RöFo - Fortschritte auf dem Gebiet der Röntgenstrahlen und der bildgebenden Verfahren, 2022
Purpose Evaluation of machine learning-based fully automated artery-specific coronary artery calc... more Purpose Evaluation of machine learning-based fully automated artery-specific coronary artery calcium (CAC) scoring software, using semi-automated software as a reference. Methods A total of 505 patients underwent non-contrast-enhanced calcium scoring computed tomography (CSCT). Automated, machine learning-based software quantified the Agatston score (AS), volume score (VS), and mass score (MS) of each coronary artery [right coronary artery (RCA), left main (LM), circumflex (CX) and left anterior descending (LAD)]. Identified CAC of readers who annotated the data with semi-automated software served as a reference standard. Statistics included comparisons of evaluation time, agreement of identified CAC, and comparisons of the AS, VS, and MS of the reference standard and the fully automated algorithm. Results The machine learning-based software correlated strongly with the reference standard for the AS, VS, and MS (Spearmanʼs rho > 0.969) (p 0.919) (p
Abstract Purpose To evaluate the transient artifact augmentation of microtubes in magnetic resona... more Abstract Purpose To evaluate the transient artifact augmentation of microtubes in magnetic resonance imaging by fluid injection. Methods Twenty‐one fluorinated ethylene propylene catheters (inner diameter 760 μm) were filled with three different contrast media at various concentrations (Ferucarbotran, Resovist®, Bayer Schering Pharma; Manganese dichloride, MnCl2, Sigma‐Aldrich; Gadobutrol, Gadovist®, Bayer Schering Pharma). Artifact appearance was determined in an ex vivo phantom at 1.5 T using three different sequences: T1‐weighted three‐dimensional volume interpolated breath‐hold examination, T2‐weighted turbo spin echo, and T1‐weighted fast low angle shot. Catheter angulation to the main magnetic field (B0) was varied. Influence of parameters on artifact diameters was assessed with a multiple linear regression similar to an analysis of variance. Results Artifact diameter was significantly influenced by the contrast agent (p < 0.001), concentration of the contrast agent (p < 0.001), angulation of the phantom to B0 with the largest artifact at 90° (p < 0.001), and encoding direction with a larger diameter in phase encoding direction (PED, p < 0.001). Mean artifact diameters at 90° angulation to B0 in PED were 18.5 ± 5.4 mm in 0.5 mmol/ml Ferucarbotran, 8.7 ± 2.5 mm in 1 mmol/ml Gadobutrol, and 11.6 ± 4.6 mm in 5 mmol/ml MnCl2. Conclusions Fluid‐based contrast agents might be applied to interventional devices and thus temporarily augment the artifact ensuring both visibility and safe navigation.
The tibial nutrient artery (TNA) is the major diaphyseal artery of the tibia supplying two thirds... more The tibial nutrient artery (TNA) is the major diaphyseal artery of the tibia supplying two thirds of the inner osseous cortex. Hence, iatrogenic injury of the TNA endangers the integrity of the tibial blood supply and may compromise fracture healing. The incidence of its injury in the setting of external fixation for lower limb fractures has not been previously investigated. The aim of this study was to evaluate the incidence of TNA injury in the context of external fixation and to characterize the topography of the fixator pins in relation to the TNA canal (TNAC). Patients who underwent external fixation for distal femoral fractures and for tibial (proximal, shaft, and distal) fractures and had a postoperative computed tomography study were retrospectively included. The following parameters were retrieved: 1) Pin characteristics (orientation and cortical position of the pins), 2) The anatomic relationship between the TNAC and external fixation pin (topography above/below and at the...
Hypotheses about psychological processes are often tested using traditional mediation analysis. T... more Hypotheses about psychological processes are often tested using traditional mediation analysis. This analysis relies onmeasurement of a transmitting variable. Conducting this analysis has become almost synonymous with examining processhypotheses. An alternative strategy to mediation analysis (the Testing-a-Process-hypothesis-by-an-Interaction Strategy, TPIS) isillustrated here. TPIS is based on a fully experimental design whereby a hypothesized process is tested by an interaction betweenthe hypothesized cause of an effect and a contextual variable. In the interaction term, the contextual variable allows comparisonof the causal effect observed when the process is uninterrupted to the effect observed when the process is interrupted. Thus, TPIS translatesatheoreticalprocesshypothesis intoastatisticalinteractionhypothesisthatusesafully experimental designtodirectlyexamine the hypothesized process.
Statistical mediation and moderation have most prominently been distinguished by Baron and Kenny ... more Statistical mediation and moderation have most prominently been distinguished by Baron and Kenny (1986). More complex models that combine both of these effects have recently received increased attention, namely mediated moderation and moderated mediation (e.g., Muller, Judd, & Yzerbyt, 2005). Presently the focus is on a three variable model that is often claimed to represent an instance of moderated mediation or mediated moderation. More specifically, in this model a single variable is considered to simultaneously mediate and moderate the same effect. We show that this specific model however cannot be considered either an instance of mediated moderation nor of moderated mediation. Also, we argue that this particular model is a priori misspecified. A data pattern that seems to agree with this model is recognized as plausible, but it indicates that the model must be modified in one of two ways to be methodologically sound. We conclude by recommending to not use this three variable model and to consider evidence that seemingly agrees with it as evidence that the three variable model is inadequate.
While other research on social exclusion and rejection has revealed anti-social behavioral respon... more While other research on social exclusion and rejection has revealed anti-social behavioral respones to exclusion, research on ostracism in the Cyberball paradigm has found pro-social rather than anti-social behavioral reactions to ostracism. Participants have, however, not been given the opportunity to reciprocate ostracism within the Cyberball game. Three studies reported here tested whether ostracized participants retaliate in kind if given an opportunity to do so. Across all of them, common ostracism effects that have been found in the past were replicated, but no retaliation was detected.
Judgments about individual group members are often colored by judgments about the entire group. T... more Judgments about individual group members are often colored by judgments about the entire group. Through such an assimilation effect, an individual norm violator from a positively evaluated group, for example an ingroup, can be expected to be evaluated less negatively than an outgroup norm violator. This hypothesis however contrasts with evidence that ingroup norm violators are often derogated compared to outgroup norm violators, a phenomenon known as the Black Sheep Effect (BSE). The discussion of differences between the explanations of these opposite predictions (assimilation vs. BSE) lead us to the prediction that assimilation (and not a BSE) occurs if the ingroup adheres more to the societal norm than the outgroup and thus conveys positive valence to which an ingroup deviant evaluation is assimilated. This predicted pattern was indeed found in Study 1 and replicated in Study 2. Additionally, Study 2 provides evidence that this effect is, consistent with the present theorizing, mediated by group valence. The current research suggests that a BSE can be eliminated or even reversed by assimilation effects -a suggestion that is in line with other differentiations in the literature regarding the circumstances under which a BSE, no difference, or even ingroup favoritism occurs. (195 words)
Following realistic group-conXict theory, negative interdependence between groups (e.g., competit... more Following realistic group-conXict theory, negative interdependence between groups (e.g., competition) leads to prejudice towards the opposing outgroup. Based on research on mindset priming, it is hypothesized that competition increases prejudice, regardless of whether the derogated outgroup is involved in the competition or not. In Experiment 1, participants remembered an event involving either competition or cooperation; in Experiments 2 and 3 they participated in a competitive, cooperative, or individual assessment of their knowledge. Subsequent measures indicated that competition results in higher levels of prejudice, even when it is not related to the intergroup context. Additional evidence suggests that this eVect is not driven by the transfer of negative aVect or ego-depletion. Possible underlying cognitive processes are discussed.
RöFo - Fortschritte auf dem Gebiet der Röntgenstrahlen und der bildgebenden Verfahren, 2022
Purpose Evaluation of machine learning-based fully automated artery-specific coronary artery calc... more Purpose Evaluation of machine learning-based fully automated artery-specific coronary artery calcium (CAC) scoring software, using semi-automated software as a reference. Methods A total of 505 patients underwent non-contrast-enhanced calcium scoring computed tomography (CSCT). Automated, machine learning-based software quantified the Agatston score (AS), volume score (VS), and mass score (MS) of each coronary artery [right coronary artery (RCA), left main (LM), circumflex (CX) and left anterior descending (LAD)]. Identified CAC of readers who annotated the data with semi-automated software served as a reference standard. Statistics included comparisons of evaluation time, agreement of identified CAC, and comparisons of the AS, VS, and MS of the reference standard and the fully automated algorithm. Results The machine learning-based software correlated strongly with the reference standard for the AS, VS, and MS (Spearmanʼs rho > 0.969) (p 0.919) (p
Abstract Purpose To evaluate the transient artifact augmentation of microtubes in magnetic resona... more Abstract Purpose To evaluate the transient artifact augmentation of microtubes in magnetic resonance imaging by fluid injection. Methods Twenty‐one fluorinated ethylene propylene catheters (inner diameter 760 μm) were filled with three different contrast media at various concentrations (Ferucarbotran, Resovist®, Bayer Schering Pharma; Manganese dichloride, MnCl2, Sigma‐Aldrich; Gadobutrol, Gadovist®, Bayer Schering Pharma). Artifact appearance was determined in an ex vivo phantom at 1.5 T using three different sequences: T1‐weighted three‐dimensional volume interpolated breath‐hold examination, T2‐weighted turbo spin echo, and T1‐weighted fast low angle shot. Catheter angulation to the main magnetic field (B0) was varied. Influence of parameters on artifact diameters was assessed with a multiple linear regression similar to an analysis of variance. Results Artifact diameter was significantly influenced by the contrast agent (p < 0.001), concentration of the contrast agent (p < 0.001), angulation of the phantom to B0 with the largest artifact at 90° (p < 0.001), and encoding direction with a larger diameter in phase encoding direction (PED, p < 0.001). Mean artifact diameters at 90° angulation to B0 in PED were 18.5 ± 5.4 mm in 0.5 mmol/ml Ferucarbotran, 8.7 ± 2.5 mm in 1 mmol/ml Gadobutrol, and 11.6 ± 4.6 mm in 5 mmol/ml MnCl2. Conclusions Fluid‐based contrast agents might be applied to interventional devices and thus temporarily augment the artifact ensuring both visibility and safe navigation.
The tibial nutrient artery (TNA) is the major diaphyseal artery of the tibia supplying two thirds... more The tibial nutrient artery (TNA) is the major diaphyseal artery of the tibia supplying two thirds of the inner osseous cortex. Hence, iatrogenic injury of the TNA endangers the integrity of the tibial blood supply and may compromise fracture healing. The incidence of its injury in the setting of external fixation for lower limb fractures has not been previously investigated. The aim of this study was to evaluate the incidence of TNA injury in the context of external fixation and to characterize the topography of the fixator pins in relation to the TNA canal (TNAC). Patients who underwent external fixation for distal femoral fractures and for tibial (proximal, shaft, and distal) fractures and had a postoperative computed tomography study were retrospectively included. The following parameters were retrieved: 1) Pin characteristics (orientation and cortical position of the pins), 2) The anatomic relationship between the TNAC and external fixation pin (topography above/below and at the...
Hypotheses about psychological processes are often tested using traditional mediation analysis. T... more Hypotheses about psychological processes are often tested using traditional mediation analysis. This analysis relies onmeasurement of a transmitting variable. Conducting this analysis has become almost synonymous with examining processhypotheses. An alternative strategy to mediation analysis (the Testing-a-Process-hypothesis-by-an-Interaction Strategy, TPIS) isillustrated here. TPIS is based on a fully experimental design whereby a hypothesized process is tested by an interaction betweenthe hypothesized cause of an effect and a contextual variable. In the interaction term, the contextual variable allows comparisonof the causal effect observed when the process is uninterrupted to the effect observed when the process is interrupted. Thus, TPIS translatesatheoreticalprocesshypothesis intoastatisticalinteractionhypothesisthatusesafully experimental designtodirectlyexamine the hypothesized process.
Statistical mediation and moderation have most prominently been distinguished by Baron and Kenny ... more Statistical mediation and moderation have most prominently been distinguished by Baron and Kenny (1986). More complex models that combine both of these effects have recently received increased attention, namely mediated moderation and moderated mediation (e.g., Muller, Judd, & Yzerbyt, 2005). Presently the focus is on a three variable model that is often claimed to represent an instance of moderated mediation or mediated moderation. More specifically, in this model a single variable is considered to simultaneously mediate and moderate the same effect. We show that this specific model however cannot be considered either an instance of mediated moderation nor of moderated mediation. Also, we argue that this particular model is a priori misspecified. A data pattern that seems to agree with this model is recognized as plausible, but it indicates that the model must be modified in one of two ways to be methodologically sound. We conclude by recommending to not use this three variable model and to consider evidence that seemingly agrees with it as evidence that the three variable model is inadequate.
While other research on social exclusion and rejection has revealed anti-social behavioral respon... more While other research on social exclusion and rejection has revealed anti-social behavioral respones to exclusion, research on ostracism in the Cyberball paradigm has found pro-social rather than anti-social behavioral reactions to ostracism. Participants have, however, not been given the opportunity to reciprocate ostracism within the Cyberball game. Three studies reported here tested whether ostracized participants retaliate in kind if given an opportunity to do so. Across all of them, common ostracism effects that have been found in the past were replicated, but no retaliation was detected.
Judgments about individual group members are often colored by judgments about the entire group. T... more Judgments about individual group members are often colored by judgments about the entire group. Through such an assimilation effect, an individual norm violator from a positively evaluated group, for example an ingroup, can be expected to be evaluated less negatively than an outgroup norm violator. This hypothesis however contrasts with evidence that ingroup norm violators are often derogated compared to outgroup norm violators, a phenomenon known as the Black Sheep Effect (BSE). The discussion of differences between the explanations of these opposite predictions (assimilation vs. BSE) lead us to the prediction that assimilation (and not a BSE) occurs if the ingroup adheres more to the societal norm than the outgroup and thus conveys positive valence to which an ingroup deviant evaluation is assimilated. This predicted pattern was indeed found in Study 1 and replicated in Study 2. Additionally, Study 2 provides evidence that this effect is, consistent with the present theorizing, mediated by group valence. The current research suggests that a BSE can be eliminated or even reversed by assimilation effects -a suggestion that is in line with other differentiations in the literature regarding the circumstances under which a BSE, no difference, or even ingroup favoritism occurs. (195 words)
Following realistic group-conXict theory, negative interdependence between groups (e.g., competit... more Following realistic group-conXict theory, negative interdependence between groups (e.g., competition) leads to prejudice towards the opposing outgroup. Based on research on mindset priming, it is hypothesized that competition increases prejudice, regardless of whether the derogated outgroup is involved in the competition or not. In Experiment 1, participants remembered an event involving either competition or cooperation; in Experiments 2 and 3 they participated in a competitive, cooperative, or individual assessment of their knowledge. Subsequent measures indicated that competition results in higher levels of prejudice, even when it is not related to the intergroup context. Additional evidence suggests that this eVect is not driven by the transfer of negative aVect or ego-depletion. Possible underlying cognitive processes are discussed.
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Papers by Johann Jacoby
We show that this specific model however cannot be considered either an instance of mediated moderation nor of moderated mediation. Also, we argue that this particular model is a priori misspecified. A data pattern that seems to agree with this model is recognized as plausible, but it indicates that the model must be modified in one of two ways to be methodologically sound. We conclude by recommending to not use this three variable model and to consider evidence that seemingly agrees with it as evidence that the three variable model is inadequate.
We show that this specific model however cannot be considered either an instance of mediated moderation nor of moderated mediation. Also, we argue that this particular model is a priori misspecified. A data pattern that seems to agree with this model is recognized as plausible, but it indicates that the model must be modified in one of two ways to be methodologically sound. We conclude by recommending to not use this three variable model and to consider evidence that seemingly agrees with it as evidence that the three variable model is inadequate.