פרסומים

This research uncovers a groundbreaking link between electron spin and proton transport in biological environment, using lysozyme as a model system. Proton transfer, vital in many life processes, is shown to couple with electron spin polarization, a discovery aligned with the Chiral Induced Spin Selectivity (CISS) effect. Specifically, we show that proton conduction through the lysozyme crystal is selective to the polarization of injected electrons, highlighting a synergy between spin polarization and information transfer in life. This mechanism provides insights into proton-coupled electron transfer (PCET) processes, emphasizing the role of chirality in biological processes. These findings bridge quantum physics with biochemistry enabling better understanding and opening the possibility of controlled information transfer in biological environments. Proton transport plays a fundamental role in many biological and chemical systems. In life, proton transport is crucial for biochemical and physiological functions. It is usually accepted that the main mechanism of proton transfer is a result of hopping between neighboring water molecules and amino acid side chains. It was recently suggested that the proton transfer can be simultaneously coupled with electron transfer. As life is homochiral, proton transfer in biology is occurring in a chiral environment. In this environment, the chiral-induced spin selectivity effect relating to electron transfer and chirality is expected to occur. The present work establishes that the proton transfer is coupled to a specific electron spin polarization in lysozyme crystals, associating proton transfer to electron movement and polarization. To preserve total angular momentum, this motion may be coupled to chiral phonons that propagate in the crystal. Our work shows that the interaction of the electrons' spin and phonons is very significant in proton transfer through lysosome crystals. Injecting the opposite electron spin into the lysosome crystal results in a significant change in proton transfer impedance. This study presents the support for the proton-coupled electron transfer mechanism and indicates the importance of spin polarization in the process.This research uncovers a groundbreaking link between electron spin and proton transport in biological environment, using lysozyme as a model system. Proton transfer, vital in many life processes, is shown to couple with electron spin polarization, a discovery aligned with the Chiral Induced Spin Selectivity (CISS) effect. Specifically, we show that proton conduction through the lysozyme crystal is selective to the polarization of injected electrons, highlighting a synergy between spin polarization and information transfer in life. This mechanism provides insights into proton-coupled electron transfer (PCET) processes, emphasizing the role of chirality in biological processes. These findings bridge quantum physics with biochemistry enabling better understanding and opening the possibility of controlled information transfer in biological environments. Proton transport plays a fundamental role in many biological and chemical systems. In life, proton transport is crucial for biochemical and physiological functions. It is usually accepted that the main mechanism of proton transfer is a result of hopping between neighboring water molecules and amino acid side chains. It was recently suggested that the proton transfer can be simultaneously coupled with electron transfer. As life is homochiral, proton transfer in biology is occurring in a chiral environment. In this environment, the chiral-induced spin selectivity effect relating to electron transfer and chirality is expected to occur. The present work establishes that the proton transfer is coupled to a specific electron spin polarization in lysozyme crystals, associating proton transfer to electron movement and polarization. To preserve total angular momentum, this motion may be coupled to chiral phonons that propagate in the crystal. Our work shows that the interaction of the electrons' spin and phonons is very significant in proton transfer through lysosome crystals. Injecting the opposite electron spin into the lysosome crystal results in a significant change in proton transfer impedance. This study presents the support for the proton-coupled electron transfer mechanism and indicates the importance of spin polarization in the process.

This essay examines poems about cremation written by adherents of both 19^th-century German bourgeois initiatives to reintroduce cremation and the early 20^th-century German proletarian freethought movement. Supporters of these currents held secularist views. Cremation poems can be considered a laboratory of secularism in which certain secularist truths and beliefs could be formulated and expressed in compelling ways. Notably, these poems fleshed out secularism by paying particular attention to its emotional aspects. The poems discussed point to the existence of a secularist, cremationist emotional community across class and temporal boundaries. The essay contributes to the study of secularist mentalities and convictions in the 19^th and 20^th centuries, probing the role of poetry in establishing secularist themes and positions.

 

September 2024: Carolin Kosuch is a historian with research interests in Jewish history, secularism, anarchism and intellectual history. After holding positions at Leipzig’s Simon Dubnow Institute for Jewish History and Culture and the German Historical Institute in Rome, she completed her habilitation project on secularism and death in Western modernities at the chair of Rebekka Habermas, University of Göttingen, in summer 2023. She teaches courses in 19^th and 20^th century transnational history, the history of gender, technology and Jewish history. Her work was funded by the German Research Foundation. Since winter term 2023/24, she represents the chair of Rebekka Habermas (December 2023) at the University of Göttingen.

Protein–protein interactions are modulated by their environment. High macromolecular solute concentrations crowd proteins and shift equilibria between protein monomers and their assemblies. We aim to understand the mechanism of crowding by elucidating the molecular-level interactions that determine dimer stability. Using 19F-NMR spectroscopy, we studied the effects of various polyethylene glycols (PEGs) on the equilibrium thermodynamics of two protein complexes: a side-by-side and a domain-swap dimer. Analysis using our mean-field crowding model shows that, contrary to classic crowding theories, PEGs destabilize both dimers through enthalpic interactions between PEG and the monomers. The enthalpic destabilization becomes more dominant with increasing PEG concentration because the reduction in PEG mesh size with concentration diminishes the stabilizing effect of excluded volume interactions. Additionally, the partially folded domain-swap monomers fold in the presence of PEG, contributing to dimer stabilization at low PEG concentrations. Our results reveal that polymers crowd protein complexes through multiple conjoined mechanisms, impacting both their stability and oligomeric state.

Innovations, such as symbolic artifacts, are a product of cognitive abilities but also of cultural context. Factors that may determine the emergence and retention of an innovation include the population's pre-existing cultural repertoire, exposure to relevant ways of thinking, and the invention's utility. Thus, we suggest that the production of symbolic artifacts is not guaranteed even in cognitively advanced societies.

The electoral success of right-wing populist parties is often attributed to disaffection among certain voters. But while economic explanations for this disaffection are theoretically clear and quantifiable, explanations centered on cultural factors offer vaguer accounts that are harder to evaluate empirically. We address this problem by theoretically distinguishing between five different “storylines” about the cultural origins of populism, and then test them using extensive data from Europe and the United States. Our analysis indicates that concerns about ethno-cultural change induced by immigration are central to understanding the populist vote; so, but to a lesser extent, is rural resentment and status anxiety. In contrast, explanations centered on communal disintegration or an intergenerational values divide are pertinent in only specific cases. The analysis helps disentangle the cultural forces associated with the rise of populism and highlights the heterogeneous coalitions that form the populist base across different countries.

This paper explores the role of self-image concerns and a sense of entitlement in decisions involving resource allocation, when individuals can choose to seek or avoid information about the needs of others. We review research showing that people often engage in willful ignorance to protect their moral self-image while pursuing their self-interest. We propose, however, that to fully understand self-image protection as a driver of deliberate ignorance, it is essential to examine the underlying attitudes that support and sustain this motivation. As an example, we highlight the moderating role of entitlement, showing that individuals with a high sense of entitlement are less likely to avoid information and more likely to help. These findings underscore the interplay between moral self-concept and worldview in shaping social behavior.

Cathepsin K (CTSK), a proteolytic enzyme that degrades the extracellular matrix, is recognized as a significant therapeutic target for osteoporosis, osteoarthritis, and rheumatoid arthritis. Due to adverse effects, no clinically approved drugs exist for CTSK. In order to develop safer therapeutics, highly selective CTSK inhibitors are required to elucidate the origins of side effects. Here, we developed various hybrid inhibitors by combining peptide sequences with small organic molecules. An acyloxymethyl ketone electrophile was incorporated as a bioisostere of the glycine–glycine cleavage site and inverse peptide sequences to enhance prime site interactions, as seen in the crystal structure. Additionally, a diphenyl group was incorporated to improve nonprime site interactions, culminating in highly selective and potent irreversible CTSK inhibitors with negligible off-target binding by closely related cathepsins. These novel inhibitors were also designed to attach to targeting moieties, further reducing off-target effects in vivo. Our findings demonstrate that these highly selective inhibitors are nontoxic, effectively inhibit bone resorption by human osteoclasts, block CTSK activity in cells and their nuclei, and inhibit activity in human lung cancer tissue. This study highlights significant advancements in designing CTSK inhibitors with potential clinical applications for lung cancer and osteoclast-related conditions.

Background

Academically productive dialogue activities in classrooms aspire to be inclusive, such that students of all capabilities participate meaningfully and equally in discussions.

Aim

We empirically examine the extent to which this aspiration is achieved regarding students of different prior achievement levels.

Sample

Low- (N = 33), mid- (N = 90), and high-achieving (N = 22) upper elementary students participated in whole-classroom discussions around texts, facilitated by six highly motivated, trained teachers.

Method

Based on a quantitative ethnography approach, we coded 5975 separate speech turns and compared aggregated differences across the three subgroups using Epistemic Network Analysis (ENA).

Results

Whereas no differences were found in amount of speech turns, statistically significant differences were found in the quality of participation: Low-achievers' discussion participation was characterized by recitation-style talk, reduced network connectivity, and repetitive loops, compared to higher connectivity and more complex argumentative reasoning in their high-achieving classmates' network model. A follow-up qualitative analysis uncovered some of the social dynamics behind this inferior participation pattern, and highlighted the potentially stymieing behavior of peers.

Conclusion

The findings underscore the need for more empirical research that takes into account differences in quality of student participation in dialogic activities and the reasons behind it.

This study explores the utilization of digital light processing (DLP) printing to fabricate complex structures using native gelatin as the sole structural component for applications in biological implants. Unlike approaches relying on synthetic materials or chemically modified biopolymers, this research harnesses the inherent properties of gelatin to create biocompatible structures. The printing process is based on a crosslinking mechanism using a di-tyrosine formation initiated by visible light irradiation. Formulations containing gelatin were found to be printable at the maximum documented concentration of 30 wt%, thus allowing the fabrication of overhanging objects and open embedded. Cell adhesion and growth onto and within the gelatin-based 3D constructs were evaluated by examining two implant fabrication techniques: (1) cell seeding onto the printed scaffold and (2) printing compositions that contain cells (cell-laden). The preliminary biological experiments indicate that both the cell-seeding and cell-laden strategies enable making 3D cultures of chondrocytes within the gelatin constructs. The mechanical properties of the gelatin scaffolds have a compressive modulus akin to soft tissues, thus enabling the growth and proliferation of cells, and later degrade as the cells differentiate and form a grown cartilage. This study underscores the potential of utilizing non-modified protein-only bioinks in DLP printing to produce intricate 3D objects with high fidelity, paving the way for advancements in regenerative tissue engineering.

This article proposes a new classification of legal remedies that cuts across existing classifications. It argues that all remedies involving the transfer of resources are positioned along a continuum from close to remote, which determines their “distance factor.” The basic distinction is between remedies provided directly by the injurer to the injured and remedies that are provided through third parties. The article presents the results of two original, preregistered experiments designed to examine the effect of the distance factor on perceptions of, and preferences for, various remedies from the perspectives of both the injured and injurers. The experiments reveal that even when the remedy is monetary, both injured and injurers prefer the remedy with the smaller distance factor. Specifically, both parties believe that direct compensation leads to better outcomes than payment via a third party with regard to rectifying the harm done, granting satisfaction to the injured, treating the injured and injurer with respect, improving the bilateral relations, and increasing the injurer's sense of responsibility for the harm. These findings are relevant to the various goals that the law wishes to promote, such as corrective justice, economic efficiency, or distributive justice. They vindicate the importance of private law, offer a more attractive justification for it than the one offered by Civil Recourse Theory, and support pluralism in remedial modes.

How social complexity evolved remains a long-standing enigma. In most animal groups, social complexity is typically classified into a few discrete classes. This approach is oversimplified and constrains our inference of social evolution to a narrow trajectory consisting of transitions between classes. Such categorical classifications also limit quantitative studies on the molecular and environmental drivers of social complexity. The recent accumulation of relevant quantitative data has set the stage to overcome these limitations. Here, we propose a data-driven, high-dimensional approach for studying the full diversity of social phenotypes. We curated and analyzed a comprehensive dataset encompassing 17 social traits across 80 species and studied the evolution of social complexity in bees. We found that honey bees, stingless bees, and bumble bees underwent a major evolutionary transition ∼80 mya, inconsistent with the stepwise progression of the social ladder conceptual framework. This major evolutionary transition was followed by a phase of substantial phenotypic diversification of social complexity. Other bee lineages display a continuum of social complexity, ranging from solitary to simple societies, but do not reach the levels of social complexity seen in honey bees, stingless bees, and bumble bees. Bee evolution, therefore, provides a remarkable demonstration of a macroevolutionary process in which a major transition removed biological constraints and opened novel evolutionary opportunities, driving the exploration of the landscape of social phenotypes. Our approach can be extended to incorporate additional data types and readily applied to illuminate the evolution of social complexity in other animal groups.

How social complexity evolved remains a long-standing enigma. In most animal groups, social complexity is typically classified into a few discrete classes. This approach is oversimplified and constrains our inference of social evolution to a narrow trajectory consisting of transitions between classes. Such categorical classifications also limit quantitative studies on the molecular and environmental drivers of social complexity. The recent accumulation of relevant quantitative data has set the stage to overcome these limitations. Here, we propose a data-driven, high-dimensional approach for studying the full diversity of social phenotypes. We curated and analyzed a comprehensive dataset encompassing 17 social traits across 80 species and studied the evolution of social complexity in bees. We found that honey bees, stingless bees, and bumble bees underwent a major evolutionary transition \~80 mya, inconsistent with the stepwise progression of the social ladder conceptual framework. This major evolutionary transition was followed by a phase of substantial phenotypic diversification of social complexity. Other bee lineages display a continuum of social complexity, ranging from solitary to simple societies, but do not reach the levels of social complexity seen in honey bees, stingless bees, and bumble bees. Bee evolution, therefore, provides a remarkable demonstration of a macroevolutionary process in which a major transition removed biological constraints and opened novel evolutionary opportunities, driving the exploration of the landscape of social phenotypes. Our approach can be extended to incorporate additional data types and readily applied to illuminate the evolution of social complexity in other animal groups.

This article explores the work of Israeli artist Avner Pinchover, focusing on his engagement with violence as both a performative act and an aesthetic strategy. Incorporating video and still image documentation to challenge the very cultural frameworks that embrace him, Pinchover's controlled yet unpredictable interventions—ranging from sculptural destruction to performative gestures—blur the lines between art and vandalism, iconoclasm and institutional critique and resonate beyond the art scene to reflect broader socio-political conflicts, particularly within the Israeli-Palestinian context. By exposing the "elastic" boundaries of institutionalized art through transgressive yet aestheticized acts, Pinchover's performative violence compels us to confront a deep-seated fascination with aggression controlled and mediated by cultural structures.