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Detailed feedback on exercises helps learners become proficient but is time-consuming for educators and, thus, hardly scalable. This manuscript evaluates how well Generative Artificial Intelligence (AI) provides automated feedback on complex multimodal exercises requiring coding, statistics, and economic reasoning. Besides providing this technology through an easily accessible web application, this article evaluates the technology’s performance by comparing the quantitative feedback (i.e., points achieved) from Generative AI models with human expert feedback for 4,349 solutions to marketing analytics exercises. The results show that automated feedback produced by Generative AI (GPT-4) provides almost unbiased evaluations while correlating highly with (r = 0.94) and deviating only 6 % from human evaluations. GPT-4 performs best among seven Generative AI models, albeit at the highest cost. Comparing the models’ performance with costs shows that GPT-4, Mistral Large, Claude 3 Opus, and Gemini 1.0 Pro dominate three other Generative AI models (Claude 3 Sonnet, GPT-3.5, and Gemini 1.5 Pro). Expert assessment of the qualitative feedback (i.e., the AI’s textual response) indicates that it is mostly correct, sufficient, and appropriate for learners. A survey of marketing analytics learners shows that they highly recommend the app and its Generative AI feedback. An advantage of the app is its subject-agnosticism—it does not require any subject- or exercise-specific training. Thus, it is immediately usable for new exercises in marketing analytics and other subjects.
Einige Beiträge zum aktuellen ZfL-Jahresthema erinnerten zuletzt an dieser Stelle daran, dass das Begriffspaar "Aktivismus und Wissenschaft" von einem alten Spannungsverhältnis geprägt ist, welches sich gegenwärtig wieder bemerkbar macht. [...] Tatsächlich sehen sich Forschende heutzutage immer öfter dazu genötigt, den unmittelbar praktischen Mehrwert ihrer Arbeit im Namen eines vermeintlichen Aktivismus zu Markte zu tragen, nicht zuletzt, um den Empfang etwaiger Fördergelder zu rechtfertigen. [...] So drängt sich die Frage auf, worin eigentlich der kritische Zug im Verhältnis von Wissenschaft und Aktivismus liegt, wenn die institutionelle Konvergenz der Aktivismen von oben und unten zur Affirmation tendiert? [...] Möglicherweise ist es lohnenswert, Geulens Verfahren des Rückgriffs aufzunehmen und sich auf ein weiteres streitbares Beispiel aus der frühesten Geschichte des Aktivismusbegriffs zu besinnen, von dem zuweilen behauptet wird, es handele sich um die früheste Okkurenz dieses Wortes überhaupt. Die Rede ist vom sogenannten "literarischen Aktivismus", auf den auch Henning Trüper in seinem Blogbeitrag zum ZfL-Jahresthema anspielt, wenn er vom "Umfeld des Expressionismus" spricht, in dem der "Aktivismusbegriff nach dem Ersten Weltkrieg erstmals politisch Fuß fasste". Was hat es hiermit auf sich? Tatsächlich ist es so, dass Kurt Hiller (1885–1972) - deutsch-jüdischer Publizist, expressionistischer Impresario und pazifistischer Aktivist - diese Wortprägung für sich beansprucht. So soll bei einem Treffen seines Berliner Kreises anno 1914 "Literarischer Aktivismus" als Name der von ihm gegründeten, "ethisch-politischen" Bewegung beschlossen worden sein. Die Organe dieses Aktivismus waren vorrangig Periodika, allen voran die ab 1916 von Hiller und seinem Kreis herausgegebene Zeitschrift "Das Ziel: Aufrufe zu tätigem Geist", in deren Namen sich bereits eine gewisse Vorstellung von Aktivität ankündigt.
Soziodizee des Kapitalismus
(2024)
Mnemonic but not contextual feedback signals defy dedifferentiation in the aging early visual cortex
(2024)
Perception is an intricate interplay between feedforward visual input and internally generated feedback signals that comprise concurrent contextual and time-distant mnemonic (episodic and semantic) information. Yet, an unresolved question is how the composition of feedback signals changes across the lifespan and to what extent feedback signals undergo age-related dedifferentiation, that is, a decline in neural specificity. Previous research on this topic has focused on feedforward perceptual representation and episodic memory reinstatement, suggesting reduced fidelity of neural representations at the item and category levels. In this fMRI study, we combined an occlusion paradigm that filters feedforward input to the visual cortex and multivariate analysis techniques to investigate the information content in cortical feedback, focusing on age-related differences in its composition. We further asked to what extent differentiation in feedback signals (in the occluded region) is correlated to differentiation in feedforward signals. Comparing younger (18–30 years) and older female and male adults (65–75 years), we found that contextual but not mnemonic feedback was prone to age-related dedifferentiation. Semantic feedback signals were even better differentiated in older adults, highlighting the growing importance of generalized knowledge across ages. We also found that differentiation in feedforward signals was correlated with differentiation in episodic but not semantic feedback signals. Our results provide evidence for age-related adjustments in the composition of feedback signals and underscore the importance of examining dedifferentiation in aging for both feedforward and feedback processing.
Mitochondria are dynamic organelles exhibiting diverse shapes. While the variation of shapes, ranging from spheres to elongated tubules, and the transition between them, are clearly seen in many cell types, the molecular mechanisms governing this morphological variability remain poorly understood. Here, we propose a novel shaping mechanism based on the interplay between the inner and outer mitochondrial membranes. Our biophysical model suggests that the difference in surface area, arising from the pulling of the inner membrane into cristae, correlates with mitochondrial elongation. Analysis of live cell super-resolution microscopy data supports this correlation, linking elongated shapes to the extent of cristae in the inner membrane. Knocking down cristae shaping proteins further confirms the impact on mitochondrial shape, demonstrating that defects in cristae formation correlate with mitochondrial sphericity. Our results suggest that the dynamics of the inner mitochondrial membrane are important not only for simply creating surface area required for respiratory capacity, but go beyond that to affect the whole organelle morphology. This work explores the biophysical foundations of individual mitochondrial shape, suggesting potential links between mitochondrial structure and function. This should be of profound significance, particularly in the context of disrupted cristae shaping proteins and their implications in mitochondrial diseases.
Highlights
• It is important to distinguish acute provoked seizures due to autoimmune encephalitis from chronic unprovoked seizures due to autoimmune-associated epilepsy.
• Currently it is hardly possible in an individual AIE/ALE/RE patient to separate acute provoked seizures from chronic unprovoked seizures due to limitations in determining seizure outcomes, unclear time courses, potential causal interactions between both seizure origins, compartmentalized immune-inflammation, and a lack of licensed drugs to reliably resolve immune-inflammation in the brain parenchyma.
• This makes it hard to decide when to terminate ASMs and to counsel the individual patient regarding driving abilities and other behavioral restrictions and recommendations.
• Studies are urgently needed to define clinical and paraclinical biomarkers in a hypothesis-free, data-driven approach reliably predicting (or not) the development of AAE and the cognitive and behavioral outcome in the due course of an individual patient´s disease.
• These studies should be experimentally validated in suitable animal models.
Abstract
The current International League Against Epilepsy (ILAE) definition and classification guidelines for the first time introduced the category of immune-mediated focal epilepsy in addition to structural, genetic, infectious, and metabolic aetiologies. Moreover, the ILAE Autoimmunity and Inflammation Taskforce recently provided a conceptual framework for the distinction between acute “provoked” seizures in the acute phase of autoimmune encephalitis from chronic “unprovoked” seizures due to autoimmune-associated epilepsy. The first category predominately applies to those autoimmune encephalitis patients with autoantibodies against cell surface neural antigens, in whom autoantibodies are assumed to exert a direct ictogenic effect without overt structural damage. These patients do not exhibit enduring predisposition to seizures after the “acute phase” encephalitis, and thus do not fulfil the definition of epilepsy. The second category applies to those autoimmune encephalitis patients with autoantibodies against intracellular neural antigens and Rasmussen's encephalitis, in whom T cells are assumed to cause epileptogenic effects through immune-inflammation and overt structural damage. These patients do exhibit enduring predisposition to seizures after the “acute phase” of encephalitis and thus fulfil the definition of epilepsy. AAE may result from both, ongoing brain autoimmunity and associated structural brain damage according to the current ILAE definition and classification guideline. We here discuss the shortcomings and defaults of this concept and suggest an unbiased translationally validated and data-driven approach to predict in an individual encephalitis patient the propensity to develop (or not) AAE and the cognitive and behavioural outcome.
We present a relativistic Shakhov-type generalization of the Anderson-Witting relaxation time model for the Boltzmann collision integral to modify the ratio of momentum diffusivity to thermal diffusivity. This is achieved by modifying the path on which the single particle distribution function fk approaches local equilibrium f0k by constructing an intermediate Shakhov-type distribution fSk similar to the 14-moment approximation of Israel and Stewart. We illustrate the effectiveness of this model in case of the Bjorken expansion of an ideal gas of massive particles and the damping of longitudinal waves through an ultrarelativistic ideal gas.
Highlights
• Solidification and cooling of an intruded dyke or sill within the middle or shallow crust generate stresses of order 200 MPa, which relax on time scales of a few years to million years.
• Stresses may exceed the brittle strength forming tensile fractures.
• Combined with the pressure gradient within the over-pressurized felsic melts, this explains the migration of felsic contact melt into shrinkage cracks (Sederholm-type veins).
Abstract
Rapid emplacement of a mafic dyke or sill at mid-crustal depth heats and possibly melts the felsic wall rock followed by solidification. Associated volume changes generate stresses, possibly enforcing brittle failure and melt migration. We model the evolution of melting, solidification, temperature, and stress including visco-elastic relaxation in 1D - dykes or -sills using realistic rock rheologies of the Weschnitz pluton (Odenwald). For deep emplacement (Case 1, 15.3 km) extensive contact melting of the wall rock occurs, for shallow emplacement (Case 2, 10 km) it is negligible. The stresses are zero at high melt fractions, but increase during solidification and cooling: The intrusion orthogonal stress is always zero. The intrusion parallel stress σ‖ within the intrusion is tensile (O(200 MPa)). It relaxes on a time scale between a few years (Case 1) and 0.6 m.y. (Case 2). Within the wall rock σ‖ is compressive during heating, but becomes tensile under solidification and cooling. Wall rock stresses relax on a time scale of months to 100 years. A Deborah number is defined based on viscous to thermal relaxation allowing generalization of our results. Adding lithostatic stresses, the total stresses of Case 1 remain below the brittle strength, while for Case 2 they may exceed it. Adding the lithostatic pressure to the melt pressure, the effective stresses exceed the brittle strength and intrusion orthogonal tensile fractures are predicted. Combined with the pressure gradient within the over-pressurized felsic melts generated in the wall rock, this explains the migration of felsic contact melt into shrinkage cracks of the mafic sill in the Weschnitz pluton.
Das radioaktive Edelgas Radon und seine ebenfalls radioaktiven Zerfallsprodukte machen den größten Teil der natürlichen Strahlenbelastung in Deutschland aus. Trotz der Einstufung als krebserregend für Lungenkrebs wird es zur Therapie entzündlicher Krankheiten eingesetzt. Der hauptsächliche Aufnahmemechanismus ist dabei die Inkorporation über die Atmung, wobei Radon auch über die Haut aufgenommen werden kann. Radon wird dabei über das Blut im gesamten Körper verteilt und kann in Gewebe mit hoher Radonlöslichkeit akkumulieren. Die Zerfallsprodukte verbleiben jedoch in der Lunge, zerfallen dort, bevor sie abtransportiert werden können und schädigen das dortige Gewebe.
Die Lungendosis wird laut Simulationen zum größten Teil durch die kleinsten Radon-Zerfallsprodukte (< 10 nm) bestimmt, die besonders effektiv im Respirationstrakt anheften. Die erzeugte Dosis ist dabei aufgrund der inhomogenen Anlagerung der Zerfallsprodukte lokal stark variabel. In Simulationen wurden Bifurkationen als Ort besonders hoher Deposition identifiziert, wobei die experimentelle Datenlage zur Deposition kleinster Radon-Zerfallsprodukte eingeschränkt ist. Aufgrund des Anstiegs der Komplexität von Simulationen oder Experimenten wird in den meisten Betrachtungen nicht der oszillatorische Atemzyklus berücksichtigt, sondern lediglich ein einseitig gerichteter Luftstrom betrachtet. Im Rahmen dieser Arbeit wurde ein experimentelles Modell entwickelt und etabliert, das die Messung der Deposition von Radon-Zerfallsprodukten ermöglicht und zwischen drei Größenfraktionen (Freie Zerfallsprodukte: < 10 nm, Cluster: 20-100 nm, Angelagerte Zerfallsprodukte: > 100 nm) unterscheiden kann. Der Luftfluss durch das Modell bildet sowohl die Inhalation als auch die Exhalation ab. Erste Experimente mit dem neu entwickelten Messaufbau konnten die aus Simulationen bekannte erhöhte Deposition der freien Zerfallsprodukte in einer Bifurkation abbilden. Die Vergrößerung des Bifurkationswinkels von 70° auf 180° zeigte lediglich einen minimalen Anstieg in der Größenordnung des Messfehlers. Der dominierende Prozess der Anlagerung der freien Zerfallsprodukte ist die Brown'sche Molekularbewegung, die unabhängig vom Bifurkationswinkel ist. Dennoch kann ein veränderter Winkel die Luftströmung und entstehende Turbulenzen verändern, wodurch die Deposition beeinflusst werden kann. Dies lässt sich jedoch mit dem hier benutzten Messaufbau nicht auflösen. Entgegen der Beobachtungen in der Literatur führte die Erhöhung der Atemfrequenz von 12 auf 30 Atemzüge pro Minute, in den im Rahmen dieser Arbeit durchgeführten Experimenten, zu keiner messbaren Veränderung der Deposition. Diese Beobachtung ist auf die Entstehung gegensätzlicher Effekte zurückzuführen. Einerseits führt eine schnellere Luftströmung zu kürzeren Aufenthaltszeiten der freien Zerfallsprodukte im Modell, wodurch die Deposition unwahrscheinlicher wird. Andererseits entstehen vermehrt sekundäre Strömungen und absolut betrachtet werden mehr Partikel durch das Modell gepumpt. Es ist davon auszugehen, dass sich diese Effekte im hier getesteten Bereich aufheben.
Als potentielle Schutzmaßnahme zur Reduktion der Lungendosis konnte im Rahmen dieser Arbeit die Filtereffzienz von Gesichtsmasken (OP-Masken, FFP2 Masken) gegenüber Radon und seinen Zerfallsprodukten bestimmt werden. Während Radon nicht gefiltert wird, wurden die freien Zerfallsprodukte fast vollständig (> 98%) und die Cluster zum größten Teil (≈ 80 %) zurückgehalten.
Radon selbst kann im gesamten Organismus verteilt werden und dort in Gewebe akkumulieren. Zur Bestimmung der Dosis wird dabei auf biokinetische Modelle zurückgegriffen. Diese sind von der Qualität ihrer Eingabeparameter abhängig, wobei beispielsweise die Werte zur Verteilung von Radon zwischen Blut und Gewebe auf experimentell gewonnenen Löslichkeitswerten aus Mäusen und Ratten beruhen. Unbekannte Werte werden von der Internationalen Strahlenschutzkommission basierend auf der Gewebezusammensetzung als gewichteter Mittelwert berechnet. In dieser Arbeit wurde die Löslichkeit in humanen Blutproben und wässrigen Lösungen verschiedener Konzentrationen der Blutproteine Hämoglobin und Albumin bestimmt. Es löste sich mehr Radon in Plasma als in Erythrozytenkonzentrat und Vollblut. Die Protein-Lösungen zeigten keine Konzentrationsabhängigkeit der Löslichkeit, sondern lediglich in hitzedenaturiertem Hämoglobin wurde eine niedrigere Löslichkeit gemessen. Basierend auf diesen Beobachtungen, sollte die These überprüft werden, ob sich die Löslichkeit einer Mischung als gewichteter Mittelwert der einzelnen Löslichkeiten berechnen lässt. Daher wurden diese in einer Mischung aus zwei Flüssigkeiten (1-Pentanol, Ölsäure) bestimmt. Die experimentell bestimmte Löslichkeit war dabei fast doppelt so groß wie der berechnete Wert. Dieser Unterschied kann dadurch zustande kommen, dass bei einer Berechnung basierend auf der Zusammensetzung die Wechselwirkungen zwischen den Lösungsmitteln vernachlässigt werden. Dies verdeutlicht die Notwendigkeit experimenteller Daten zur Verteilung und Lösung von Radon in verschiedenem Gewebe.
We measure the Born cross section for the reaction e+e−→ηhc from s√=4.129 to 4.600~GeV using data sets collected by the BESIII detector running at the BEPCII collider. A resonant structure in the cross section line shape near 4.200~GeV is observed with a statistical significance of 7σ. The parameters of this resonance are measured to be \MeasMass\ and \MeasWidth, where the first uncertainties are statistical and the second systematic.
We measure triangular flow relative to the reaction plane at 3 GeV center-of-mass energy in Au+Au collisions at the BNL Relativistic Heavy Ion Collider. A significant v3 signal for protons is observed, which increases for higher rapidity, higher transverse momentum, and more peripheral collisions. The triangular flow is essentially rapidity-odd with a slope at mid-rapidity, dv3/dy|(y=0), opposite in sign compared to the slope for directed flow. No significant v3 signal is observed for charged pions and kaons. Comparisons with models suggest that a mean field potential is required to describe these results, and that the triangular shape of the participant nucleons is the result of stopping and nuclear geometry.
We report results on an elastic cross section measurement in proton-proton collisions at a center-of-mass energy s√=510 GeV, obtained with the Roman Pot setup of the STAR experiment at the Relativistic Heavy Ion Collider (RHIC). The elastic differential cross section is measured in the four-momentum transfer squared range 0.23≤−t≤0.67 GeV2. We find that a constant slope B does not fit the data in the aforementioned t range, and we obtain a much better fit using a second-order polynomial for B(t). The t dependence of B is determined using six subintervals of t in the STAR measured t range, and is in good agreement with the phenomenological models. The measured elastic differential cross section dσ/dt agrees well with the results obtained at s√=546 GeV for proton--antiproton collisions by the UA4 experiment. We also determine that the integrated elastic cross section within the STAR t-range is σfidel=462.1±0.9(stat.)±1.1(syst.)±11.6(scale) μb.
We report results on an elastic cross section measurement in proton-proton collisions at a center-of-mass energy s√=510 GeV, obtained with the Roman Pot setup of the STAR experiment at the Relativistic Heavy Ion Collider (RHIC). The elastic differential cross section is measured in the four-momentum transfer squared range 0.23≤−t≤0.67 GeV2. We find that a constant slope B does not fit the data in the aforementioned t range, and we obtain a much better fit using a second-order polynomial for B(t). The t dependence of B is determined using six subintervals of t in the STAR measured t range, and is in good agreement with the phenomenological models. The measured elastic differential cross section dσ/dt agrees well with the results obtained at s√=546 GeV for proton--antiproton collisions by the UA4 experiment. We also determine that the integrated elastic cross section within the STAR t-range is σfidel=462.1±0.9(stat.)±1.1(syst.)±11.6(scale) μb.
We report results on an elastic cross section measurement in proton-proton collisions at a center-of-mass energy s√=510 GeV, obtained with the Roman Pot setup of the STAR experiment at the Relativistic Heavy Ion Collider (RHIC). The elastic differential cross section is measured in the four-momentum transfer squared range 0.23≤−t≤0.67 GeV2. We find that a constant slope B does not fit the data in the aforementioned t range, and we obtain a much better fit using a second-order polynomial for B(t). The t dependence of B is determined using six subintervals of t in the STAR measured t range, and is in good agreement with the phenomenological models. The measured elastic differential cross section dσ/dt agrees well with the results obtained at s√=546~GeV for proton--antiproton collisions by the UA4 experiment. We also determine that the integrated elastic cross section within the STAR t-range is σfidel=462.1±0.9(stat.)±1.1(syst.)±11.6(scale) μb.
Atomic nuclei are self-organized, many-body quantum systems bound by strong nuclear forces within femtometer-scale space. These complex systems manifest a diverse set of shapes~, traditionally explored via non-invasive spectroscopic techniques at low energies. Their instantaneous shapes, obscured by long-timescale quantum fluctuations, are considered not directly observable at low energy. We introduce a complementary method, collective flow assisted nuclear shape imaging, to image the nuclear global shape by colliding them at ultrarelativistic speeds and analyzing the collective response of outgoing debris. This technique captures a collision-specific snapshot of the spatial matter distribution in the nuclei, which, through the hydrodynamic expansion, leaves imprints on the particle momentum distribution patterns observed in detectors. We benchmark this method in collisions of ground state Uranium-238 nuclei, known for its elongated, axial-symmetric shape. Our findings, while confirming an overall deformation broadly consistent with prior low-energy experiments, also indicate a small deviation from axial symmetry in the nuclear ground state. This approach marks a new way of imaging nuclei, especially those with uncertain shape characteristics, and refines initial conditions in high-energy nuclear collisions. It tackles the important issue of nuclear structure evolution across various energy scales.
We report the first measurements of cumulants, up to 4𝑡ℎ order, of deuteron number distributions and protondeuteron correlations in Au+Au collisions recorded by the STAR experiment in phase-I of Beam Energy Scan (BES) program at the Relativistic Heavy Ion Collider. Deuteron cumulants, their ratios, and proton-deuteron mixed cumulants are presented for different collision centralities covering a range of center-of-mass energy per nucleon pair √𝑠NN = 7.7 to 200 GeV. It is found that the cumulant ratios at lower collision energies favor a canonical ensemble over a grand canonical ensemble in thermal models. An anti-correlation between proton and deuteron multiplicity is observed across all collision energies and centralities, consistent with the expectation from global baryon number conservation. The UrQMD model coupled with a phase-space coalescence mechanism qualitatively reproduces the collision-energy dependence of cumulant ratios and proton-deuteron correlations.