Segmenting Scientific Abstracts into Discourse Categories: A Deep Learning-Based Approach for Sparse Labeled Data

The abstract of a scientific paper distills the contents of the paper into a short paragraph. In the biomedical literature, it is customary to structure an abstract into discourse categories like BACKGROUND, OBJECTIVE, METHOD, RESULT, and CONCLUSION, but this segmentation is uncommon in other fields like computer science. Explicit categories could be helpful for more granular, that is, discourse-level search and recommendation. The sparsity of labeled data makes it challenging to construct supervised machine learning solutions for automatic discourse-level segmentation of abstracts in non-bio domains. In this paper, we address this problem using transfer learning. In particular, we define three discourse categories BACKGROUND, TECHNIQUE, OBSERVATION-for an abstract because these three categories are the most common. We train a deep neural network on structured abstracts from PubMed, then fine-tune it on a small hand-labeled corpus of computer science papers. We observe an accuracy of 75% on the test corpus. We perform an ablation study to highlight the roles of the different parts of the model. Our method appears to be a promising solution to the automatic segmentation of abstracts, where the labeled data is sparse.Comment: to appear in the proceedings of JCDL'202

Multifractal scaling of electronic transmission resonances in perfect and imperfect Fibonacci δ\delta-function potentials

We present here a detailed multifractal scaling study for the electronic transmission resonances with the system size for an infinitely large one dimensional perfect and imperfect quasiperiodic system represented by a sequence of $\delta$-function potentials. The electronic transmission resonances in the energy minibands manifest more and more fragmented nature of the transmittance with the change of system sizes. We claim that when a small perturbation is randomly present at a few number of sites, the nature of electronic states will change and this can be understood by studying the electronic transmittance with the change of system size. We report the different critical states manifested in the size variation of the transmittance corresponding to the resonant energies for both perfect and imperfect cases through multifractal scaling study for few of these resonances.Comment: 7 pages, (Hard copies of 5 figures available on request from [email protected]

Circular Orbits in Extremal Reissner Nordstrom Spacetimes

Circular null geodesic orbits, in extremal Reissner-Nordstrom spacetimes, are examined with regard to their stability, and compared with similar orbits in the near-extremal situation. Extremization of the effective potential for null circular orbits shows the existence of a stable circular geodesic in the extremal spacetime, precisely {\it on} the event horizon, which coincides with its null geodesic generator. Such an orbit also emerges as a global minimum of the effective potential for circular {\it timelike} orbits. This type of geodesic is of course absent in the corresponding near-extremal spacetime, as we show here, testifying to differences between the extremal limit of a generic RN spacetime and the exactly extremal geometry.Comment: 13 Pages Latex 2e, no figures; title of paper, abstract and contents modified substantively following critique of anonymous refere

An augmented space recursion study of the electronic structure of rough epitaxial overlayers

In this communication we propose the use of the Augmented Space Recursion as an ideal methodology for the study of electronic and magnetic structures of rough surfaces, interfaces and overlayers. The method can take into account roughness, short-ranged clustering effects, surface dilatation and interdiffusion. We illustrate our method by an application of Fe overlayer on Ag (100) surface.Comment: 22 pages, Latex, 6 postscript figure

Effects of one-step alkaline and two-step alkaline/dilute acid and alkaline/steam explosion pretreatments on the structure of isolated pine lignin

Biological valorization of biomass most often depends on the efficient reduction of plant cell wall recalcitrance and conversion of lignin – the most recalcitrant constituent – to fuels, chemicals and/or value-added substances. Lignin conversion to fuels and value-added chemicals requires a sound understanding of the structure of lignin before and after different pretreatments. In the current work, an effort has been made to compare the structural differences in isolated pine lignin after one- (alkaline) and two-step (alkaline/dilute acid and alkaline/steam explosion) pretreatments. Our results indicate removal of the low molecular weight fraction of lignin after an initial alkaline pretreatment. A subsequent dilute acid pretreatment resulted in the loss of lignin inter-unit linkages such as β-O-4’ aryl ethers. However, with a steam explosion pretreatment, lignin exhibited a competing condensation process leading to increased condensed lignin structures.Fil: Das, Parthapratim. Oak Ridge National Laboratory; Estados Unidos. University of Tennessee; Estados UnidosFil: Stoffel, Romina Bettiana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Materiales de Misiones. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Instituto de Materiales de Misiones; Argentina. University of Tennessee; Estados UnidosFil: Area, Maria Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Materiales de Misiones. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Instituto de Materiales de Misiones; ArgentinaFil: Ragauskas, Arthur J.. University of Tennessee; Estados Unidos. Oak Ridge National Laboratory; Estados Unido

Nickel Bis-Diphosphine Complexes: Controlling the Binding and Heterolysis of H₂

Two new Ni­(II) complexes, the homoleptic [Ni­(8P^Cy₂N^H)₂]²⁺ complex (8P^Cy₂N^H = 3,7-cyclohexyl-1-amino-3,7-diphosphacyclooctane) containing two pendant amines on adjacent ligands, and the heteroleptic [Ni­(8P^Cy₂N^H)­(dppe)]²⁺ complex (dppe = bis­(diphenylphosphino)­ethane) containing only a single pendant amine, have been synthesized, and their electrochemical properties are reported. The [Ni­(8P^Cy₂N^H)­(dppe)]²⁺ complex is capable of heterolytically cleaving hydrogen, allowing for the first observation of an endo-protonated nickel hydride related to the [Ni­(P^R₂N^{R^′}₂)₂]²⁺ family of complexes. The [Ni­(8P^Cy₂N^H)­(dppe)]²⁺ complex did not exhibit electrocatalytic H₂ oxidation activity; however, [Ni­(8P^Cy₂N^H)₂]²⁺ is an active electrocatalyst for H₂ oxidation with a maximum turnover frequency (<i>k</i>_obs) of 18 s^–1 under 1 atm H₂ at <i>E</i>_cat/2 = −0.71 V versus the ferrocenium/ferrocene (Cp₂Fe^+/0) couple. In addition to an analysis of the effect of the number of pendant amines on the rates of electrocatalytic H₂ oxidation of compounds related to the [Ni­(P^R₂N^{R^′}₂)₂]²⁺ family, the effect of the secondary pendant amine on intermolecular deprotonation is discussed

Nickel Bis-Diphosphine Complexes: Controlling the Binding and Heterolysis of H₂

Two new Ni­(II) complexes, the homoleptic [Ni­(8P^Cy₂N^H)₂]²⁺ complex (8P^Cy₂N^H = 3,7-cyclohexyl-1-amino-3,7-diphosphacyclooctane) containing two pendant amines on adjacent ligands, and the heteroleptic [Ni­(8P^Cy₂N^H)­(dppe)]²⁺ complex (dppe = bis­(diphenylphosphino)­ethane) containing only a single pendant amine, have been synthesized, and their electrochemical properties are reported. The [Ni­(8P^Cy₂N^H)­(dppe)]²⁺ complex is capable of heterolytically cleaving hydrogen, allowing for the first observation of an endo-protonated nickel hydride related to the [Ni­(P^R₂N^{R^′}₂)₂]²⁺ family of complexes. The [Ni­(8P^Cy₂N^H)­(dppe)]²⁺ complex did not exhibit electrocatalytic H₂ oxidation activity; however, [Ni­(8P^Cy₂N^H)₂]²⁺ is an active electrocatalyst for H₂ oxidation with a maximum turnover frequency (<i>k</i>_obs) of 18 s^–1 under 1 atm H₂ at <i>E</i>_cat/2 = −0.71 V versus the ferrocenium/ferrocene (Cp₂Fe^+/0) couple. In addition to an analysis of the effect of the number of pendant amines on the rates of electrocatalytic H₂ oxidation of compounds related to the [Ni­(P^R₂N^{R^′}₂)₂]²⁺ family, the effect of the secondary pendant amine on intermolecular deprotonation is discussed

Use of sewage in split doses to enhance water productivity for fish culture

The problem of sewage disposal has received great attention worldwide. The raw sewage contains a variety of high inorganic and organic matters that affect natural water environment. To mitigate such problem, sewage may be recycled through aquaculture practice. Sewage recycling in aquaculture enhances water productivity through nutrients input. Proper loading of sewage ensures viable aquaculture; otherwise, fish mortality occurs due to poor water quality. To optimize sewage application, two different experiments were conducted, each with four treatments. In both experiments, three fish species namely rohu (Labeo rohita Hamilton, 1822), mrigal (Cirrhinus mrigala Hamilton, 1822), and bata (Labeo bata Hamilton, 1822) were tested in triplicate in FRP (Fibre-Reinforced Plastic) tanks. Different sewage concentrations (0, 25%, 50% and 75%) used in first experiment were prepared by mixing freshwater, showing Biochemical Oxygen Demand (BOD) 2.0 ± 0.4 mg/L, 10.8 ± 1.4 mg/L, 19.6 ± 1.5 mg/L and 41.6 ± 2.58 mg/L, respectively. After 30 days rearing, results showed ≥75% fish survival in sewage concentrations up to 50% with BOD level 19.6 ± 1.5 mg/L. Less than 50% fish survived in 75% sewage concentration, with BOD level as 41.6 ± 2.58 mg/L. The second experiment was conducted for 90 days considering 50% sewage concentration as basal dose with BOD level as 19.6 mg/L as an acceptable limit for fish survival. Split doses of sewage were applied in T1, T2 and T3 treatments fortnightly, weekly and semi-weekly intervals, while single dose was used in C (control) treatment. Application of split doses resulted better hydro-biological changes, including nutrients recovery, in T1, T2 and T3 than that of single dose in control. Fish growth plotted with net primary productivity (NPP), phytoplankton and zooplankton densities exhibited positive correlations in T2 (12 doses) and T3 (24 doses), considered as optimal doses to ensure better water productivity for desirable fish production than sewage with single dose or limited doses (6 doses)

Catalytic Oxidation of Alcohol via Nickel Phosphine Complexes with Pendant Amines

Nickel complexes were prepared with diphosphine ligands that contain pendant amines, and these complexes catalytically oxidize primary and secondary alcohols to their respective aldehydes and ketones. Kinetic and mechanistic studies of these prospective electrocatalysts were performed to understand what influences the catalytic activity. For the oxidation of diphenylmethanol, the catalytic rates were determined to be dependent on the concentration of both the catalyst and the alcohol and independent of the concentration of base and oxidant. The incorporation of pendant amines to the phosphine ligand results in substantial increases in the rate of alcohol oxidation with more electron-donating substituents on the pendant amine exhibiting the fastest rates