The Dreyfus affair: an exposition of the case with its political and literary dissension.

Typewritten sheets in cover. Thesis (M.A.)--Boston University Bibliography: 3 p. at end

On strong algebrability of families of non-measurable functions of two variables

Recently Tomasz Natkaniec in [On lineability of families of non-measurable functions of two variable. Rev. R. Acad. Cienc. Exactas F\'is. Nat. Ser. A Mat. RACSAM, 115(1):Paper No. 33, 10, 2021] studied the lineability problem for several classes of non-measurable functions in two variables. In this note we improve his results in the direction of algebrability. In particular, we show that most of the classes considered by Natkaniec contain free algebras with $2^{\mathfrak{c}}$ many generators

Norcoclaurine synthase: the mechanism and biocatalytic potential of a Pictet-Spenglerase

In plants, the enzyme norcoclaurine synthase (NCS) catalyses the formation of (S)- norcoclaurine via the Pictet–Spengler condensation of dopamine and 4- hydroxyphenylacetaldehyde (4-HPAA). (S)-Norcoclaurine is the precursor to all benzylisoquinoline alkaloids (BIAs), a diverse group of over 2500 natural products. The aim of this project was to elucidate the mechanism of NCS in order to enable the rational engineering of NCS activity. Variants of NCS were screened for activities with various substrates, forming novel tetrahydroisoquinolines (THIQs). NCS was combined with other enzymes in biocatalytic cascades to produce THIQs. Initially, an N-terminally truncated NCS from Thalictrum flavum (Δ19TfNCS) was expressed. Problems with the purification of Δ19TfNCS led to the use of a different truncate, Δ29TfNCS. This enzyme and variants were expressed and purified. The effect of mutations on the activity, kinetics and substrate specificity of Δ29TfNCS led to the conclusion that NCS operates with a ‘dopamine-first’ mechanism. Computational analysis, including molecular dynamics and docking experiments, supported this conclusion. Furthermore, rational engineering of substrate specificity was demonstrated. Next, the biocatalytic potential of NCS was investigated. Biotransformation conditions, such as enzyme or lysate loading, were optimised before demonstrative examples of milligram scale biotransformations were performed. Then, NCS and a transaminase were combined in a one-pot ‘triangular’ biocatalytic cascade to produce chiral BIAs. An additional chemical step led to the one-pot formation of chiral tetrahydroprotoberberines (berbines). The cascades were demonstrated on a milligram preparative scale. Methods for screening NCS mutants were examined: various enzyme preparations, reaction conditions and reporter systems were tested and evaluated. Subsequently, NCS mutants were screened for activities with numerous amines and aldehydes. NCS activity was identified with some α-substituted aldehydes and ketones. Selected mutants demonstrated an increase in activity compared to wild-type for these unusual substrates. Notably, high conversions were revealed for cyclohexanone derivatives. A number of resulting cyclohexane-spiro-THIQs were characterised

Free group of Hamel functions

We construct a free group of continuum many generators among those autobijections of $\mathbb{R}$ which are also Hamel bases of $\mathbb{R}^2$, with identity function included. We also observe two new cases when a real function is a composition of two real functions which are Hamel bases of $\mathbb{R}^2$

Оценка влияния качества внесения удобрений на урожайность сельскохозяйственных культур

To study the dependence of crop yields on the quality of fertilizer application, the authors theoretically investigated the responsiveness of plants to increasing fertilizer doses and the distribution of the fertilizer dose over the field. We obtained a mathematical model of the dependence of yields on the dose and the quality of fertilizer application. It was revealed that the average dose and the unevenness of their distribution, which is characterized by the coefficient of variation, affect the yield of agricultural crops, and consequently the effectiveness of fertilizers. As unevenness increases, the responsiveness function transforms: the maximum possible yield decreases significantly, the maximums of the graphs shift towards smaller doses. The decrease in yield also depends significantly on the nature of the responsiveness functions. The greatest fall of this indicator should be expected with its parabolic change depending on the increasing doses of fertilizers applied. It has been proved that when applying 40 kg of active ingredient (ai) per 1 hectare and increasing the coefficient of dose variation from 0 to 60 percent, the yield reduction does not exceed 1 percent, at higher doses (120 kg ai per ha) it reaches 7 percent. It is established that the yield depends on the degree of uneven distribution of fertilizers, the fertilizer dose and the type of yield curves.Чтобы изучить зависимость урожайности сельхозкультур от качества внесения удобрений, авторы теоретически исследовали функции отзывчивости растений на возрастающие дозы удобрений и закон распределения дозы удобрений по полю. Получили математическую модель зависимости урожайности от дозы и качества внесения удобрений. Выявили, что на урожайность сельхозкультур, а соответственно и эффективность удобрений влияют как средняя доза, так и неравномерность распределения удобрений, характеризуемая коэффициентом вариации. Установили, что по мере увеличения неравномерности происходит трансформация функции отзывчивости: максимально возможная урожайность значительно падает, максимумы графиков смещаются в сторону меньших доз. Снижение урожайности также существенно зависит от характера функций отзывчивости. Определили, что наибольшее падение этого показателя следует ожидать при его параболическом изменении в зависимости от возрастающих доз внесенных удобрений. Доказано, что при внесении 40 кг действующего вещества (д.в.) на 1 га и увеличении коэффициента вариации дозы от 0 до 60 процентов снижение урожайности не превышает 1 процента, при более высоких дозах (120 кг д.в. на 1 га) оно достигает 7 процентов. Установлено, что урожайность зависит от степени неравномерности распределении удобрений, дозы удобрений и вида кривых урожайности

Plant biosynthetic gene clusters in the context of metabolic evolution

Plants produce a wide range of structurally and biosynthetically diverse natural products to interact with their environment. These specialised metabolites typically evolve in limited taxonomic groups presumably in response to specific selective pressures. With the increasing availability of sequencing data, it has become apparent that in many cases the genes encoding biosynthetic enzymes for specialised metabolic pathways are not randomly distributed on the genome. Instead they are physically linked in structures such as arrays, pairs and clusters. The exact function of these clusters is debated. In this review we take a broad view of gene arrangement in plant specialised metabolism, examining types of structures and variation. We discuss the evolution of biosynthetic gene clusters in the wider context of metabolism, populations and epigenetics. Finally, we synthesise our observations to propose a new hypothesis for biosynthetic gene cluster formation in plants

One-pot chemoenzymatic synthesis of trolline and tetrahydroisoquinoline analogues

Chemoenzymatic reaction cascades can provide access to chiral compounds from low-cost starting materials in one pot. Here we describe one-pot asymmetric routes to tetrahydroisoquinoline alkaloids (THIAs) using the Pictet-Spenglerase norcoclaurine synthase (NCS) followed by a cyclisation, to give alkaloids with two new heterocyclic rings. These reactions operated with a high atom economy to generate THIAs in high yields

The Role of Central Asian Traditions in Mongolian Fine Arts

The article considers the role of Central Asian traditions in the formation and development of Mongolian fine arts. The authors reveal the significance of various factors for the formation of the original stylistics, which manifested itself in the methods, techniques and pictorial means typical of Mongolian art. The article defines the role of Indian artistic traditions in the development of Mongolian fine arts. The authors claim that Mongolian religious painting on scrolls is a bright artistic phenomenon based on the strict canon developed in India and inherited by many cultures of Asia. The means of artistic depiction, iconography, a system of proportions, borrowed and modified by the Mongols, had been developed in the cradle of Indian civilisation. The purpose of the article is to study the features of Mongolian fine arts on the basis of ethnic traditions, as well as to consider this phenomenon using the example of traditional and contemporary painting. Multiculturalism conditioned by the polyethnic nature of the region played an important role in the history of Mongolian culture. The renewal of ethnocultural experience is related to the artistic traditions brought from India, Tibet and China, but in Mongolian art, there is no predominance of any forms of other cultures. Hence, the art is original and has its unique features. As a result of the combination of the ornamental pictorial technique of nomadic cultures with the painting techniques of sedentary peoples, an artistic style based on the Buddhist canon, supplemented by original ethnocultural elements, was formed. In the process of mastering and developing the artistic experience based on the traditions of planar painting, icon painting, arts and crafts, folklore, a new art direction "Mongol Zurag" appeared in the 20th century. The creative method of modern masters proves that while working in various trends, genres, techniques, individual manners, they preserve and develop national traditions in painting. Consequently, the preservation of the artistic-aesthetic heritage of the ethnos has a positive effect on fine arts and the vitality of culture in general

'Dopamine-first' mechanism enables the rational engineering of the norcoclaurine synthase aldehyde activity profile

Norcoclaurine synthase (NCS) (EC 4.2.1.78) catalyzes the Pictet–Spengler condensation of dopamine and an aldehyde, forming a substituted (S)-tetrahydroisoquinoline, a pharmaceutically important moiety. This unique activity has led to NCS being used for both in vitro biocatalysis and in vivo recombinant metabolism. Future engineering of NCS activity to enable the synthesis of diverse tetrahydroisoquinolines is dependent on an understanding of the NCS mechanism and kinetics. We assess two proposed mechanisms for NCS activity: (a) one based on the holo X-ray crystal structure and (b) the ‘dopamine-first’ mechanism based on computational docking. Thalictrum flavum NCS variant activities support the dopamine-first mechanism. Suppression of the non-enzymatic background reaction reveals novel kinetic parameters for NCS, showing it to act with low catalytic efficiency. This kinetic behaviour can account for the ineffectiveness of recombinant NCS in in vivo systems, and also suggests NCS may have an in planta role as a metabolic gatekeeper. The amino acid substitution L76A, situated in the proposed aldehyde binding site, results in the alteration of the enzyme's aldehyde activity profile. This both verifies the dopamine-first mechanism and demonstrates the potential for the rational engineering of NCS activity