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We analyzed the diversity of bacterial communities, metabolic activity, pH, and anthropogenic impact in the water of the estuaries and estuarine waters of the rivers in Southern Baikal in 2018 with different chemical composition. The chemical composition of waters and values of total microbial count (TMC), organotrophic bacteria (OB), and bacterial production (BP) depended on the geographical position, length of the rivers, and their water quality. In rivers with water acidification, we did not detect an effect of pH on TMC, abundance of OB, or total amount of mesophilic aerobic and facultative anaerobic microorganisms (PC). In rivers with a discharge of untreated domestic sewage, there was an increase in the content of dissolved organic carbon (DOC), concentration of nutrients, number of fecal and mesophilic bacteria, and high metabolic activity of microorganisms. The value of bacterioplankton production reached 0.26 to 12.41 per day−1; TMC – 0.155 ± 0.002 to 3.474 ± 0.044 million cells/mL. Using the massive parallel sequencing of fragments encoding the V2–V3 region of the 16S rRNA gene, we studied the diversity of bacteria and estimated the influence of chemical composition on the diversity of communities. As in other freshwater ecosystems and the pelagic zone of Lake Baikal, the members of freshwater Proteobacteria, Actinobacteria, Bacteroidetes, Cyanobacteria, and Verrucomicrobia predominated in the estuaries and estuarine waters of the rivers. The obtained data on the number and diversity of hygiene indicator bacteria suggested fecal pollution of the rivers of Southern Baikal.

We studied the microbial communities associated with the Baikal ostracods, Candona sp. (Candonidae). Bacterial biofilms were identified on the shell valves of the ostracods localized near epibiotic ciliates of the genus Lagenophrys (Ciliophora: Lagenoprydae). In situ hybridization confirmed the presence of eubacterial cells in different parts of the ostracod’s body. Bacteria of two morphotypes were detected in bacterial biofilms, including filamentous bacteria. Next-generation sequencing of 16S rRNA bacterial gene fragment allowed us to identify representatives of five bacterial phyla. Members of the phyla Proteobacteria and Bacteroidetes typical of non-marine epibiotic associations of ostracods were dominant taxa in the ostracod microbiomes. Members of other taxa (Actinobacteria, Gracilibacteria and Cyanobacteria) are likely facultative and consumed by ostracods together with detritus. In the ostracod microbiome, a significant proportion (20% of all reads) belonged to the sequences of the genus Rickettsia related to intracellular parasites.

This article presents the first experimental data on the ability of microbial communities from sediments of the Gorevoy Utes natural oil seep to degrade petroleum hydrocarbons under anaerobic conditions. Like in marine ecosystems associated with oil discharge, available electron acceptors, in particular sulfate ions, affect the composition of the microbial community and the degree of hydrocarbon conversion. The cultivation of the surface sediments under sulfate-reducing conditions led to the formation of a more diverse bacterial community and greater loss of n-alkanes (28%) in comparison to methanogenic conditions (6%). Microbial communities of both surface and deep sediments are more oriented to degrade polycyclic aromatic hydrocarbons (PAHs), to which the degree of the PAH conversion testifies (up to 46%) irrespective of the present electron acceptors. Microorganisms with the uncultured closest homologues from thermal habitats, sediments of mud volcanoes, and environments contaminated with hydrocarbons mainly represented microbial communities of enrichment cultures. The members of the phyla Firmicutes, Chloroflexi, and Caldiserica (OP5), as well as the class Deltaproteobacteria and Methanomicrobia, were mostly found in enrichment cultures. The influence of gas-saturated fluids may be responsible for the presence in the bacterial 16S rRNA gene libraries of the sequences of "rare taxa": Planctomycetes, Ca. Atribacteria (OP9), Ca. Armatimonadetes (OP10), Ca. Latescibacteria (WS3), Ca. division (AC1), Ca. division (OP11), and Ca. Parcubacteria (OD1), which can be involved in hydrocarbon oxidation.

Diversity of methano- and methylotrophic bacteria in enrichments from the oxidized sediment layer maintained at 10°C in mineral media with nitrogen compounds ( $${\text{NO}}_{3}^{ - }$$ and $${\text{NH}}_{4}^{ + }$$ ) and methanol was studied using high-throughput sequencing of the V2–V3 region of the 16S rRNA gene. Methanotrophs of the bottom sediment belonged to the order Methylococcales, with predominance of the genus Methylobacter (6.4 and 4.6% of the total number of sequences, respectively). Members of the methylotrophic community belonged to the genus Methylotenera (family Methylophilaceae). Enrichments in the medium with ammonium and methane were characterized by the highest diversity of methanotrophs, containing 22 OTUs of the family Methylococcaceae, nine of which were not detected under other cultivation conditions. Altogether, only six out of 28 OTUs of methanotrophic bacteria exhibited similarity to cultured members of Methylobacter, Metyloglobulus, and Methylomicrobium, while others showed different levels of similarity (94–99%) to uncultured members of the family Methylococcaceae. The presence of 0.01% methanol promoted preferential development of methylotrophic bacteria, while 0.5% methanol suppressed the growth of methanotrophic bacteria irrespective of the nitrogen source added.

The first results of a study into the microbiomes of benthic invertebrates found in sites with seeps (containing methane, oil, or a combination of methane and mud) and an underwater low-temperature vent of Lake Baikal are presented. Microorganisms were detected in the intestine of an oligochaete from the cold methane seep using microscopy. Analysis of 16S rRNA gene libraries revealed that the highest diversity of microorganisms was found in the nematode microbiomes where the members of 11 phyla were identified. Some of the detected prokaryotes are methanogens, nitrifiers, and nitrogen fixators, while some are involved in the sulfur cycle. Methanotrophs were detected in the microbiomes of oligochaetes and chironomids. The microbiomes of nematodes, chironomids, and bathynellids are composed of members of the Bacteroidetes and Firmicutes phyla, which are related to the symbiotic bacteria found in insects and animals from other ecotopes. Microorganisms typically found in the water and sediments of Lake Baikal were also detected in the invertebrates microbiomes.

The review summarizes the results of recent studies of microbial communities of the Lake Baikal sediments obtained using diverse techniques. In the sediments of the areas of stable sedimentation metabarcoding revealed predominance of members of the phyla Alpha- and Gammaproteobacteria (including Betaproteobacteriales), Bacteroidetes, Acidobacteria, Verrucomicrobia, and Thaumarchaeota, which are also common in other freshwater lakes. In the areas of discharge of gas-bearing mineralized fluids, the structure of microbial communities varied depending on the presence of electron acceptors and intensity and component composition of gas-bearing fluids responsible for microbial migration from the deep zone to the upper sediment layers and vice versa. Methanogenic archaea detected in Baikal sediments belonged to the groups capable of all four known catabolic pathways of methanogenesis: hydrogenotrophic, acetoclastic, methylotrophic, and hydrogen-dependent methylotrophic ones. Predominant members of the Baikal archaeal community, hydrogenotrophic methanogens of the family Methanoregulaceae (genera Methanoregula and Methano-sphaerula, as well as uncultured lineages), hydrogen-dependent methylotrophic archaea of the order Methanomassiliicoccales, and acetoclastic methanogens of the family Methanosaetaceae (genus Methanothrix (Methanosaeta)), were the same as in methanogenic communities of other freshwater lakes. Experimental evidence was obtained for anaerobic methane oxidation (AOM) via the nitrate- and nitrite-dependent pathways by archaea of the ANME-2d subcluster and bacteria of the phylum NC10. Structures of the 16S rRNA genes, mcrA, and pmoA exhibited high identity to those of the known freshwater organisms performing this process. Diversity of microbial communities at the sites of natural oil seepage differed at the order and family levels, as well as by the presence of alkane hydroxylases in the genes of the cultured species.

Carboniferous conodont biostratigraphy comprises regional zonations that reflect the palaeogeographical distribution of taxa and distinct shallow-water and deep-water conodont biofacies. Some species have a global distribution and can effect high quality correlations. These taxa are incorporated into definitions of global Carboniferous chronostratigraphic units. A standard global Carboniferous zonation has not been developed. The lowermost Mississippian is zoned by Siphonodella species, excepet in shallow-water facies, where other polygnathids are used. Gnathodus species radiated during the Tournaisian and are used to define many Mississippian zones. A late Tournaisian maximum in diversity, characterized by short-lived genera, was followed by lower diversity faunas of Gnathodus species and carminate genera through the Visean and Serpukhovian. By the late Visean and Serpukhovian, Lochriea provides better biostratigraphic resolution. Shallow-water zonations based on Cavusgnathus and Mestognathus are difficult to correlate. An extinction event near the base of the Pennsylvanian was followed by the appearance of new gnathodid genera: Rhachistognathus , Declinognathodus , Neognathodus , Idiognathoides and Idiognathodus . By the middle of the Moscovian, few genera remained: Idiognathodus , Neognathodus and Swadelina. During the middle Kasimovian and Gzhelian, only Idiognathodus and Streptognathodus species were common. Near the end of the Gzhelian, a rediversification of Streptognathodus species extended into the Cisuralian.

[Image: see text] Kratom is widely consumed in the United States for self-treatment of pain and opioid withdrawal symptoms. Mitragynine is the most abundant alkaloid in kratom and is a μ-opioid receptor agonist. 7-Hydroxymitragynine (7-HMG) is a mitragynine metabolite that is a more potent and efficacious opioid than its parent mitragynine. 7-HMG contributes to mitragynine’s antinociceptive effects in mice, but evidence suggests it may also have a higher abuse potential. This in vitro study demonstrates that 7-HMG is stable in rodent and monkey plasma but is unstable in human plasma. Surprisingly, in human plasma 7-HMG is converted to mitragynine pseudoindoxyl, an opioid that is even more potent than either mitragynine or 7-HMG. This novel metabolite is formed in human plasma to a much greater extent than in the preclinical species tested (mouse, rat, dog, and cynomolgus monkey) and due to its μ-opioid potency may substantially contribute to the pharmacology of kratom in humans to a greater extent than in other tested species.

Mitragynine is the most abundant psychoactive alkaloid derived from the leaves of Mitragyna speciosa (kratom), a tropical plant indigenous to regions of Southeast Asia. Mitragynine displays a moderate affinity to opioid receptors, and kratom is often self-prescribed to treat pain and/or opioid addiction. The purpose of this study was to investigate the safety and pharmacokinetic properties of mitragynine in the dog. Single dose oral (5 mg/kg) and intravenous (0.1 mg/kg) pharmacokinetic studies of mitragynine were performed in female beagle dogs. The plasma concentrations of mitragynine were measured using ultra-performance liquid chromatography coupled with a tandem mass spectrometer, and the pharmacokinetic properties were analyzed using non-compartmental analysis. Following intravenous administration, mitragynine showed a large volume of distribution (Vd, 6.3 ± 0.6 L/kg) and high clearance (Cl, 1.8 ± 0.4 L/h/kg). Following oral mitragynine dosing, first peak plasma (Cmax, 278.0 ± 47.4 ng/mL) concentrations were observed within 0.5 h. A potent mu-opioid receptor agonist and active metabolite of mitragynine, 7-hydroxymitragynine, was also observed with a Cmax of 31.5 ± 3.3 ng/mL and a Tmax of 1.7 ± 0.6 h in orally dosed dogs while its plasma concentrations were below the lower limit of quantification (1 ng/mL) for the intravenous study. The absolute oral bioavailability of mitragynine was 69.6%. Administration of mitragynine was well tolerated, although mild sedation and anxiolytic effects were observed. These results provide the first detailed pharmacokinetic information for mitragynine in a non-rodent species (the dog) and therefore also provide significant information for allometric scaling and dose predictions when designing clinical studies.

The results of field studies of the species composition and productive parameters (biomass, photosynthesis rate, chlorophyll a content, and assimilation numbers) of microalgae in the plankton and the interstitial icy waters of Lake Baikal southern littoral area obtained in March 2018 are presented. A comprehensive study of the ice and phytoplankton algae showed that their productive activity was relatively low at most stations. Their higher values observed near river mouths with significant anthropogenic pollution were caused by both the additional nutrient input and development of small-sized algae, primarily of phytoflagellates, which indicate water pollution by organic matter inflowing to Lake Baikal with its tributaries. Using the principal component method, we failed to reveal reliable correlation between the primary producers and the microorganisms decomposing organic matter into mineral substances (the correlation coefficient was 0.49). The differences between the stations subject to anthropogenic impact and the reference ones indicate that access to easily mineralized organic matter promoted the massive development of phytoflagellates. Although large-cell diatoms common in the lake were absent, primary production at these sites reached 100 to 280 mg C m−2, which was comparable with the values obtained for abundant diatom blooms during the under-ice period. High functional potential of the algae at the areas subject to anthropogenic impact results in significant biomass accumulation, which leads eutrophication of the littoral zone and may lead to increased primary production of the pelagic zone.

Although in sediments of Lake Baikal process of anaerobic oxidation methane was revealed by radioisotope techniques, by of the methane profile we know a little about the microorganisms carrying out this process. Here we studied diversity of archaeal communities in different types geological structures (methane seeps and mud volcano) on Lake Baikal with different composition of pore waters and the discharged fluid. In investigate were used different methods molecular biology including of high-throughput sequencing of gene 16S rRNA and PCR analysis different genes of AOM (mcrA). Molecular analysis did not reveal methane-oxidizing archaea ANME-1, -2, or -3, which are responsible for anaerobic oxidation of methane in marine sediments. Hydrogenotrophic methanogenic archaea representatives of the orders Methanomicrobiales, Methanococcales, as well as acetoclastic methanogens of the order Methanosarsinales were abundant in a mud volcano at Lake Baikal. In investigation sites we found divers M. nitroreducens-like archaea (ANME-2d subcluster) both in deep sediments of a methane seeps and in a mud volcanoes. Their closest homologues involved in process anaerobic oxidation of methane in different freshwater systems, bioreactors, paddy field soils.

Kratom alkaloids have mostly been evaluated for their opioid activity but less at other targets that could contribute to their physiological effects. Here, we investigated the in vitro and in vivo activity of kratom alkaloids at serotonin receptors (5-HTRs). Paynantheine and speciogynine exhibited high affinity for 5-HT(1A)Rs and 5-HT(2B)Rs, unlike the principal kratom alkaloid mitragynine. Both alkaloids produced antinociceptive properties in rats via an opioid receptor-independent mechanism, and neither activated 5-HT(2B)Rs in vitro. Paynantheine, speciogynine, and mitragynine induced lower lip retraction and antinociception in rats, effects blocked by a selective 5-HT(1A)R antagonist. In vitro functional assays revealed that the in vivo 5-HT(1A)R agonistic effects may be due to the metabolites 9-O-desmethylspeciogynine and 9-O-desmethylpaynantheine and not the parent compounds. Both metabolites did not activate 5-HT(2B)R, suggesting low inherent risk of causing valvulopathy. The 5-HT(1A)R agonism by kratom alkaloids may contribute to the mood-enhancing effects associated with kratom use.

Recently many novel lineages of methanogens being suggested via metagenomics approaches. Most of these lineages potentially capable of methanogenesis from 1-methylated compounds, a pathway that had previously received comparably little attention. Analysis of the 16S rRNA gene diversity showed that in the bottom sediments of Lake Baikal methylotrophic methanogens as well as H2-depended methylotrophic methanogens are represented. However, under cultivation conditions, the addition of methanol stimulated methane production only in the case of microbial communities from upper silts. Among the methylotrophic methanogens in enrichment cultures, representatives of the genera Methanosarcina and Methanomethylovorans were identified.

Kratom (Mitragyna speciosa) is a psychoactive plant popular in the United States for the self-treatment of pain and opioid addiction. For standardization and quality control of raw and commercial kratom products, an ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed and validated for the quantification of ten key alkaloids, namely: corynantheidine, corynoxine, corynoxine B, 7-hydroxymitragynine, isocorynantheidine, mitragynine, mitraphylline, paynantheine, speciociliatine, and speciogynine. Chromatographic separation of diastereomers, or alkaloids sharing same ion transitions, was achieved on an Acquity BEH C18 column with a gradient elution using a mobile phase containing acetonitrile and aqueous ammonium acetate buffer (10mM, pH 3.5). The developed method was linear over a concentration range of 1-200 ng/mL for each alkaloid. The total analysis time per sample was 22.5 minutes. The analytical method was validated for accuracy, precision, robustness, and stability. After successful validation, the method was applied for the quantification of kratom alkaloids in alkaloid-rich fractions, ethanolic extracts, lyophilized teas, and commercial products. Mitragynine (0.7%-38.7% w/w), paynantheine (0.3%-12.8% w/w), speciociliatine (0.4%-12.3% w/w), and speciogynine (0.1%-5.3% w/w) were the major alkaloids in the analyzed kratom products/extracts. Minor kratom alkaloids (corynantheidine, corynoxine, corynoxine B, 7-hydroxymitragynine, isocorynantheidine) were also quantified (0.01%-2.8% w/w) in the analyzed products; however mitraphylline was below the lower limit of quantification in all analyses.

Using the Illumina MiSeq platform, we have studied the diversity of bacteria and archaea in three rivers of the southeastern end of Lake Baikal in the under-ice period of 2018. In analysed 16S rRNA gene libraries of all rivers, we have identified sequences of 12 bacterial phyla: Actinobacteria, Bacteroidetes, Cyanobacteria, Elusimicrobia, Epsilonbacteraeota, Fibrobacteres, Firmicutes, Omnitrophicaeota, Patescibacteria, Planctomycetes, Proteobacteria, and Verrucomicrobia. The contribution of minor taxa to the microbiomes from the estuaries of the rivers Solzan and Bolshaya Osinovka is more significant. Three phyla (Thaumarchaeota, Euryarchaeota and Crenarchaeota) and one superphylum (DPANN) represent archaea. The diversity of bacteria and archaea in the investigated ecotopes has its specifics and is not identical to that found in the pelagic zone of Southern Baikal. Bacteria show phylogenetic diversity at the level of families and genera, whereas archaea – at the level of phyla. In the microbiomes, we have identified microorganisms involved in various stages of transformation of organic and inorganic substances.

The objective of the study was to investigate the changes of the kidney functions in mature rats with rapid acetylation type, under conditions of subacute cadmium-nitrate intoxication and preventive introduction of Echinacea purpurea. Methods. Male rats, 6 months of age, with rapid acetylation type, were divided into 3 groups: І – control; ІІ – rats with of subacute cadmium-nitrate intoxication model; ІІІ – rats receiving intragastric alcohol tincture of fresh rhizomes with roots of Echinacea purpurea (LC “State Municipal Enterprise “Pharmaceutical Plant Vishpha””, Ukraine; 0,25 mk/rg). Results. Under the effect of preventive introduction of Echinacea purpurea in rats with rapid acetylation type and cadmium-nitrate lesion of the kidneys, diuresis and glomerular filtration rate became normal; distal transport of sodium ions increased; hyponatraemia and decreased natriuresis remained without changes; concentrations of creatinine in the blood plasma, potassium ions in the blood plasma and urine, kaliuresis decreased. Similar to the group of rats without Echinacea purpurea, proximal reabsorption of sodium ions, which is standardized by glomerular filtration, decreased. Conclusion. Under conditions of preventive introduction of Echinacea purpurea, volume regulating kidney function is maintained in mature rats with rapid acetylation type and subacute cadmium-nitrate intoxication, but it does not prevent the development of toxic nephropathy, with prevailing lesion of the nephron proximal portion, disorders of ion regulating kidney function and water-electrolytic balance.

The First Appearance Datum (FAD) of the conodont Lochriea ziegleri in the lineage Lochriea nodosa–L. ziegleri has been considered the most suitable definition and global correlation-level for a revised base of the Serpukhovian Stage. Abundant specimens of Lochriea are recorded throughout the Late Visean–early Serpukhovian interval in the Naqing section, South China. Among them, the P1 elements, with wide morphological variability, enable confirmation and refinement of main lineages within the genus. Two lineages are proposed: 1) noded Lochriea species, such as L. mononodosa–L. nodosa–L. ziegleri, L. senckenbergica and L. multinodosa, and 2) ridged Lochriea species such as L. monocostata–L. costata–L. cruciformis. The possibility for their phylogenetic relationships is evaluated in this paper.

The impacts of high-intensity light (HIL) (4 h) and UV-B radiation (1 h) on the photosynthetic activity, content of photosynthetic and UV-absorbing pigments (UAPs), activity of antioxidant enzymes (ascorbate peroxidase (APX) and guaiacol-dependent peroxidase (GPX)), content of thiobarbituric acid reactive substances (TBARs), expression of some light-regulated genes in 25-day-old wild type (WT) and the cryptochrome 1 (Cry1) hy4 mutant of A. thaliana Col-0 plants grown under blue light (BL) were studied. HIL and UV-B treatments led to decreases in the photosynthetic rate (Pn), photochemical activity of PSII (FV/FM) and PSII performance index (PIABS) of WT and mutant plants grown under high-intensity BL (HBL) and moderate intensity BL (MBL). However, in HBL plants, the decrease in the photosynthetic activity in hy4 plants was significantly greater than that in WT plants. In addition, hy4 HBL plants demonstrated lowered UAP and carotenoid contents as well as lower activity of APX and GPX enzymes. The difference in the decline in the photosynthetic activity of WT and hy4 plants grown at MBL in response to HIL was nonsignificant, while that in response to UV-B was small. We assume that the deficiency in cryptochrome 1 under HIL irradiation disrupts the interaction between HY5 and HFR1 transcription factors and photoreceptors, which affects the transcription of light-induced genes, such as CAB1, PSY and PAL1 linked to carotenoid and flavonoid biosynthesis. It was concluded that PA stress resistance in WT and hy4 plants depends on the light intensity and reduced stress resistance of hy4 at HBL, is likely linked to low UAP and carotenoid contents as well as lowered APX and GPX enzyme activities in hy4 mutants.

BACKGROUND AND OBJECTIVES: 7-Hydroxymitragynine (7-HMG) is an oxidative metabolite of mitragynine, the most abundant alkaloid in the leaves of Mitragyna speciosa (otherwise known as kratom). While mitragynine is a weak partial μ-opioid receptor (MOR) agonist, 7-HMG is a potent and full MOR agonist. It is produced from mitragynine by the cytochrome P450 (CYP) 3A, a drug-metabolizing CYP isoform predominate in the liver that is also highly expressed in the intestine. Given the opioidergic potency of 7-HMG, a single oral dose pharmacokinetic and safety study of 7-HMG was performed in beagle dogs. METHODS: Following a single oral dose (1 mg/kg) of 7-HMG, plasma samples were obtained from healthy female beagle dogs. Concentrations of 7-HMG were determined using ultra-performance liquid chromatography coupled with a tandem mass spectrometer (UPLC-MS/MS). Pharmacokinetic parameters were calculated using a model-independent non-compartmental analysis of plasma concentration-time data. RESULTS: Absorption of 7-HMG was rapid, with a peak plasma concentration (C(max), 56.4 ± 1.6 ng/mL) observed within 15 min post-dose. In contrast, 7-HMG elimination was slow, exhibiting a mono-exponential distribution and mean elimination half-life of 3.6 ± 0.5 h. Oral dosing of 1 mg/kg 7-HMG was well-tolerated with no observed adverse events or significant changes to clinical laboratory tests. CONCLUSIONS: These results provide the first pharmacokinetic and safety data for 7-HMG in the dog, and therefore contribute to the understanding of the putative pharmacological role of 7-HMG resulting from an oral delivery of mitragynine from kratom.

Kratom, Mitragyna speciosa Korth., is being widely consumed in the United States for pain management and the reduction of opioid withdrawal symptoms. The central nervous system (CNS) active alkaloids of kratom, including mitragynine, 7-hydroxymitragynine, and numerous additional compounds, are believed to derive their effects through opioid receptor activity. There is no literature describing the systemic exposure of many of these alkaloids after the consumption of kratom. Therefore, we have developed and validated a bioanalytical method for the simultaneous quantitation of 11 kratom alkaloids (mitragynine, 7-hydroxymitragynine, corynantheidine, speciogynine, speciociliatine, paynantheine, corynoxine, corynoxine-B, mitraphylline, ajmalicine, and isospeciofoline) in rat plasma. The validated method was used to analyze oral pharmacokinetic study samples of lyophilized kratom tea (LKT) and a marketed product, OPMS liquid shot, in rats. Among the 11 alkaloids, only mitragynine, 7-hydroxymitragynine, speciociliatine, and corynantheidine showed systemic exposure 8 h postdose, and the dose-normalized systemic exposure of these four alkaloids was higher (1.6-2.4-fold) following the administration of the commercial OPMS liquid. Paynantheine and speciogynine levels were quantifiable up to 1 h postdose, whereas none of the other alkaloids were detected. In summary, the method was successfully applied to quantify the exposure of individual kratom alkaloids after an oral dose of traditional or commercial products. This information will contribute to understanding the role of each alkaloid in the overall pharmacology of kratom and elucidating the pharmacokinetic differences between traditional and commercial kratom products.

Background In 2018, the Farm Bill mandated the United States Department of Agriculture to develop regulations governing the cultivation, processing, and marketing of industrial hemp. Industrial hemp is defined as Cannabis sativa L. with a total Δ-9-tetrahydrocannabinol (Δ-9-THC) content ≤0.3%. Therefore, for hemp to become an agricultural commodity, it is important to regulate production by developing standard methods for sampling and testing of the plant material. Methods An ultra-performance liquid chromatography-tandem mass spectrometry analytical method for the quantification of twelve cannabinoids was developed. The method was applied to a regulatory sampling trial of three hemp varieties cultivated for cannabidiol (CBD) production. Two samples were taken from 28 plants with one sample being flower only while the other was a composite sample that included flowers, leaves, and stems. Results The assay method was validated for specificity, range, repeatability, reproducibility, and recovery in accordance with all applicable standards for analytical methods. The results of the regulatory study indicated a significant decrease in the concentration of total Δ-9-THC and total CBD of 0.09% and 1.32%, respectively, between a flower only and a composite sample. Conclusions There are many factors that may influence reported total Δ-9-THC content in industrial hemp. A robust analytical method was developed to analyze hemp samples in a trial regulatory study. The results indicate that the way hemp is sampled and analyzed may influence the legality of a crop, which could have negative economic and legal consequences.

BackgroundLake Baikal is the largest body of liquid freshwater on Earth. Previous studies have described the microbial composition of this habitat, but the viral communities from this ecosystem have not been characterized in detail.ResultsHere, we describe the viral diversity of this habitat across depth and seasonal gradients. We discovered 19,475 bona fide viral sequences, which are derived from viruses predicted to infect abundant and ecologically important taxa that reside in Lake Baikal, such as Nitrospirota, Methylophilaceae, and Crenarchaeota. Diversity analysis revealed significant changes in viral community composition between epipelagic and bathypelagic zones. Analysis of the gene content of individual viral populations allowed us to describe one of the first bacteriophages that infect Nitrospirota, and their extensive repertoire of auxiliary metabolic genes that might enhance carbon fixation through the reductive TCA cycle. We also described bacteriophages of methylotrophic bacteria with the potential to enhance methanol oxidation and the S-adenosyl-L-methionine cycle.ConclusionsThese findings unraveled new ways by which viruses influence the carbon cycle in freshwater ecosystems, namely, by using auxiliary metabolic genes that act upon metabolisms of dark carbon fixation and methylotrophy. Therefore, our results shed light on the processes through which viruses can impact biogeochemical cycles of major ecological relevance.

We have assessed the diversity of bacteria near oil-methane (area I) and methane (area II) seeps in the pelagic zone of Lake Baikal using massive parallel sequencing of 16S rRNA, pmoA, and mxaF gene fragments amplified from total DNA. At depths from the surface to 100 m, sequences belonging to Cyanobacteria dominated. In the communities to a depth of 200 m of the studied areas, Proteobacteria dominated the deeper layers of the water column. Alphaproteobacteria sequences were predominant in the community near the oil-methane seep, while the community near the methane seep was characterized by the prevalence of Alpha- and Gammaproteobacteria. Among representatives of these classes, type I methanotrophs prevailed in the 16S rRNA gene libraries from the near-bottom area, and type II methanotrophs were detected in minor quantities at different depths. In the analysis of the libraries of the pmoA and mxaF functional genes, we observed the different taxonomic composition of methanotrophic bacteria in the surface and deep layers of the water column. All pmoA sequences from area I were type II methanotrophs and were detected at a depth of 300 m, while sequences of type I methanotrophs were the most abundant in deep layers of the water column of area II. All mxaF gene sequences belonged to Methylobacterium representatives. Based on comparative analyses of 16S rRNA, pmoA, and mxaF gene fragment libraries, we suggest that there must be a wider spectrum of functional genes facilitating methane oxidation that were not detected with the primers used.

Lochriea ziegleri is the conodont species that bears the highest potential to be the index for the base of Serpukhovian. Proposed phylogenetic lineages within the genus Lochriea, particularly the lineage L. nodosa–L. ziegleri, can be confirmed by the latest studies of the succession of the respective species in sections of north-western Ireland and the Rhenish Mountains of Germany; in these regions the first occurrence datum (FOD) of L. ziegleri is in the P2a zone or the comparable Neoglyphioceras suerlandense ammonoid zone. In the Cantabrian Mountains and the South Urals, the FODs of L. ziegleri are possibly located within ammonoid zones characterized by the genera Revilloceras and early representatives of Dombarites zones with falcatoid ornament.

Corynantheidine, a minor alkaloid found in Mitragyna speciosa (Korth.) Havil, has been shown to bind to opioid receptors and act as a functional opioid antagonist, but its unique contribution to the overall properties of kratom remains relatively unexplored. The first validated bioanalytical method for the quantification of corynantheidine in rat plasma is described. The method was linear in the dynamic range from 1–500 ng/mL, requires a small plasma sample volume (25 μL), and a simple protein precipitation method for extraction of the analyte. The separation was achieved with Waters BEH C18 2.1 × 50 mm column and the 3-minute gradient of 10 mM ammonium acetate buffer (pH = 3.5) and acetonitrile as mobile phase. The method was validated in terms of accuracy, precision, selectivity, sensitivity, recovery, stability, and dilution integrity. It was applied to the analysis of the male Sprague Dawley rat plasma samples obtained during pharmacokinetic studies of corynantheidine administered both intravenously (I.V.) and orally (P.O.) (2.5 mg/kg and 20 mg/kg, respectively). The non-compartmental analysis performed in Certara Phoenix® yielded the following parameters: clearance 884.1 ± 32.3 mL/h, apparent volume of distribution 8.0 ± 1.2 L, exposure up to the last measured time point 640.3 ± 24.0 h*ng/mL, and a mean residence time of 3.0 ± 0.2 h with I.V. dose. The maximum observed concentration after a P.O. dose of 213.4 ± 40.4 ng/mL was detected at 4.1 ± 1.3 h with a mean residence time of 8.8 ± 1.8 h. Absolute oral bioavailability was 49.9 ± 16.4 %. Corynantheidine demonstrated adequate oral bioavailability, prolonged absorption and exposure, and an extensive extravascular distribution. In addition, imaging mass spectrometry analysis of the brain tissue was performed to evaluate the distribution of the compound in the brain. Corynantheidine was detected in the corpus callosum and some regions of the hippocampus.

Methane production by microbial communities from Lake Baikal bottom sediments with different chemical composition of pore water was studied. Methane production was more active in the media supplemented with H2: CO2 and H2 + CH3COONa, rather than on media with acetate as the sole source of carbon and energy. Addition of methanol stimulated methane production only in the case of microbial communities from upper silts. Ability of the communities to produce methane correlated reliably with the concentrations of the NO3–, SO42−, Cl–, and CH3COO– ions in the pore water of the relevant sediments. Cultivation of communities from the mud volcano sediments resulted in development of methanogenic archaea of the family Methanocellaсеае in the media supplemented with H2: CO2 and H2 + CH3COONa, while methanogenic archaea in the communities cultivated without additional substrates belonged to the genera Methanoregula, Methanobacterium, and Methanosaeta.

Reconstructions of paleo-seawater chemistry are largely inferred from biogenic records of epicontinental seas. Recent studies provide considerable evidence for large-scale spatial and temporal variability in the environmental dynamics of these semi-restricted seas that leads to the decoupling of epicontinental isotopic records from those of the open ocean. We present conodont apatite δ 18 O PO 4 and 87Sr/86Sr records spanning 24 Myr of the late Mississippian through Pennsylvanian derived from the U–Pb calibrated cyclothemic succession of the Donets Basin, eastern Ukraine. On a 2 to 6 Myr-scale, systematic fluctuations in bioapatite δ 18 O PO 4 and 87Sr/86Sr broadly follow major shifts in the Donets onlap–offlap history and inferred regional climate, but are distinct from contemporaneous more open-water δ 18 O PO 4 and global seawater Sr isotope trends. A −1 to −6‰ offset in Donets δ 18 O PO 4 values from those of more open-water conodonts and greater temporal variability in δ 18 O PO 4 and 87Sr/86Sr records are interpreted to primarily record climatically driven changes in local environmental processes in the Donets sea. Systematic isotopic shifts associated with Myr-scale sea-level fluctuations, however, indicate an extrabasinal driver. We propose a mechanistic link to glacioeustasy through a teleconnection between high-latitude ice changes and atmospheric pCO2 and regional monsoonal circulation in the Donets region. Inferred large-magnitude changes in Donets seawater salinity and temperature, not archived in the more open-water or global contemporaneous records, indicate a modification of the global climate signal in the epicontinental sea through amplification or dampening of the climate signal by local and regional environmental processes. This finding of global climate change filtered through local processes has implications for the use of conodont δ 18 O PO 4 and 87Sr/86Sr values as proxies of paleo-seawater composition, mean temperature, and glacioeustasy.

Under laboratory conditions, the microbial communities of bottom sediments of a mud volcano Peschanka (Lake Baikal) were found to carry out anaerobic methane oxidation (AOM). After 16 days of anaerobic cultivation of the enrichment cultures, methane content in the gas phase decreased, and microbial consortia were established. The content of carbon, nitrogen, and oxygen determined by energy dispersive X-ray spectroscopy (EDS) was higher than in the nearby sediment particles. The presence of bacteria of the NC10 phylum and archaea of the ANME-2d cluster was established by fluorescent in situ hybridization (FISH).

Massive parallel sequencing of the 16S rRNA gene fragments was used to investigate the composition and diversity of microbial communities in sediments from Southern Baikal to a depth of 9 cm with 1-cm step. In the layers from the sediment surface to the lower border of oxygen penetration (2 cm), organotrophic bacteria with high similarity to the heterotrophic species Luteolibacter luojiensis constituted the largest fraction of the community. In the formation zone of Fe/Mn crusts (3–5 cm), Proteobacteria and Actinobacteria predominated in the community, while the share of Cyanobacteria was considerable. The lower reduced layers showed an increased contribution of the Bacteroidetes, while the shares of the taxa predominant in the higher layers remained significant. Analysis of archaeal 16S rRNA gene amplicons revealed predominance of the soil and aquatic Thaumarchaeota (Marine Group I lineage), which are involved in anaerobic ammonium oxidation, practically in all sediment layers. The buried oxidized layer (6–7 cm), where members of the uncultured Marine Benthic Group D lineage of the order Thermoplasmatales (Euryarchaeota) predominated, was an exception in this regard. Small numbers of archaea of the Baikal-1 lineages (below 1%) were observed in the communities from the 6–7 and 7–8 cm layers, while the archaea involved in anaerobic methane oxidation (including the ANME-2d group) were not detected.

We studied details of the conodont assemblages in two deep-water sections spanning the mid-Carboniferous boundary at Guizhou, South China. Forty-six species/subspecies were identified belonging to ...

An abundant and taxonomically diverse conodont association was recovered from the Bashkirian strata at the Luokun section, southern Guizhou, South China. Forty-six species and subspecies, which belong to 10 genera, were identified. Seven conodont zones were recognized. They are, in ascending order, the Declinognathodus noduliferus , Idiognathoides sulcatus sulcatus , Idiognathoides sinuatus , Idiognathoides sulcatus parvus , “ Streptognathodus ” expansus M1, “ Streptognathodus ” expansus M2, and Diplognathodus cf. ellesmerensis zones. The base of the Bashkirian in the Luokun section is identified by the first occurrence of Declinognathodus noduliferus . Declinognathodus praenoduliferus and D. cf. bernesgae occur in the underlying beds. The base of the Moscovian can be recognized by the first occurrence of Diplognathodus cf. ellesmerensis , which is one of the most significant markers for the Bashkirian–Moscovian boundary in China. The conodont zonation is compared with that of the Naqing section nearby, as well as with that of the contemporaneous deposits of the South Urals, Donets Basin, North America and other areas.

Using scanning electron microscopy we investigated the epibiotic associations of peritrichial sessile ciliates of the Lagenophrys (Ciliophora: Lagenoprydae) and prokaryotes of various morphologies on the surface of endemic amphipods Macropereiopus florii (Dybowsky 1874) and ostracods Candona (Candonidae). We noted biofouling and mineralization in the areas of formation of a bacterial biofilm, which includes Fe, P, and other elements. High-throughput sequencing on the Illumina MiSeq platform showed the presence of such bacterial phyla as Actinobacteria, Gracilibacteria, Cyanobacteria, Proteobacteria, Bacteroidetes in the ostracod microbiome, of which the latter two were dominant. Sequence analysis of the 16S rRNA gene fragment showed epibiotic microorganisms that are related to the colorless sulfur bacteria Thiothrix sp. More than 50% of all sequences were attributed to endosymbiont bacteria of the genus Rickettsia, and the presence of endosymbionts of the genus Ca. Cardinium was shown for the first time for Baikal ostracods.

Highlights • We have synthesized a wide range of tris-(2-hydroxyethyl)ammonium arylchalcogenylacetates, “protatranes”. • “Protatranes” are growth stimulators of hydrocarbon-oxidizing Rhodococcus erythropolis bacteria isolated from Lake Baikal. • The effect of “protatranes” on growth of Pseudomonas fluorescens is less obvious. • The effect of stimulants on Rhodococcus erythropolis is likely due to the structure of protatranes and the cell wall of bacteria., Under natural conditions, biodegradation processes proceed slowly, especially in regions with low temperature. To activate vital processes in hydrocarbon-oxidizing microorganisms at low temperatures, biologically active compounds can be employed as growth stimulants. A low-temperature (10 °C) study has shown that tris-(2 hydroxyethyl) ammonium arylchalcogenylacetates, “protatranes” exert an effect on the growth of hydrocarbon-oxidizing strains of Rhodococcus erythropolis and Pseudomonas fluorescens, isolated from natural oil seepage on Lake Baikal. It has been found that “protatranes”, at microconcentrations, increase the growth rate of R. erythropolis bacteria by 2–16 times. It has been established that compounds slightly effect the growth of P. fluorescens. The positive effect of “protatranes” compounds on the growth rate of hydrocarbon-oxidizing microorganisms at low positive temperatures can be used for the development of environmentally benign methods for the restoration of natural objects after their contamination with oil.

1. Mitragynine is the major indole-based alkaloid of Mitragyna speciosa (kratom). Decoctions (teas) of the plant leaves have been used traditionally for cough, diarrhoea, pain, hypertension and for the treatment of opioid addiction. In the West, kratom has become increasingly utilized for mood elevation, pain treatment and as a means of self-treating opioid addiction. 2. Metabolic pathways of mitragynine were identified in human liver microsomes (HLM) and S9 fractions. A total of thirteen metabolites were identified, four oxidative metabolites and a metabolite formed by demethylation at the 9-methoxy group were the major metabolites of mitragynine. 3. The cytochrome P450 enzymes involved in the metabolism of mitragynine were identified using selective chemical inhibitors of HLM and recombinant cytochrome P450. The metabolism of mitragynine was predominantly carried out through the CYP3A4 with minor contributions by CYP2D6 and CYP2C9. The formation of five oxidative metabolites (Met2, Met4, Met6, Met8 and Met11) was catalyzed by the CYP3A4. 4. In summary, mitragynine was extensively metabolized in HLM primarily to O-demethylated and mono-oxidative metabolites. The CYP3A4 enzyme plays a predominant role in the metabolic clearance of mitragynine and also in the formation of 7-hydroxymitragynine (Met2), a known active minor alkaloid identified in the leaf material.

A modification of the previously designed individual-based simulation model of population dynamics of a mass pelagic species, Daphnia longispina, is presented. This model includes several important patterns related with dormancy. The model describes a population as an ordered list of individuals with specific sets of traits. For each individual, its energy traits are calculated, and the probabilities of different outcomes are assigned or calculated for various life situations. This variant significantly differs from the previous chemosignal blocks that modify Daphnia behavior. After receiving a chemical signal (predator kairomones or sex pheromones), adult Daphnia of the model population can avoid predation with a certain probability by diel vertical migrations and can increase the efficiency of sexual reproduction through the active search for a sexual partner. Simulation experiments in which the ability to detect different chemical signals was excluded, sequentially or in combination, were used to investigate the role of chemoreception in the population dynamics and the seasonal adaptations of planktonic crustaceans (dormancy, based on photoperiod accepting along with food ability with maternal transmission of environmental information in a chain of generation). For the first time, a quantitative estimate for the role of such information has been obtained as the ratio between the annual production levels of model populations that possess or lack the ability to perceive chemical signals of predators and mating partners. According to the present version of the model, chemoreception increased the annual production of the model population by 1.5 times. Thus, biological information is a significant factor enabling individual hydrobiont populations to fine-tune their adaptations to the particular environmental conditions of a given aquatic habitat.

Retinoic acid (RA), the active metabolite of vitamin A, functions through nuclear receptors, one of which is the retinoic acid receptor (RAR). Though the RAR is essential for various aspects of vertebrate development, little is known about the role of RAR in nonchordate invertebrates. Here, we examined the potential role of an invertebrate RAR in mediating chemotropic effects of retinoic acid. The RAR of the protostome Lymnaea stagnalis is present in the growth cones of regenerating cultured motorneurons, and a synthetic RAR agonist (EC23), was able to mimic the effects of retinoic acid in inducing growth cone turning. We also examined the ability of the natural retinoids, all-trans RA and 9-cis RA, as well as the synthetic RAR agonists, to disrupt embryonic development in Lymnaea. Developmental defects included delays in embryo hatching, arrested eye, and shell development, as well as more severe abnormalities such as halted development. Developmental defects induced by some (but not all) synthetic RAR agonists were found to mimic those induced by addition of high concentrations of the natural retinoid isomers. These pharmacological data support a possible physiological role for the RAR in axon guidance and embryonic development of an invertebrate protostome species.

Invertebrates dominate the animal world in terms of abundance, diversity and biomass, and play critical roles in maintaining ecosystem function. Despite their obvious importance, disproportionate research attention remains focused on vertebrates, with knowledge and understanding of invertebrate ecology still lacking. Due to their inherent advantages, usage of camera traps in ecology has risen dramatically over the last three decades, especially for research on mammals. However, few studies have used cameras to reliably detect fauna such as invertebrates or used cameras to examine specific aspects of invertebrate ecology. Previous research investigating the interaction between wolf spiders (Lycosidae: Lycosa spp.) and the lesser hairy-footed dunnart (Sminthopsis youngsoni) found that camera traps provide a viable method for examining temporal activity patterns and interactions between these species. Here, we re-examine lycosid activity to determine whether these patterns vary with different environmental conditions, specifically between burned and unburned habitats and the crests and bases of sand dunes, and whether cameras are able to detect other invertebrate fauna. Twenty-four cameras were deployed over a 3-month period in an arid region in central Australia, capturing 2,356 confirmed images of seven invertebrate taxa, including 155 time-lapse images of lycosids. Overall, there was no clear difference in temporal activity with respect to dune position or fire history, but twice as many lycosids were detected in unburned compared to burned areas. Despite some limitations, camera traps appear to have considerable utility as a tool for determining the diel activity patterns and habitat use of larger arthropods such as wolf spiders, and we recommend greater uptake in their usage in future.

Speciociliatine is a minor indole alkaloid found in kratom, a southeast Asian medicinal plant, used for centuries to increase energy, enhance mood, and mitigate pain and opioid dependence. An ultra-performance liquid chromatography tandem mass spectrometry method was developed and validated to quantify speciociliatine in rat plasma. The quantitation range was 3-600 ng/mL. The validated method was applied to a preclinical pharmacokinetic study in male Sprague-Dawley rats after 2.5 mg/kg intravenous (I.V.) and 20 mg/kg oral (P.O.) dosing. The plasma was analyzed to obtain concentration-time profiles and results were subjected to non-compartmental analysis to determine pharmacokinetic parameters including volume of distribution (6.2 ± 2.3 L/kg I.V.), clearance (0.7 ± 0.2 L/hr/kg), and absolute oral bioavailability (20.7 %). Speciociliatine had higher systemic exposure and lower clearance compared to the other kratom alkaloids mitragynine and corynantheidine. The speciociliatine pharmacokinetic parameters described here will help to better understand the overall effects reported with kratom product use.

Massive parallel sequencing (the Roche 454 platform) of the 16S rRNA gene fragments was used to investigate microbial diversity in the sediments of the Posolsk Bank cold methane seep. Bacterial communities from all sediment horizons were found to contain members of the phyla Actinobacteria, Bacteroidetes, Deinococcus-Thermus, Firmicutes, Nitrospirae, Chloroflexi, Proteobacteria, and the candidate phyla Aminicenantes (OP8) and Atribacteria (OP9). Among Bacteria, members of the Chloroflexi and Proteobacteria were the most numerous (42 and 46%, respectively). Among archaea, the Thaumarchaeota predominated in the upper sediment layer (40.1%), while Bathyarchaeota (54.2%) and Euryarchaeota (95%) were predominant at 70 and 140 cm, respectively. Specific migration pathways of fluid flows circulating in the zone of gas hydrate stability (400 m) may be responsible for considerable numbers of the sequences of Chloroflexi, Acidobacteria, and the candidate phyla Aminicenantes and Atribacteria in the upper sediment layers and of the Deinococcus-Thermus phylum in deep bottom sediments.

Bacterial mats formed by a colorless sulfur bacterium Thioploca sp. in the area of the Posolsk Bank cold methane seep (southern Baikal) were studied using electron microscopy and phylogenetic analysis. Morphologically the bacteria were identified as Thioploca ingrica. Confocal microscopy of DAPI-stained samples revealed numerous rod-shaped, filamentous, and spiral microorganisms in the sheaths, as well as inside and between the trichomes. Transmission electron microscopy revealed nonvacuolated bacteria and small cells without cell envelopes within the sheath. Bacteria with pronounced intracytoplasmic membranes characteristic of type I methanotrophs were observed at the outer side of the sheath. Based on analysis of the 16S rRNA gene sequences, the following phyla were identified in the sheath community: Bacteroidetes, Nitrospira, Chloroflexi, Planctomycetes, Verrucomicrobia, γ-, and δ-Proteobacteria, Euryarchaeota, Crenarchaeota, and Thaumarchaeota, as well as anammox bacteria. A hypothetical scheme of matter flows in the Lake Baikal bacterial mats was proposed based on the data on metabolism of the cultured homologues.

Fluctuation of the summer day-time temperatures in the mid-latitudes in a range from 16 to 30°C should not have irreversible negative effects on plants, but may influence metabolic processes including the oxidative stress. To test the effect of moderately high temperature on oxidative stress induced by lead in the leaves of Plantago major L.; the plants were incubated in a water solution of 0, 150, 450, and 900 μM Pb (NO3)2 at 20 and 28°C. Plant reactions were evaluated by the content of thiobarbituric acid reactive substances and ascorbate peroxidase and glutathione reductase activities in leaves after 2, 24, 48, and 72 h. The Pb concentration in the leaves rose with the increase in the Pb content and was higher at 20°C. The increase in stomatal resistance caused by Pb was higher at 28°C. The contents of TBARS increased after 2 h of plant exposure to Pb and the increase was the highest at 900 μM Pb, 28°C. The AsP activity increased up to 50% after 24 h of Pb-treatment at 28°C; the highest increase in glutathione reductase activity was observed after 72 h at 20°C. Thus, the moderately high temperature 28°C compared with optimal 20°C caused a decrease in Pb accumulation in Plantago leaves but amplified the negative effects of lead, especially in the beginning of stress development.

Late Bashkirian and early Moscovian conodonts are abundant and diverse at the Naqing section, South China. All conodont genera known to have numerous species in the late Bashkirian–early Moscovian are recorded here, including Declinognathodus, Diplognathodus, Gondolella, Idiognathodus, Idiognathoides, Mesogondolella, Neognathodus, and Neolochriea. At Naqing, many species of these genera provide a succession of conodont chronomorphoclines throughout the Bashkirian–Moscovian boundary interval. They demonstrate that deposition was remarkably continuous through the boundary interval, a major criterion for selecting a Global Stratotype Section and Point (GSSP). This paper describes the current state of knowledge for several of these chronomorphoclines, and also provides an updated range chart of conodonts recovered from the Naqing section and their correlation with other regions. The taxon that best matches the current concept for the base of the Moscovian Stage in its type region is the phylogenetic first occurrence of Diplognathodus ellesmerensis. An ancestral form with most of the characteristics of D. ellesmerensis occurs at Naqing. More specimens are needed to completely document the chronomorphocline, but because D. ellesmerensis is found worldwide — including that close to the base of the type Moscovian — its evolutionary first occurrence would provide an almost ideal GSSP to define the base of the international Moscovian Stage.

Microbial diversity in the sediments of the Kara Sea shelf and the southern Yenisei Bay, differing in pore water mineralization, was studied using massive parallel pyrosequencing according to the 454 (Roche) technology. Members of the same phyla (Cyanobacteria, Verrucomicrobia, Actinobacteria, Proteobacteria, and Bacteroidetes) predominated in bacterial communities of the sediments, while their ratio and taxonomic composition varied within the phyla and depended on pore water mineralization. Increasing salinity gradient was found to coincide with increased share of the γ-Proteobacteria and decreased abundance of α- and β-Proteo- bacteria, as well as of the phyla Verrucomicrobia, Chloroflexi, Chlorobi, and Acidobacteria. Archaeal diversity was lower, with Thaumarchaeota predominant in the sediments with high and low mineralization, while Crenarchaeota predominated in moderately mineralized sediments. Microbial communities of the Kara Sea shelf and Yenisei Gulf sediments were found to contain the organisms capable of utilization of a broad spectrum of carbon sources, including gaseous and petroleum hydrocarbons.

Early diagenesis of organic matter in bottom sediments of Lake Baikal is a focus of many geochemical studies, because it is one of the few sites of petroleum formation in a nonmarine environment. Although Baikal is a rift lake and considered one of the prospective fields for deep biosphere investigations, the transformation processes of organic matter by microbial communities from deep bottom sediments and likely entering of the microorganisms from deep sediments into the near-surface sediments were not previously studied in Lake Baikal. The natural microbial community from near-surface sediments of the cold methane seep Goloustnoe (Southern Baikal Basin) was incubated with methane and the diatom Synedra acus at 80°C and 49.5 atm to simulate catagenesis. The 11-month incubation yielded the enrichment culture of viable thermophilic microorganisms. Their presence in low-temperature sediment layers may be indicative of their migration through fault zones together with gas-bearing fluids. After cultur...

To better understand the species composition and nutrition of deepwater sponges in Lake Baikal, we determined the depth, habitat, and stable isotopic signatures for deepwater sponges. All sponge specimens except one were collected at depths below the photic zone and in a variety of benthic habitats including methane seeps and hydrothermal vents. The freshwater sponge species of Lake Baikal generally occurred in aggregations (fields, carpets, and belts), and mainly on hard substrates (different types of bedrock and argillite, and bitumen). New maximum depth records were established for three species. The deepwater sponges clustered into two groups, based on their isotopic values, with members of one group assimilating organic carbon from photosynthetic sources and exhibiting δ13C values (−32 to −26.9‰) similar to those reported previously for littoral sponges. Members of the second group, distinguished by highly depleted δ13C values (−65 to −37.3‰), participate in a chemosynthetic food web. δ15N values of the deepwater sponges ranged widely (2.1–16.7‰) suggesting that they assimilate nitrogen from environmental sources and possibly from their microbial symbionts. Conservation of deepwater sponge diversity is therefore, likely dependent on the diversity of resources found in different habitats.

Background An expedited discharge protocol for uncomplicated appendicitis was developed at a Canadian academic hospital to determine if patients could be safely discharged home early without negatively impacting care and patient satisfaction. Methods A non-randomized prospective quality improvement project was completed between February 01, 2017 and January 31, 2018. The project included patients between 16 and 65 years with uncomplicated appendicitis managed with laparoscopic appendectomy. The primary outcome was average length of stay post PACU. 30 day ED visit, cross-sectional imaging and readmission rate were balancing measures. The CTM-3 tool was used to measure patient satisfaction. Results 450 patients had emergent laparoscopic appendectomy. 287 (63.8%) patients met the project inclusion criteria. The average length of stay decreased 41.0% to 13.1 h. The 30 day ED visit, cross-sectional imaging and readmission rate were 9.8%, 4.5% and 1.0% respectively compared with 8.1%, 4.5% and 2.5% at baseline. Patient satisfaction was 3.72/4 compared to 3.74/4. Conclusion An expedited discharge after an uncomplicated laparoscopic appendectomy is safe and feasible without a negative impact on 30-day ED visit, diagnostic imaging or readmission.