“Digital In, Digital Out?“ – Evidence for a Curvilinear Relationship Between IT Experience in Top Management Teams and Firms’ Digital Orientation

To drive digital transformation, firms are increasingly adding IT-experienced executives to their top management team (TMT). Yet, whether IT-experienced executives can aid firms to achieve digital transformation remains unresolved theoretically and empirically. Drawing on human capital and group literature, we propose that there are limits to the benefits received from adding IT-experienced executives to a TMT, resulting in a curvilinear relationship between the share of IT-experienced executives in the TMT and a firm’s digital orientation. We also propose that this relationship is moderated by CEO entrepreneurial orientation and power concentration in the TMT. We test and find support for most of our hypotheses using a secondary panel data set comprising 1,855 firm-year observations from 256 firms listed in the S&P 500 between 2005 and 2017

Protection Motivation Theory and Contingent Valuation: Perceived Realism, Threat and WTP Estimates for Biodiversity Protection

We report on a discrete-choice CV study conducted in Germany to value the WTP for biodiversity protection in less developed countries. To systematically investigate survey realism and subjective threat assessment from the loss of biodiversity described in the scenario the study includes questions to uncover the constructs of Protection Motivation Theory, which is introduced to the CV literature. The patterns of responses to such questions are analysed using an Expectation-Maximization algorithm to derive class membership probabilities. These are found to match the predictions of Protection Motivation Theory and systematically improve the logistic analysis of the WTP responses

The asphericity of F-18-fluorodeoxyglucose uptake as new prognostic parameter in patients with head-and-neck cancer

Einleitung: Kopf-Hals-Karzinome sind die fünfthäufigste Krebsart in Deutschland. Sie werden aufgrund unspezifischer Symptome bei dem überwiegenden Teil der Patienten erst in einem fortgeschrittenen Krankheitsstadium diagnostiziert. Kommt es zu einem Rezidiv, schränkt dies die Restlebenserwartung stark ein. Einen potentiellen Beitrag zur Identifizierung von Hochrisiko- patienten mit hoher Rezidivgefahr kann die Positronenemissionstomographie (PET) bieten. Bereits in früheren Studien wurde versucht, mittels 18F-FDG-PET Messwerte zu gewinnen, die es ermöglichen das Outcome der Patienten zu prognostizieren. Dabei wurden besonders der Uptake des Tracers in Form des standardized uptake value (SUV) und sein Spitzenwert (SUVmax) sowie das metabolische Tumorvolumen (MTV) untersucht. Die Heterogenität eines Karzinoms als neuer Parameter wurde schon bei anderen Krebsarten erfolgreich zur Vorhersage des Patienten- Outcomes benutzt. Ziel dieser Studie ist es, den neuen und einfach zu bestimmenden Parameter Asphärizität (ASP) als Wert der räumlichen Heterogenität auf seine prädiktiven Fähigkeiten für das Outcome zu überprüfen und mit SUVmax und MTV zu vergleichen. Methodik: Es wurden retrospektiv 57 prätherapeutische PET- Aufnahmen von Patienten mit Kopf-Hals-Karzinomen bezüglich des FDG-Uptakes des Primärtumors bzw. des Rezidives quantitativ mit Hilfe der Software Rover 3D ausgewertet. In die univariate Analyse gingen ein: Geschlecht, Manifestation (Primärmanifestation vs. Rezidiv), Stadium nach UICC, Lokalisation des Primärtumors, Lymphknotenstatus, Vorhandensein von Fernmetastasen, SUVmax, MTV und ASP. Stellte sich ein Wert in der Cox-Regression zur Berechnung der Hazardrate als statistisch signifikant heraus, so wurde dieser anhand von Kaplan-Meier-(KM)-Kurven auf seine prädiktiven Fähigkeiten für das Gesamtüberleben (OAS) und das progressionsfreie Überleben (PFS) untersucht. Als Trennwert eines Parameters diente jeweils der Median. Schließlich wurde eine multivariate Analyse zur Identifizierung signifikanter unabhängiger Parameter durchgeführt. Die KM-Kurven wurden mit Log-rank-Tests verglichen. ROC-Kurven der Werte SUVmax, MTV und ASP wurden zum Vergleich der Sensitivität und Spezifität für Endpunktereignisse von OAS und PFS erstellt. Ergebnisse: Die univariate Regression zeigte, dass das Vorliegen eines Rezidives, ein großes MTV (> 17,2 ml) und eine hohe ASP (> 20,1) signifikante Risikofaktoren für ein schlechtes Outcome darstellen, nicht jedoch SUVmax. Die KM- Kurvenanalyse konnte für ASP und MTV einen prädiktiven Wert für OAS und PFS nachweisen. Der prognostische Wert von ASP steigt bei großem MTV gegenüber einem kleinen MTV. Die Kombination aus ASP und MTV jeweils über dem Median stellt einen hochsignifikanten unabhängigen Risikofaktor dar und ist stark prognostisch relevant für das Outcome, jedoch nur bei Patienten mit Primärmanifestation. Das Vorliegen eines Rezidives ist ein unabhängiger signifikanter Risikofaktor für ein schlechtes Outcome, unabhängig von ASP, MTV oder SUVmax. Schlussfolgerung: Die Asphärizität ermöglicht bei Erstmanifestation von Karzinomen des oberen Aerodigestivtraktes – besonders in der Kombination mit einem großen metabolischen Tumorvolumen – eine gute Vorhersage für das Gesamtüberleben und das progressionsfreie Überleben. Der Kombinationsparamter aus hoher ASP und großem MTV ist ein signifikanter unabhängiger Risikofaktor für ein verkürztes PFS und OAS. SUVmax hat dagegen keine prognostische Relevanz in dem untersuchten Kollektiv.Objectives: Head-and-neck cancer is the fifth most common cancer type in Germany. Due to mostly unspecific symptoms the tumor is associated with a delayed diagnosis in most patients. In case of a recurrence, the life expectancy is highly limited. Positron emission tomography with the glucose analog F-18-fluorodeoxyglucose could be used to identify patients with a high risk of recurrence and adverse outcome. In recent studies the prognostic significance of standard PET parameters such as standardized uptake value (SUV), maximum SUV (SUVmax) and the metabolic tumor volume (MTV) has been explored. The measurement of heterogeneity is a fairly new concept, but showed promising results in earlier studies in other types of cancer. The aim of this study was to evaluate the new and easy-to-measure parameter asphericity (ASP), a measure of spatial heterogeneity, and its prognostic value concerning the outcome of patients with head-and- neck cancer in comparison to the standard PET parameters SUVmax and MTV. Methods: Pretherapeutic FDG PET/CT images of 57 patients with head-and-neck cancer were retrospectively evaluated. The FDG images of either the primary or recurrent tumor were segmented and quantitatively analyzed using the ROVER 3D software. The following variables were included in an univariate statistical analysis: manifestation (first manifestation of the tumor versus recurrence), tumor stage (UICC), presence of lymph node metastases, presence of distant metastases, localization of the primary tumor, gender, MTV, SUVmax and ASP. Each variable was tested by univariate Cox proportional-hazards regression in order to identify all the variables with a statistically significant prognostic value. These variables were further analyzed by Kaplan- Meier-analysis with respect to both overall- (OAS) and progression free survival (PFS). OAS and PFS curves were separated by the median of the respective parameter and then compared by log- rank test. Finally, multivariate Cox regression was performed for the relevant variables to identify independent risk factors. Additionally, ROC curves of SUVmax, MTV, and ASP were used for direct comparison of sensitivity and specificity for prediction of death and recurrence. Results: Univariate Cox regression showed that a high risk, i.e. short survival, was significantly associated with tumor recurrence (versus first manifestation), large MTV (> 17.2 ml) and high ASP (> 20.1). Kaplan-Meier-analysis revealed a statistically significant relevance with respect for OAS and PFS for both MTV and ASP, and showed that ASP provided incremental prognostic value in addition to MTV particularly in tumors with a large MTV. The incremental prognostic value of ASP was lower in small tumors. Thus, the combination of high MTV with high ASP was associated with a particularly high risk for poor outcome, and the combined parameter proved as an independent prognostic factor by multivariate analysis. However, this combined parameter had a very high prognostic value only in patients with first tumor presentation. Tumor recurrence per se was associated with a poor prognosis independent of the different PET parameters. Conclusion: Tumor asphericity of the pretherapeutic FDG tumor uptake, especially in tumors with a high metabolic tumor volume, provides significant prognostic information with respect to PFS and OAS in patients with primary head-and-neck cancer. In combination with the metabolic tumor volume, asphericity appears to be the strongest independent predictor of tumor progression and shorter overall and progression free survival by multivariate analysis. SUV on the other hand did not show any prognostic relevance in our patient subset

The Message Shapes Phonology

Based on a diverse and complementary set of theoretical and empirical findings, we describe an approach to phonology in which sound patterns are shaped by the trade-off between biases supporting message transmission accuracy and resource cost. We refer to this approach as Message-Oriented Phonology. The evidence suggests that these biases influence the form of messages, defined with reference to a language's morphemes, words or higher levels of meaning, rather than influencing phonological categories directly. Integrating concepts from information theory and Bayesian inference with the existing body of phonological research, we propose a testable model of phonology that makes quantitative predictions. Moreover, we show that approaching language as a system of message transfer provides greater explanatory coverage of a diverse range of sound patterns

When will it change the lane? A probabilistic regression approach for rarely occurring events

Understanding traffic situations in dynamic traffic environments is an essential requirement for autonomous driving. The prediction of the current traffic scene into the future is one of the main problems in this context. In this publication we focus on highway scenarios, where the maneuver space for traffic participants is limited to a small number of possible behavior classes. Even though there are many publications in the field of maneuver prediction, most of them set the focus on the classification problem, whether a certain maneuver is executed or not. We extend approaches which solve the classification problem of lane-change behavior by introducing the novel aspect of estimating a continuous distribution of possible trajectories. Our novel approach uses the probabilities which are assigned by a Random Decision Forest to each of the maneuvers lane following, lane change left and lane change right. Using measured data of a vehicle and the knowledge of the typical lateral movement of vehicles over time taken from realworlddata, we derive a Gaussian Mixture Regression method. For the final result we combine the predicted probability density functions of the regression method and the computed maneuver probabilities using a Mixture of Experts approach. In a large scale experiment on real world data collected on multiple test drives we trained and validated our prediction model and show the gained high prediction accuracy of the proposed method

Pretherapeutic FDG-PET total metabolic tumor volume predicts response to induction therapy in pediatric Hodgkin’s lymphoma

Abstract Background Standardized treatment in pediatric patients with Hodgkin’s lymphoma (HL) follows risk stratification by tumor stage, erythrocyte sedimentation rate and tumor bulk. We aimed to identify quantitative parameters from pretherapeutic FDG-PET to assist prediction of response to induction chemotherapy. Methods Retrospective analysis in 50 children with HL (f:18; m:32; median age, 14.8 [4–18] a) consecutively treated according to EuroNet-PHL-C1 (n = 42) or -C2 treatment protocol (n = 8). Total metabolic tumor volume (MTV) in pretherapeutic FDG-PET was defined using a semi-automated, background-adapted threshold. Metabolic (SUVmax, SUVmean, SUVpeak, total lesion glycolysis [MTV*SUVmean]) and heterogeneity parameters (asphericity [ASP], entropy, contrast, local homogeneity, energy, and cumulative SUV-volume histograms) were derived. Early response assessment (ERA) was performed after 2 cycles of induction chemotherapy according to treatment protocol and verified by reference rating. Prediction of inadequate response (IR) in ERA was based on ROC analysis separated by stage I/II (1 and 26 patients) and stage III/IV disease (7 and 16 patients) or treatment group/level (TG/TL) 1 to 3. Results IR was seen in 28/50 patients (TG/TL 1, 6/12 patients; TG/TL 2, 10/17; TG/TL 3, 12/21). Among all PET parameters, MTV best predicted IR; ASP was the best heterogeneity parameter. AUC of MTV was 0.84 (95%-confidence interval, 0.69–0.99) in stage I/II and 0.86 (0.7–1.0) in stage III/IV. In patients of TG/TL 1, AUC of MTV was 0.92 (0.74–1.0); in TG/TL 2 0.71 (0.44–0.99), and in TG/TL 3 0.85 (0.69–1.0). Patients with high vs. low MTV had IR in 86 vs. 0% in TG/TL 1, 80 vs. 29% in TG/TL 2, and 90 vs. 27% in TG/TL 3 (cut-off, > 80 ml, > 160 ml, > 410 ml). Conclusions In this explorative study, high total MTV best predicted inadequate response to induction therapy in pediatric HL of all pretherapeutic FDG-PET parameters – in both low and high stages as well as the 3 different TG/TL. Trial registration Ethics committee number: EA2/151/16 (retrospectively registered)

Additional file 1: of Pretherapeutic FDG-PET total metabolic tumor volume predicts response to induction therapy in pediatric Hodgkin’s lymphoma

Supplemental materials. Results of additional analysis on delineation with a fixed relative threshold (MTVt41) and a fixed absolute threshold (MTV2.5) in comparison with the background-adapted semi-automated delineation presented in the main manuscript (MTVBG) [39]. (DOCX 3060 kb

Atmospheric photooxidation and ozonolysis of sabinene: reaction rate coefficients, product yields, and chemical budget of radicals

The oxidation of sabinene by the hydroxyl radical (OH) and ozone (O3) was investigated under atmospherically relevant conditions in the atmospheric simulation chamber SAPHIR (Simulation of Atmospheric Photochemistry In a Large Reaction Chamber) at Forschungszentrum Jülich, Germany. The rate coefficients of the reactions of sabinene with OH and with O3 were determined. The temperature dependence between 284 to 340 K of the rate coefficient of the reaction of sabinene with OH, kSAB+OH, was measured for the first time using an OH reactivity instrument, resulting in an Arrhenius expression of (1.67 ± 0.16) × 10−11 × exp((575 ± 30)/T) cm3 s−1. The values agree with those determined in chamber experiments in this work and reported in the literature for ∼ 298 K within the uncertainties of measurements. The ozonolysis reaction rate coefficient of sabinene (kSAB+O3) determined in chamber experiments at a temperature of (278 ± 2) K is (3.4 ± 0.8) × 10−17 cm3 s−1, which is 58 % lower than the value reported in the literature for room temperature. The measurement of products from the oxidation of sabinene by OH resulted in an acetone yield of (21 ± 15) %, a formaldehyde yield of (46 ± 25) %, and a sabinaketone yield of (18 ± 16) %. All yields determined in the chamber experiments agree well with values from previous laboratory studies within their uncertainties. In addition, the formaldehyde yield determined in this study is consistent with that predicted by the sabinene OH-oxidation mechanism which was devised from quantum chemical calculations by Wang and Wang (2018), whereas the acetone yield is about 15 % higher than that predicted by the mechanism. In the ozonolysis experiments, the analysis of product measurements results in an acetone yield of (5 ± 2) %, a formaldehyde yield of (48 ± 15) %, a sabinaketone yield of (31 ± 15) %, and an OH radical yield of (26 ± 29) %. The OH radical yield is lower than expected from the theoretical mechanism in Wang and Wang (2017), but the value still agrees within the uncertainty. An analysis of the chemical budget of OH radicals was performed for the chamber experiments. The analysis reveals that the destruction rate of the OH radical matches the production rate of OH, suggesting that there is no significant missing OH source for example from isomerization reactions of peroxy radicals for the experimental conditions in this work

Software-assisted dosimetry in peptide receptor radionuclide therapy with ¹⁷⁷Lutetium-DOTATATE for various imaging scenarios

<div><p>In peptide receptor radionuclide therapy (PRRT) of patients with neuroendocrine neoplasias (NENs), intratherapeutic dosimetry is mandatory for organs at risk (e.g. kidneys) and tumours. We evaluated commercial dosimetry software (Dosimetry Toolkit) using varying imaging scenarios, based on planar and/or tomographic data, regarding the differences in calculated organ/tumour doses and the use for clinical routines. A total of 16 consecutive patients with NENs treated by PRRT with ¹⁷⁷Lu-DOTATATE were retrospectively analysed. Single-photon emission computed tomography (SPECT)/low-dose computed tomography (CT) of the thorax and abdomen and whole body (WB) scintigraphy were acquired up to 7 days p.i. (at a maximum of five imaging time points). Different dosimetric scenarios were evaluated: (1) a multi-SPECT-CT scenario using SPECT/CT only; (2) a planar scenario using WB scintigraphy only; and (3) a hybrid scenario using WB scintigraphy in combination with a single SPECT/low-dose CT. Absorbed doses for the kidneys, liver, spleen, lungs, bladder wall and tumours were calculated and compared for the three different scenarios. The mean absorbed dose for the kidneys estimated by the multi-SPECT-CT, the planar and the hybrid scenario was 0.5 ± 0.2 Sv GBq^-1, 0.8 ± 0.4 Sv GBq^-1 and 0.6 ± 0.3 Sv GBq^-1, respectively. The absorbed dose for the residual organs was estimated higher by the planar scenario compared to the multi-SPECT-CT or hybrid scenario. The mean absorbed tumour doses were 2.6 ± 1.5 Gy GBq^-1 for the multi-SPECT-CT, 3.1 ± 2.2 Gy GBq^-1 for the hybrid scenario and 5.3 ± 6.3 Gy GBq^-1 for the planar scenario. SPECT-based dosimetry methods determined significantly lower kidney doses than the WB scintigraphy-based method. Dosimetry based completely on SPECT data is time-consuming and tedious. Approaches combining SPECT/CT and WB scintigraphy have the potential to ensure compromise between accuracy and user-friendliness.</p></div

ROI/VOI comparison of all three imaging scenarios 24 h p.i. of the same patient.

<p>The delineations of lungs, liver, kidneys, spleen, bladder and tumour (white, in the liver) are shown. (A) 2D presentation (summed coronal slice) of the 3D VOIs of the multi-SPECT-CT scenario. (B) Geometric mean image of the planar scenario with all ROIs. The small elongated delineations (*) next to the ROIs were used for background correction. (C) Geometric mean image of the WB scintigraphies with SPECT/CT based VOIs (hybrid scenario). Here, overlapping regions of interest were automatically removed (#) and corrected.</p