Directed Evolution of an Efficient and Thermostable PET Depolymerase

The recent discovery of a hydrolytic enzyme, IsPETase, that can deconstruct poly(ethylene) terephthalate (PET), has sparked great interest in biocatalytic approaches to recycle plastics. Realisation of commercial utility will require the development of robust engineered enzymes that meet the demands of industrial processes. Although rationally engineered variants of PETases have been reported, enzymes that have been experimentally optimised through iterative rounds of directed evolution - the go-to method for engineering industrially useful biocatalysts – have not yet been described. Here, we report the development and implementation of an automated, high-throughput directed evolution platform for engineering polymer degrading enzymes. Evaluation of >13,000 IsPETase variants, applying catalytic activity at elevated temperatures as a primary selection pressure, afforded a HotPETase variant with 21 mutations that has a melting temperature of 82.5C and can therefore operate near or above the glass transition temperature of PET (60-70C). HotPETase can depolymerise semi-crystalline PET more rapidly than previously reported PETases and can selectively deconstruct the PET component of a laminated packaging multi-material. Structural characterisation of HotPETase reveals several interesting features that have emerged during evolution to improve thermotolerance and catalytic performance. Our study establishes laboratory evolution as a platform to engineer useful plastic degrading enzymes to underpin biocatalytic plastic recycling processes.

The appearance of DNA bands pattern based on the result of primary selection of RAPD orchid Phaius spp.

This study aimed to examine the appearance of the DNA band pattern resulted from the selection of RAPD primers on Phaius spp. namely Phaius tankervillae, Phaius montanus, Phaius collasus and Phaius amboinensis. The research material was performed in the Center for Plant Conservation of the LIPI Bogor Botanical Gardens. Molecular analysis was carried out at the Laboratory of the Center for Horticultural and Tropical Studies IPB using RAPD. The study showed that the 2 primers RAPD OPA 02 and OPA 16 can be used for DNA amplification of orchids Phaius spp (Phaius tankervillae, Phaius montanus Phaius collasus and Phaius amboinensis) because they produce clear DNA bands. The result of PCR amplification on Phaius tankervillae, Phaius montanus, Phaius collasus, and Phaius amboinensis using OPA 02 and OPA 16 primers produced 11 and 9 DNA bands, respectively, with an average of 5 DNA bands per primer. In the band pattern at 800 bp on OPA 02 primers resulting sharp and clear band pattern quality.

The use of the forest management database in the process of primary selection of stands within forest genetic resources

The forest management database is used for the primary selection of the candidate stands for inclusion in forest genetic resources (FGR). The management and primary processing of the forest management database was performed with the support of standard functions of commonly used software (Microsoft Excel). In 2020, the primary identification area of FGR was 75.7 thousand ha of land covered with forests in the central area of the Republic of Moldova. As a result of the data processing, 12.7 thousand ha, or 16.8% of the study area, of candidate stands were selected for inclusion in the FGR.

Wheat Breeding Research In The Zarafshan Oasis Of The Republic Of Uzbekistan

The article describes the results of research on the selection of varieties suitable for the soil and climatic conditions of the Republic of Uzbekistan based on the study of samples of the world collection of wheat in the breeding process and the creation of new varieties and primary selection by mixing them with one variety.

Predictive Validity of the Air Force Officer Qualifying Test (AFOQT) for Pilot Performance

The Air Force Qualifying Test (AFOQT) has been the primary selection test battery for officer candidates in the US Air Force since 1953. Despite a wealth of literature on the validity of the AFOQT in predicting pilot performance, there is less evidence on its validity generalization. This study investigated the predictive validity of 16 AFOQT subtests and its Pilot composite via psychometric meta-analytic procedures. Based on 32 independent samples from 26 studies, results indicated that pilot performance is best predicted by subtests indicative of perceptual speed, aviation-related aptitude and knowledge, and quantitative ability constructs, and least predicted by subtests indicative of verbal ability construct. Evidence for validity generalization of AFOQT subtests is presented, and implications for practical use are discussed.

Economic or financial substantiation for smart city solutions: a literature study

The research is aimed to find the answer for the research question: Do the researchers demonstrate economic or financial substantiation for implementation of smart solutions for different dimensions of smart city? The goal of the research is to determine the publications presenting the economic or financial substantiations for smart solutions for smart city and to determine the type of the provided substantiation. It is very important, since Smart City is becoming our life step by step, though the components of it are introduced without any economic study, estimation and substantiation. This research is done to discover the areas where such substantiations exist, and to estimate the possibility of applying the methods, described in these studies, for smart solutions in smart city. The study considers the academic articles in English included in Scopus database and available online in full text. The primary selection comprised 927 publications for the period 1993-2020, and only 22 of them contained the comprehensive or close to comprehensive economic or financial analysis. This fact demonstrates the lack of economic and financial researches in the sphere of Smart City. The study allows the scholars to use the reviewed publications as providing the economic and financial basis for smart city; it also demonstrates the areas of smart city and smart solutions where specialists in economy can apply their competences.

Критерії відбору та первинна обробка емпіричного матеріалу паралельного корпусу юридичних текстів

The article deals with the formation of criteria for the primary selection of legal texts for the English-Ukrainian parallel corpus of legal texts. The author has developed a classification of legal texts on the basis of the style and text genres, taking into account the types of legal acts, and makes an attempt to combine legal and linguistic characteristics applicable to the classification of legal documents. The article proposes the structure of the metadata card for corpus texts (original and translation), which are tested on text samples. The need for metatext data and extra-linguistic information for working with corpus texts is substantiated in the article.