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Bibliometrics
Research Project Search
Bibliometric Analysis for the U.S. Environmental Protection Agency/Office of Research and Development’s Land Research Program
April 8, 2008
This is a bibliometric analysis of the papers prepared by researchers of the U.S. Environmental Protection Agency (EPA) for the Land Research Program. For this analysis, a total of 1,378 publications published from 1997 to 2007 were reviewed. The 1,378 journal publications were cited 20,253 times in the journals covered by Thomson’s Web of Science1 and Scopus2. Of the 1,378 journal publications, 1,280 (93%) have been cited at least once in a journal.
Searches of Thomson Scientific’s Web of Science and Scopus were conducted to obtain times cited data for the journal publications. The analysis was completed using Thomson’s Essential Science Indicators (ESI) and Journal Citation Reports (JCR) as benchmarks. ESI provides access to a unique and comprehensive compilation of essential science performance statistics and science trends data derived from Thomson’s databases. For this analysis, the ESI highly cited papers thresholds as well as the hot papers thresholds were used to assess the influence and impact of the Land publications. JCR is a recognized authority for evaluating journals. It presents quantifiable statistical data that provide a systematic, objective way to evaluate the world’s leading journals and their impact and influence in the global research community. The two key measures used in this analysis to assess the journals in which the EPA Land papers were published are the Impact Factor and Immediacy Index. The Impact Factor is a measure of the frequency with which the “average article” in a journal has been cited in a particular year. The Impact Factor helps evaluate a journal’s relative importance, especially when compared to other journals in the same field. The Immediacy Index is a measure of how quickly the “average article” in a journal is cited. This index indicates how often articles published in a journal are cited within the same year and it is useful in comparing how quickly journals are cited.
The report includes a summary of the results of the bibliometric analysis, an assessment of the 1,378 Land journal articles analyzed by ESI field (e.g., Chemistry, Environment/Ecology), an analysis of the journals in which the Land papers were published, a table of the highly cited researchers in the Land Research Program, and information on the patents/patent applications that have resulted from the program.
SUMMARY OF RESULTS
- More than one-sixth of the 1,378 Land journal publications are highly cited papers. 249 (18.1%) of the 1,378 Land journal publications qualify as highly cited when using the ESI criteria for the top 10% of highly cited publications. This is 1.8 times the number expected. 19 (1.4%) of the Land journal papers qualify as highly cited when using the ESI criteria for the top 1%, which is 1.4 times the number expected. 2 (0.2%) of the Land publications qualify as very highly cited when using the criteria the ESI criteria for the top 0.1% of highly cited publications. No journal publications qualify as extremely highly cited when using the criteria for the top 0.01% threshold for the most highly cited papers.
- The Land journal publications are more highly cited than the average paper. Using the ESI average citation rates for papers published by field as the benchmark, in 12 of the 16 fields in which the 1,378 Land journal papers were published, the ratio of actual to expected cites is greater than 1, indicating that the Land journal publications are more highly cited than the average papers in those fields. For all 16 fields combined, the ratio of total number of cites to the total number of expected cites (20,253 to 14,215.4) is 1.4, indicating that the Land journal papers are more highly cited than the average paper.
- One-quarter of the Land journal papers are published in high impact journals. 362 of the 1,378 journal papers were published in the top 10% of journals ranked by JCR Impact Factor, representing 26.3% of the Land journal publications. This number is 2.6 times higher than expected. 340 of the 1,378 papers appear in the top 10% of journals ranked by JCR Immediacy Index, representing 24.7% of EPA’s Land journal publications. This number is 2.5 times higher than expected.
- There were two hot papers among the 1,378 Land publications. Using the hot paper thresholds established by ESI as a benchmark, 2 (0.2%) hot papers were identified in the analysis. Hot papers are papers that are highly cited shortly after they are published. This number is twice the number expected.
- The authors of the Land journal publications cite themselves much less than the average author. 966 of the 20,253 total cites are author self-cites. This 4.8% author self-citation rate is well below the accepted range of 10-30% author self-citation rate.
- 41 of the 2,309 authors of the Land journal publications are included in ISIHighlyCited.com, which is a database of the world’s most influential researchers who have made key contributions to science and technology during the period from 1981 to 1999.
- 4 patents were issued and 1 patent application was filed by investigators from 1997 to 2007 for research that was conducted under EPA’s Land Research Program. The patents were cited by 5 other patents.
Highly Cited Land Publications
All of the journals covered by ESI are assigned a field, and to compensate for varying citation rates across scientific fields, different thresholds are applied to each field. Thresholds are set to select highly cited papers to be listed in ESI. Different thresholds are set for both field and year of publication. Setting different thresholds for each year allows comparable representation for older and younger papers for each field.
The 1,378 Land journal publications reviewed for this analysis were published in journals that were assigned to 16 of the 22 ESI fields. The distribution of the papers among these 16 fields and the number of citations by field are presented in Table 1.
Table 1. Land Journal Publications by ESI Fields
| ESI Field | No. of Citations |
No. of EPA Land Papers |
Average Cites/Paper |
Agricultural Sciences |
54 |
7 |
7.7 |
Biology & Biochemistry |
967 |
72 |
13.4 |
Chemistry |
2,565 |
173 |
14.8 |
Clinical Medicine |
41 |
8 |
5.1 |
Computer Science |
20 |
5 |
4.0 |
Engineering |
1,432 |
185 |
7.7 |
Environment/Ecology |
11,308 |
703 |
16.1 |
Geosciences |
437 |
53 |
8.2 |
Materials Science |
247 |
14 |
17.6 |
Mathematics |
1 |
1 |
1.0 |
Microbiology |
1,654 |
55 |
30.1 |
Molecular Biology & Genetics |
116 |
5 |
23.2 |
Multidisciplinary |
25 |
1 |
25.0 |
Pharmacology & Toxicology |
405 |
15 |
27.0 |
Physics |
204 |
11 |
18.5 |
Plant & Animal Science |
777 |
70 |
11.1 |
Total = 16 |
Total = 20,253 |
Total = 1,378 |
14.7 |
There are 249 (18.1% of the 1,378 journal papers analyzed) highly cited Land journal publications in 13 of the 16 fields—Biology & Biochemistry, Chemistry, Clinical Medicine, Computer Science, Engineering, Environment/Ecology, Geosciences, Materials Science, Microbiology, Molecular Biology & Genetics, Multidisciplinary, Physics, and Plant & Animal Science—when using the ESI criteria for the top 10% of papers. Table 2 shows the number of Land journal publications in those 13 fields that meet the top 10% threshold in ESI.
Table 2. Number of Highly Cited Land Journal Publications by Field (top 10%)
| ESI Field | No. of Citations |
No. of Papers |
Average Cites/Paper |
% of Land Papers in Field |
Biology & Biochemistry |
145 |
3 |
48.3 |
4.2% |
Chemistry |
1,210 |
29 |
41.7 |
16.8% |
Clinical Medicine |
11 |
2 |
5.5 |
25.0% |
Computer Science |
10 |
1 |
10.1 |
20.0% |
Engineering |
811 |
43 |
18.9 |
23.2% |
Environment/Ecology |
5,650 |
125 |
45.2 |
17.8% |
Geosciences |
184 |
6 |
30.7 |
11.3% |
Materials Science |
209 |
5 |
41.8 |
35.7% |
Microbiology |
774 |
10 |
77.4 |
18.2% |
Molecular Biology & Genetics |
64 |
1 |
64.0 |
20.0% |
Multidisciplinary |
25 |
1 |
25.0 |
100.0% |
Physics |
123 |
4 |
30.8 |
36.4% |
Plant & Animal Science |
493 |
19 |
25.9 |
27.1% |
Total = 9 |
Total = 9,709 |
Total = 249 |
39.0 |
18.1% |
Nineteen (1.4%) of the journal publications analyzed qualify as highly cited when using the ESI criteria for the top 1% of papers. These publications are in 7 of the 22 fields—Chemistry, Clinical Medicine, Engineering, Environment/Ecology, Geosciences, Materials Science, and Microbiology. Table 3 shows the 19 papers by field that meet the top 1% threshold in ESI. The citations for these 19 papers are provided in Tables 4 through 10. Two (0.2%) of the Land journal publications meet the top 0.1% ESI thresholds for highly cited papers, which is twice the number expected to meet this threshold. None of the Land journal publications actually meet the top 0.01% threshold in ESI, which is not surprising given that the expected number of publications to meet this threshold for this program is 0.1.
Table 3. Number of Highly Cited Land Journal Publications by Field (top 1%)
| ESI Field | No. of Citations |
No. of Papers |
Average Cites/Paper |
% of Land Papers in Field |
Chemistry |
379 |
3 |
126.3 |
1.7% |
Clinical Medicine |
3 |
1 |
3.0 |
12.5% |
Engineering |
179 |
4 |
44.8 |
2.2% |
Environment/Ecology |
600 |
6 |
100.0 |
0.8% |
Geosciences |
14 |
1 |
14.0 |
1.9% |
Materials Science |
180 |
2 |
90.0 |
14.3% |
Microbiology |
324 |
2 |
162.0 |
3.6% |
Total = 2 |
Total = 1,679 |
Total = 19 |
88.4 |
1.4% |
Table 4. Highly Cited Land Journal Publications in the Field of Chemistry (top 1%)
| No. of Cites | First Author |
Paper |
148 |
Wang J |
Sol-gel-derived thick-film amperometric immunosensors. Analytical Chemistry 1998;70(6):1171-1175. |
130 |
Ravikovitch PI |
Unified approach to pore size characterization of microporous carbonaceous materials from N-2, Ar, and CO2 adsorption isotherms. Langmuir 2000;16(5):2311-2320. |
101 |
Ravikovitch PI |
Characterization of micro- and mesoporosity in SBA-15 materials from adsorption data by the NLDFT method. Journal of Physical Chemistry B 2001;105(29):6817-6823. |
Table 5. Highly Cited Land Journal Publications in the Field of Clinical Medicine (top 1%)
| No. of Cites | First Author |
Paper |
3 |
Levin M |
Modulation of the respiratory burst by organochlorine mixtures in marine mammals, humans, and mice. Journal of Toxicology and Environmental Health, Part A: Current Issues 2007;70(1):73-83. |
Table 6. Highly Cited Land Journal Publications in the Field of Engineering (top 1%)
| No. of Cites | First Author |
Paper |
67 |
Annable MD |
Partitioning tracers for measuring residual NAPL: field-scale test results. Journal of Environmental Engineering-ASCE 1998;124(6):498-503. |
54 |
Puls RW |
Long-term performance monitoring for a permeable reactive barrier at the US Coast Guard Support Center, Elizabeth City, North Carolina. Journal of Hazardous Materials 1999;68(1-2):109-124. |
49 |
Feeney R |
Microfabricated ultramicroelectrode arrays: developments, advances, and applications in environmental analysis. Electroanalysis 2000;12(9):677-684. |
9 |
He F |
Stabilization of Fe-Pd nanoparticles with sodium carboxymethyl cellulose for enhanced transport and dechlorination of trichloroethylene in soil and groundwater. Industrial & Engineering Chemistry Research 2007;46(1):29-34. |
Table 7. Highly Cited Land Journal Publications in the Field of Environment/Ecology (top 1%)
| No. of Cites | First Author |
Paper |
120 |
Xia GS |
Adsorption-partitioning uptake of nine low-polarity organic chemicals on a natural sorbent. Environmental Science & Technology 1999;33(2):262-269. |
106 |
Su CM |
Arsenate and arsenite removal by zerovalent iron: kinetics, redox transformation, and implications for in situ groundwater remediation. Environmental Science & Technology 2001;35(7):1487-1492. |
73 |
Mazdai A |
Polybrominated diphenyl ethers in maternal and fetal blood samples. Environmental Health Perspectives 2003;111(9):1249-1252. |
240 |
Hites RA |
Polybrominated diphenyl ethers in the environment and in people: a meta-analysis of concentrations. Environmental Science & Technology 2004;38(4):945-956. |
29 |
Lien HL |
High-level arsenite removal from groundwater by zero-valent iron. Chemosphere 2005;59(3):377-386. |
32 |
Hoh E |
Brominated flame retardants in the atmosphere of the east-central United States. Environmental Science & Technology 2005;39(20):7794-7802. |
Table 8. Highly Cited Land Journal Publications in the Field of Geosciences (top 1%)
| No. of Cites | First Author |
Paper |
14 |
Lin CJ |
Scientific uncertainties in atmospheric mercury models I: model science evaluation. Atmospheric Environment 2006;40(16):2911-2928. |
Table 9. Highly Cited Land Journal Publications in the Field of Materials Science (top 1%)
| No. of Cites | First Author |
Paper |
81 |
Neimark AV |
Capillary condensation in MMS and pore structure characterization. Microporous and Mesoporous Materials 2001;44:697-707. |
99 |
Zhang WX |
Nanoscale iron particles for environmental remediation: an overview. Journal of Nanoparticle Research 2003;5(3-4):323-332. |
Table 10. Highly Cited Land Journal Publications in the Field of Microbiology (top 1%)
| No. of Cites | First Author |
Paper |
189 |
Macnaughton SJ |
Microbial population changes during bioremediation of an experimental oil spill. Applied and Environmental Microbiology 1999;65(8):3566-3574. |
135 |
Gelvin SB |
Agobacterium-mediated plant transformation: the biology behind the ‘gene-Jockeying’ tool. Microbiology and Molecular Biology Reviews 2003;67(1):16+. |
Ratio of Actual Cites to Expected Citation Rates
The expected citation rate is the average number of cites that a paper published in the same journal in the same year and of the same document type (article, review, editorial, etc.) has received from the year of publication to the present. Using the ESI average citation rates for papers published by field as the benchmark, in 12 of the 16 fields in which the EPA Land journal papers were published, the ratio of actual to expected cites is greater than 1, indicating that the Land journal publications are more highly cited than the average papers in those fields (see Table 11). For all 16 fields combined, the ratio of total number of cites to the total number of expected cites (20,253 to 14,215.4) is 1.4, indicating that the Land journal publications are more highly cited than the average paper.
Table 11. Ratio of Actual Cites to Expected Cites for Land Journal Publications by Field
| ESI Field | Total Cites |
Expected Cite Rate |
Ratio |
Agricultural Sciences |
54 |
45.9 |
1.2 |
Biology & Biochemistry |
967 |
1,178.4 |
0.8 |
Chemistry |
2,565 |
1,872.0 |
1.4 |
Clinical Medicine |
41 |
35.4 |
1.2 |
Computer Science |
20 |
17.9 |
1.1 |
Engineering |
1,432 |
795.2 |
1.8 |
Environment/Ecology |
11.308 |
7,833.0 |
1.4 |
Geosciences |
437 |
445.8 |
1.0 |
Materials Science |
247 |
56.5 |
4.4 |
Mathematics |
1 |
5.2 |
0.2 |
Microbiology |
1,654 |
1,022.0 |
1.5 |
Molecular Biology & Genetics |
116 |
128.7 |
0.9 |
Multidisciplinary |
25 |
6.4 |
3.9 |
Pharmacology & Toxicology |
405 |
178.3 |
2.3 |
Physics |
204 |
97.7 |
2.1 |
Plant & Animal Science |
777 |
497.0 |
1.6 |
TOTAL |
20,253 |
14,215.4 |
1.4 |
JCR Benchmarks
Impact Factor. The JCR Impact Factor is a well known metric in citation analysis. It is a measure of the frequency with which the “average article” in a journal has been cited in a particular year. The Impact Factor helps evaluate a journal’s relative importance, especially when compared to others in the same field. The Impact Factor is calculated by dividing the number of citations in the current year to articles published in the 2 previous years by the total number of articles published in the 2 previous years.
Table 12 indicates the number of Land journal publications published in the top 10% of journals, based on the JCR Impact Factor. Three hundred sixty-two (362) of 1,378 journal papers were published in the top 10% of journals, representing 26.3% of EPA’s Land journal publications. This indicates that more than one-quarter of the Land journal publications are published in the highest quality journals as determined by the JCR Impact Factor, which is 2.6 times higher than the expected percentage.
Table 12. Land Journal Publications in Top 10% of Journals by JCR Impact Factor
| EPA Land Papers in that Journal | Journal |
Impact Factor(IF) |
JCR IF Rank |
1 |
Science |
30.028 |
9 |
1 |
Annual Review of Pharmacology and Toxicology |
22.808 |
26 |
1 |
Microbiology and Molecular Biology Reviews |
15.864 |
40 |
1 |
Chemical Society Reviews |
13.690 |
61 |
1 |
FEMS Microbiology Reviews |
8.691 |
140 |
1 |
Trends in Microbiology |
8.335 |
146 |
3 |
Trends in Biotechnology |
7.843 |
163 |
2 |
Journal of the American Chemical Society |
7.696 |
168 |
1 |
Current Opinion in Biotechnology |
6.949 |
193 |
1 |
Plant Journal |
6.565 |
213 |
1 |
Nucleic Acids Research |
6.317 |
222 |
3 |
Plant Physiology |
6.125 |
232 |
5 |
Environmental Health Perspectives |
5.861 |
255 |
1 |
Journal of Biological Chemistry |
5.808 |
260 |
1 |
Structure |
5.738 |
267 |
17 |
Analytical Chemistry |
5.646 |
276 |
1 |
Chemistry of Materials |
5.104 |
330 |
1 |
TRAC-Trends in Analytical Chemistry |
5.068 |
337 |
1 |
Toxicology and Applied Pharmacology |
4.722 |
397 |
1 |
Environmental Microbiology |
4.630 |
406 |
1 |
Critical Reviews in Solid State and Materials Sciences |
4.500 |
427 |
1 |
Antioxidants and Redox Signaling |
4.491 |
431 |
1 |
Progress in Energy and Combustion Science |
4.333 |
456 |
1 |
Journal of Materials Chemistry |
4.287 |
464 |
2 |
Genetics |
4.242 |
475 |
2 |
Biosensors & Bioelectronics |
4.132 |
496 |
3 |
Journal of Physical Chemistry B |
4.115 |
501 |
8 |
Electrophoresis |
4.101 |
506 |
1 |
Biochemical Journal |
4.100 |
507 |
199 |
Environmental Science & Technology |
4.040 |
518 |
6 |
Journal of Bacteriology |
3.993 |
533 |
9 |
Applied Catalysis B-Environmental |
3.942 |
548 |
1 |
Inorganic Chemistry |
3.911 |
557 |
10 |
Langmuir |
3.902 |
558 |
1 |
Advances in Colloid and Interface Science |
3.790 |
591 |
4 |
Geochimica et Cosmochimica Acta |
3.751 |
609 |
2 |
Biomacromolecules |
3.664 |
642 |
3 |
Drug Metabolism and Disposition |
3.638 |
646 |
1 |
Biochemistry |
3.633 |
648 |
3 |
Journal of Analytical Atomic Spectrometry |
3.630 |
650 |
6 |
Toxicological Sciences |
3.598 |
662 |
1 |
Journal of Chromatography A |
3.554 |
678 |
32 |
Applied and Environmental Microbiology |
3.532 |
682 |
1 |
Electrochemistry Communications |
3.484 |
699 |
2 |
Ecological Applications |
3.470 |
708 |
4 |
Journal of Membrane Science |
3.442 |
717 |
1 |
Journal of the American Society for Mass Spectrometry |
3.307 |
767 |
1 |
Limnology and Oceanography |
3.287 |
774 |
3 |
Analyst |
3.198 |
804 |
2 |
Journal of Chemical Physics |
3.166 |
814 |
1 |
Chemical Research in Toxicology |
3.162 |
818 |
3 |
FEMS Microbiology Ecology |
3.157 |
822 |
1 |
Journal of Physical Chemistry A |
3.047 |
863 |
Total = 362 |
|
|
|
Immediacy Index. The JCR Immediacy Index is a measure of how quickly the average article in a journal is cited. It indicates how often articles published in a journal are cited within the year they are published. The Immediacy Index is calculated by dividing the number of citations to articles published in a given year by the number of articles published in that year.
Table 13 indicates the number of Land journal publications published in the top 10% of journals, based on the JCR Immediacy Index. Three hundred forty (340) of the 1,378 papers appear in the top 10% of journals, representing 24.7% of the Land journal papers. This indicates that nearly one-fourth of the Land journal papers are published in the highest quality journals as determined by the JCR Immediacy Index, which is 2.5 times higher than the expected percentage.
Table 13. Land Journal Publications in Top 10% of Journals by JCR Immediacy Index
| EPA Land Papers in that Journal | Journal |
Immediacy Index(II) |
JCR II Rank |
1 |
Annual Review of Pharmacology and Toxicology |
7.059 |
|
1 |
Science |
5.555 |
|
1 |
Chemical Society Reviews |
2.586 |
|
1 |
Nucleic Acids Research |
1.744 |
|
1 |
Journal of the North American Benthological Society |
1.568 |
|
2 |
Journal of the American Chemical Society |
1.510 |
|
1 |
Microbiology and Molecular Biology Reviews |
1.472 |
|
1 |
Structure |
1.323 |
|
1 |
Plant Journal |
1.222 |
|
1 |
Antioxidants and Redox Signaling |
1.131 |
|
1 |
Journal of Biological Chemistry |
1.110 |
|
3 |
Trends in Biotechnology |
1.025 |
|
5 |
Environmental Health Perspectives |
0.994 |
|
1 |
FEMS Microbiology Reviews |
0.976 |
|
1 |
Trends in Microbiology |
0.959 |
|
3 |
Journal of Analytical Atomic Spectrometry |
0.940 |
|
3 |
Analyst |
0.925 |
|
2 |
Genetics |
0.919 |
|
3 |
Plant Physiology |
0.900 |
|
6 |
Journal of Bacteriology |
0.894 |
|
1 |
Journal of Materials Chemistry |
0.882 |
|
1 |
Environmental Microbiology |
0.850 |
|
1 |
Earth Planets and Space |
0.848 |
|
1 |
Biochemical Journal |
0.847 |
|
17 |
Analytical Chemistry |
0.795 |
|
1 |
Limnology and Oceanography |
0.784 |
|
3 |
Drug Metabolism and Disposition |
0.768 |
|
2 |
Biosensors & Bioelectronics |
0.756 |
|
1 |
TRAC-Trends in Analytical Chemistry |
0.752 |
|
1 |
Journal of the American Society for Mass Spectrometry |
0.746 |
|
6 |
Toxicological Sciences |
0.734 |
|
1 |
Journal of Physical Chemistry A |
0.730 |
|
1 |
Biochemistry |
0.726 |
|
2 |
Journal of Chemical Physics |
0.721 |
|
1 |
Journal of Experimental Biology |
0.719 |
|
2 |
Ecological Engineering |
0.716 |
|
1 |
Inorganic Chemistry |
0.699 |
|
1 |
Chemistry of Materials |
0.692 |
|
3 |
Journal of Geophysical Research |
0.684 |
|
1 |
Chemical Research in Toxicology |
0.663 |
|
4 |
Geochimica et Cosmochimica Acta |
0.658 |
|
199 |
Environmental Science & Technology |
0.646 |
|
3 |
Journal of Physical Chemistry B |
0.637 |
|
32 |
Applied and Environmental Microbiology |
0.634 |
|
10 |
Langmuir |
0.623 |
|
1 |
Tetrahedron Letters |
0.597 |
|
1 |
Pure and Applied Chemistry |
0.586 |
|
1 |
Environmental Research |
0.583 |
|
2 |
Biomacromolecules |
0.566 |
|
Total = 340 |
|
|
|
Hot Papers
ESI establishes citation thresholds for hot papers, which are selected from the highly cited papers in different fields, but the time frame for citing and cited papers is much shorter—papers must be cited within 2 years of publication and the citations must occur in a 2-month time period. Papers are assigned to 2-month periods and thresholds are set for each period and field to select 0.1% of papers.
Using the hot paper thresholds established by ESI as a benchmark, 2 hot papers, representing 0.2% of the Land papers, were identified in two fields—Environment/Ecology and Materials Science. The number of Land hot papers is 2 times higher than expected. The hot papers are listed in Table 14.
Table 14. Hot Papers Identified Using ESI Thresholds
| Field | ESI Hot Papers Threshold |
No. of Cites in 2-Month Period |
Paper |
Environment/ Ecology |
8 |
9 cites in January-February 2005 |
Hites RA. Polybrominated diphenyl ethers in the environment and in people: a meta-analysis of concentrations. Environmental Science & Technology 2004;38(4):945-956. |
Materials Science |
3 |
4 cites in July-August 2001 |
Neimark AV, Ravikovitch PI. Capillary condensation in MMS and pore structure characterization. Microporous and Mesoporous Materials 2001;44:697-707. |
Author Self-Citation
Self-citations are journal article references to articles from that same author (i.e., the first author). Because higher author self-citation rates can inflate the number of citations, the author self-citation rate was calculated for the Land papers. Of the 20,253 total cites of the 1,378 journal publications, 966 are author self-cites—a 4.8% author self-citation rate. Garfield and Sher3 found that authors working in research-based disciplines tend to cite themselves on the average of 20% of the time. MacRoberts and MacRoberts4 claim that approximately 10-30% of all the citations listed fall into the category of author self-citation. Kovacic and Misak5 reported a 20% author self-citation rate for medical literature. Therefore, the 4.8% self-cite rate for the Land papers is well below the range for author self-citation.
Highly Cited Researchers
A search of Thomson’s ISIHighlyCited.com revealed that 41 (1.8%) of the 2,309 authors of the Land papers are highly cited researchers. ISIHighlyCited.com is a database of the world’s most influential researchers who have made key contributions to science and technology during the period from 1981 to 1999. The highly cited researchers identified during this analysis of the Land publications are presented in Table 15.
Table 15. Highly Cited Researchers Authoring Land Journal Publications
| Highly Cited Researcher | Affiliation |
ESI Field |
Abriola, Linda M. |
University of Michigan |
Environment/Ecology |
Alexander, Martin |
Cornell University |
Environmental Ecology |
Allen, Herbert E. |
University of Delaware |
Environment/Ecology |
Ankley, Gerald |
U.S. Environmental Protection Agency |
Environment/Ecology |
Arey, Janet |
University of California-Riverside |
Environment/Ecology |
Brusseau, Mark L. |
University of Arizona |
Environment/Ecology |
Curl, Robert F. |
Rice University |
Chemistry |
Dillon, Peter J. |
Trent University |
Environment/Ecology |
Drew, Malcolm C. |
Texas A&M University |
Plant & Animal Science |
Giesy, John P. |
Michigan State University |
Environment/Ecology |
Gillham, Robert W. |
University of Waterloo |
Environment/Ecology |
Gray Jr., Leon Earl |
U.S. Environmental Protection Agency |
Pharmacology |
Gschwend, Philip Michael |
Massachusetts Institute of Technology |
Environment/Ecology |
Hammock, Bruce D. |
University of California-Davis |
Agricultural Sciences |
Hansen, Dave J. |
U.S. Environmental Protection Agency (formerly) |
Environment/Ecology |
Hildemann, Lynn M. |
Stanford University |
Environment/Ecology |
Hites, Ronald A. |
Indiana University |
Engineering |
Inouye, Sumiko |
University of Medicine and Dentistry of New Jersey |
Microbiology |
Jones, Ronald Norman |
JONES Group/JMI Laboratories |
Microbiology |
Jury, William A. |
University of California-Riverside |
Engineering |
Kitanidis, Peter K. |
Stanford University |
Engineering |
Landrum, Peter F. |
National Oceanic and Atmospheric Administration |
Environment/Ecology |
Lee, Kuo-Hsiung |
University of North Carolina |
Agricultural Sciences |
Lindberg, Steven E. |
Oak Ridge National Laboratory |
Environment/Ecology |
Luthy, Richard G. |
Stanford University |
Environment/Ecology |
McCarty, Perry L. |
Stanford University |
Engineering |
McClements, David Julian |
University of Massachusetts |
Agricultural Sciences |
Müller, Rolf |
Philipps University, Germany |
Microbiology |
Navrotsky, Alexandra |
University of California-Davis |
Geosciences |
Pignatello, Joseph J. |
Connecticut Agricultural Experiment Station |
Environment/Ecology |
Rao, P. Suresh Chandra |
Purdue University |
Engineering |
Reeves, Philip G. |
U.S. Department of Agriculture |
Agricultural Sciences |
Roberts, Paul V. |
Stanford University |
Engineering |
Ryals, John A. |
Paradigm Genetics, Inc. |
Plant & Animal Science |
Schindler, David W. |
University of Alberta |
Environment/Ecology |
Seib, Paul A. |
Kansas State University |
Agricultural Sciences |
Sparks, Donald Lewis |
University of Delaware |
Environment/Ecology |
Suidan, Makram T. |
University of Cincinnati |
Environment/Ecology |
Tiedje, James M. |
Michigan State University |
Microbiology Environment/Ecology |
Weber, Walter J. |
University of Michigan |
Engineering |
White, David C. |
University of Tennessee |
Microbiology |
Total = 41 |
|
|
Patents
There were four patents issued to and one patent application filed by investigators from 1997 to 2007 for research that was conducted under EPA’s Land Research Program. The patents were cited by five other patents (see Table 16).
Table 16. Patents from the Land Research Program (1997-2007)
| Patent/Patent Application No. | Inventor(s) |
Title |
Patent Date |
Patents that Referenced This Patent |
U.S. Patent No. 6,248,218 |
Linkous CA |
Closed cycle photocatalytic process for decomposition of hydrogen sulfide to its constituent elements. |
June 19, 2001 |
Referenced by 2 patents: |
U.S. Patent No. 6,455,759 |
Vierstra RD |
Expression of multiple proteins in transgenic plants. |
September 24, 2002 |
Referenced by 2 patents: |
U.S. Patent No. 6,572,829 |
Linkous CA, Muradov NZ |
Closed cycle photocatalytic process for decomposition of hydrogen sulfide to its constituent elements. |
June 3, 2003 |
Referenced by 1 patent: |
U.S. Patent No. 7,220,391 |
Huang CP, Linkous CA |
UV photochemical option for closed cycle decomposition of hydrogen sulfide |
May 22, 2007 |
Referenced by 0 patents |
U.S. Patent Application No. 200060021928 |
Diallo MS |
Water treatment by dendrimer enhanced filtration |
February 2, 2006 |
Not applicable |
2 Scopus is a large abstract and citation database of research literature and quality Web sources designed to support the literature research process. Scopus offers access to 15,000 titles from 4,000 different publishers, more than 12,850 academic journals (including coverage of 535 Open Access journals, 750 conference proceedings, and 600 trade publications), 27 million abstracts, 245 million references, 200 million scientific Web pages, and 13 million patent records.
3 Garfield E, Sher IH. New factors in the evaluation of scientific literature through citation indexing. American Documentation 1963;18(July):195-210.
4 MacRoberts MH, MacRoberts BR. Problems of citation analysis: a critical review. Journal of the American Society of Information Science 1989;40(5):342-349.