Radboud University Nijmegen

About: Radboud University Nijmegen is a education organization based out in Nijmegen, Gelderland, Netherlands. It is known for research contribution in the topics: Population & Randomized controlled trial. The organization has 35417 authors who have published 83035 publications receiving 3285064 citations. The organization is also known as: Catholic University of Nijmegen & Radboud University.

Multigroup Analysis in Partial Least Squares (PLS) Path Modeling: Alternative Methods and Empirical Results

Abstract: Purpose – Partial least squares (PLS) path modeling has become a pivotal empirical research method in international marketing. Owing to group comparisons' important role in research on international marketing, we provide researchers with recommendations on how to conduct multigroup analyses in PLS path modeling. Methodology/approach – We review available multigroup analysis methods in PLS path modeling and introduce a novel confidence set approach. A characterization of each method's strengths and limitations and a comparison of their outcomes by means of an empirical example extend the existing knowledge of multigroup analysis methods. Moreover, we provide an omnibus test of group differences (OTG), which allows testing the differences across more than two groups. Findings – The empirical comparison results suggest that Keil et al.'s (2000) parametric approach can generally be considered more liberal in terms of rendering a certain difference significant. Conversely, the novel confidence set approach and Henseler's (2007) approach are more conservative. Originality/value of paper – This study is the first to deliver an in-depth analysis and a comparison of the available procedures with which to statistically assess differences between group-specific parameters in PLS path modeling. Moreover, we offer two important methodological extensions of existing research (i.e., the confidence set approach and OTG). This contribution is particularly valuable for international marketing researchers, as it offers recommendations regarding empirical applications and paves the way for future research studies aimed at comparing the approaches' properties on the basis of simulated data.

Transient ferromagnetic-like state mediating ultrafast reversal of antiferromagnetically coupled spins

Abstract: The dynamics of spin ordering in magnetic materials is of interest for both fundamental understanding and progress in information-processing and recording technology. Radu et al. study spin dynamics in a ferrimagnetic gadolinium–iron–cobalt (GdFeCo) alloy that is optically excited at a timescale shorter than the characteristic magnetic exchange interaction between the Gd and Fe spins. Using element-specific X-ray magnetic circular dichroism spectroscopy, they show that the Gd and Fe spins switch directions at very different timescales. As a consequence, an unexpected transient ferromagnetic state emerges. These surprising observations, supported by simulations, provide a possible new concept of manipulating magnetic order on a timescale of the exchange interaction. Ferromagnetic or antiferromagnetic spin ordering is governed by the exchange interaction, the strongest force in magnetism1,2,3,4. Understanding spin dynamics in magnetic materials is an issue of crucial importance for progress in information processing and recording technology. Usually the dynamics are studied by observing the collective response of exchange-coupled spins, that is, spin resonances, after an external perturbation by a pulse of magnetic field, current or light. The periods of the corresponding resonances range from one nanosecond for ferromagnets down to one picosecond for antiferromagnets. However, virtually nothing is known about the behaviour of spins in a magnetic material after being excited on a timescale faster than that corresponding to the exchange interaction (10–100 fs), that is, in a non-adiabatic way. Here we use the element-specific technique X-ray magnetic circular dichroism to study spin reversal in GdFeCo that is optically excited on a timescale pertinent to the characteristic time of the exchange interaction between Gd and Fe spins. We unexpectedly find that the ultrafast spin reversal in this material, where spins are coupled antiferromagnetically, occurs by way of a transient ferromagnetic-like state. Following the optical excitation, the net magnetizations of the Gd and Fe sublattices rapidly collapse, switch their direction and rebuild their net magnetic moments at substantially different timescales; the net magnetic moment of the Gd sublattice is found to reverse within 1.5 picoseconds, which is substantially slower than the Fe reversal time of 300 femtoseconds. Consequently, a transient state characterized by a temporary parallel alignment of the net Gd and Fe moments emerges, despite their ground-state antiferromagnetic coupling. These surprising observations, supported by atomistic simulations, provide a concept for the possibility of manipulating magnetic order on the timescale of the exchange interaction.

Doxorubicin alone versus intensified doxorubicin plus ifosfamide for first-line treatment of advanced or metastatic soft-tissue sarcoma: a randomised controlled phase 3 trial

Abstract: Summary Background Effective targeted treatment is unavailable for most sarcomas and doxorubicin and ifosfamide—which have been used to treat soft-tissue sarcoma for more than 30 years—still have an important role Whether doxorubicin alone or the combination of doxorubicin and ifosfamide should be used routinely is still controversial We assessed whether dose intensification of doxorubicin with ifosfamide improves survival of patients with advanced soft-tissue sarcoma compared with doxorubicin alone Methods We did this phase 3 randomised controlled trial (EORTC 62012) at 38 hospitals in ten countries We included patients with locally advanced, unresectable, or metastatic high-grade soft-tissue sarcoma, age 18–60 years with a WHO performance status of 0 or 1 They were randomly assigned (1:1) by the minimisation method to either doxorubicin (75 mg/m 2 by intravenous bolus on day 1 or 72 h continuous intravenous infusion) or intensified doxorubicin (75 mg/m 2 ; 25 mg/m 2 per day, days 1–3) plus ifosfamide (10 g/m 2 over 4 days with mesna and pegfilgrastim) as first-line treatment Randomisation was stratified by centre, performance status (0 vs 1), age ( vs ≥50 years), presence of liver metastases, and histopathological grade (2 vs 3) Patients were treated every 3 weeks till progression or unacceptable toxic effects for up to six cycles The primary endpoint was overall survival in the intention-to-treat population The trial is registered with ClinicalTrialsgov, number NCT00061984 Findings Between April 30, 2003, and May 25, 2010, 228 patients were randomly assigned to receive doxorubicin and 227 to receive doxorubicin and ifosfamide Median follow-up was 56 months (IQR 31–77) in the doxorubicin only group and 59 months (36–72) in the combination group There was no significant difference in overall survival between groups (median overall survival 12·8 months [95·5% CI 10·5–14·3] in the doxorubicin group vs 14·3 months [12·5–16·5] in the doxorubicin and ifosfamide group; hazard ratio [HR] 0·83 [95·5% CI 0·67–1·03]; stratified log-rank test p=0·076) Median progression-free survival was significantly higher for the doxorubicin and ifosfamide group (7·4 months [95% CI 6·6–8·3]) than for the doxorubicin group (4·6 months [2·9–5·6]; HR 0·74 [95% CI 0·60–0·90], stratified log-rank test p=0·003) More patients in the doxorubicin and ifosfamide group than in the doxorubicin group had an overall response (60 [26%] of 227 patients vs 31 [14%] of 228; p vs 40 [18%] of 223 patients), neutropenia (93 [42%] vs 83 [37%]), febrile neutropenia (103 (46%) vs 30 [13%]), anaemia (78 [35%] vs 10 [5%]), and thrombocytopenia (75 [33%]) vs one [ Interpretation Our results do not support the use of intensified doxorubicin and ifosfamide for palliation of advanced soft-tissue sarcoma unless the specific goal is tumour shrinkage These findings should help individualise the care of patients with this disease Funding Cancer Research UK, EORTC Charitable Trust, UK NHS, Canadian Cancer Society Research Institute, Amgen