Publications

Modern molecular microbiology elucidates the organizational principles of bacterial biofilms via detailed examination of the interplay between signaling and gene regulation. A complementary biophysical approach studies the mesoscopic dependencies at the cellular and multicellular levels with a distinct focus on intercellular forces and mechanical properties of whole biofilms. Here, motivated by recent advances in biofilm research and in other, seemingly unrelated fields of biology and physics, we propose a perspective that links the biofilm, a dynamic multicellular organism, with the physical processes occurring in the extracellular milieu. Using Bacillus subtilis as an illustrative model organism, we specifically demonstrate how such a rationale explains biofilm architecture, differentiation, communication, and stress responses such as desiccation tolerance, metabolism, and physiology across multiple scales—from matrix proteins and polysaccharides to macroscopic wrinkles and water-filled channels.

Biofilm research has grown exponentially over the last decades, arguably due to their contribution to hospital acquired infections when they form on foreign body surfaces such as catheters and implants. Yet, translation of the knowledge acquired in the laboratory to the clinic has been slow and/or often it is not attempted by research teams to walk the talk of what is defined as ‘bench to bedside’. We therefore reviewed the biofilm literature to better understand this gap. Our search revealed substantial development with respect to adapting surfaces and media used in models to mimic the clinical settings, however many of the in vitro models were too simplistic, often discounting the composition and properties of the host microenvironment and overlooking the biofilm- implant-host interactions. Failure to capture the physiological growth conditions of biofilms in vivo results in major differences between lab-grown- and clinically-relevant biofilms, particularly with respect to phenotypic profiles, virulence, and antimicrobial resistance, and they essentially impede bench-to-bedside translatability. In this review, we describe the complexity of the biological processes at the biofilm-implant-host interfaces, discuss the prerequisite for the development and characterization of biofilm models that better mimic the clinical scenario, and propose an interdisciplinary outlook of how to bioengineer biofilms in vitro by converging tissue engineering concepts and tools.   

Gulag-survivor narratives tend to combine individual and communal concerns, which are sometimes artistically amalgamated. The relationship between them can be further understood with the help of trauma studies, though the application of the concept of trauma to Gulag literature is not unproblematic. This paper focusses on signs of trauma in Shalamov’s stories “The Seizure”, “On Tick”, and “The First Tooth”, the latter showing how individual trauma blends with collective/cultural trauma associated with the loss of confidence in communal identity. These are versions of the cultural trauma of Russian intelligentsia, stemming from enforced departures from its humanistic ideals.

Central and Eastern Europe (CEE) countries faced significant political, economic, social, and technological transformations over the last four decades. Democratic processes, after relative stabilization, tremble again around polarizing values, populist leaders, or nationalistic ideologies. Online communication, especially social media platforms, play a vital role in shaping how citizens interact with the state, political actors, media, and other citizens. The book focuses on some of the challenges democratic institutions in the region face, in transforming and sustaining civil society and attempts to capture how the digital media environments mitigate or exacerbate those challenges. Included manuscripts focus on the role that online platforms play in the satisfaction with democracy in the CEE region, the interactions between journalists and political actors, the strategic media coverage of elections, affective polarization and political antagonism, and discursive attempts to discourage young people from civic engagement.

Do the leaders of minority communities in divided cities influence group members’ expressed willingness to engage politically with rival groups? Studies typically  link group members' willingness to engage with rival groups to direct contact between individuals from opposing groups. However, such contact is problematic in divided cities, wherein opportunities to interact are scarce and frowned upon. Focusing on the contested urban space of Jerusalem, we find indications that the diverse nature of community leadership in East Jerusalem can influence Palestinian residents’ attitudes toward political engagement with Israeli Authorities via The ‘middlemen’ role can explain the influence that have in divided cities. They their constituents and the other group's members or institutions. Our analysis employs original data from a public of East Jerusalem immediately prior to the Jerusalem 2018 It has ramifications regarding urban governance for other divided cities.

How is the electoral behavior of minorities shaped by past violence? Recent studies found that displacement increases hostility between perpetrators and displaced individuals, but there has been paltry research on members of surviving communities. We argue that the latter exhibit the opposite pattern because of their different condition. Violence will cause cross-generational vulnerability, fear and risk-aversion— leading the surviving communities to seek protection and avoid conflict by signalling loyalty and rejecting nationalist movements. In their situation as an excluded minority in the perpetrators’ state, they will be more likely to vote for out-group parties. Exploiting exogenous battlefield dynamics that created inter-regional variation in the Palestinian exodus (1947-1949), microlevel measurements that capture the damage of violence, and an original longitudinal data set, we show that Palestinian villages in Israel more severely impacted by the 1948 war have a much higher vote share to Jewish parties even seventy years later. Survey evidence further supports our theory, revealing that this pattern exists only for members of the surviving communities, and not among displaced individuals. The findings shed new light on the complex social relations that guide political decision-making in post-war settings and divided societies that suffer from protracted conflicts.

There is a need to shift the absorbance of biomolecules to the optical transparency window of tissue for applications in optogenetics and photo-pharmacology. There are a few strategies to achieve the so-called red shift of the absorption maxima. Herein, a series of 11 merocyanine dyes were synthesized and employed as chromophores in place of retinal in bacteriorhodopsin (bR) to achieve a bathochromic shift of the absorption maxima relative to bR’s \({\lambda }_{\mathrm{max}}^{a}\) of 568 nm. Assembly with the apoprotein bacterioopsin (bO) led to stable, covalently bound chromoproteins with strongly bathochromic absorbance bands, except for three compounds. Maximal red shifts were observed for molecules 9, 2, and 8 in bR where the \({\lambda }_{\mathrm{max}}^{a}\) was 766, 755, and 736 nm, respectively. While these three merocyanines have different end groups, they share a similar structural feature, namely, a methyl group which is located at the retinal equivalent position 13 of the polyene chain. The absorption and fluorescence data are also presented for the retinal derivatives in their aldehyde, Schiff base (SB), and protonated SB (PSB) forms in solution. According to their hemicyanine character, the PSBs and their analogue bRs exhibited fluorescence quantum yields (Φ_f) several orders of magnitude greater than native bR (Φ_f 0.02 to 0.18 versus 1.5 × 10^–5 in bR) while also exhibiting much smaller Stokes shifts than bR (400 to 1000 cm⁻¹ versus 4030 cm⁻¹ in bR). The experimental results are complemented by quantum chemical calculations where excellent agreement between the experimental \({\lambda }_{\mathrm{max}}^{a}\)and the calculated \({\lambda }_{\mathrm{max}}^{a}\) was achieved with the second-order algebraic-diagrammatic construction [ADC(2)] method. In addition, quantum mechanics/molecular mechanics (QM/MM) calculations were employed to shed light on the origin of the bathochromic shift of merocyanine 2 in bR compared with native bR.

We present a simple approach for patterning metal nanoparticles into periodic superstructures on flat films spanning centimeter-square areas. Our approach is based on capillary force lithography, a soft lithography method that is used to impart topography to molten polymer films, and applies it to block copolymer films to obtain substrates featuring both topographic and chemical contrasts that can serve as templates for the selective deposition of nanoparticles. Here we show that flattening the films by exposure to solvent vapour prior to nanoparticle deposition not only retains chemical heterogeneity but also provides access to unique hierarchically-organized nanoparticle superstructures that are unattainable by other methods. Such structures could be useful for optical, sensor, and catalytic applications.