130,603 research outputs found
MeSH term explosion and author rank improve expert recommendations
No full textInformation overload is an often-cited phenomenon that reduces the productivity, efficiency and efficacy of scientists. One challenge for scientists is to find appropriate collaborators in their research. The literature describes various solutions to the problem of expertise location, but most current approaches do not appear to be very suitable for expert recommendations in biomedical research. In this study, we present the development and initial evaluation of a vector space model-based algorithm to calculate researcher similarity using four inputs: 1) MeSH terms of publications; 2) MeSH terms and author rank; 3) exploded MeSH terms; and 4) exploded MeSH terms and author rank. We developed and evaluated the algorithm using a data set of 17,525 authors and their 22,542 papers. On average, our algorithms correctly predicted 2.5 of the top 5/10 coauthors of individual scientists. Exploded MeSH and author rank outperformed all other algorithms in accuracy, followed closely by MeSH and author rank. Our results show that the accuracy of MeSH term-based matching can be enhanced with other metadata such as author rank
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
The influence of sediment nutrient dynamics on the response of lake ecosystems to restoration and climate change
No full textHuman activities such as urban settlement, farming, forestry and recreation, have caused deterioration of water quality in many freshwater lakes worldwide. Apart from anthropogenic impacts, it is also recognized that climate has a direct influence on lake water temperature, nutrient loads, phytoplankton abundance and chemistry. However, little is known about the potential effects of future climate change on lake water quality. Understanding the dynamics, abundance and availability of nutrient pools in lake bottom sediments is fundamentally important for predicting how, and over what time-scales, lake ecosystems will respond to future scenarios such as climate change, in-lake restoration or altered external nutrient loading. Through a sediment field study on 14 different lakes, and applications of complex lake ecosystem models to three New Zealand lakes, this study examined the spatial and temporal dynamics of sediment nutrient concentrations, and made considerations of the effects of restoration measures and future climate change on lake water quality.
To gain insight into processes influencing the dynamics of horizontal and vertical gradients of sediment nutrient concentrations, intact sediment cores were collected from twelve lakes within the Bay of Plenty province, North Island of New Zealand. In addition, intact sediment cores were collected from shallow Lake Te Waihora (Ellesmere) in the Canterbury province, South Island of New Zealand and shallow Lake Taihu in the Jaingsu province, China. The observed vertical concentration profiles of total phosphorus (TP) in the sediments revealed that the shape of these profiles can be similar across gradients of widely differing trophic status. Empirical and mechanistic steady state profile models were derived to describe the vertical distribution of total carbon (TC), total nitrogen (TN) and TP concentrations in the sediments. These models revealed that density-driven burial and biodiffusive mixing, which in the models also includes effects of redox-driven gradients, are strongly correlated with vertical gradients of sediment TC, TN and TP content, whereas lake trophic status was not.
Despite enhancing knowledge of the processes influencing vertical gradients of sediment nutrient concentrations, little is known about the rates at which sediment nutrient concentrations may change as a response to changes in external loading or climate. Studies into the composition of bottom sediments have been undertaken intermittently over the past three decades for the 12 lakes in the Bay of Plenty. These studies, together with the data collected in this study, were used to quantify temporal changes in sediment chemistry across the lakes. Comparison of the data collected in this study with results from a survey in 1995 showed that surficial sediment (0-2 cm) TP concentrations have increased in three of the 12 lakes, at rates ranging from 27.5 to 114.4 mg P kg-1 dry wt yr-1. TN concentrations in surficial sediments have increased in nine of the 12 lakes at rates ranging from 51.8 to 869.2 mg N kg-1 dry wt yr-1. A correlation analysis revealed that temporal changes in sediment TP and TN concentrations were not significantly linearly related (pgt0.05) to catchment area or temporal changes of different water column indices considered to reflect lake trophic state, including annual mean water column concentrations of TP, TN or chlorophyll a (Chl a).
While vertical profiles of sediment nutrient concentrations can be used to provide information about historical changes of trophic status in lakes, little is known about horizontal variability of sediment nutrient concentrations, including possibly relationships with horizontal variations in water column variables. In the large, shallow and eutrophic Lake Taihu, China, there are distinct horizontal water column concentration gradients of nutrients and Chl a. Concentrations are generally high in the north, where some of the major polluted tributaries enter the lake, and relatively low in the south, where macrophytes generally are abundant. To test whether these water column concentration gradients are similarly reflected in spatial heterogeneity of nutrient concentrations within the bottom sediments of Lake Taihu, I examined correlations between concentrations of TP and TN in surficial sediments (0-2 cm) and TP, TN and Chl a concentrations in water column samples determined for 32 sites in 2005. Linear correlation analysis revealed that surficial sediment TP concentrations across the 32 stations were related significantly, though weakly, to annual mean water column concentrations of TP and TN as well as Chl a. Correlations of surficial sediment TN with water column variables were, however, not significant (p gt 0.05).
To better understand the effects of future climate change on lakes of different trophic status, I applied the one-dimensional lake ecosystem model, DYRESM-CAEDYM, to oligo-mesotrophic Lake Okareka, eutrophic Lake Rotoehu and highly eutrophic Lake Te Waihora. All three models were calibrated based on a three-year period (July 2002 - June 2005) and validated on a separate two-year period (July 2005 - June 2007). The model simulations generally showed good agreement with observed data for temperature, dissolved oxygen (DO), and total nutrient and Chl a concentrations. To represent a possible future climate of 2100, temperature predictions were derived from the regional climate model, DARLAM, based on the Intergovernmental Panel on Climate Change (IPCC) A2 scenario, which suggests that air temperatures by the year 2100 will increase by an average of 2.5 'C and 2.7 'C for the Bay of Plenty and the Canterbury province, respectively, relative to the base scenario (years 2002-2007). Model simulations of the future climate scenarios indicate that climatic changes generally will lead to a degradation of lake water quality in all three lakes, especially during summer months, and further suggest that the effects on annual mean surface concentrations of TP, TN and Chl a will be equivalent to an increase in external TN and TP loading by 25-50%. Simulations for Lake Rotoehu, where diatoms and cyanophytes were represented in the conceptual model, further suggest that cyanophytes will be more abundant in the future, increasing by gt15% in annual mean biomass. Although the effects of climate change may be delayed or slightly mediated by the chemical resilience of the sediment nutrient pools, the effects of climate change on lake water quality in the New Zealand lakes will be of a magnitude that should be considered as management strategies are planned and implemented, thus increasing the probability of successful preservation or improvement in water quality in future decades
"Closing the R&D Gap, Evaluating the Sources of R&D Spending"
No full textBoth spending and tax policies have been implemented in the United States with the goal of stimulating private sector research and development (R&D). Karier questions whether current R&D policy, especially the research and experimentation tax credit, can contribute to closing the gap between nondefense expenditures on R&D in the United States and such expenditures in other countries, such as Japan and Germany. He also explores possible changes to our current R&D policy to make it more effective.
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Scholarly Communication and Publishing Lunch and Learn Talk #11: The ULS Open Access Author Fee Fund
No full textAt the May 2014 talk, you will learn about the ULS Open Access Author Fee Fund--what it is, why we do it, how it works, and how the program is going so far
sj-docx-1-jtt-10.1177_1357633X221150279 - Supplemental material for Effect of telemonitoring on readmissions for acute exacerbation of chronic obstructive pulmonary disease: A randomized clinical trial
No full textSupplemental material, sj-docx-1-jtt-10.1177_1357633X221150279 for Effect of telemonitoring on readmissions for acute exacerbation of chronic obstructive pulmonary disease: A randomized clinical trial by Frank D Andersen, Christian Trolle, Asger Roer Pedersen, Maria L Køpfli, Sanne Børgesen, Michael S Jensen, and Charlotte Hyldgaard in Journal of Telemedicine and Telecare</p
Blueprint for a unifying framework for synthesis of aquatic ecodynamics
No full textQuantitative assessments of aquatic ecosystem dynamics and services are required to guide decision support activities and assess how socioeconomic scenarios of human development impact our aquatic environment. However, we are poorly equipped to predict across a broad range of scales the physical, biogeochemical and ecological interactions that control carbon and nutrient flux pathways, despite a plethora of models and model approaches that have emerged. Our models have languished due to ambiguities and lack of agreement in model conceptualisations, a focus on point-scale rather than system-scale validation, and a general inability to deal with uncertainty, particularly in spatially-resolved interdisciplinary models. Further, the site-specific and highly disciplinary nature of many model applications limits synthesis and transferability of knowledge between sites. Here we outline a blueprint for an integrative approach to address these barriers by facilitating: i) the integration of inter-disciplinary modelling approaches, ii) reducing uncertainty through a multi-scale validation approach and managed assimilation of environmental sensing data, and iii) cross-domain synthesis.Matthew R. Hipsey, David P. Hamilton, Paul C. Hanson, Justin D. Brookes, Dennis Trolle, Louise C. Bruc
The R&D Tax Incentives
No full textThis article sets out some background information and reflections of the author on the R&D tax incentive schemes included in the Common Corporate Tax Base (CCTB) Proposal. In particular the author analyzes the stimulus to private R&D through ad hoc tax incentives included in the CCTB Proposal and dives into the actual provisions included in the Proposal highlighting the most relevant issues connected with their design and interpretation. Moreover, the author explores the interaction between the CCTB Proposal and the granting by Member States of domestic R&D tax incentives
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