Lake sediment records of persistent organic pollutants and polycyclic aromatic hydrocarbons in Southern Siberia mirror the changing fortunes of the Russian economy over the past 70 years

Persistent organic pollutants (POPs) and polycyclic aromatic hydrocarbons (PAHs) have previously been detected in the surface sediments, water, and endemic organisms of Lake Baikal, a UNESCO World Heritage Site. The Selenga River is the primary source of freshwater to Lake Baikal, and transports pollutants accumulating in the Selenga River basin to the lake. Sources of POPs and PAHs in the Selenga River basin grew through the 20th century. In the present study, temporal changes in the concentrations of PAHs and POPs were reconstructed from two lakes in the Selenga River basin over the past 150 years using paleolimnological techniques. Increased concentrations in PAHs and PCBs were recorded initially in the 1930s. The 1940s–1980s was the period of greatest exposure to organic contamination, and concentrations of dichlorodiphenyltrichloroethane (DDT), polychlorinated biphenyls (PCBs), hexachlorocyclohexanes (HCHs) and many PAHs peaked between the 1960s and 1980s in the two lakes. Declines in concentrations and fluxes were recorded for most PAHs and POPs in the 1980s and 1990s. Temporal trends in concentrations of total and individual compounds/congeners of PAH, PCBs, and polybrominated diphenyl ethers (PBDEs) indicate the contribution of both local and regional sources of contamination in the 20th and 21st centuries. Temporal variations in contaminants can be linked to economic and industrial growth in the former USSR after World War II and the economic decline of Russia in the late-1980s and early-1990s, as well as global trends in industrialization and development during the mid-20th century

Enema abuse by mothers of children presenting to the emergency room at the University of Calabar Teaching Hospital

Enema is largely used and widely abused in our community for various ailments including fever, constipation; abdominal pains vomiting and even diarrhoea.Objectives: To describe the abuse of enema at home in the Calabar area, and the associated findings among children who received enema.Method: Children admitted to the Children Emergency Unit of the University of Calabar Teaching Hospital with history of enema use at home were recruited into the study. The presenting symptoms, type of enema used and associated findings were documented. Relevant investigations were carried out where necessary. Tables and simple proportions were used to analyze the data.Results: Twenty two children were seen with enema abuse over a six months period. Diarrhoea diseases and fever were the predominant reasons why enema was given. Types of enema given were herbal concoctions in 13(59.1%) plain water enema in 8(36.4%) and salt water enema in one (4.5%) child. Electrolytes derangements were the commonest associated findings. Others were convulsions/coma, intestinal perforation, acute renal failure and severe dehydration from diarrhoea.Conclusion: Enema abuse is a continuing cultural phenomenon in the Calabar area. It is associated with severe consequences including intestinal perforation. Enema abuse should form part of history taking in this environment and child care practitioners should actively search for possible complications. Most importantly, health education to stem this widespread practice

Telomere length regulation: coupling DNA end processing to feedback regulation of telomerase

The conventional DNA polymerase machinery is unable to fully replicate the ends of linear chromosomes. To surmount this problem, nearly all eukaryotes use the telomerase enzyme, a specialized reverse transcriptase that utizes its own RNA template to add short TG-rich repeats to chromosome ends, thus reversing their gradual erosion occurring at each round of replication. This unique, non-DNA templated mode of telomere replication requires a regulatory mechanism to ensure that telomerase acts at telomeres whose TG tracts are too short, but not at those with long tracts, thus maintaining the protective TG repeat cap at an appropriate average length. The prevailing notion in the field is that telomere length regulation is brought about through a negative feedback mechanism that counts TG repeat-bound protein complexes to generate a signal that regulates telomerase action. This review summarizes experiments leading up to this model and then focuses on more recent experiments, primarily from yeast, that begin to suggest how this counting mechanism might work. The emerging picture is that of a complex interplay between the conventional DNA replication machinery, DNA damage response factors, and a specialized set of proteins that help to recruit and regulate the telomerase enzyme

Clinical characteristics of bloodstream infections due to ampicillin-sulbactam-resistant, non-extended-spectrum-β-lactamase-producing Escherichia coli and the role of TEM-1 hyperproduction

Ampicillin-sulbactam is commonly used as an empirical therapy for invasive infections where Escherichia coli is a potential pathogen. We evaluated the clinical and microbiologic characteristics of bloodstream infection due to E. coli, with focus on cases that were nonsusceptible to ampicillin-sulbactam and not producing extended-spectrum beta-lactamase (ESBL). Of a total of 357 unique bacteremic cases identified between 2005 and 2008, 111 (31.1%) were intermediate or resistant to ampicillin-sulbactam by disk testing. In multivariate analysis, a history of liver disease, organ transplant, peptic ulcer disease, and prior use of ampicillin-sulbactam were independent risk factors for bloodstream infection with ampicillin-sulbactam-nonsusceptible E. coli. Among cases that received ampicillin-sulbactam as an empirical therapy, an early clinical response was observed in 65% (22/34) of susceptible cases but in only 20% (1/5) of nonsusceptible cases. Among 50 ampicillin-sulbactam-resistant isolates examined, there was no clonal relatedness and no evidence of production of inhibitor-resistant TEM (IRT). Instead, the resistance was attributed to hyperproduction of TEM-1 beta-lactamase in the majority of isolates. However, promoter sequences of bla(TEM-1) did not predict resistance to ampicillin-sulbactam. While the plasmid copy number did not differ between representative resistant and susceptible isolates, the relative expression of bla(TEM-1) was significantly higher in two of three resistant isolates than in three susceptible isolates. These results suggest high-level bla(TEM-1) expression as the predominant cause of ampicillin-sulbactam resistance and also the presence of yet-unidentified factors promoting overexpression of bla(TEM-1) in these isolates

Diatom community responses to long-term multiple stressors at Lake Gusinoye, Siberia

The information, practices and views in this article are those of the author(s) and do not necessarily reflect the opinion of the Royal Geographical Society (with IBG). © 2019 The Authors. Geo: Geography and Environment published by John Wiley & Sons Ltd and the Royal Geographical Society (with the Institute of British Geographers). Global freshwater systems are threatened by multiple anthropogenic stressors via impacts on ecological structure and function necessary to maintain their health. In order to properly manage freshwater ecosystems, we must have a better understanding of the ecological response to human-induced stressors, especially in multiple stressor environments. When long-term observational records are scarce or non-existent, paleolimnology provides a means to understanding ecological response to long-term stress. Lake Gusinoye is a large, deep lake in continental southeast Siberia, and has been subject to multiple human-induced stressors since the 19th century. Diatom assemblages since the late 17th century were reconstructed from a Lake Gusinoye sediment core to increase our understanding of the response of primary producer communities to centuries of environmental change. Records of anthropogenic contamination of Lake Gusinoye (as indicated by spheroidal carbonaceous particle, trace metal, and element records) indicate increases in regional and local development c. 1920. Diatom assemblages were initially dominated by Aulacoseira granulata, which declined beginning in the 18th century, likely as a response to hydrological change in the Gusinoye basin due to regional climate warming following the termination of the Little Ice Age (LIA). Significant diatom compositional turnover was observed since the 19th century at Lake Gusinoye. Since the early 20th century, Lake Gusinoye diatom assemblages have changed more profoundly as a result of multiple anthropogenic stressors, including nutrient influx, aquaculture, and wastewater discharge from the Gusinoozersk State Regional Power Plant. Recent diatom assemblages are dominated by Lindavia ocellata and nutrient-rich species, including Fragilaria crotonensis and Asterionella formosa. Evidence of continued nutrient enrichment at Lake Gusinoye is likely due to aquaculture in the lake, and suggests potential interactive effects of warming regional temperatures and increasing nutrients (eutrophication)

Thrombospondin-1-N-Terminal Domain Induces a Phagocytic State and Thrombospondin-1-C-Terminal Domain Induces a Tolerizing Phenotype in Dendritic Cells

In our previous study, we have found that thrombospondin-1 (TSP-1) is synthesized de novo upon monocyte and neutrophil apoptosis, leading to a phagocytic and tolerizing phenotype of dendritic cells (DC), even prior to DC-apoptotic cell interaction. Interestingly, we were able to show that heparin binding domain (HBD), the N-terminal portion of TSP-1, was cleaved and secreted simultaneously in a caspase- and serine protease- dependent manner. In the current study we were interested to examine the role of HBD in the clearance of apoptotic cells, and whether the phagocytic and tolerizing state of DCs is mediated by the HBD itself, or whether the entire TSP-1 is needed. Therefore, we have cloned the human HBD, and compared its interactions with DC to those with TSP-1. Here we show that rHBD by itself is not directly responsible for immune paralysis and tolerizing phenotype of DCs, at least in the monomeric form, but has a significant role in rendering DCs phagocytic. Binding of TSP-1-C-terminal domain on the other hand induces a tolerizing phenotype in dendritic cells

Holographic RG flow of the shear viscosity to entropy density ratio in strongly coupled anisotropic plasma

We study holographic RG flow of the shear viscosity tensor of anisotropic, strongly coupled N=4 super-Yang-Mills plasma by using its type IIB supergravity dual in anisotropic bulk spacetime. We find that the shear viscosity tensor has three independent components in the anisotropic bulk spacetime away from the boundary, and one of the components has a non-trivial RG flow while the other two have a trivial one. For the component of the shear viscosity tensor with non-trivial RG flow, we derive its RG flow equation, and solve the equation analytically to second order in the anisotropy parameter 'a'. We derive the RG equation using the equation of motion, holographic Wilsonian RG method, and Kubo's formula. All methods give the same result. Solving the equation, we find that the ratio of the component of the shear viscosity tensor to entropy density 'eta/s' flows from above '1/4pi' at the horizon (IR) to below '1/4pi' at the boundary (UV) where it violates the holographic shear viscosity (Kovtun-Son-Starinets) bound and where it agrees with the other longitudinal component.Comment: 17 pages, 2 figures, slight change on the title, more background material added, references added, accepted for publication in JHE

Escherichia coli induces apoptosis and proliferation of mammary cells

Mammary cell apoptosis and proliferation were assessed after injection of Escherichia coli into the left mammary quarters of six cows. Bacteriological analysis of foremilk samples revealed coliform infection in the injected quarters of four cows. Milk somatic cell counts increased in these quarters and peaked at 24 h after bacterial injection. Body temperature also increased, peaking at 12 h postinjection, The number of apoptotic cells was significantly higher in the mastitic tissue than in the uninfected control. Expression of Bax and interleukin-1 beta converting enzyme increased in the mastitic tissue at 24 h and 72 h postinfection, whereas Bcl-2 expression decreased at 24 h but did not differ significantly from the control at 72 h postinfection, Induction of matrix metalloproteinase-g, stromelysin-1 and urokinase-type plasminogen activator was also observed in the mastitic tissue. Moreover, cell proliferation increased in the infected tissue, These results demonstrate that Escherichia coli-induced mastitis promotes apoptosis and cell proliferation

Configurational Entropy and Diffusivity of Supercooled Water

We calculate the configurational entropy S_conf for the SPC/E model of water for state points covering a large region of the (T,rho) plane. We find that (i) the (T,rho) dependence of S_conf correlates with the diffusion constant and (ii) that the line of maxima in S_conf tracks the line of density maxima. Our simulation data indicate that the dynamics are strongly influenced by S_conf even above the mode-coupling temperature T_MCT(rho).Comment: Significant update of reference

Commercializing Biomedical Research Through Securitization Techniques

Biomedical innovation has become riskier, more expensive and more difficult to finance with traditional sources such as private and public equity. Here we propose a financial structure in which a large number of biomedical programs at various stages of development are funded by a single entity to substantially reduce the portfolio's risk. The portfolio entity can finance its activities by issuing debt, a critical advantage because a much larger pool of capital is available for investment in debt versus equity. By employing financial engineering techniques such as securitization, it can raise even greater amounts of more-patient capital. In a simulation using historical data for new molecular entities in oncology from 1990 to 2011, we find that megafunds of $5–15 billion may yield average investment returns of 8.9–11.4% for equity holders and 5–8% for 'research-backed obligation' holders, which are lower than typical venture-capital hurdle rates but attractive to pension funds, insurance companies and other large institutional investors