Integer codes correcting burst and random asymmetric errors within a byte

In most communication networks, error probabilities 1?→?0 and 0?→?1 are equally likely to occur. However, in some optical networks, such as local and access networks, this is not the case. In these networks, the number of received photons never exceeds the number of transmitted ones. Hence, if the receiver operates correctly, only 1?→?0 errors can occur. Motivated by this fact, in this paper, we present a class of integer codes capable of correcting burst and random asymmetric (1?→?0) errors within a b-bit byte. Unlike classical codes, the proposed codes are defined over the ring of integers modulo 2^b ?1. As a result, they have the potential to be implemented in software without any hardware assist.     

When induction meets memory: evidence for gradual transition from similarity-based to category-based induction

The ability to perform induction appears early; however, underlying mechanisms remain unclear. Some argue that early induction is category based, whereas others suggest that early induction is similarity based. Category- and similarity-based induction should result in different memory traces and thus in different memory accuracy. Performing induction resulted in low memory accuracy in adults and 11-year-olds, whereas 5-, and 7-year-olds were highly accurate (Experiment 1). After training to perform category-based induction, 5- and 7-year-olds exhibited patterns of accuracy similar to those of adults (Experiment 2). Furthermore, 7-year-olds, but not 5-year-olds, retained this training over time (Experiment 3). With novel categories, even adults performed similarity-based induction, exhibiting high memory accuracy (Experiment 4). These results suggest a gradual transition from similarity- to category-based induction with familiar categories.     

The Influence of Academic Migration on the Intellectual Potential of Russia

The emigration of highly-qualified academics (‘brain drain’) is considered an essential factor in the decline of the human capital of post-Soviet Russia. However, statistics show that the scale of this phenomenon since 2000 was minor. The Russian scientists who went abroad for permanent residence or for a contract job abroad represented no more than 2% of Russian scientists with Candidate or Doctor of Science degrees. Yet, at the same time, the relatively new concept of ‘brain circulation’ gains more popularity. The departure of Russian scientists abroad is not only a threat to the development of domestic science but, paradoxically, also the chance to give additional stimulus to its development.     

Effects of the shape and size of a mooring line surface buoy on the mooring load of wave energy converters

This paper describes the physical model testing of a wave energy converter (WEC) undertaken in the Henot-watt wave basin during October 2010 as part of the SUPERGEN2 project funded by the British gover...     

Use of Polarised Light Microscopy to Improve Conservation of Parchment

ABSTRACT

The preservation state of parchment primarily depends on the structure of the collagen fibre network, which in turn is responsible for optical anisotropy, i.e. birefringence. Polarised light microscopy can therefore be used as a non-invasive technique that allows recording of birefringence distribution in the parchment, which directly relates to stress–strain distribution. Using samples from diverse sources (commercial parchment, parchment used by restorers for book binding, and parchment fabricated for the purpose of this study), we assessed the capability of polarised light microscopy for various diagnostics. We performed, for instance, identification of gelatinised regions, layered or ?brous regions in parchment cross section, qualitative analysis of parchment fat content (lipids), observation of stress-induced patterns resulting from tensile tests, and observation of water diffusion. These proof-of-principle experiments extend the capability of polarised light microscopy far beyond its common use and open the path to its deployment in conservation studies.     

Seroprevalence of SARS-CoV-2 in Croatian solid-organ transplant recipients

IntroductionThe data on the coronavirus disease (COVID-19) in solid-organ transplant recipients (SOTRs) in Croatia is unknown. The aim of this study was to analyze the seroprevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in Croatian SOTRs.Materials and methodsFrom 7 September to 27 November 2020 (beginning of the second COVID-19 pandemic wave), a cross-sectional screening for COVID-19 was performed in the adult outpatient liver (LTRs; N = 280) and kidney transplant recipients (KTRs; N = 232). Serum samples were initially tested for SARS-CoV-2 IgG antibodies using a commercial enzyme-linked immunosorbent assay (ELISA; Vircell Microbiologists, Granada, Spain). All positive samples were confirmed using a virus neutralization test (VNT). Data on risk exposure and COVID-19 related symptoms were collected using a questionnaire.ResultsThe transplanted cohort’s seroprevalence detected by ELISA and VNT was 20.1% and 3.1%, respectively. Neutralizing (NT) antibodies developed in 15.6% of anti-SARS-CoV-2 ELISA IgG positive SOTRs. The difference in seropositivity rates between LTRs and KTRs was not statistically significant (ELISA 21.1% vs. 19.0%, P = 0.554; VNT 3.6% vs. 2.6%, P = 0.082). Overall VNT positivity rates were higher in patients who reported participation in large community events (5.9% vs. 1.0%; P = 0.027) as well as in patients who reported COVID-19 related symptoms in the past six months. In addition, symptomatic VNT positive patients showed significantly higher (P = 0.031) NT antibody titers (median 128, interquartile range (IQR) = 32-128) compared to asymptomatic patients (median 16, IQR = 16-48).ConclusionsThis study showed that 15.6% of anti-SARS-CoV-2 ELISA positive Croatian SOTRs developed NT antibodies indicating protective immunity. Further studies are needed to determine the dynamic of NT antibodies and COVID-19 immunity duration in immunocompromised populations such as LTRs and KTRs.     

THE NEW CONVENTION ‐ PROTOCOL ON INTENTIONS OR WORKING AGREEMENT?

A Joint Council of Europe/UNESCO Convention on the Recognition of Qualifications Concerning Higher Education in the European Region is a necessary evolution that takes into account the increased political and economic integration of Europe, the mobility of academic staff members and students, and the diversification of higher education. The latter tendency, indeed, explains the stress on general principles, particularly on recognition, in the draft Joint Convention, rather than on equivalence and attempts at formulating detailed equivalence procedures. However, along with the stress on recognition must come common agreement as to the guarantee of quality and on procedures for accreditation, on the one hand, and access to information on one another's education programmes and their quality ratings, on the other hand. The Joint Council of Europe/UNESCO Convention will be backed by the excellent European National Information Centres on Academic Recognition and Mobility (ENIC).     

THE CROATIAN ACADEMY OF SCIENCES AND ARTS PAST AND FUTURE

The Croatian Academy of Sciences and Arts traces its origins back to efforts to create a learned society in Croatia during the first half of the Nineteenth Century. At first concerned exclusively with the language, literature, and history of Croatia, it evolved into an eclectic organization conducting and sponsoring research in a wide rage of disciplines and fields. Currently, the work of the Academy is concentrated in eight departments and is conducted by eleven scientific councils, ten committees, and twenty research units. Since its founding, the Academy has published almost 3,400 books.