122,735 research outputs found
Supplemental_file.docx_R1 – Supplemental material for 1,8-Diazabicyclo[5.4.0]undec-7-ene-mediated formation of N-sulfinyl imines
No full textSupplemental material, Supplemental_file.docx_R1 for 1,8-Diazabicyclo[5.4.0]undec-7-ene-mediated formation of N-sulfinyl imines by Manjunatha M Ramaiah, Priya Babu Shubha, Pavan Kumar Prabhala and Nanjunda Swamy Shivananju in Journal of Chemical Research</p
Use of stable isotopes, organic and inorganic chemistry to identify pollution sources and weathering processes in two small tropical rivers in southwestern India
No full textThe two main objectives of this study were to assess pollution dynamic from organic and inorganic major ion chemistry and stable isotopes (δ15N and δ18O) and to determine the weathering processes using carbon isotopes in two tropical river basins, i.e. Nethravati and Swarna, along southwest coast of India. These short length river basins (around 100 km) are characterized by high annual rainfall, warm temperature, high runo" (~3300mm) draining Precambrian basement rocks composed of green-stones, granitic-gneiss, charnockite and meta sediments. Intense silicate weathering is induced by high runo" and warm temperature (Gurumurthy et al., 2012). In this study, stable isotopes (δ15N & δ18O)of organic molecules from sewage and agricultural effluents,and carbon isotopes (δ13C) of dissolved organic carbon (DOC) and dissolved inorganic carbon (DIC) were measured to trace agricultural and domestic pollution and to identify the sources of inorganic carbon and the nature of chemical weathering in these river basins. Carbon isotopes measured on DIC reveals sources of carbon into the river, such as carbonate/silicate weathering of rocks, mineralization of organic matter from C3/C4 plants, soil and atmospheric CO2. The nitrate and phosphate levels remain low, with values ranging from 5 to 9 μM, and 0 to 2 μM respectively. The δ13C DIC values range from =-9.03 +/- 0.99 for the Swarna basin to -8.08 +/-0.78 for the Nethravati basin. These values point to a mixing of carbonate and silicate weathering products with a dominance of C3 vegetation, prevalent in the Western Ghats. The DOC values for both river basins are very low and very close: 0.72 +/- 0.09 mg/L (Swarna river) and 0.62 +/-0.11 mg/L (Nethravati river). This indicates that the contributions of organic matter from the adjacent forests and the $ood plains are very low during the sampling period. The analysis of organic acids reveals low amount of Oxalate and Acetate, and trace of Malate and Tartaric acids. The dissolved and particulate organic carbon (DOC and POC) concentrations are very low in these two rivers. During the dry season, river discharge is mainly supplied by groundwater with generally low contents in dissolved and particulate fractions. Even if we observe low concentration, we measured higher DOC and POC in the Swarna river. These higher DOC concentrations are accompanied with lower SUVA value. This indicates that more labile DOC (less aromaticity) is exported within this basin during dry season. C/N values in POC also show that the organic carbon is “fresher” and is probably more autochtonous than in the Nethravati river. Indeed, C/N value are closer of an autochthonous production (C/N : 2-6) than allochthonous one (C/N: 8-20). These observations can be explained as the Svarna watershed land use is more agricultural than in Nethravati. Agricultural lands generally export signi%cant amount of nutrients to rivers and participate to enhance autochthonous productivity. Autochthonous organic carbon production is more labile and less aromatic
Interplay of non-covalent interactions in ribbon-like guanosine self-assembly : a NMR crystallography study
No full textA NMR crystallography study shows how intermolecular NH...O, NH...N, OH...N, OH...O and CH–π interactions stabilize the ribbon-like supramolecular structures of three different guanosine derivatives; guanosine dihydrate (G), 3/, 5/–O– dipropanolyl deoxyguanosine (dGC(3)2) and 3/, 5/ –O– isopropylideneguanosine hemihydrate (Gace). Experimental solid-state 1H NMR spectra obtained at 20 T using fast Magic-Angle Spinning (MAS), here at 75 kHz, are presented for a dihydrate of G. For each guanosine derivative, the role of specific interactions is probed by means of NMR chemical shifts calculated using the Density Functional Theory (DFT) Gauge-Including Projector-Augmented Wave (GIPAW) approach for the full crystal and extracted isolated single molecules. Specifically, the isolated molecule to full crystal transformations result in net changes in the GIPAW calculated 1H NMR chemical shifts of up to 8 ppm for OH...O, up to 6.5 ppm for NH...N and up to 4.6 ppm for NH...O hydrogen bonds; notably, the presence of water molecules in G and Gace reinforces the molecular stacking through strong OH...O hydrogen bonds. The sugar conformations are markedly different in G, dG(C3)2 and Gace, and it is shown that the experimental 13C solid-state NMR chemical shift at the C8 position is a reliable indicator of a ‘syn’ (> 135 ppm) or ‘anti’ (< 135 ppm) conformer
Co-existence of distinct supramolecular assemblies in solution and in the solid state
No full textThe formation of distinct supramolecular assemblies, including a metastable species, is revealed for a lipophilic guanosine (G) derivative in solution and in the solid state. Structurally different G-quartet based assemblies are formed in chloroform depending on the nature of the cation, anion and salt concentration, as characterized by circular dichroism and time course diffusion-ordered NMR spectroscopy data. Intriguingly, even the presence of potassium ions that stabilize G-quartets in chloroform was insufficient to exclusively retain such assemblies in the solid state, leading to the formation of mixed quartet and ribbon-like assemblies as revealed by fast magic-angle spinning (MAS) NMR spectroscopy. Distinct N-H∙∙∙N and N-H∙∙∙O intermolecular hydrogen bonding interactions drive quartet and ribbon-like self-assembly resulting in markedly different 2D 1H solid-state NMR spectra, thus facilitating a direct identification of mixed assemblies. A dissolution NMR experiment confirmed that the quartet and ribbon interconversion is reversible - further demonstrating the changes that occur in the self-assembly process of a lipophilic nucleoside upon a solid-state to solution-state transition and vice versa. A systematic study for complexation with different cations (K+, Sr2+) and anions (picrate, ethanoate and iodide) emphasises that the existence of a stable solution or solid-state structure may not reflect the stability of the same supramolecular entity in another phase
TPRpred: a tool for prediction of TPR-, PPR- and SEL1-like repeats from protein sequences
No full textAbstract Background Solenoid repeat proteins of the Tetratrico Peptide Repeat (TPR) family are involved as scaffolds in a broad range of protein-protein interactions. Several resources are available for the prediction of TPRs, however, they often fail to detect divergent repeat units. Results We have developed TPRpred, a profile-based method which uses a P-value-dependent score offset to include divergent repeat units and which exploits the tendency of repeats to occur in tandem. TPRpred detects not only TPR-like repeats, but also the related Pentatrico Peptide Repeats (PPRs) and SEL1-like repeats. The corresponding profiles were generated through iterative searches, by varying the threshold parameters for inclusion of repeat units into the profiles, and the best profiles were selected based on their performance on proteins of known structure. We benchmarked the performance of TPRpred in detecting TPR-containing proteins and in delineating the individual repeats therein, against currently available resources. Conclusion TPRpred performs significantly better in detecting divergent repeats in TPR-containing proteins, and finds more individual repeats than the existing methods. The web server is available at http://tprpred.tuebingen.mpg.de, and the C++ and Perl sources of TPRpred along with the profiles can be downloaded from ftp://ftp.tuebingen.mpg.de/ebio/protevo/TPRpred/.</p
Preventive psychiatry from public health perspectives
No full textThe focus in public health has been shifted to noncommunicable diseases (NCD) in last decade. Mental health is gaining momentum as fifth NCD. The concept of prevention in psychiatry is new, but an interesting area from public health perspectives. The concepts of primary, secondary, and tertiary prevention relevant to psychiatry are discussed. Among primary prevention interventions, universal, selective, and indicated prevention strategies in psychiatry are discussed with examples from published literature. Challenges in preventive psychiatric practice on issue of payments, available standard of evidence, and best health-care professionals for its delivery are also discussed. There is a need to focus on preventive psychiatric interventions, especially in developing countries
A Multi-Language Comparison of Influences on Author Verification using Character N-Grams
No full textWe create a new multi-language corpus for author verification based on Wikipedia talkpages, and evaluate the influence that differences in topic and time have on character n-gram author profiles. Topic alignment between two texts is found to increase author verification precision, and an authors writing style is found to change over time, but not more significantly after 3 years than after 1 year.Information ArchitectureWISElectrical Engineering, Mathematics and Computer Scienc
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
The vanishing author in computer-generated works: a critical analysis of recent Australian case law
No full textAbstract
The use of software is ubiquitous in the creation of many copyright works, yet the requirement in copyright law that every work have a human author who engages in independent intellectual effort means that its use may prevent copyright subsistence. Several recent Australian cases have refocused attention on authorship as an essential criterion of copyright subsistence, and these cases suggest that much computer-produced output may be authorless and thus lack copyright protection. This article, the first in a two-part series, analyses how each case deals with the question of authorship of computer-produced works and why the use of software diminishes copyright protection for a significant number of computer-generated works. The article critiques the application of conventional notions of human authorship developed in the pre-computer age to modern productions and suggests alternative approaches to authorship that satisfy both the major objectives of copyright policy and the need to adapt to the computer age. The article argues that, without a broader judicial approach to authorship of computer-generated works, Parliament must remedy the lacuna in protection for these ‘authorless’ works. Possible solutions for reform are suggested. In a forthcoming article, the author comprehensively examines those reform proposals
Polyphenols fingerprinting in olive oils through maximum-quantum NMR spectroscopy
No full textAn NMR protocol based on multiple-quantum spectroscopy is presented for an analytical screening of polyphenols in olive oils. Three Italian olive oils with different total polyphenols content were used as study case. A total of 24 compounds were identified as follows: 1 polyphenol in the 5Q–1Q, 15 more in the 4Q–1Q, and 8 components in the 3Q–1Q spectra, consisting of organic phenols, secoiridoids, lignans, and flavonols. In the three Italian olive oils investigated here, the polyphenols profile turned out to be significantly different, with specific characteristics going beyond simple considerations based on the total polyphenol content. The approach presented here can be easily extended for rapid qualitative and semi-quantitative screening of the polyphenol composition in many food products
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