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Wege zur Steigerung von Interesse und Leistung im Bereich Forschungsmethoden bei Studierenden der Erziehungswissenschaft. Vom (Nicht-)Wirken einer Nutzwertintervention
No full textDer Erwerb forschungsmethodischer Kompetenzen ist zentral im erziehungswissenschaftlichen Studium, stößt jedoch häufig auf geringes Interesse. Nutzwertinterventionen sollen dieses Interesse durch Steigerung der wahrgenommenen Relevanz fördern, zeigen aber uneinheitliche Effekte. Diese Arbeit untersucht, ob berufliche Zukunftsvorstellungen der Studierenden die Wirksamkeit einer solchen Intervention beeinflussen. In Teilstudie 1 (N = 34) erhöhte die Intervention weder Nutzenwahrnehmung noch Interesse; berufliche Zukunftsvorstellungen zeigten keinen moderierenden Effekt. Teilstudie 2 (N = 13 Interviews) beleuchtete die Perspektive der Teilnehmenden: Unklare Aufgabenstellungen und Schwierigkeiten bei der Ableitung praxisrelevanter Bezüge erschwerten die Reflexion über den potenziellen Nutzen. Die Ergebnisse liefern Hinweise für die theoretische Weiterentwicklung und hochschuldidaktische Umsetzung von Maßnahmen zur Förderung forschungsmethodischer Kompetenzen.Developing research methodology skills is a core component of educational science programs, yet it often meets with limited student interest. Utility-value interventions aim to enhance such interest by increasing perceived relevance, but their effects have been inconsistent. This study examines whether students’ occupational possible selves moderate the effectiveness of such an intervention. In Study 1 (N = 34), the intervention increased neither perceived utility nor interest; occupational possible selves showed no moderating effect. Study 2 (N = 13 interviews) explored participants’ perspectives: unclear task instructions and difficulties in identifying practice-relevant connections hindered deeper reflection on potential utility. The findings offer insights for the theoretical refinement and higher education implementation of measures designed to foster research methodology skills
A magnetic resonance imaging based radiomics model to predict mitosis cycles in intracranial meningioma
No full textThe aim of this study was to develop a magnetic resonance imaging (MRI) based radiomics model to predict mitosis cycles in intracranial meningioma grading prior to surgery. Preoperative contrast-enhanced T1-weighted (T1CE) cerebral MRI data of 167 meningioma patients between 2015 and 2020 were obtained, preprocessed and segmented using the 3D Slicer software and the PyRadiomics plugin. In total 145 radiomics features of the T1CE MRI images were computed. The criterion on the basis of which the feature selection was made is whether the number of mitoses per 10 high power field (HPF) is greater than or equal to zero. Our analyses show that machine learning algorithms can be used to make accurate predictions about whether the number of mitoses per 10 HPF is greater than or equal to zero. We obtained our best model using Ridge regression for feature pre-selection, followed by stepwise logistic regression for final model construction. Using independent test data, this model resulted in an AUC (Area under the Curve) of 0.8523, an accuracy of 0.7941, a sensitivity of 0.8182, a specificity of 0.7500 and a Cohen’s Kappa of 0.5576. We analyzed the performance of this model as a function of the number of mitoses per 10 HPF. The model performs well for cases with zero mitoses as well as for cases with more than one mitosis per 10 HPF. The worst model performance (accuracy = 0.6250) is obtained for cases with one mitosis per 10 HPF. Our results show that MRI-based radiomics may be a promising approach to predict the mitosis cycles in intracranial meningioma prior to surgery. Specifically, our approach may offer a non-invasive means of detecting the early stages of a malignant process in meningiomas prior to the onset of clinical symptoms
Der nächste große Erdrutsch:Betrachtungen zur niederländischen Parlamentswahl vom 22. November 2023
No full textIn den letzten Jahrzehnten haben sich die politischen Kräfteverhältnisse in den Niederlanden kontinuierlich und dabei oftmals drastisch gewandelt. Nach den einzelnen Parlamentswahlen wurde in der Berichterstattung immer wieder von politischen Erdrutschen gesprochen. Bei der Wahl am 22. November 2023 wurden alle bisherigen Rekorde hinsichtlich des Ausmaßes der Verschiebungen übertroffen. Es ist somit zweifelsohne gerechtfertigt, von einem historischen Wahlergebnis zu sprechen. Die Resultate der Abstimmung haben aber noch aus anderen Gründen weit über die Landesgrenzen hinaus für intensive Diskussionen gesorgt. Der wichtigste hiervon ist sicherlich der Wahlsieg der nationalpopulistischen Partij voor de Vrijheid (PVV), die 23,5 Prozent der Stimmen erhielt und damit mit deutlichem Abstand zur stärksten politischen Kraft wurde. In diesem Sammelband findet eine Auseinandersetzung mit zentralen Kontexten, Resultaten und Auswirkungen der Wahl vom 22. November 2023 statt
The Up-or-out Rule
No full textDie Up-or-out-Regel besagt, dass Assistenten in Partnerschaften (oder auch Universitäten) nach einer gewissen Zeit zu Partnern aufsteigen oder die Partnerschaft verlassen müssen. Eine dauerhafte Assistententätigkeit ist nicht möglich. Dies wirft die Frage auf, warum nicht Assistent bleiben darf, wer auf dieser Position seine Kosten mehr als erwirtschaftet, auch wenn seine Produktivität zur Beförderung zum Partner nicht ausreicht. Es werden unterschiedliche ökonomische Erklärungsansätze zur Beantwortung dieser Frage untersucht. Nach Zurückweisung des weit verbreiteten, aber unplausiblen Ansatzes, dass die Partnerschaft zur Selbstbindung an ihr implizites Beförderungsversprechen Assistenten in deren eigenem Interesse entlassen muss, lautet die Antwort, dass in Partnerschaften die fragliche Situation gar nicht auftritt und die Anwendung der Up-or-out-Regel deshalb als effizient einzuschätzen ist.The up-or-out rule states that assistants in partnerships (or universities) must become partners after a certain period of time or have to leave the partnership. Permanent assistantship is not possible. This raises the question of why someone is not being allowed to remain an assistant if he generates more in this position than he costs, even if his productivity is insufficient to promote him to a partner. Different economic explanations to answer this question are examined. After rejecting the widespread but implausible approach that the partnership has to dismiss assistants in their own interest in order to bind themselves to their implicit promotion promise, the answer is that in partnerships the situation in question does not occur at all and the application of the up-or-down out rule is therefore to be assessed as efficient
Disentangling the impact of cerebrospinal fluid formation and neuronal activity on solute clearance from the brain
No full textBackground: Despite recent attention, pathways and mechanisms of fluid transposition in the brain are still a matter of intense discussion and driving forces underlying waste clearance in the brain remain elusive. Consensus exists that net solute transport is a prerequisite for efficient clearance. The individual impact of neuronal activity and cerebrospinal fluid (CSF) formation, which both vary with brain state and anesthesia, remain unclear. Methods: To separate conditions with high and low neuronal activity and high and low CSF formation, different anesthetic regimens in naive rat were established, using Isoflurane (ISO), Medetomidine (MED), acetazolamide or combinations thereof. With dynamic contrast-enhanced MRI, after application of low molecular weight contrast agent (CA) Gadobutrol to cisterna magna, tracer distribution was monitored as surrogate for solute clearance. Simultaneous fiber-based Ca2+-recordings informed about the state of neuronal activity under different anesthetic regimen. T2-weighted MRI and diffusion-weighted MRI (DWI) provided size of subarachnoidal space and aqueductal flow as surrogates for CSF formation. Finally, a pathway and mechanism-independent two-compartment model was introduced to provide a measure of efficiency for solute clearance from the brain. Results: Anatomical imaging, DWI and Ca2+-recordings confirmed that conditions with distinct levels of neuronal activity and CSF formation were achieved. A sleep-resembling condition, with reduced neuronal activity and enhanced CSF formation was achieved using ISO+MED and an awake-like condition with high neuronal activity using MED alone. CA distribution in the brain correlated with the rate of CSF formation. The cortical brain state had major influence on tracer diffusion. Under conditions with low neuronal activity, higher diffusivity suggested enlargement of extracellular space, facilitating a deeper permeation of solutes into brain parenchyma. Under conditions with high neuronal activity, diffusion of solutes into parenchyma was hindered and clearance along paravascular pathways facilitated. Exclusively based on the measured time signal curves, the two-compartment model provided net exchange ratios, which were significantly larger for the sleep-resembling condition than for the awake-like condition. Conclusions: Efficiency of solute clearance in brain changes with alterations in both state of neuronal activity and CSF formation. Our clearance pathway and mechanism agnostic kinetic model informs about net solute transport, solely based on the measured time signal curves. This rather simplifying approach largely accords with preclinical and clinical findings
Eine Untersuchung zum Effekt von Cafedrin/ Theodrenalin versus Noradrenalin zur Therapie der intraoperativen Hypotension auf renale Stressbiomarker:Eine studienbegleitende Analyse von klinischen Daten zum Vergleich von Theodrenalin/ Cafedrin und Noradrenalin zur Behandlung der intraoperativen Hypotonie bei gefäßchirurgischen Patienten
No full textIn dieser monozentrischen Substudie wurde der Effekt von Cafedrin/Theodrenalin im Vergleich zu Noradrenalin auf den renalen Stressbiomarker ([TIMP-2][IGFBP7]) bei Patienten mit intraoperativer Hypotension (IOH) untersucht. Die Patienten wurden im Rahmen der HERO-Studie nach Induktion der Allgemeinanästhesie randomisiert entweder mit Cafedrin/Theodrenalin oder Noradrenalin behandelt. Dabei wurden prä- als auch postoperative Messungen der renalen Biomarker analysiert. Die Differenz betrug 0,17 ng/ml in der Cafedrin/Theodrenalin-Gruppe und 0,18 ng/ml in der Noradrenalin-Gruppe, mit einem p-Wert von 0,317. Es zeigte sich kein signifikanter Unterschied zwischen den Gruppen hinsichtlich der prä- und posteroperativer Differenz von [TIMP-2][IGFBP7]. Damit zeigen die Ergebnisse keinen Vorteil von Cafedrin/Theodrenalin gegenüber Noradrenalin in Bezug auf die Reduktion renaler Stressbiomarker
Establishment of a 3D co-culture model to investigate the role of primary fibroblasts in ductal carcinoma in situ of the breast
No full textBackground: Ductal carcinoma in situ (DCIS) is a precursor form of breast cancer. 13%–50% of these lesions will progress to invasive breast cancer, but the individual progression risk cannot be estimated. Therefore, all patients receive the same therapy, resulting in potential overtreatment of a large proportion of patients. Aims: The role of the tumor microenvironment (TME) and especially of fibroblasts appears to be critical in DCIS development and a better understanding of their role may aid individualized treatment. Methods and results: Primary fibroblasts isolated from benign or malignant punch biopsies of the breast and MCF10DCIS.com cells were seeded in a 3D cell culture system. The fibroblasts were cultured in a type I collagen layer beneath a Matrigel layer with MCF10DCIS.com cells. Dye-quenched (DQ) fluorescent collagen I and IV were used in collagen and Matrigel layer respectively to demonstrate proteolysis. Confocal microscopy was performed on day 2, 7, and 14 to reveal morphological changes, which could indicate the transition to an invasive phenotype. MCF10DCIS.com cells form smooth, round spheroids in co-culture with non-cancer associated fibroblasts (NAFs). Spheroids in co-culture with tumor-associated fibroblasts (TAFs) appear irregularly shaped and with an uneven surface; similar to spheroids formed from invasive cells. Therefore, these morphological changes represent the progression of an in situ to an invasive phenotype. In addition, TAFs show a higher proteolytic activity compared to NAFs. The distance between DCIS cells and fibroblasts decreases over time. Conclusion: The TAFs seem to play an important role in the progression of DCIS to invasive breast cancer. The better characterization of the TME could lead to the identification of DCIS lesions with high or low risk of progression. This could enable personalized oncological therapy, prevention of overtreatment and individualized hormone replacement therapy after DCIS
GEFAAR: a generic framework for the analysis of antimicrobial resistance providing statistics and cluster analyses
No full textEasy access to antimicrobial resistance data and meaningful visualization is essential to guide the empirical antimicrobial treatment and to promote the rational use of antimicrobial agents. Currently available solutions are commonly externally hosted, centralized systems. However, there is a need for close monitoring by local analysis tools. To fill this gap, we developed GEFAAR—a generic framework for the analysis of antimicrobial resistance data. Following the example of the German Robert Koch Institute (RKI), an interactive web-application is provided to determine basic pathogen and resistance statistics. In addition to the RKI’s externally maintained database, our application provides a generic framework to import tabular data and to analyze them safely in a local environment. Moreover, our application offers an intuitive web-based user interface to visualize resistance trend analysis as well as advanced cluster analyses on species- or clinic/unit level to generate alerts of potential transmission events
Knotless Suture Anchors Display Favorable Elongation but an Inferior Ultimate Failure Load Versus Titanium Suture Anchors and All-Suture Anchors: A Biomechanical Comparison in a Porcine Model
No full textBackground: Several types of suture anchors, which differ in their working principles, are available for fixation of ligamentous structures in knee surgery. How the choice of a suture anchor type influences the biomechanical stability of ligament fixation is largely unknown. Purpose: To compare the biomechanical properties of different suture anchor designs regarding primary stability for tendon fixation and repair in medial collateral ligament (MCL) surgery. Study Design: Controlled laboratory study. Methods: The primary stability of MCL fixation was assessed in a porcine model utilizing 1 of 3 suture anchor types: a 5.5-mm titanium suture anchor (TSA), a 2.8-mm all-suture anchor (ASA), or a 5.5-mm polyether ether ketone knotless suture anchor (KLSA). Primary stability was assessed using a uniaxial material testing machine. Cyclic loading at 50 N and 100 N was applied for 500 cycles each, followed by a load-to-failure test. Results: After 500 cycles at 50 N, the KLSA (2.4 ± 0.3 mm) showed significantly (P < .05) reduced elongation in comparison to the TSA (4.0 ± 0.9 mm) and ASA (3.6 ± 0.7 mm), and after 500 cycles at 100 N, the KLSA (6.5 ± 1.4 mm) again showed significantly (P < .05) reduced elongation in comparison to the TSA (11.0 ± 2.2 mm) and ASA (12.0 ± 3.6 mm). However, the KLSA (213 ± 27 N) showed a significantly (P < .05) inferior ultimate failure load in comparison to the TSA (300 ± 20 N) and ASA (348 ± 23 N). In comparison to the TSA (113.0 ± 11.0 N/mm) and ASA (113.6 ± 14.4 N/mm), the KLSA (150.7 ± 11.6 N/mm) displayed the highest stiffness (P < .05). No significant differences were observed regarding yield load. Conclusion: KLSAs displayed significantly reduced elongation, at the cost of a reduced ultimate failure load, in comparison to TSAs and ASAs.
Clinical Relevance: Surgeons should be aware that differences exist between different suture anchor types regarding their biomechanical stability. KLSAs may be favorable for fixation of peripheral ligaments in knee surgery
MePMe-seq: antibody-free simultaneous m6A and m5C mapping in mRNA by metabolic propargyl labeling and sequencing
No full textInternal modifications of mRNA have emerged as widespread and versatile regulatory mechanism to control gene expression at the post-transcriptional level. Most of these modifications are methyl groups, making S-adenosyl-L-methionine (SAM) a central metabolic hub. Here we show that metabolic labeling with a clickable metabolic precursor of SAM, propargyl-selenohomocysteine (PSH), enables detection and identification of various methylation sites. Propargylated A, C, and G nucleosides form at detectable amounts via intracellular generation of the corresponding SAM analogue. Integration into next generation sequencing enables mapping of N6-methyladenosine (m6A) and 5-methylcytidine (m5C) sites in mRNA with single nucleotide precision (MePMe-seq). Analysis of the termination profiles can be used to distinguish m6A from 2′-O-methyladenosine (Am) and N1-methyladenosine (m1A) sites. MePMe-seq overcomes the problems of antibodies for enrichment and sequence-motifs for evaluation, which was limiting previous methodologies. Metabolic labeling via clickable SAM facilitates the joint evaluation of methylation sites in RNA and potentially DNA and proteins