16 research outputs found
Sorting suffixes of two-pattern strings
No full textRecently, several authors presented linear recursive algorithms for sorting suffixes of a string. All these algorithms employ a similar three-step approach, based on an initial division of the suffixes of x into two sets: in step 1 sort the first set using recursive reduction of the problem, in step 2 determine the order of the suffixes in the second set based on the order of the suffixes in the first set, and in step 3 merge the two sets together. To optimize such analgorithm either for space or time, it may not be sufficient to optimize one of the three steps, since in doing so, one might increase the resources required for the others to an unacceptable extent. Franek, Lu, and Smyth introduced two-pattern strings as a generalization of Sturmian strings. Like Sturmian strings, two-pattern strings are generated by iterated morphisms, but they exhibit a much richer structure. In this paper we show that the suffixes of two-pattern strings can be sorted in linear time using a variant of the three step approach outlined above. It turns out that, given the order of the suffixes in a two-pattern string, one can almost directly list in linear time all the suffixes of its expansion under a two-pattern morphism
THE SAFETY AND EFFICACY OF A SILYMARIN AND SELENIUM COMBINATION IN MEN AFTER RADICAL PROSTATECTOMY - A SIX MONTH PLACEBO-CONTROLLED DOUBLE-BLIND CLINICAL TRIAL
No full textOperations on factor automata.
No full textThe thesis concerns pattern matching (PM) using factor automata (FA). PM methods often employ pattern or text preprocessing to speed up the PM algorithms. PM using FA is a kind of PM with text preprocessing suitable especially for searching for substrings of the given text, but it can be also used for locating repetitions, for counting the number of occurrences of the pattern in the text, as a part of a compression algorithm, etc. The advantage of the text preprocessing is mostly demonstrated in multiple PM in the same text. Whenever the text is changed during the multiple PM, the FA has to be reconstructed just after the each change in the text. The construction of the whole FA is too time-consuming (the required time is linear with respect to the size of the text), though the change in the text may be very simple. The new approach described in this thesis consists in reflecting the changes in the text directly into the FA resulting there is no longer needed the whole construction of the FA after each change in the text. The reconstruction of the whole automaton is replaced by modification algorithms for each required change in the text. The changes in the text are defined as a text edit operations and the modification algorithms modifies the FA to represent the new text after each such text edit operation. The thesis introduces a theoretical model of relationship between the text and its FA and it describes a general methodology for discovering FA modification algorithms for other text edit operations. This methodology is then used to derive and to describe modification algorithms for four basic text edit operations. It also introduces a new FA construction method.Available from STL Prague, CZ / NTK - National Technical LibrarySIGLECZCzech Republi
Impact of the COVID-19 pandemic on nuclear medicine departments in Europe
No full textSince the beginning of the year 2020, the coronavirus-19 disease (COVID-19) pandemic has undoubtedly posed significant challenges to healthcare systems worldwide. It has also affected, in a way previously unimaginable, our lifestyle and the way we relate to each other, not only at work, but also in the community and in the family setting. Healthcare systems worldwide have been forced to make huge alterations to be able to handle the different stages of the pandemic. [...
Reduction of cardiac imaging tests during the COVID-19 pandemic: The case of Italy. Findings from the IAEA Non-invasive Cardiology Protocol Survey on COVID-19 (INCAPS COVID)
No full textBackground: In early 2020, COVID-19 massively hit Italy, earlier and harder than any other European country. This caused a series of strict containment measures, aimed at blocking the spread of the pandemic. Healthcare delivery was also affected when resources were diverted towards care of COVID-19 patients, including intensive care wards. Aim of the study: The aim is assessing the impact of COVID-19 on cardiac imaging in Italy, compare to the Rest of Europe (RoE) and the World (RoW). Methods: A global survey was conducted in May–June 2020 worldwide, through a questionnaire distributed online. The survey covered three periods: March and April 2020, and March 2019. Data from 52 Italian centres, a subset of the 909 participating centres from 108 countries, were analyzed. Results: In Italy, volumes decreased by 67% in March 2020, compared to March 2019, as opposed to a significantly lower decrease (p < 0.001) in RoE and RoW (41% and 40%, respectively). A further decrease from March 2020 to April 2020 summed up to 76% for the North, 77% for the Centre and 86% for the South. When compared to the RoE and RoW, this further decrease from March 2020 to April 2020 in Italy was significantly less (p = 0.005), most likely reflecting the earlier effects of the containment measures in Italy, taken earlier than anywhere else in the West. Conclusions: The COVID-19 pandemic massively hit Italy and caused a disruption of healthcare services, including cardiac imaging studies. This raises concern about the medium- and long-term consequences for the high number of patients who were denied timely diagnoses and the subsequent lifesaving therapies and procedures
International Impact of COVID-19 on the Diagnosis of Heart Disease
No full textBackground: The coronavirus disease 2019 (COVID-19) pandemic has adversely affected diagnosis and treatment of noncommunicable diseases. Its effects on delivery of diagnostic care for cardiovascular disease, which remains the leading cause of death worldwide, have not been quantified. Objectives: The study sought to assess COVID-19's impact on global cardiovascular diagnostic procedural volumes and safety practices. Methods: The International Atomic Energy Agency conducted a worldwide survey assessing alterations in cardiovascular procedure volumes and safety practices resulting from COVID-19. Noninvasive and invasive cardiac testing volumes were obtained from participating sites for March and April 2020 and compared with those from March 2019. Availability of personal protective equipment and pandemic-related testing practice changes were ascertained. Results: Surveys were submitted from 909 inpatient and outpatient centers performing cardiac diagnostic procedures, in 108 countries. Procedure volumes decreased 42% from March 2019 to March 2020, and 64% from March 2019 to April 2020. Transthoracic echocardiography decreased by 59%, transesophageal echocardiography 76%, and stress tests 78%, which varied between stress modalities. Coronary angiography (invasive or computed tomography) decreased 55% (p < 0.001 for each procedure). In multivariable regression, significantly greater reduction in procedures occurred for centers in countries with lower gross domestic product. Location in a low-income and lower–middle-income country was associated with an additional 22% reduction in cardiac procedures and less availability of personal protective equipment and telehealth. Conclusions: COVID-19 was associated with a significant and abrupt reduction in cardiovascular diagnostic testing across the globe, especially affecting the world's economically challenged. Further study of cardiovascular outcomes and COVID-19–related changes in care delivery is warranted
