Bias in the journal impact factor

The ISI journal impact factor (JIF) is based on a sample that may represent half the whole-of-life citations to some journals, but a small fraction (<10%) of the citations accruing to other journals. This disproportionate sampling means that the JIF provides a misleading indication of the true impact of journals, biased in favour of journals that have a rapid rather than a prolonged impact. Many journals exhibit a consistent pattern of citation accrual from year to year, so it may be possible to adjust the JIF to provide a more reliable indication of a journal's impact.Comment: 9 pages, 8 figures; one reference correcte

Impact Factor: outdated artefact or stepping-stone to journal certification?

A review of Garfield's journal impact factor and its specific implementation as the Thomson Reuters Impact Factor reveals several weaknesses in this commonly-used indicator of journal standing. Key limitations include the mismatch between citing and cited documents, the deceptive display of three decimals that belies the real precision, and the absence of confidence intervals. These are minor issues that are easily amended and should be corrected, but more substantive improvements are needed. There are indications that the scientific community seeks and needs better certification of journal procedures to improve the quality of published science. Comprehensive certification of editorial and review procedures could help ensure adequate procedures to detect duplicate and fraudulent submissions.Comment: 25 pages, 12 figures, 6 table

Substrate transport activation is mediated through second periplasmic loop of transmembrane protein MalF in maltose transport complex of <em>Escherichia coli</em>.

In a recent study we described the second periplasmic loop P2 of the transmembrane protein MalF (MalF-P2) of the maltose ATP-binding cassette transporter (MalFGK(2)-E) as an important element in the recognition of substrate by the maltose-binding protein MalE. In this study, we focus on MalE and find that MalE undergoes a structural rearrangement after addition of MalF-P2. Analysis of residual dipolar couplings (RDCs) shows that binding of MalF-P2 induces a semiopen state of MalE in the presence and absence of maltose, whereas maltose is retained in the binding pocket. These data are in agreement with paramagnetic relaxation enhancement experiments. After addition of MalF-P2, an increased solvent accessibility for residues in the vicinity of the maltose-binding site of MalE is observed. MalF-P2 is thus not only responsible for substrate recognition, but also directly involved in activation of substrate transport. The observation that substrate-bound and substrate-free MalE in the presence of MalF-P2 adopts a similar semiopen state hints at the origin of the futile ATP hydrolysis of MalFGK(2)-E