implementation of inclusion and exclusion criteria, we retrieved 44 studies with 53 outcome analyses. We then classified the papers according to the type of studied NET (26 Pan-NETs, 59.1%; 3 metastatic liver NETs (6.8%), 2 small intestinal NETs, 4.5%; colorectal, rectal, non-specified gastroenteropancreatic and non-specified gastrointestinal NETs had from 1 study each, 2.3%). The most frequently used AI algorithms were Supporting Vector Classification/Machine (14 analyses, 29.8%), Convolutional Neural Network and Random Forest (10 analyses each, 21.3%), Random Forest (9 analyses, 19.1%), Logistic Regression (8 analyses, 17.0%), and Decision Tree (6 analyses, 12.8%). There was high heterogeneity on the description of the prediction model, structure of datasets, and performance metrics, whereas the majority of studies did not report any external validation set. Future studies should aim at incorporating a uniform structure in accordance with existing guidelines for purposes of reproducibility and research quality, which are prerequisites for integration into clinical practice
Central bank independence : a critical view
No full textWhile expansive literature on central bank independence contains some criticisms to the independent central bank quasi-paradigm, few critical analyses have been undertaken in the years between Friedman (1962) and Posen (1994). The author extends Posen's analysis to developing countries, discussing more broadly and systematically the reasons why merely instituting an independent central bank may not bring about its professed benefits, especially in developing countries. The author argues that widely reported empirical tests that are purported to support the central bank independence proposition are plagued by potential problems of simultaneity, reverse causality, missing variables, and measurement errors. Yet one can not make positive recommendations about institutional arrangements for central banks if causality relations are not well established. Institutions are shaped by a country's record of and preferences for inflation and may have little influence on them. The author also argues that the purported benefits of an independent central bank may be eroded by conflicts between fiscal and monetary policy and by inherent problems of central bank institutional design (especially mechanisms for board appointments, public accountability, and budgetary control). If these institutional problems are not solved, problems of dynamic inconsistency traditionally associated with monetary policy are not eliminated,but merely transformed. The author suggests that the benefits of central bank independence are less likely obtained in less developed countries with shallow financial markets. Accordingly, central bank independence should be granted at a later stage in a country's financial sector development. If a less developed country seeks to establish a low-inflation path, it should concentrate on instituting financial policy reforms (such as liberalization and privatization) that bolster opposition to inflation rather than easily reversible and practically meaningless changes in legal and institutional structures. This will better ensure the sustainability -- and hence the credibility -- of the government's anti-inflation stance. Fiscal policy is often at the root of macroeconomic disturbances in developing countries. Fiscal policy is more deserving of special protection from politics because of fiscal dominance over monetary policy and its greater vulnerability to private interests. The author suggests that the solution might be to make fiscal policy less susceptible to political pressures by creating an independent fiscal board. Tying the fiscal hands of government may seem a far-fetched idea. But would it not make more sense to force discipline on fiscal policy directly rather than indirectly through monetary policy?Economic Theory&Research,National Governance,Banks&Banking Reform,Economic Stabilization,Macroeconomic Management
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