A collection of coauthored papers is the new norm for doctoral dissertations in the natural and biomedical sciences, yet there
is no consensus on how to partition authorship credit between PhD candidates and their coauthors. Guidelines for PhD programs
vary but tend to specify only a suggested range for the number of papers to be submitted for evaluation, sometimes supplemented
with a requirement for the PhD candidate to be the principal author on the majority of submitted papers. Here I use harmonic
counting to quantify the actual amount of authorship credit attributable to individual PhD graduates from two Scandinavian
universities in 2008. Harmonic counting corrects for the inherent inflationary and equalizing biases of routine counting methods,
thereby allowing the bibliometrically identifiable amount of authorship credit in approved dissertations to be analyzed with
unprecedented accuracy. Unbiased partitioning of authorship credit between graduates and their coauthors provides a post hoc
bibliometric measure of current PhD requirements, and sets a de facto baseline for the requisite scientific productivity of
these contemporary PhD’s at a median value of approximately 1.6 undivided papers per dissertation. Comparison with previous
census data suggests that the baseline has shifted over the past two decades as a result of a decrease in the number of submitted
papers per candidate and an increase in the number of coauthors per paper. A simple solution to this shifting baseline syndrome
would be to benchmark the amount of unbiased authorship credit deemed necessary for successful completion of a specific PhD
program, and then monitor for departures from this level over time. Harmonic partitioning of authorship credit also facilitates
cross-disciplinary and inter-institutional analysis of the scientific output from different PhD programs. Juxtaposing bibliometric
benchmarks with current baselines may thus assist the development of harmonized guidelines and transparent transnational quality
assurance procedures for doctoral programs by providing a robust and meaningful standard for further exploration of the causes
of intra- and inter-institutional variation in the amount of unbiased authorship credit per dissertation.
Authors:Nils Baumann, Thuro Arnold, and Martin Lonschinski
In situ leaching of uranium ores with sulfuric acid during active uranium mining activity on the Gessenheap has caused longstanding
environmental problems of acid mine drainage and elevated concentrations of uranium. To study there remediation measures the
test site Gessenwiese, a recultivated former uranium mining heap near Ronnenburg/East Thuringia/Germany, was installed as
a part of a research program of the Friedrich-Schiller University Jena to study, among other techniques, the phytoremediation
capacity of native and selected plants towards uranium. In the first step the uranium speciation in surface seepage and soil
pore waters from Gessenwiese, ranging in pH from 3.2 to 4.0, were studied by time-resolved laser-induced fluorescence spectroscopy
(TRLFS). Both types of water samples showed mono-exponential luminescence decay, indicating the presence of only one major
species. The detected emission bands were found at 477.5, 491.8, 513.0, 537.2, 562.3, and 590.7 nm in case of the surface
water samples, and were found at 477.2, 493.2, 513.8, 537.0, 562.4, and 590.0 nm in case of the soil water samples. These
characteristic peak maxima together with the observed mono-exponential decay indicated that the uranium speciation in the
seepage and soil pore waters is dominated by the uranium (VI) sulfate species UO2SO4(aq). Due to the presence of luminescence quenchers in the natural water samples the measured luminescence lifetimes of the UO2SO4(aq) species of 1.0–2.6 μs were reduced in comparison to pure uranium sulfate solutions, which show a luminescence lifetime of
4.7 μs. These results convincingly show that in the pH range of 3.2–4.0 TRLFS is a suitable and very useful technique to study
the uranium speciation in naturally occurring water samples.
Authors:Seval Koç, Nil Toplan, Kenan Yildiz, and H. Özkan Toplan
The non-isothermal kinetics of mullite formation from both non-activated and mechanically activated kaolinite have been studied by differential thermal analysis (DTA). Kaolinite was mechanically activated in a planetary mill, while amorphization in the structure was studied by X-ray diffraction analysis. It was established that the mechanical activation especially affected the loss of structural water. The activation energies depending on the conversion for mullite formation have been calculated from the DTA curves by using the non-isothermal method of Coats and Redfern at heating rates of 5, 10, 15, and 20 °C min−1. The mechanical activation and amorphization of the kaolinite brings to the formation of mullite at a lower heating temperature.
Authors:Eda Elmas, Kenan Yildiz, Nil Toplan, and H. Özkan Toplan
The non-isothermal kinetics of mullite formation from both non-activated and mechanically activated kaolinite + alumina ceramic system have been studied by differential thermal analysis (DTA). The mixture of kaolinite and alumina was activated mechanically in a planetary mill, while amorphization in the kaolinite and alumina structure was studied by X-ray diffraction analysis. The activation energies depending on the conversion for mullite formation have been calculated from the DTA curves by using the non-isothermal method of Coats and Redfern at heating rates of 5, 10, 15, and 20 °C min−1. The mechanical activation of the kaolinite and alumina mixture resulted in the decrease in activation energy values for mullite formation.
Authors:Viorel Chihaia, Karl Sohlberg, Viorel Sasca, Nicolae Doca, Alexandru Popa, and Nils Jaeger
The reduction kinetics with CO of the 12-molybdophosphoric—HPMo, 1-vanado-11-molybdophosphoric—HPVMo acids and their salts with NH4+, K+ and Cs+ cations were studied for reduction/reoxidation cycles with mixtures of CO:Ar and O2: Ar, by means of “in situ” UV–Vis–DRS measurements. The reflectivity versus time curves registered during the reduction/reoxidation processes for the HPMo and HPVMo and its salts with NH4+, K+ and Cs+ cations, at the constant wavelength of 620 nm and different reaction temperatures between 523 and 623 K, were processed as the Kubelka–Munk function versus time. The linear shape of Kubelka–Munk function versus time curves for the reduction process suggests apparent zeroth order kinetics and it was used for the calculation of apparent activation energy. The kinetic compensation effect between the apparent activation energy and the pre-exponential factor was observed. The Kubelka–Munk function versus time curves for the reoxidation process consist of two steps, the first with a very fast reaction rate and the second with a slow reaction rate. An explanation for their shape is proposed. The heteropoly oxomolybdates reach a degree of reoxidation higher than heteropoly compounds containing vanadium together with molybdenum.
Authors:Christina Grothusen, Tim Attmann, Christine Friedrich, Sandra Freitag-Wolf, Nils Haake, Jochen Cremer, and Jan Schöttler
This study investigated factors determining the long-term outcome and quality of life of patients with a prolonged intensive care unit (ICU) stay after cardiac surgery.
A retrospective analysis was performed in 230 patients that had undergone cardiac surgery and suffered from a post-operative ICU stay of 7 or more days at our institution. Among 11 pre-, 13 intra-, and 14 post-operative variables, factors influencing 5-year outcome were identified by logistic regression analysis. Quality of life was determined using the Short Form-36 questionnaire.
In-hospital mortality was 12%. One hundred and eleven of 187 patients (59%) were alive after 5 years. Non-survivors were older (70 vs. 65 years, p=0.005) and had a higher additive EuroSCORE (7 vs. 5, p=0.034). Logistic regression identified pre-operative atrial fibrillation (AF), (28 vs. 10%, p=0.003) as the strongest predictor for a 5-year outcome, followed by myocardial infarction (62 vs. 41%, p=0.005), and prolonged mechanical ventilation (8 vs. 5 days, p=0.036). Survivors did not show an impaired physical component summary SF-36 score (39 vs. 46, p=0.737) or mental component summary score (55 vs. 55, p=0.947) compared to an age-matched German Normative Sample.
Pre-operative AF proved to be the most important factor determining the 5-year outcome of patients with a prolonged ICU stay after cardiac surgery. Neither physical nor mental health appeared to be impaired in these patients.
Authors:Fatema Moni Chowdhury, Mohammed Ziaur Rahman, Md Murshed Hasan Sarkar, Fazle Rabbi, Sirajul Islam Khan, Chowdhury Rafiqul Ahsan, and Nils-Kåre Birkeland
Recently, we reported the induction of protective immunity by environmental Escherichia albertii strain DM104 against Shigella dysenteriae in guinea pig model. In this study, we assessed three different immunization routes, such as intranasal, oral, and intrarectal routes, and revealed differences in immune responses by measuring both the serum IgG and mucosal IgA antibody titers. Protective efficacy of different routes of immunization was also determined by challenging immunized guinea pigs against live S. dysenteriae. It was found that intranasal immunization showed promising results in terms of antibody response and protective efficacy. All these results reconfirm our previous findings and additionally point out that the intranasal immunization of the environmental E. albertii strain DM104 in guinea pig model can be a better live vaccine candidate against shigellosis.