Very long O-antigen chains enhance fitness during Salmonella-induced colitis by increasing bile resistance.

Intestinal inflammation changes the luminal habitat for microbes through mechanisms that have not been fully resolved. We noticed that the FepE regulator of very long O-antigen chain assembly in the enteric pathogen Salmonella enterica serotype Typhimurium (S. Typhimurium) conferred a luminal fitness advantage in the mouse colitis model. However, a fepE mutant was not defective for survival in tissue, resistance to complement or resistance to polymyxin B. We performed metabolite profiling to identify changes in the luminal habitat that accompany S. Typhimurium-induced colitis. This analysis suggested that S. Typhimurium-induced colitis increased the luminal concentrations of total bile acids. A mutation in fepE significantly reduced the minimal inhibitory concentration (MIC) of S. Typhimurium for bile acids in vitro. Oral administration of the bile acid sequestrant cholestyramine resin lowered the concentrations of total bile acids in colon contents during S. Typhimurium infection and significantly reduced the luminal fitness advantage conferred by the fepE gene in the mouse colitis model. Collectively, these data suggested that very long O-antigen chains function in bile acid resistance of S. Typhimurium, a property conferring a fitness advantage during luminal growth in the inflamed intestine

A transitional fossil mite (Astigmata: Levantoglyphidae fam. n.) from the early Cretaceous suggests gradual evolution of phoresy-related metamorphosis

Abstract Metamorphosis is a key innovation allowing the same species to inhabit different environments and accomplish different functions, leading to evolutionary success in many animal groups. Astigmata is a megadiverse lineage of mites that expanded into a great number of habitats via associations with invertebrate and vertebrate hosts (human associates include stored food mites, house dust mites, and scabies). The evolutionary success of Astigmata is linked to phoresy-related metamorphosis, namely the origin of the heteromorphic deutonymph, which is highly specialized for phoresy (dispersal on hosts). The origin of this instar is enigmatic since it is morphologically divergent and no intermediate forms are known. Here we describe the heteromorphic deutonymph of Levantoglyphus sidorchukae n. gen. and sp. (Levantoglyphidae fam. n.) from early Cretaceous amber of Lebanon (129 Ma), which displays a transitional morphology. It is similar to extant phoretic deutonymphs in its modifications for phoresy but has the masticatory system and other parts of the gnathosoma well-developed. These aspects point to a gradual evolution of the astigmatid heteromorphic morphology and metamorphosis. The presence of well-developed presumably host-seeking sensory elements on the gnathosoma suggests that the deutonymph was not feeding either during phoretic or pre- or postphoretic periods

ФУНКЦИИ, ЗАДАЮЩИЕ ЗАВИСИМОСТИ ЗЕРНИСТЫХ АЛГОРИТМОВ

In case of parallel grained affine algorithm a method of obtaining dependences is developed. Propositions to formalize the dependences in parallel grained algorithms are stated and proved.Разработан метод получения информационной структуры зернистых алгоритмов с аффинными зависимостями. Сформулированы и доказаны утверждения, позволяющие формализовать нахождение всех функций зависимостей глобального уровня

New approach to synthesis of nitronyl and imino nitroxides based on SNH methodology

It is shown that SN H approach opens new possibilities in the synthesis of polyfunctional nitronyl and imino nitroxides. It is found that the interaction of 4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazol-3-oxide-1- oxyl lithium salt Li1 with 3,6-diaryl-1,2,4-triazines leads to formation of the corresponding triazines bearing nitronyl nitroxide or imino nitroxide substituent at position 5 of the heterocycle. The reaction of Li1 with pyridazine-N-oxide gives rise to nitroxide with buten-3-ynyl substituent 5. Spin-labeled 5 could be readily transformed by the use of 1,3-dipolar and nucleophilic addition reactions, as well as oxidative coupling, that gives a large group of new paramagnets: 2-(1H-pyrazol-5-yl)vinyl-, 2-ethynylcyclopropyl- , 2-(3-(ethoxycarbonyl) isoxazol-5-yl)vinyl-, 1-(pyrrolidin-1-yl)but-3-ynyl- substituted nitronyl nitroxide and a diradical - 2,2′-((1E,7E)-octa-1,7- dien-3,5-diyne-1,8-diyl)bis(4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazol-3-oxide- 1-oxyl). The new nitroxides were characterized by X-ray single crystal data, ESR and static magnetic susceptibility measurements. © ARKAT USA, Inc

Изменения климата западной части Российской Арктики в 1980–2021 гг. Часть 2. Температура почвы, снег, влажность

Based on average monthly data from the re-analysis of NASA MERRA-2 satellite measurements, the paper explores climatic changes in the temperature of the upper 1.5 meters of soil (TS), the thickness and area of the snow cover (SC), the moisture content of the top layer of soil 1 meter thick (SM) and air humidity at a height of 2 meters from the surface (AH) in the western part of the Russian Arctic (60°–75° N, 30°–85° E) for 1980–2021. The time interval considered is divided into two periods: 1980–2000 and 2001–2021. The differences between the average values of the parameters studied for these periods are calculated. The climatic changes that have occurred for the winter and summer seasons, as well as for each month of the year, are considered separately. Calculation of linear and quadratic trends has revealed an accelerating growth in the TS of the region studied in the period 2001–2021. A decrease in the thickness of the SC and a significant reduction in the area of the SC in November and April are shown. An increase in SM was found in the southwest and east of the region studied in the period 2001–2021, and a significant increase in AH in the western part of the Russian Arctic over the time interval studied is shown. Moreover, the growth of AH over the waters of the Barents, Kara and White Seas significantly accelerated in 2001–2021 compared to 1980–2000.По среднемесячным данным реанализа спутниковых измерений NASA MERRA-2 исследованы климатические изменения температуры верхних 1,5 метров почвы (ТП), толщины и площади снежного покрова (СП), влагосодержания верхнего слоя почвы толщиной 1 метр (ВП) и влажности воздуха на высоте 2 метра от поверхности (ВВ) в регионе западной части Российской Арктики (60°–75° с. ш., 30°–85° в. д.) за 1980–2021 гг. Рассматриваемый временной интервал разбит на 2 периода: 1980–2000 гг. и 2001–2021 гг. Вычислены разности между средними значениями исследуемых параметров за эти периоды. Отдельно рассмотрены климатические изменения, произошедшие для зимнего и летнего сезонов, а также для каждого месяца года. С помощью вычисления линейных и квадратичных трендов обнаружен ускоряющийся рост ТП исследуемого региона в 2001–2021 гг. Показано уменьшение толщины СП и существенное сокращение площади СП в ноябре и апреле. Обнаружен рост ВП на юго-западе и востоке исследуемого региона в период 2001–2021 гг., и показано значительное увеличение ВВ западной части Российской Арктики за исследуемый временной интервал. Причем рост ВВ существенно ускорился в 2001–2021 гг. по сравнению с 1980–2000 гг. над акваториями Баренцева, Карского и Белого морей

Изменения климата западной части Российской Арктики в 1980–2021 гг. Часть 1. Температура воздуха, осадки, ветер

The warming of the Arctic climate is confirmed by changes in the main hydrometeorological values of the atmosphere and ocean over a long period of time, and it is most pronounced in the recent decades. Based on monthly average data from the reanalysis of NASA MERRA-2 satellite measurements, we studied climate changes in air temperature, precipitation, and wind speed in the region of the western part of the Russian Arctic (60°–75° N, 30°–85° E) over 1980–2021. The transition between 2000 and 2001 was chosen as the time boundary between the periods, based on the application of the model of stepwise transitions from one quasi-stationary regime to another. Using this method, 2001 was found to be the smallest step year in the western Russian Arctic region. Significant changes in the parameters studied between the periods 1980–2000 and 2001–2021 are shown. Moreover, the strongest increase in temperature was observed for the months of November and April, which indicates a shift in the boundaries of the seasons — a later start and an early end of winter. It was found that in the period 2001–2021 the temperature increased most rapidly in the water areas of the Barents and Kara seas, and this growth occurred with acceleration. Negative temperature changes were found in the winter season in the areas where large rivers flow into the Barents and Kara Seas. It is hypothesized that this is due to the detected increase in the amount of precipitation in the catchment area of these rivers in 2001–2021 compared to 1980–2000. It is shown that the detected increase in the amount of precipitation is associated with a significant change in the atmospheric circulation in the region under study. In the summer season and September the western wind intensified in the region under study. During the winter season 2001–2021 in the Barents and Kara Seas the south wind increased compared to 1980–2000. Thus, significant changes in the climate of the western part of the Russian Arctic occurred during the time period considered. Westerly transport from the North Atlantic has intensified, precipitation has increased, and there has been an accelerated rise in temperature. All this contributed to the “atlantification” of the climate of the western part of the Russian Arctic.По среднемесячным данным реанализа спутниковых измерений NASA MERRA-2 исследованы климатические изменения температуры воздуха, количества атмосферных осадков и скорости ветра в регионе западной части Российской Арктики (60–75° с. ш., 30–85° в. д.) за 1980–2021 гг. Показаны существенные изменения этих параметров между периодами 1980–2000 гг. и 2001–2021 гг., причем наиболее сильное увеличение температуры наблюдалось для ноября и апреля, что свидетельствует о произошедшем смещении границ сезонов — более позднем начале и раннем завершении зимы. Обнаружено, что в период 2001–2021 гг. температура быстрее всего росла в акваториях Баренцева и Карского морей и этот рост происходил с ускорением. Найдены отрицательные изменения температуры в зимний сезон в районах впадения крупных рек в Баренцево и Карское моря. Выдвинута гипотеза, что это вызвано обнаруженным увеличением количества осадков на водосборе этих рек в 2001–2021 гг. по сравнению с 1980–2000 гг. Показано, что обнаруженное увеличение количества осадков связано с существенным изменением циркуляции атмосферы в исследуемом регионе. В летний сезон и сентябре в исследуемом регионе произошло усиление западного ветра. В зимний сезон 2001–2021 гг. в Баренцевом и Карском морях произошло усиление южного ветра по сравнению с 1980–2000 гг

Reactions of Chlorine Dioxide with Organic Compounds

Data on the reactivity of chlorine dioxide with organic compounds from various classes are summarized. Early investigations of the reactions of chlorine dioxide were occurred in aqueous or predominantly aqueous solutions in general, because it used in drinking water treatment and in industry as bleaching agent. However, chlorine dioxide was not used widely as reagent in organic synthesis. In last decades the number of publications on the studying interaction of the chlorine dioxide in organic medium increased. In table presented the rate constants reactions of chlorine dioxide with organic compounds published through 2004. Most of the rate constants were determined spectrophotometrically by decay kinetics of chlorine dioxide at 360 nm. Chlorine dioxide may be used for oxidation of organic compounds, because chlorine dioxide is enough reactive and selective as an oxidant with a wide range of organic compounds based on these reaction rate constants. But the application of chlorine dioxide as reagent in organic synthesis is restrained by the lack of data on the kinetics and mechanism of reactions involving chlorine dioxide, as well as data on the product yields and composition, temperature and solvent effects, and catalysts. The pathways of products formation and probable mechanisms of reactions are discussed in the review