Mesozooplankton Graze on Cyanobacteria in the Amazon River Plume and Western Tropical North Atlantic

Diazotrophic cyanobacteria, those capable of fixing di-nitrogen (N2), are considered one of the major sources of new nitrogen (N) in the oligotrophic tropical ocean, but direct incorporation of diazotrophic N into food webs has not been fully examined. In the Amazon River-influenced western tropical North Atlantic (WTNA), diatom diazotroph associations (DDAs) and the filamentous colonial diazotrophs Trichodesmium have seasonally high abundances. We sampled epipelagic mesozooplankton in the Amazon River plume and WTNA in May-June 2010 to investigate direct grazing by mesozooplankton on two DDA populations: Richelia associated with Rhizosolenia diatoms (het-1) and Hemiaulus diatoms (het-2), and on Trichodesmium using highly specific qPCR assays targeting nitrogenase genes (nifH). Both DDAs and Trichodesmium occurred in zooplankton gut contents, with higher detection of het-2 predominantly in calanoid copepods (2.33-16.76 nifH copies organism 1). Abundance of Trichodesmium was low (2.21-4.03 nifH copies organism 1), but they were consistently detected at high salinity stations (\u3e 35) in calanoid copepods. This suggests direct grazing on DDAs, Trichodesmium filaments and colonies, or consumption as part of sinking aggregates, is common. In parallel with the qPCR approach, a next generation sequencing analysis of 16S rRNA genes identified that cyanobacterial assemblage associated with zooplankton guts was dominated by the non-diazotrophic unicellular phylotypes Synechococcus (56%) and Prochlorococcus (26%). However, in two separate calanoid copepod samples, two unicellular diazotrophs Candidatus Atelocyanobacterium thalassa (UCYN-A) and Crocosphaera watsonii (UCYN-B) were present, respectively, as a small component of cyanobacterial assemblages (\u3c 2%). This study represents the first evidence of consumption of DDAs, Trichodesmium, and unicellular cyanobacteria by calanoid copepods in an area of the WTNA known for high carbon export. These diazotroph populations are quantitatively important in the global N budget, widespread and hence, the next step is to accurately quantify grazing. Nonetheless, these results highlight a direct pathway of diazotrophic N into the food web and have important implications for biogeochemical cycles, particularly oligotrophic regions where N-2 fixation is the main source of new nitrogen

Thermal development of latent fingermarks on porous surfaces-Further observations and refinements

In a further study of the thermal development of fingermarks on paper and similar surfaces, it is demonstrated that direct contact heating of the substrate using coated or ceramic surfaces at temperatures in excess of 230 °C produces results superior to those obtained using hot air. Fingermarks can also be developed in this way on other cellulose-based substrates such as wood and cotton fabric, though ridge detail is difficult to obtain in the latter case. Fluorescence spectroscopy indicates that the phenomena observed during the thermal development of fingermarks can be reproduced simply by heating untreated white copy paper or filter paper, or these papers treated with solutions of sodium chloride or alanine. There is no evidence to suggest that the observed fluorescence of fingermarks heated on paper is due to a reaction of fingermark constituents on or with the paper. Instead, we maintain that the ridge contrast observed first as fluorescence, and later as brown charring, is simply an acceleration of the thermal degradation of the paper. Thermal degradation of cellulose, a major constituent of paper and wood, is known to give rise to a fluorescent product if sufficient oxygen is available [1-5]. However, the absence of atmospheric oxygen has only a slight effect on the thermal development of fingermarks, indicating that there is sufficient oxygen already present in paper to allow the formation of the fluorescent and charred products. In a depletion study comparing thermal development of fingermarks on paper with development using ninhydrin, the thermal technique was found to be as sensitive as ninhydrin for six out of seven donors. When thermal development was used in sequence with ninhydrin and DFO, it was found that only fingermarks that had been developed to the fluorescent stage (a few seconds of heating) could subsequently be developed with the other reagents. In the reverse sequence, no useful further development was noted for fingermarks that were treated thermally after having been developed with ninhydrin or DFO. Aged fingermarks, including marks from 1-year-old university examination papers were successfully developed using the thermal technique. © 2010 Elsevier Ireland Ltd

Genetic Comparison of Stemness of Human Umbilical Cord and Dental Pulp

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Can oral infection be a risk factor for Alzheimer’s disease?

Alzheimer’s disease (AD) is a scourge of longevity that will drain enormous resources from public health budgets in the future. Currently, there is no diagnostic biomarker and/or treatment for this most common form of dementia in humans. AD can be of early familial-onset or sporadic with a late-onset. Apart from the two main hallmarks, amyloid-beta and neurofibrillary tangles, inflammation is a characteristic feature of AD neuropathology. Inflammation may be caused by a local central nervous system insult and/or by peripheral infections. Numerous microorganisms are suspected in AD brains ranging from bacteria (mainly oral and non-oral Treponema species), viruses (Herpes simplex type I) and yeasts (Candida species). A causal relationship between periodontal pathogens/non-oral Treponema species of bacteria has been proposed via the amyloid-beta and inflammatory links. Periodontitis constitutes a peripheral oral infection that can provide the brain with intact bacteria and virulence factors and inflammatory mediators due to daily, transient bacteraemias. If and when genetic risk factors meet environmental risk factors in the brain, disease is expressed, in which neurocognition may be impacted, leading to the development of dementia. To achieve the goal of finding a diagnostic biomarker and possible prophylactic treatment for AD, there is an initial need to solve the etiological puzzle contributing to its pathogenesis. This review therefore addresses oral infection as the plausible aetiology of late onset AD (LOAD)

A novel mechanistic model for nitrogen removal in algal-bacterial photo sequencing batch reactors

© 2018 Elsevier Ltd A comprehensive mathematical model was constructed to evaluate the complex substrate and microbial interaction in algal-bacterial photo sequencing batch reactors (PSBR). The kinetics of metabolite, growth and endogenous respiration of ammonia oxidizing bacteria, nitrite oxidizing bacteria and heterotrophic bacteria were coupled to those of microalgae and then embedded into widely-used activated sludge model series. The impact of light intensity was considered for microalgae growth, while the effect of inorganic carbon was considered for each microorganism. The integrated model framework was assessed using experimental data from algal-bacterial consortia performing sidestream nitritation/denitritation. The validity of the model was further evaluated based on dataset from PSBR performing mainstream nitrification. The developed model could satisfactorily capture the dynamics of microbial populations and substrates under different operational conditions (i.e. feeding, carbon dosing and illuminating mode, light intensity, influent ammonium concentration), which might serve as a powerful tool for optimizing the novel algal-bacterial nitrogen removal processes

High-performance triazole-containing brush polymers via azide-alkyne click chemistry: a new functional polymer platform for electrical memory devices

Two series of well-defined brush polymers bearing a triazole moiety on each bristle were prepared from the click chemistry reactions of a poly(glycidyl azide) (PG) and a poly(4-azidomethylstyrene) (PS) with alkyne derivatives. The thin-film morphologies and properties, especially electrical memory performances, of these triazole-containing brush polymers were investigated in detail. The brush polymers with a triazole ring substituted with an alkyl or alkylenylphenyl group in the bristle exhibited only dielectric characteristics. By contrast, the other brush polymers bearing a triazole ring substituted with phenyl or its derivatives with a longer pi-conjugation length in the bristle demonstrated excellent unipolar permanent memory behaviors with low power consumption, high ON/OFF current ratios and high stability and reliability under ambient air conditions. Furthermore, their memory type could be tuned to p- or n-type by the incorporation of an electron-donating or -accepting group into the phenyl unit linked to the triazole moiety. Overall, this study presents the first demonstration of the azide-alkyne click chemistry synthesis of triazole moieties with substituent(s) that exhibit a resonance effect; this approach is a very powerful synthetic route to develop electrical memory polymers suitable for the low-cost mass production of high-performance, polarity-free programmable memory devices.111711Ysciescopu

Family classification without domain chaining

Motivation: Classification of gene and protein sequences into homologous families, i.e. sets of sequences that share common ancestry, is an essential step in comparative genomic analyses. This is typically achieved by construction of a sequence homology network, followed by clustering to identify dense subgraphs corresponding to families. Accurate classification of single domain families is now within reach due to major algorithmic advances in remote homology detection and graph clustering. However, classification of multidomain families remains a significant challenge. The presence of the same domain in sequences that do not share common ancestry introduces false edges in the homology network that link unrelated families and stymy clustering algorithms

Epidemiology of human infections with highly pathogenic avian influenza A(H7N9) virus in Guangdong, 2016 to 2017

We describe the epidemiology of highly pathogenic avian influenza (HPAI) A(H7N9) based on poultry market environmental surveillance and laboratory-confirmed human cases (n = 9) in Guangdong, China. We also compare the epidemiology between human cases of high- and low-pathogenic avian influenza A(H7N9) (n = 51) in Guangdong. Case fatality and severity were similar. Touching sick or dead poultry was the most important risk factor for HPAI A(H7N9) infections and should be highlighted for the control of future influenza A(H7N9) epidemics.published_or_final_versio

Epidemiology characteristics, methodological assessment and reporting of statistical analysis of network meta-analyses in the field of cancer

Because of the methodological complexity of network meta-analyses (NMAs), NMAs may be more vulnerable to methodological risks than conventional pair-wise meta-analysis. Our study aims to investigate epidemiology characteristics, conduction of literature search, methodological quality and reporting of statistical analysis process in the field of cancer based on PRISMA extension statement and modified AMSTAR checklist. We identified and included 102 NMAs in the field of cancer. 61 NMAs were conducted using a Bayesian framework. Of them, more than half of NMAs did not report assessment of convergence (60.66%). Inconsistency was assessed in 27.87% of NMAs. Assessment of heterogeneity in traditional meta-analyses was more common (42.62%) than in NMAs (6.56%). Most of NMAs did not report assessment of similarity (86.89%) and did not used GRADE tool to assess quality of evidence (95.08%). 43 NMAs were adjusted indirect comparisons, the methods used were described in 53.49% NMAs. Only 4.65% NMAs described the details of handling of multi group trials and 6.98% described the methods of similarity assessment. The median total AMSTAR-score was 8.00 (IQR: 6.00-8.25). Methodological quality and reporting of statistical analysis did not substantially differ by selected general characteristics. Overall, the quality of NMAs in the field of cancer was generally acceptable