20,992 research outputs found
What does the Web of Science five-year synchronous impact factor have to offer?
With a random sample of 10 JCR (Science) subject areas it is shown that the 2-year and the 5-year impact factor of journals lead statistically to the same ranking per category. Yet in a majority of cases, the 5-year impact factor is larger than the 2-year one.</p
Usage Bibliometrics
Scholarly usage data provides unique opportunities to address the known
shortcomings of citation analysis. However, the collection, processing and
analysis of usage data remains an area of active research. This article
provides a review of the state-of-the-art in usage-based informetric, i.e. the
use of usage data to study the scholarly process.Comment: Publisher's PDF (by permission). Publisher web site:
books.infotoday.com/asist/arist44.shtm
Study on open science: The general state of the play in Open Science principles and practices at European life sciences institutes
Nowadays, open science is a hot topic on all levels and also is one of the priorities of the European Research Area. Components that are commonly associated with open science are open access, open data, open methodology, open source, open peer review, open science policies and citizen science. Open science may a great potential to connect and influence the practices of researchers, funding institutions and the public. In this paper, we evaluate the level of openness based on public surveys at four European life sciences institute
Modification and preservation of environmental signals in speleothems
Speleothems are primarily studied in order to generate archives of climatic change and results have led to significant advances in identifying and dating major shifts in the climate system. However, the climatological meaning of many speleothem records cannot be interpreted unequivocally; this is particularly so for more subtle shifts and shorter time periods, but the use of multiple proxies and improving understanding of formation mechanisms offers a clear way forward. An explicit description of speleothem records as time series draws attention to the nature and importance of the signal filtering processes by which the weather, the seasons and longer-term climatic and other environmental fluctuations become encoded in speleothems. We distinguish five sources of variation that influence speleothem geochemistry: atmospheric, vegetation/soil, karstic aquifer, primary speleothem crystal growth and secondary alteration and give specific examples of their influence. The direct role of climate diminishes progressively through these five factors. \ud
\ud
We identify and review a number of processes identified in recent and current work that bear significantly on the conventional interpretation of speleothem records, for example: \ud
\ud
1) speleothem geochemistry can vary seasonally and hence a research need is to establish the proportion of growth attributable to different seasons and whether this varies over time. \ud
\ud
2) whereas there has traditionally been a focus on monthly mean �´18O data of atmospheric moisture, current work emphasizes the importance of understanding the synoptic processes that lead to characteristic isotope signals, since changing relative abundance of different weather types might 1Corresponding author, fax +44(0)1214145528, E-mail: [email protected] control their variation on the longer-term. \ud
\ud
3) the ecosystem and soil zone overlying the cave fundamentally imprint the carbon and trace element signals and can show characteristic variations with time. \ud
\ud
4) new modelling on aquifer plumbing allows quantification of the effects of aquifer mixing. \ud
\ud
5) recent work has emphasized the importance and seasonal variability of CO2-degassing leading to calcite precipitation upflow of a depositional site on carbon isotope and trace element composition of speleothems. \ud
\ud
6) Although much is known about the chemical partitioning between water and stalagmites, variability in relation to crystal growth mechanisms and kinetics is a research frontier. \ud
\ud
7) Aragonite is susceptible to conversion to calcite with major loss of chemical information, but the controls on the rate of this process are obscure. \ud
\ud
Analytical factors are critical to generate high-resolution speleothem records. A variety of methods of trace element analysis are available, but standardization is a common problem with the most rapid methods. New stable isotope data on Irish stalagmite CC3 compares rapid laser-ablation techniques with the conventional analysis of micromilled powders and ion microprobe methods. A high degree of comparability between techniques for �´18O is found on the mm-cm scale, but a previously described high-amplitude oxygen isotope excursion around 8.3 ka is identified as an analytical artefact related to fractionation of the laser-analysis associated with sample cracking. High-frequency variability of not less than 0.5o/oo may be an inherent feature of speleothem �´18O records
Measuring academic influence: Not all citations are equal
The importance of a research article is routinely measured by counting how
many times it has been cited. However, treating all citations with equal weight
ignores the wide variety of functions that citations perform. We want to
automatically identify the subset of references in a bibliography that have a
central academic influence on the citing paper. For this purpose, we examine
the effectiveness of a variety of features for determining the academic
influence of a citation. By asking authors to identify the key references in
their own work, we created a data set in which citations were labeled according
to their academic influence. Using automatic feature selection with supervised
machine learning, we found a model for predicting academic influence that
achieves good performance on this data set using only four features. The best
features, among those we evaluated, were those based on the number of times a
reference is mentioned in the body of a citing paper. The performance of these
features inspired us to design an influence-primed h-index (the hip-index).
Unlike the conventional h-index, it weights citations by how many times a
reference is mentioned. According to our experiments, the hip-index is a better
indicator of researcher performance than the conventional h-index
Report of the 2004 Workshop on In Situ Iron Enrichment Experiments in the Eastern and Western Subarctic Pacific
Foreword
1. BACKGROUND AND OBJECTIVES (pdf, 0.1 Mb)
2. 2004 WORKSHOP SUMMARY (pdf, < 0.1 Mb)
2.1. What have we learned from the enrichment experiments?
2.2 What are the outstanding questions?
2.3 Recommendations for SEEDS-II
3. EXTENDED ABSTRACTS OF THE 2004 WORKSHOP
3.1 Synthesis of the Iron Enrichment Experiments: SEEDS and SERIES (pdf, 0.5 Mb)
Iron fertilization experiment in the western subarctic Pacific (SEEDS)
by Atsushi Tsuda
The response of N and Si to iron enrichment in the Northeast Pacific Ocean: Results from SERIES
by David Timothy, C.S. Wong, Yukihiro Nojiri, Frank A. Whitney, W. Keith Johnson and Janet Barwell-Clarke
3.2 Biological and Physiological Responses (pdf, 0.2 Mb)
Zooplankton responses during SEEDS
by Hiroaki Saito
Phytoplankton community response to iron and temperature gradient in the NW and NE subarctic Pacific Ocean
by Isao Kudo, Yoshifumi Noiri, Jun Nishioka, Hiroshi Kiyosawa and Atsushi Tsuda
SERIES: Copepod grazing on diatoms
by Frank A. Whitney, Moira Galbraith, Janet Barwell-Clarke and Akash Sastri
The Southern Ocean Iron Enrichment Experiment: The nitrogen uptake response
by William P. Cochlan and Raphael M. Kudela
3.3 Biogeochemical Responses (pdf, 0.5 Mb)
What have we learned regarding iron biogeochemistry from iron enrichment experiments?
by Jun Nishioka, Shigenobu Takeda and W. Keith Johnson
Iron dynamics and temporal changes of iron speciation in SERIES
by W. Keith Johnson, C.S. Wong, Nes Sutherland and Jun Nishioka
Dissolved organic matter dynamics during SEEDS and SERIES experiments
by Takeshi Yoshimura and Hiroshi Ogawa
Formation of transparent exopolymer particles during the in-situ iron enrichment experiment in the western subarctic Pacific (SEEDS)
by Shigenobu Takeda, Neelam Ramaiah, Ken Furuya and Takeshi Yoshimura
Atmospheric measurement
by Mitsuo Uematsu
3.4 Prediction from Models (pdf, 0.3 Mb)
Modelling iron limitation in the North Pacific
by Kenneth L. Denman and M. Angelica Peña
A proposed model of the SERIES iron fertilization patch
by Debby Ianson, Christoph Voelker and Kenneth L. Denman
4. LIST OF PARTICIPANTS FOR THE 2004 WORKSHOP (pdf, < 0.1 Mb)
APPENDIX 1
Report of the 2000 Planning Workshop on Designing the Iron Fertilization Experiment in the Subarctic Pacific (pdf, 1 Mb)
APPENDIX 2
Terms of Reference for the Advisory Panel on Iron fertilization experiment in the subarctic Pacific Ocean (pdf, < 0.1 Mb)
APPENDIX 3
Historical List of Advisory Panel Members on Iron fertilization experiment in the subarctic Pacific Ocean (pdf, < 0.1 Mb)
APPENDIX 4
IFEP-AP Annual Reports (pdf, 0.1 Mb)
APPENDIX 5
PICES Press Articles (pdf, 0.6 Mb)
(194 page document
- …