Authors:R. Rice, Christine Borgman, Diane Bednarski, and P. Hart
Citation analysis is a useful method for studying a wide range of topics in bibliometrics and the sociology of science. However, many challenges have been made to the validity and reliability of the underlying assumptions, the data, and the methods used in citation studies. This article addresses these issues in three parts. First is a brief review of validity and reliability issues in citation research. Next we explore measurement error in a principal source of journal-to-journal citation data, the Institute for Scientific Information'sJournal Citation Reports. Possible sources of measurement error include discrepancies between citing and cited data, changed or deleted journal titles, aberrant abbreviations, and listing algorithms. The last section is a detailed description of ways to overcome some of the measurement errors. The data and examples are drawn from a journal-to-journal citation study in the fields of Communication, Information Science, and Library Science.
Authors:S. Matthews, A. Boegel, S. Eccles, S. Homann, D. Rice, J. Loftis, M. Jovanovich, R. Caufield, B. Mincher, D. Meikrantz, R. Murphy, G. Gresham, and M. Connoly
The Lawrence Livermore National Laboratory (LLNL) and the Idaho National Engineering Laboratory (INEL) are jointly investigating the decomposition of chlorinated hydrocarbons using bremsstrahlung radiation produced by electron accelerators and gamma photons from spent reactor fuel. Experimental results demonstrate an exponential type decay of concentration with dose for volatile organic compounds (VOCs) in ground water and for both polychlorinated biphenyls (PCBs) and insecticides in organic solutions. Experiments were performed at several photon energies and dose rates with various initial concentrations. Mass balance analysis suggests complete mineralization of VOCs in ground water and indicates significant degradation of PCBs and insecticides to VOC type compounds in organic solutions.
Reducing the risk of developing chronic disease, such as obesity and type 2 diabetes, is an important component of successful aging. Offspring born to mothers who exercise during pregnancy have improved body composition and metabolic profiles. However, mechanisms to explain this phenomenon are lacking.
This study examined whether maternal step counts were correlated with neonatal gene expression markers related to glucose metabolism and adipogenesis.
Physical activity levels were assessed in women with male neonates via Fitbit Flex® during the second and third trimester of pregnancy. The dartos and epidermal/dermal layers of the foreskin were collected following circumcision in full-term, singleton, neonates (n = 12 dartos and n = 14 dermal). Tissue was homogenized, RNA isolated, and a NanoString code set was run to quantify a panel of genes related to glucose metabolism and adipogenesis.
Twelve genes were correlated to steps per day with a P-value of <0.05. After adjusting for multiple comparisons, six genes remained significantly correlated to steps per day (False Discovery Rate-corrected P-value < 0.10). Notably, glucose transporter 1, adiponectin receptor 1, and CCAAT/enhancer-binding protein alpha and beta were positively correlated with steps per day, while peroxisome proliferator-activated receptor alpha and peroxisome proliferator-activated receptor gamma coactivator 1- alpha were negatively correlated with steps per day.
Maternal physical activity is associated with offspring gene expression markers of adipogenesis, insulin sensitivity and glucose uptake. Future studies should aim to mechanistically examine whether these markers are driving increased adiposity in offspring born to sedentary mothers.