Artificial Intelligence Aggregating Opinions of a Group of People

This study deals with the problems of aggregating the opinions of a group of people in such a way that the quality of the group decision surpasses the quality of the decision of the most experienced individual within the group. The methods we have studied fall in the research domain of the so called collective intelligence. We provide an overview of the state-of-the-art in the collective intelligence. We describe the method based on adaptive boosting we have proposed aggregatig the opinions of a group of people. We have implemented a web application to gather opinions of people and used the application to collect data for the experimental analysis. The model problem was to identify whether there is or there is not a tumor present in the series of X-ray images of human lungs. We have compared our proposed method to conventional methods such as majority voting. We have concluded that our proposed method can be successfully used to aggregate opinions of a group of people to increase their collective intelligence above the level of the most successful individual within the group in many cases. We have observed that the highest increase in the collective intelligence may be achieved for intelligence wise homogeneous groups what confirms the results of previous studies

Principios en el aislamiento y cultivo de condrocitos de acuerdo a buenas prácticas de laboratorio

Objectives: The objective of the present study was to determine if chondrocytes isolated from human cartilage of five elderly patients (middle age 63) with osteoarthritis (stage 3) maintain their proliferation and chondrogenic potential. Isolation and cultivation of chondrocytes was performed according to good laboratory practice (GLP) standards. Methods: Chondrocytes were isolated from cartilage biopsy by enzymatic digestion. Cultivation of cells was performed in a controlled environment (cleanroom). Phenotype characterization of chondrocytes was achieved by flow cytometry analysis. Results: Three weeks after cultivation polygonal structures typical for chondrocytes were observed, but spindle/fibroblast like morphology was also detected in culture. Flow cytometric analysis showed that chondrocytes were positive for CD44 (98,35% ± 0,50), CD90 (97,15% ± 0,13) after first passage (P1) and the cells were negative for hematopoietic marker CD45 (0,21% ± 0,11). Conclusions: Human articular chondrocytes obtained from five elderly patients with osteoarthritis maintained a chondrocyte phenotype and could be potentially used for autologous implantation. We have standardized the conditions for cultivation according to GLP standards to minimize the risk of in vitro cell contamination.Objetivos: El objetivo del presente estudio era determinar si los condrocitos aislados de cinco pacientes ancianos (edad media 63 años) con artrosis (grado 3) mantienen su proliferación y potencial condrogénico. El aislamiento y cultivo de condrocitos fueron llevados a cabo de acuerdo a los estándares de buenas prácticas de laboratorio. Métodos: Los condrocitos fueron aislados de una biopsia de cartílago mediante digestión enzimática. El cultivo fue llevado a cabo en un ambiente controlado (sala blanca). La caracterización del fenotipo de los condrocitos se logró mediante análisis de citometría de flujo. Resultados: Tras tres semanas de cultivo se podían observar estructuras poligonales propias de los condrocitos, pero también se observaba morfología de tipo fibroblasto en el cultivo. El análisis de la citometría de flujo reveló que el fenotipo de los condrocitos cultivados tras el primer pasaje era positivo para CD44 (98,92%), CD90 (97,11%) y negativo para el marcador hematopoyético CD45 (0,10%). Conclusiones: Los condrocitos articulares humanos obtenidos de cinco pacientes ancianos con artrosis mantenían un fenotipo condrocitario y podrían ser potencialmente utilizados para la implantación autóloga. Las condiciones para el cultivo fueron establecidas de acuerdo a los estándares de buenas prácticas de laboratorio para así minimizar el riesgo de contaminación celular in vitro.Slovak Research and Development Agency (APVV 0684-12); VEGA grant No.1/0772/13; Centre of Excellence for Neuroregenerative Research (project ITMS No. 26220120063)

Principios en el aislamiento y cultivo de condrocitos de acuerdo a buenas prácticas de laboratorio

OBJECTIVES: The objective of the present study was to determine if chondrocytes isolated from human cartilage of five elderly patients (mean age 63) with osteoarthritis (stage 3) maintain their proliferation and chondrogenic potential. Isolation and cultivation of chondrocytes was performed according to good laboratory practice (GLP) standards. Methods: Chondrocytes were isolated from cartilage biopsy by enzymatic digestion. Cultivation of cells was performed in a controlled environment (cleanroom). Phenotype characterization of chondrocytes was achieved by flow cytometry analysis. Results: Three weeks after cultivation, polygonal structures typical of chondrocytes were observed, but spindle/fibroblast like morphology was also detected in cultured cells. Flow cytometric analysis showed that chondrocytes were positive for CD44 (98.35% ± 0.50), CD90 (97.15% ± 0.13) after first passage (P1) and the cells were negative for hematopoietic marker CD45 (0.21% ± 0.11). ConclusionS: Human articular chondrocytes obtained from five elderly patients with osteoarthritis maintained a chondrocyte phenotype and could be potentially used for autologous implantation. We have standardized the conditions for cultivation according to GLP standards to minimize the risk of in vitro cell contamination

Goodbye Hartmann trial: a prospective, international, multicenter, observational study on the current use of a surgical procedure developed a century ago

Background: Literature suggests colonic resection and primary anastomosis (RPA) instead of Hartmann's procedure (HP) for the treatment of left-sided colonic emergencies. We aim to evaluate the surgical options globally used to treat patients with acute left-sided colonic emergencies and the factors that leading to the choice of treatment, comparing HP and RPA. Methods: This is a prospective, international, multicenter, observational study registered on ClinicalTrials.gov. A total 1215 patients with left-sided colonic emergencies who required surgery were included from 204 centers during the period of March 1, 2020, to May 31, 2020. with a 1-year follow-up. Results: 564 patients (43.1%) were females. The mean age was 65.9 ± 15.6 years. HP was performed in 697 (57.3%) patients and RPA in 384 (31.6%) cases. Complicated acute diverticulitis was the most common cause of left-sided colonic emergencies (40.2%), followed by colorectal malignancy (36.6%). Severe complications (Clavien-Dindo ≥ 3b) were higher in the HP group (P < 0.001). 30-day mortality was higher in HP patients (13.7%), especially in case of bowel perforation and diffused peritonitis. 1-year follow-up showed no differences on ostomy reversal rate between HP and RPA. (P = 0.127). A backward likelihood logistic regression model showed that RPA was preferred in younger patients, having low ASA score (≤ 3), in case of large bowel obstruction, absence of colonic ischemia, longer time from admission to surgery, operating early at the day working hours, by a surgeon who performed more than 50 colorectal resections. Conclusions: After 100 years since the first Hartmann's procedure, HP remains the most common treatment for left-sided colorectal emergencies. Treatment's choice depends on patient characteristics, the time of surgery and the experience of the surgeon. RPA should be considered as the gold standard for surgery, with HP being an exception

Analysis of development of Frenstatsko microregion

Práce se zabývá problematikou rozvoje mikroregionu Frenštátsko, se zaměřením na oblasti cestovního ruchu a zaměstnanost. Práce je rozdělena na dvě část. V první, teoretické části jsou vymezeny základní pojmy. V druhé části je samotná analýza vybraného mikroregionu ve vybraných oblastí.Ústav veřejné správy a právaDokončená práce s úspěšnou obhajobo

Actual problems of reinsurance and alternatives of their solution

Diplomová práce se zabývá problematikou zajištění, jednotlivými formami přenosu rizik a vzájemnými vztahy mezi pojistiteli a zajistiteli. Prostor je věnován nejen klasickým technikám, ale taky se práce věnuje principům alternativního přenosu rizika.This thesis is concerned with problems of reinsurance, forms of risks transfer and relations between an insurer and a reinsurer. Not only does the thesis pay attention to the familiar techniques but it also focuses on alternative forms of risk.Ústav systémového inženýrství a informatikyDokončená práce s úspěšnou obhajobo

Soft-Switching Full-Bridge DC-DC Converter with Energy Recovery Capacitor Snubber

This paper describes a high-frequency soft-switching dc-dc converter with a simple energy recovery capacitor snubber on the secondary side. The presented dc-dc full-bridge converter with the energy recovery snubber removes the main drawbacks of the classic Phase Shifted PWM (PS-PWM) dc-dc converter, e.g., the circulating current flowing during the free-wheeling interval and dependency of the soft switching on the load current. The converter utilizes a full-bridge topology with pulse-width modulation and a centre-tapped full-wave controlled rectifier with one active switch. The zero-voltage switching on the primary side is ensured by utilising only the magnetizing current of the high-frequency transformer, and thus is load-independent. The proposed energy recovery snubber is described in detailed time waveforms of the converter and verified by simulation. The control algorithm also removes the circulating current, which is typical for PS-PWM converters. The soft-switching of the secondary side transistor is achieved by a simple capacitor snubber with an energy-recovery circuit connected to the output of the dc-dc converter. The principle of operation is verified by measurements on a 2 kW, 50 kHz laboratory model of the proposed dc-dc converter

Soft-Switching Full-Bridge DC-DC Converter with Energy Recovery Capacitor Snubber

This paper describes a high-frequency soft-switching dc-dc converter with a simple energy recovery capacitor snubber on the secondary side. The presented dc-dc full-bridge converter with the energy recovery snubber removes the main drawbacks of the classic Phase Shifted PWM (PS-PWM) dc-dc converter, e.g., the circulating current flowing during the free-wheeling interval and dependency of the soft switching on the load current. The converter utilizes a full-bridge topology with pulse-width modulation and a centre-tapped full-wave controlled rectifier with one active switch. The zero-voltage switching on the primary side is ensured by utilising only the magnetizing current of the high-frequency transformer, and thus is load-independent. The proposed energy recovery snubber is described in detailed time waveforms of the converter and verified by simulation. The control algorithm also removes the circulating current, which is typical for PS-PWM converters. The soft-switching of the secondary side transistor is achieved by a simple capacitor snubber with an energy-recovery circuit connected to the output of the dc-dc converter. The principle of operation is verified by measurements on a 2 kW, 50 kHz laboratory model of the proposed dc-dc converter

Improved Digital Twin of Li-Ion Battery Based on Generic MATLAB Model

The paper describes the digital twin of a Li-ion battery cell based on the MATLAB/Simulink generic model. The digital twin is based on measured data for constant current/constant voltage charging and discharging cycles with State of Health (SoH) up to 79%, also including fast charging. Mathematical equations used for the digital twin are obtained by 3D data fitting of measured SoH, battery capacity, and battery cell current. The input to the proposed digital twin is only the measured battery cell current, and its output includes State of Charge (SoC), SoH, and battery cell voltage. The designed digital twin is tested and compared with MATLAB/Simulink generic model and battery cell measurements for constant discharging current and dynamically generated discharging current profile. The results show significant improvement in the generic MATLAB/Simulink model