Evaluating Research Activity:Impact Factor vs. Research Factor

The Impact Factor (IF) “has moved ... from an obscure bibliometric indicator to become the chief quantitative measure of the quality of a journal, its research papers, the researchers who wrote those papers, and even the institution they work in” ([2], p. 1). However, the use of this index for evaluating individual scientists is dubious. The present work compares the ranking of research units generated by the Research Factor (RF) index with that associated with the popular IF. The former, originally introduced in [38], reflects article and book publications and a host of other activities categorized as coordination activities (e.g., conference organization, research group coordination), dissemination activities (e.g., conference and seminar presentations, participation in research group), editorial activities (e.g., journal editor, associate editor, referee) and functional activities (e.g., Head of Department). The main conclusion is that by replacing the IF with the RF in hiring, tenure decisions and awarding of grants would greatly increase the number of topics investigated and the number and quality of long run projects.scientific research assessment, Impact Factor, bibliometric indices, feasible Research Factor

Evidence of diffusive fractal aggregation of TiO2 nanoparticles by femtosecond laser ablation at ambient conditions

The specific mechanisms which leads to the formation of fractal nanostructures by pulsed laser deposition remain elusive despite intense research efforts, motivated mainly by the technological interest in obtaining tailored nanostructures with simple and scalable production methods. Here we focus on fractal nanostructures of titanium dioxide, $TiO_2$, a strategic material for many applications, obtained by femtosecond laser ablation at ambient conditions. We model the fractal formation through extensive Monte Carlo simulations based on a set of minimal assumptions: irreversible sticking and size independent diffusion. Our model is able to reproduce the fractal dimensions and the area distributions of the nanostructures obtained in the experiments for different densities of the ablated material. The comparison of theory and experiment show that such fractal aggregates are formed after landing of the ablated material on the substrate surface by a diffusive mechanism. Finally we discuss the role of the thermal conductivity of the substrate and the laser fluence on the properties of the fractal nanostructures. Our results represent an advancement towards controlling the production of fractal nanostructures by pulsed laser deposition.Comment: 21 page

Ku70 Is Required for Late B Cell Development and Immunoglobulin Heavy Chain Class Switching

Immunoglobulin (Ig) heavy chain (HC) class switch recombination (CSR) is a late B cell process that involves intrachromosomal DNA rearrangement. Ku70 and Ku80 form a DNA end-binding complex required for DNA double strand break repair and V(D)J recombination. Ku70^(−/−) (K70T) mice, like recombination activating gene (RAG)-1– or RAG-2–deficient (R1T or R2T) mice, have impaired B and T cell development at an early progenitor stage, which is thought to result at least in part from defective V(D)J recombination (Gu, Y., K.J. Seidl, G.A. Rathbun, C. Zhu, J.P. Manis, N. van der Stoep, L. Davidson, H.L. Cheng, J.M. Sekiguchi, K. Frank, et al. 1997. Immunity. 7:653–665; Ouyang, H., A. Nussenzweig, A. Kurimasa, V.C. Soares, X. Li, C. Cordon-Cardo, W. Li, N. Cheong, M. Nussenzweig, G. Iliakis, et al. 1997. J. Exp. Med. 186:921–929). Therefore, to examine the potential role of Ku70 in CSR, we generated K70T mice that carry a germline Ig HC locus in which the JH region was replaced with a functionally rearranged VH(D)JH and Ig λ light chain transgene (referred to as K70T/HL mice). Previously, we have shown that B cells from R1T or R2T mice carrying these rearranged Ig genes (R1T/HL or R2T/HL mice) can undergo CSR to IgG isotypes (Lansford, R., J. Manis, E. Sonoda, K. Rajewsky, and F. Alt. 1998. Int. Immunol. 10:325–332). K70T/HL mice had significant numbers of peripheral surface IgM^+ B cells, which generated serum IgM levels similar to those of R2T/HL mice. However, in contrast to R2T/HL mice, K70T/HL mice had no detectable serum IgG isotypes. In vitro culture of K70T/HL B cells with agents that induce CSR in normal or R2T/HL B cells did lead to the induction of germline CH transcripts, indicating that initial signaling pathways for CSR were intact in K70T/HL cells. However, treatment with such agents did not lead to detectable CSR by K70T/HL B cells, and instead, led to cell death within 72 h. We conclude that Ku70 is required for the generation of B cells that have undergone Ig HC class switching. Potential roles for Ku70 in the CSR process are discusse

L’ “R-Factor”: un nuovo modo di valutare la ricerca scientifica

As pointed out in Amin e Mabe (2000, p. 1), the journal impact factor (IF) “has moved in recent years from an obscure bibliometric indicator to become the chief quantitative measure of the quality of a journal, its research papers, the researchers who wrote those papers, and even the institution they work in.” However, the use of this index for evaluating individual scientists is dubious and may “skew the course of scientific research” (Monastersky, 2005, p, 1). Moreover the IF is, at most, able to measure only the quality of a very restricted range of research activities: namely, publishing journal articles. In the present work a new indicator of a researcher quality, named the Researcher Impact Factor (RF), is introduced. It is constructed as a function of the number and quality of publications (articles, books and working papers) and of the “other activities” usually associated with being a researcher (attending and/or organizing conferences, being the Editor, Associate Editor or referee for a journal, teaching or supervising at graduate level, coordinating research groups and so on). To show the characteristics of the new index, a numerical example is carried out to rank two hypothetical scientists. The main conclusion is that by replacing the IF with the RF in hiring, tenure decisions and awarding of grants would greatly increase the number of topics investigated and the number and quality of long run projects. The Excel spreadsheet used for the computations is available on demand from the authors.Impact factor, bibliometric indices, research evaluation, researcher impact factor

Student Life_Important Information for UMaine Students Email

University of Maine System update email regarding COVID-19 sent by Student Life to students on behalf of Joan Ferrini-Mundy, President of the University of Maine and Dannel P. Malloy, Chancellor of the University of Maine System regarding the reopening of the University of Maine System campuses for the 2020 Fall Semester

Testing the Relation Between the Local and Cosmic Star Formation Histories

Recently, there has been great progress toward observationally determining the mean star formation history of the universe. When accurately known, the cosmic star formation rate could provide much information about Galactic evolution, if the Milky Way's star formation rate is representative of the average cosmic star formation history. A simple hypothesis is that our local star formation rate is proportional to the cosmic mean. In addition, to specify a star formation history, one must also adopt an initial mass function (IMF); typically it is assumed that the IMF is a smooth function which is constant in time. We show how to test directly the compatibility of all these assumptions, by making use of the local (solar neighborhood) star formation record encoded in the present-day stellar mass function. Present data suggests that at least one of the following is false: (1) the local IMF is constant in time; (2) the local IMF is a smooth (unimodal) function; and/or (3) star formation in the Galactic disk was representative of the cosmic mean. We briefly discuss how to determine which of these assumptions fail, and improvements in observations which will sharpen this test.Comment: 14 pages in LaTeX (uses aaspp4.sty). 5 postscript figures. To appear in the Astrophysical Journa

Galactic chemical evolution of heavy elements: from Barium to Europium

We follow the chemical evolution of the Galaxy for elements from Ba to Eu, using an evolutionary model suitable to reproduce a large set of Galactic (local and non local) and extragalactic constraints. Input stellar yields for neutron-rich nuclei have been separated into their s-process and r-process components. The production of s-process elements in thermally pulsing asymptotic giant branch stars of low mass proceeds from the combined operation of two neutron sources: the dominant reaction 13C(alpha,n)16O, which releases neutrons in radiative conditions during the interpulse phase, and the reaction 22Ne(alpha,n)25Mg, marginally activated during thermal instabilities. The resulting s-process distribution is strongly dependent on the stellar metallicity. For the standard model discussed in this paper, it shows a sharp production of the Ba-peak elements around Z = Z_sun/4. Concerning the r-process yields, we assume that the production of r-nuclei is a primary process occurring in stars near the lowest mass limit for Type II supernova progenitors. The r-contribution to each nucleus is computed as the difference between its solar abundance and its s-contribution given by the Galactic chemical evolution model at the epoch of the solar system formation. We compare our results with spectroscopic abundances of elements from Ba to Eu at various metallicities (mainly from F and G stars) showing that the observed trends can be understood in the light of the present knowledge of neutron capture nucleosynthesis. Finally, we discuss a number of emerging features that deserve further scrutiny.Comment: 34 pages, 13 figures. accepted by Ap