Fluorescence Analysis for Multi-Site Aluminum Binding to Natural Organic Matter

Natural organic matter (NOM) samples isolated from different water sources in Norway were compared using their fluorescence properties. Fluorescence surfaces were observed at pH 4.36 and deconvoluted using SIMPLISMA (Windig and Guilment 1991). There were a total of seven different fluorophores observed for these samples and each sampling site had between four and six ofthe fluorescent components. These components were observed to bind Al during titrations at the same pH. Multiresponse titration curves were fit using the method of Smith and Kramer (1998) and most of the binding strengths are similar to values for Suwannee River fulvic acid (1ogK’ between 4.8 and 5.5), but there are strong sites (IogK’ = 7) and weak sites (1ogK’ between 3 and 4) also observed. Results depended on the isolation method used; reverse osmosis and low pressure evaporation yielded different values but with no consistent trends

漂着者たち1739年の記録 : 小笠原諸島と鳥島

In 1739, two groups of Japanese sailors met on a remote and inhospitable island due to misfortune. Together they safely returned to Japan, where their story fascinated people from all walks of life. The men’s adventures on Ponafidin and the Bonin Islands are largely misunderstood because the official castaway repatriation interviews contain fabricated evidence and deliberate omissions. This article is a reconstruction of events into a castaway narrative, using mostly period sources, that is designed to appeal to scholars of Japanese history, maritime cultures, and communications (particularly those studying the links between culture and perception).太平洋の孤島で1739年、二組の漂流民が出会った。彼らは苦労の末日本へ戻ることができた。その話は本国で人々の関心を集めた。しかし取り調べ書の内容には、意図的に除外されたり、捏造された事柄が含まれていた。その結果、今日でも知られていなかったり、誤解されている点が多い。本稿は、彼らの漂流と遭遇の記録を検討し、再構築することによって小笠原諸島と鳥島での漂着の実態を明らかにしようと試みたものである

Aquilegia as a Model System for the Evolution and Ecology of Petals

The ranunculid genus Aquilegia holds extraordinary promise as a model system for investigating a wide range of questions relating to the evolution and ecology of petals. New genetic and genomic resources, including an extensive EST database, BAC libraries and physical maps, as well as virus-induced gene silencing are facilitating this research on multiple fronts. At the developmental genetic level, Aquilegia has been important for elucidating the developmental programme for specifying petals and petaloid characteristics. Data suggest that duplication events among the petal and stamen identity genes have resulted in sub- and neofunctionalization. This expansion of gene function does not include the petaloidy of Aquilegia sepals, however, which does not depend on the same loci that control identity of the second whorl petals. Of special interest is the elaboration of the petal into a nectar spur, a major innovation for the genus. Intra- and interspecific variation in the shape and colour of petals, especially the spurs, has been shown to be adaptative for different pollinators. Thus, understanding the genetic basis of these traits will help us connect the ecological interactions driving speciation with the genetic changes responsible for remodelling morphology. Progress in this area has focused on the multiple, parallel transitions in flower colour and nectar spur length across the genus. For flower colour, upstream transcription factors appear to be primarily targets of natural selection. Thus research in Aquilegia spans the initial evolution of petals and petaloidy to the diversification of petal morphology to the ecological basis of petal form, thereby providing a comprehensive picture of the evolutionary biology of this critical angiosperm feature.Organismic and Evolutionary Biolog

Fluorescence Analysis for Multi-Site Aluminum Binding to Natural Organic Matter

Natural organic matter (NOM) samples isolated from different water sources in Norway were compared using their fluorescence properties. Fluorescence surfaces were observed at pH 4.36 and deconvoluted using SIMPLISMA (Windig and Guilment 1991). There were a total of seven different fluorophores observed for these samples and each sampling site had between four and six ofthe fluorescent components. These components were observed to bind Al during titrations at the same pH. Multiresponse titration curves were fit using the method of Smith and Kramer (1998) and most of the binding strengths are similar to values for Suwannee River fulvic acid (1ogK’ between 4.8 and 5.5), but there are strong sites (IogK’ = 7) and weak sites (1ogK’ between 3 and 4) also observed. Results depended on the isolation method used; reverse osmosis and low pressure evaporation yielded different values but with no consistent trends

Multi-site Proton Interactions with Natural Organic Matter

Water samples from various locations in Norway were used to isolate natural organic matter (NOM). The NOM was isolated using both reverse osmosis and low-pressure low-temperature evaporation for each sample site. These samples were titrated from -log[H+] 3 to 11 at 0.1 unit intervals. The data were analyzed using the Discrete Site Analysis (DISI) technique for pKa intervals of 0.2. The acidity constants are grouped into four classes: strong (pKa \u3c 5), intermediate strong (5.1\u3c pKa \u3c 7.5), intermediate weak (7.6 \u3c pKa \u3c 9.2), and weak (pKa \u3e 9.3). All samples, regardless of isolation method, were found to contain strong and weak ligands, along with some intermediate ligands. For the same sample site, the concentration of these ligands were found to be dependent on isolation method and titration direction (acid then base vs. base then acid). In addition, the concentration and classes of ligands present were found to vary between sample sites. Suwannee River fulvic acid was analyzed as a reference sample, and was qualitatively similar to the NOM samples but quantitatively different. Overall, the differences in pKa spectra due to isolation method and/or titration direction are almost as significant as differences between sample location, but there are no consistent trends in effects of isolation method or titration direction on characterization of NOM

Chemistry in isolation: High CCH/HCO+ line ratio in the AMIGA galaxy CIG 638

Multi-molecule observations towards an increasing variety of galaxies have been showing that the relative molecular abundances are affected by the type of activity. However, these studies are biased towards bright active galaxies, which are typically in interaction. We study the molecular composition of one of the most isolated galaxies in the local Universe where the physical and chemical properties of their molecular clouds have been determined by intrinsic mechanisms. We present 3 mm broad band observations of the galaxy CIG 638, extracted from the AMIGA sample of isolated galaxies. The emission of the J=1-0 transitions of CCH, HCN, HCO+, and HNC are detected. Integrated intensity ratios between these line are compared with similar observations from the literature towards active galaxies including starburst galaxies (SB), active galactic nuclei (AGN), luminous infrared galaxies (LIRG), and GMCs in M33. A significantly high ratio of CCH with respect to HCN, HCO+, and HNC is found towards CIG 638 when compared with all other galaxies where these species have been detected. This points to either an overabundance of CCH or to a relative lack of dense molecular gas as supported by the low HCN/CO ratio, or both. The data suggest that the CIG 638 is naturally a less perturbed galaxy where a lower fraction of dense molecular gas, as well as a more even distribution could explain the measured ratios. In this scenario the dense gas tracers would be naturally dimmer, while the UV enhanced CCH, would be overproduced in a less shielded medium.Comment: Letter accepted for publication in A&

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Predictors of breastfeeding duration among women in Kuwait: results of a prospective cohort study

The purposes of this paper are to report the prevalence of breastfeeding to six months among women in Kuwait and to determine the factors that are associated with the duration of breastfeeding. A cohort of 373 women recruited from maternity wards in four hospitals in Kuwait city were followed from birth to 26 weeks postpartum. The association of any and full breastfeeding duration and predictor variables were explored using multivariate Cox’s proportional hazards models. At six months, 39% of all infants were receiving some breast milk and only 2% of infants had been fully breastfed to 26 weeks. Women born in other Arab countries were less likely to discontinue breastfeeding than women born in Kuwait. Other factors positively associated with breastfeeding duration were level of maternal education, higher parity, infant being demand fed in hospital and a preference for breastfeeding on the part of the infant’s father and maternal grandmother. The introduction of a pacifier before four weeks of age and the mother intending to return to work by six months were negatively associated with duration. These findings present a number of opportunities for prolonging breastfeeding duration in Kuwait

Structural and ferromagnetic properties of an orthorhombic phase of MnBi stabilized with Rh additions

The article addresses the possibility of alloy elements in MnBi which may modify the thermodynamic stability of the NiAs-type structure without significantly degrading the magnetic properties. The addition of small amounts of Rh and Mn provides an improvement in the thermal stability with some degradation of the magnetic properties. The small amounts of Rh and Mn additions in MnBi stabilize an orthorhombic phase whose structural and magnetic properties are closely related to the ones of the previously reported high-temperature phase of MnBi (HT~MnBi). To date, the properties of the HT~MnBi, which is stable between $613$ and $719$~K, have not been studied in detail because of its transformation to the stable low-temperature MnBi (LT~MnBi), making measurements near and below its Curie temperature difficult. The Rh-stabilized MnBi with chemical formula Mn$_{1.0625-x}$Rh$_{x}$Bi [$x=0.02(1)$] adopts a new superstructure of the NiAs/Ni$_2$In structure family. It is ferromagnetic below a Curie temperature of $416$~K. The critical exponents of the ferromagnetic transition are not of the mean-field type but are closer to those associated with the Ising model in three dimensions. The magnetic anisotropy is uniaxial; the anisotropy energy is rather large, and it does not increase when raising the temperature, contrary to what happens in LT~MnBi. The saturation magnetization is approximately $3$~$\mu_B$/f.u. at low temperatures. While this exact composition may not be application ready, it does show that alloying is a viable route to modifying the stability of this class of rare-earth-free magnet alloys.Comment: 9 pages, 10 figure