פרסומים

Only recently has it been recognized that the transcriptome of bacteria and archaea can be spatiotemporally regulated. All types of prokaryotic transcripts-rRNAs, tRNAs, mRNAs, and regulatory RNAs-may acquire specific localization and these patterns can be temporally regulated. In some cases bacterial RNAs reside in the vicinity of the transcription site, but in many others, transcripts show distinct localizations to the cytoplasm, the inner membrane, or the pole of rod-shaped species. This localization, which often overlaps with that of the encoded proteins, can be achieved either in a translation-dependent or translation-independent fashion. The latter implies that RNAs carry sequence-level features that determine their final localization with the aid of RNA-targeting factors. Localization of transcripts regulates their posttranscriptional fate by affecting their degradation and processing, translation efficiency, sRNA-mediated regulation, and/or propensity to undergo RNA modifications. By facilitating complex assembly and liquid-liquid phase separation, RNA localization is not only a consequence but also a driver of subcellular spatiotemporal complexity. We foresee that in the coming years the study of RNA localization in prokaryotes will produce important novel insights regarding the fundamental understanding of membrane-less subcellular organization and lead to practical outputs with biotechnological and therapeutic implications. This article is categorized under: RNA Export and Localization > RNA Localization Regulatory RNAs/RNAi/Riboswitches > Regulatory RNAs RNA Interactions with Proteins and Other Molecules > Protein-RNA Interactions: Functional Implications.

Previous studies have concluded that the wind-input vorticity in ocean gyres is balanced by bottom pressure torques (BPT), when integrated over latitude bands. However, the BPT must vanish when integrated over any area enclosed by an isobath. This constraint raises ambiguities regarding the regions over which BPT should close the vorticity budget, and implies that BPT generated to balance a local wind stress curl necessitates the generation of a compensating, non-local BPT and thus non-local circulation. This study aims to clarify the role of BPT in wind-driven gyres using an idealized isopycnal model. Experiments performed with a single-signed wind stress curl in an enclosed, sloped basin reveal that BPT balances the winds only when integrated over latitude bands. Integrating over other, dynamically-motivated definitions of the gyre, such as barotropic streamlines, yields a balance between wind stress curl and bottom frictional torques. This implies that bottom friction plays a non-negligible role in structuring the gyre circulation. Non-local bottom pressure torques manifest in the form of along-slope pressure gradients associated with a weak basin-scale circulation, and are associated with a transition to a balance between wind stress and bottom friction around the coasts. Finally, a suite of perturbation experiments is used to investigate the dynamics of BPT. To predict the BPT, the authors extend previous theory that describes propagation of surface pressure signals from the gyre interior toward the coast along planetary potential vorticity contours. This theory is shown to agree closely with the diagnosed contributions to the vorticity budget across the suite of model experiments.

The incidence of cocaine abuse is increasing especially in the U.K. where the rates are among the highest in Europe. In addition to its role as a psychostimulant, cocaine has profound effect on brain metabolism, impacting glycolysis and impairing oxidative phosphorylation. Cocaine exposure alters metabolic gene expression and protein networks in brain regions including the prefrontal cortex, the ventral tegmental area and the nucleus accumbens, the principal nuclei of the brain reward system. Here, we focus on how cocaine impacts mitochondrial function, in particular through alterations in electron transport chain function, reactive oxygen species (ROS) production and oxidative stress (OS), mitochondrial dynamics and mitophagy. Finally, we describe the impact of cocaine on brain energy metabolism in the developing brain following prenatal exposure. The plethora of mitochondrial functions altered following cocaine exposure suggest that therapies maintaining mitochondrial functional integrity may hold promise in mitigating cocaine pathology and addiction.

The incidence of cocaine abuse is increasing especially in the U.K. where the rates are among the highest in Europe. In addition to its role as a psychostimulant, cocaine has profound effect on brain metabolism, impacting glycolysis and impairing oxidative phosphorylation. Cocaine exposure alters metabolic gene expression and protein networks in brain regions including the prefrontal cortex, the ventral tegmental area and the nucleus accumbens, the principal nuclei of the brain reward system. Here, we focus on how cocaine impacts mitochondrial function, in particular through alterations in electron transport chain function, reactive oxygen species (ROS) production and oxidative stress (OS), mitochondrial dynamics and mitophagy. Finally, we describe the impact of cocaine on brain energy metabolism in the developing brain following prenatal exposure. The plethora of mitochondrial functions altered following cocaine exposure suggest that therapies maintaining mitochondrial functional integrity may hold promise in mitigating cocaine pathology and addiction.

This work aims to develop a detailed mechanistic understanding of the role of a graft polymer architecture on lithium ion (Li+) transport in poly(ethylene oxide)-based polymer electrolytes. Specifically, we compare Li+ transport in poly(ethylene oxide) (PEO) versus poly(oligo oxyethylene methacrylate) (POEM) polymers doped with lithium bis(trifluoromethanesulfonyl) (LiTFSI) salts, using both experimental electrochemical characterization and molecular dynamics (MD) simulations. Our results indicate that POEM exhibits a range of relaxation processes that cannot be interpreted solely in terms of glass-transition temperature (Tg) effects. Due to its side-chain architecture, the segmental relaxation of POEM is nonuniform across ether oxygens (EOs) and shows a more pronounced sensitivity to temperature above Tg compared to PEO. Moreover, POEM also exhibits a nonuniform Li+ coordination behavior, in which Li+ is primarily solvated by two different chains in POEM, compared to a single chain in PEO. Li+ transport in POEM occurs via two events with distinct characteristic times: a fast intrachain hopping along side chains and a slow interchain hopping between side chains. Taken together, the relaxation processes and ion transport mechanisms identified in POEM provide useful insights into design of more effective solid polymer electrolytes.

Ionic conductivity is governed primarily by the segmental mobility of the side-chain ethylene oxide units which form effective solvation sites, rather than system-wide dynamics.

The KNOTTED1-LIKE HOMEOBOX PROTEIN1 (KD1) gene is highly expressed in flower and leaf abscission zones (AZs), and KD1 was reported to regulate tomato flower pedicel abscission via alteration of the auxin gradient and response in the flower AZ (FAZ). The present work was aimed to further examine how KD1 regulates signaling factors and regulatory genes involved in pedicel abscission, by using silenced KD1 lines and performing a large-scale transcriptome profiling of the FAZ before and after flower removal, using a customized AZ-specific microarray. The results highlighted a differential expression of regulatory genes in the FAZ of KD1-silenced plants compared to the wild-type. In the TAPG4::antisense KD1-silenced plants, KD1 gene expression decreased before flower removal, resulting in altered expression of regulatory genes, such as epigenetic modifiers, transcription factors, posttranslational regulators, and antioxidative defense factors occurring at zero time and before affecting auxin levels in the FAZ detected at 4 h after flower removal. The expression of additional regulatory genes was altered in the FAZ of KD1-silenced plants at 4-20 h after flower removal, thereby leading to an inhibited abscission phenotype, and downregulation of genes involved in abscission execution and defense processes. Our data suggest that KD1 is a master regulator of the abscission process, which promotes abscission of tomato flower pedicels. This suggestion is based on the inhibitory effect of KD1 silencing on flower pedicel abscission that operates via alteration of various regulatory pathways, which delay the competence acquisition of the FAZ cells to respond to ethylene signaling.

This study focuses on the perceived community social climate's role as a capital for retaining knowledge-workers in the region. The conceptualization of the perceived community social climate includes seven dimensions: network participation, amenities, collective efficacy, neighborhood ambiance, civic participation, tolerance for diversity, and trust among residents. We offer a measurement scale suitable for measuring physical and virtual interactions. We validated the scale with exploratory and confirmatory factor analysis on a sample of 533 university graduates in Israel. We apply the new measure to investigate the effect of the perceived community social climate on university graduates' staying intentions in the community. We analyzed the data utilizing Multiple-Indicators-Multiple-Causes (MIMIC) model. The findings show that: i) collective efficacy and civic participation motivate neighborhood staying intentions; ii) collective efficacy is motivated by neighborhood amenities, network participation, and social trust; iii) social trust mediates between collective efficacy, neighborhood ambiance, and tolerance-for-diversity; iv) civic participation derives from to neighborhood ambiance and network participation.

This study focuses on the perceived community social climate's role as a capital for retaining knowledge-workers in the region. The conceptualization of the perceived community social climate includes seven dimensions: network participation, amenities, collective efficacy, neighborhood ambiance, civic participation, tolerance for diversity, and trust among residents. We offer a measurement scale suitable for measuring physical and virtual interactions. We validated the scale with exploratory and confirmatory factor analysis on a sample of 533 university graduates in Israel. We apply the new measure to investigate the effect of the perceived community social climate on university graduates' staying intentions in the community. We analyzed the data utilizing Multiple-Indicators-Multiple-Causes (MIMIC) model. The findings show that: i) collective efficacy and civic participation motivate neighborhood staying intentions; ii) collective efficacy is motivated by neighborhood amenities, network participation, and social trust; iii) social trust mediates between collective efficacy, neighborhood ambiance, and tolerance-for-diversity; iv) civic participation derives from to neighborhood ambiance and network participation.

We employed a differentiated goods market analysis where we utilized, in addition to the prevailing goods’ attributes, different types of the sellers’ attributes including trust indicators. We incorporated both sets of attributes into a structural model of the whole market including demand and pricing equations with the hotels as an outside good. Applying the model to Stockholm’s Airbnb market reveals that hosts’ attributes significantly affect market performance. Simulations of market scenarios show that the very high review scores and the Superhost certification help Airbnb compete with hotels and increase profitability. We also show that the “Airbnb plus” luxury program, which makes the apartments a closer substitute for hotels, leads to an increase in Airbnb’s market welfare. Our analysis provides a framework for understanding the full impact of the different attributes of the products, their providers, and their management in the sharing-economy accommodation market.

This article examines Jewish Christian relations in the High Middle Ages through the prism of religious architecture and ritual, focusing on the architecture of Jewish ritual baths from the Rhineland region in Germany. I argue that the baths of Speyer, Worms, Friedberg, Offenburg and Cologne were designed to maximize the experiential power of ritual immersion and arouse symbolic associations to support the ceremony. Architectural details such as unusual depth, ornament, lighting schemes and monumentality contributed to a spectrum of immersion ceremonies described in contemporary sources. These are contextualized in concurrent developments in Christian religious architecture and ceremonial use of architectural space.

Root exudates alter the rhizosphere's physical properties, but the impact that these changes have on solute transport is unknown. In this study, we tested the effects of chia mucilage and wheat root exudates (WREs) on the transport of iodide and potassium in saturated or unsaturated soil. Saturated solute breakthrough experiments, conducted in loamy sand soil or coarser textured quartz sand, revealed that increasing the exudate concentration in soil resulted in non-equilibrium solute transport. This behavior was demonstrated by an initial solute breakthrough after fewer pore volumes (PVs) and the arrival of the peak solute concentration after greater PVs in soil mixed with exudates compared to soil without exudates. These patterns were more pronounced for the coarser textured quartz sand than for the loamy sand soil, and in soil mixed with mucilage than in soil mixed WREs. Parameter fits to these breakthrough curves with a mobile-immobile transport model indicated the fraction of immobile water increased as the concentration of exudates increased. For example, in quartz sand the estimated immobile fraction increased from 0 without exudates to 0.75 at a mucilage concentration of 0.2%. The solutes' breakthrough under unsaturated conditions was also altered by the exudates, demonstrated by a smaller volume of water extracted from soil mixed with exudates, compared to soil without exudates, before the arrival of the peak solute concentration. The results indicate that exudates alter the rhizosphere's transport properties; we hypothesize that this is due to exudates creating low-conducting flow paths that result in a physical non-equilibrium solute transport.

The microbial community inhabiting a plant's root zone plays a crucial role in plant health and protection. To assess the ability of commercial plant growth-promoting products to enhance the positive effects of this environment, two products containing beneficial soil bacteria and a product containing plant extracts were tested on Zantedeschia aethiopica and Ornithogalum dubium. The products were tested in two different growing media: a soil and a soilless medium. The effects of these products on Pectobacterium brasiliense, the causal agent of soft rot disease, were also evaluated in vitro, and on naturally occurring infections in the greenhouse. The growing medium was found to have the strongest effect on the microbial diversity of the root-associated microbiome, with the next-strongest effect due to plant type. These results demonstrate that either a single bacterial strain or a product will scarcely reach the level that is required to influence soil microbial communities. In addition, the microbes cultured from these products, could not directly inhibit Pectobacterium growth in vitro. We suggest density-based and functional analyses in the future, to study the specific interactions between plants, soil type, soil microbiota and relevant pathogens. This should increase the effectiveness of bio-supplements and soil disinfestation with natural products, leading to more sustainable, environmentally friendly solutions for the control of bacterial plant diseases.