1,645 research outputs found
StyleCheck: An Automated Stylistic Analysis Tool
StyleCheck is a user-friendly tool with multiple functions designed to aid in the production of quality writing. Its features include stylistic analysis (on both document-wide and individual-sentence scales) and spelling and grammar check, as well as generating suggested replacements for all types of errors. In addition, StyleCheck includes the capability to identify the famous author (out of a limited corpus) with the style most similar to the user\u27s. The source code for StyleCheck is available online at: https://github.com/alexpwelton/StyleChec
Evidence of secondary relaxations in the dielectric spectra of ionic liquids
We investigated the dynamics of a series of room temperature ionic liquids
based on the same 1-butyl-3-methyl imidazolium cation and different anions by
means of broadband dielectric spectroscopy covering 15 decades in frequency
(10^(-6)-10^9 Hz), and in the temperature range from 400 K down to 35 K. An
ionic conductivity is observed above the glass transition temperature T_{g}
with a relaxation in the electric modulus representation. Below T_{g}, two
relaxation processes appear, with the same features as the secondary
relaxations typically observed in molecular glasses. The activation energy of
the secondary processes and their dependence on the anion are different. The
slower process shows the characteristics of an intrinsic Johari-Goldstein
relaxation, in particular an activation energy E_{beta}=24k_{B}T_{g} is found,
as observed in molecular glasses.Comment: Major revision, submitted to Phys. Rev. Let
Macroinvertebrate sampling of wooded and open sections of tributaries of the R, Itchen - May 1998
Diminishing returns drive altruists to help extended family
Altruism between close relatives can be easily explained. However, paradoxes arise when organisms divert altruism towards more distantly related recipients. In some social insects, workers drift extensively between colonies and help raise less related foreign brood, seemingly reducing inclusive fitness. Since being highlighted by W. D. Hamilton, three hypotheses (bet hedging, indirect reciprocity and diminishing returns to cooperation) have been proposed for this surprising behaviour. Here, using inclusive fitness theory, we show that bet hedging and indirect reciprocity could only drive cooperative drifting under improbable conditions. However, diminishing returns to cooperation create a simple context in which sharing workers is adaptive. Using a longitudinal dataset comprising over a quarter of a million nest cell observations, we quantify cooperative payoffs in the Neotropical wasp Polistes canadensis, for which drifting occurs at high levels. As the worker-to-brood ratio rises in a workerâs home colony, the predicted marginal benefit of a worker for expected colony productivity diminishes. Helping related colonies can allow effort to be focused on related brood that are more in need of care. Finally, we use simulations to show that cooperative drifting evolves under diminishing returns when dispersal is local, allowing altruists to focus their efforts on related recipients. Our results indicate the power of nonlinear fitness effects to shape social organization, and suggest that models of eusocial evolution should be extended to include neglected social interactions within colony networks
Graph Theoretic Analysis of Brain Connectomics in Multiple Sclerosis: Reliability and Relationship to Cognition
Research suggests that disruption of brain networks might explain cognitive deficits in multiple sclerosis (MS). The reliability and effectiveness of graph-theoretic network metrics as measures of cognitive performance were tested in 37 people with MS and 23 controls. Specifically, relationships to cognitive performance (linear regression against the Paced Auditory Serial Addition Test [PASAT-3], Symbol Digit Modalities Test [SDMT] and Attention Network Test [ANT]) and one-month reliability (using the intra-class correlation coefficient [ICC]) of network metrics were measured using both resting-state functional and diffusion MRI data. Cognitive impairment was directly related to measures of brain network segregation and inversely related to network integration (prediction of PASAT-3 by small-worldness, modularity, characteristic path length, R2=0.55; prediction of SDMT by small-worldness, global efficiency and characteristic path length, R2=0.60). Reliability of the measures over one month in a subset of 9 participants was mostly rated as good (ICC>0.6) for both controls and MS patients in both functional and diffusion data but was highly dependent on the chosen parcellation and graph density, with the 0.2-0.5 density range being the most reliable. This suggests that disrupted network organisation predicts cognitive impairment in MS and its measurement is reliable over a 1-month period. These new findings support the hypothesis of network disruption as a major determinant of cognitive deficits in MS and the future possibility of the application of derived metrics as surrogate outcomes in trials of therapies for cognitive impairment
Beyond megadrought and collapse in the Northern Levant: The chronology of Tell Tayinat and two historical inflection episodes, around 4.2ka BP, and following 3.2ka BP
There has been considerable focus on the main, expansionary, and inter-regionally linked or âglobalisingâ periods in Old World pre- and proto-history, with a focus on identifying, analyzing and dating collapse at the close of these pivotal periods. The end of the Early Bronze Age in the late third millennium BCE and a subsequent âintermediateâ or transitional period before the Middle Bronze Age (~2200â1900 BCE), and the end of the Late Bronze Age in the late second millennium BCE and the ensuing period of transformation during the Early Iron Age (~1200â900 BCE), are key examples. Among other issues, climate change is regularly invoked as a cause or factor in both cases. Recent considerations of âcollapseâ have emphasized the unpredictability and variability of responses during such periods of reorganization and transformation. Yet, a gap in scholarly attention remains in documenting the responses observed at important sites during these âtransformativeâ periods in the Old World region. Tell Tayinat in southeastern Turkey, as a major archaeological site occupied during these two major âin betweenâ periods of transformation, offers a unique case for comparing and contrasting differing responses to change. To enable scholarly assessment of associations between the local trajectory of the site and broader regional narratives, an essential preliminary need is a secure, resolved timeframe for the site. Here we report a large set of radiocarbon data and incorporate the stratigraphic sequence using Bayesian chronological modelling to create a refined timeframe for Tell Tayinat and a secure basis for analysis of the site with respect to its broader regional context and climate history
Process analysis of ionic liquid-based blends as H2S absorbents: search for thermodynamic/kinetic synergies
Acid gas absorption by ionic liquids (ILs) has arisen as a promising alternative technique for biogas or natural gas upgrading. In the present work, IL-based blends are evaluated for potential thermodynamic/kinetic synergistic effects on hydrogen sulfide (H2S) capture through physical and/or chemical absorption. First, a molecular simulation analysis by means of COSMO-RS was used to select IL-based blends with enhanced H2S absorbent thermodynamic properties. Physical absorption parameters of reference (KHenry) for H2S in several IL-based blends were calculated at 298 K, involving both IL mixtures and conventional industrial absorbents (tetraglyme (TGM)) with ILs at different compositions. A Henry's constant deviation parameter (ÎHKHenryH2S) was employed to analyze the nonideal effects of the mixture on H2S gas solubility in IL-based blends. In addition, the viscosities and diffusivities of the IL-based blends were estimated as key parameters controlling H2S diffusion and absorbent uptake rates. From this analysis, a sample of IL-based blends with promising thermodynamic and kinetic properties was selected for H2S physical absorption. A process simulation analysis using the COSMO-based/Aspen Plus methodology was then carried out and the selected absorbents were evaluated by modeling H2S capture in an industrial-scale commercial packed column. One IL, 1-butyl-3-methylimidazoium acetate ([Bmim][OAc]), presenting high H2S chemical absorption and a low viscous industrial solvent (TGM) were also included. The strong kinetic control of H2S capture by physical absorption indicated the limited potential performance of IL-based blends or neat ILs in industrial equipment. In contrast, the COSMO/Aspen analysis revealed that adequate formulations based on [Bmim][OAc] and TGM present enhanced H2S absorbent properties compared to the neat compounds. These computational results may be used to guide future experimental research to design new H2S absorbents, reducing the highly demanding experimental inputFinancial support from Ministerio de EconomĂa y Competitividad of Spain (project CTQ2017-89441-R) and Comunidad de Madrid (project P2018/EMT4348) is acknowledge
Diminishing returns drive altruists to help extended family
This is the author accepted manuscript. The final version is available from nature Research via the DOI in this recordData availability:
The transitions data for P. canadensis are available in the Supplementary Information.Code availability:
The statistical code and individual-based simulation code are available in the Supplementary Information.Altruism between close relatives can be easily explained. However, paradoxes arise when organisms divert altruism towards more distantly related recipients. In some social insects, workers drift extensively between colonies and help raise less related foreign brood, seemingly reducing inclusive fitness. Since being highlighted by W. D. Hamilton, three hypotheses (bet hedging, indirect reciprocity and diminishing returns to cooperation) have been proposed for this surprising behaviour. Here, using inclusive fitness theory, we show that bet hedging and indirect reciprocity could only drive cooperative drifting under improbable conditions. However, diminishing returns to cooperation create a simple context in which sharing workers is adaptive. Using a longitudinal dataset comprising over a quarter of a million nest cell observations, we quantify cooperative payoffs in the Neotropical wasp Polistes canadensis, for which drifting occurs at high levels. As the worker-to-brood ratio rises in a workerâs home colony, the predicted marginal benefit of a worker for expected colony productivity diminishes. Helping related colonies can allow effort to be focused on related brood that are more in need of care. Finally, we use simulations to show that cooperative drifting evolves under diminishing returns when dispersal is local, allowing altruists to focus their efforts on related recipients. Our results indicate the power of nonlinear fitness effects to shape social organization, and suggest that models of eusocial evolution should be extended to include neglected social interactions within colony networks.Smithsonian Tropical Research Institute (STRI)National Geographic SocietyNatural Environment Research Council (NERC)European Research Council (ERC
- âŠ