Development of the visual white matter pathways mediates development of electrophysiological responses in visual cortex

The latency of neural responses in the visual cortex changes systematically across the lifespan. Here, we test the hypothesis that development of visual white matter pathways mediates maturational changes in the latency of visual signals. Thirty-eight children participated in a cross-sectional study including diffusion magnetic resonance imaging (MRI) and magnetoencephalography (MEG) sessions. During the MEG acquisition, participants performed a lexical decision and a fixation task on words presented at varying levels of contrast and noise. For all stimuli and tasks, early evoked fields were observed around 100 ms after stimulus onset (M100), with slower and lower amplitude responses for low as compared to high contrast stimuli. The optic radiations and optic tracts were identified in each individual's brain based on diffusion MRI tractography. The diffusion properties of the optic radiations predicted M100 responses, especially for high contrast stimuli. Higher optic radiation fractional anisotropy (FA) values were associated with faster and larger M100 responses. Over this developmental window, the M100 responses to high contrast stimuli became faster with age and the optic radiation FA mediated this effect. These findings suggest that the maturation of the optic radiations over childhood accounts for individual variations observed in the developmental trajectory of visual cortex responses

Reading Reece Jones’s Violent Borders: Refugees and the Right to Move

This forum is around Violent Borders: Refugees and the Right to Move by Reece Jones, the winning volume of the first edition of the biennial book award of the Political Geography Research Group of the Royal Geographic Society with IBG (PolGRG) in conjunction with Political Geography Journal. The book award was established in 2016 to give recognition to new academic volumes that engage with the thematic remit of PolGRG and contribute to develop the diverse field of political geography more widely. In line with the diversity of PolGRG interests and membership, the PolGRG Book Award is aimed at published volumes advancing the debate around themes spanning territoriality and sovereignty; states, cities, and citizenship; geopolitics, political economy and political ecology; migration, globalization and (post)colonialism; social movements and governance; peace, conflict and security. All this appreciating the implications of these phenomena with gender, race, class, sexuality and religion. Importantly, the idea of a book award was conceived to reward the slow and cumulative work that goes into publishing scholarly volumes

Beyond incommensurability: Jerusalem and Stockholm from an ordinary cities perspective

This paper’s core argument is that we should start creating theories that encompass different cities and include them in a more flexible and relational comparative framework. This must include a new urban terminology which does not continue the all-too-fashionable labelling of cities on a continuum between first world and third world, global North-West and South-East or as I emphasize below, including what have been labelled extremely contested cities in a more flexible and relational ordinary cities framework. To introduce such a comparative approach, I will examine Jerusalem and Stockholm via three contrastive and relational patterns: institutional segregation; urban violence; and non-governmental organization involvement in planning. In so doing, I point towards the necessity to open up research on extreme urban conflicts, suggesting that when assessing specific contextual patterns, those labelled as extremely contested cities (such as Jerusalem) share more similarities with other more ordinary cities (represented by Stockholm) than was previously perceived, often stemming from ethnic, racial and class conflicts revolving around issues of politics, culture and identity, among others

Learning from Jerusalem: Rethinking urban conflicts in the 21st century Introduction

Jerusalem - its past, present and future - will serve as the foundation of our understanding of the geographies of cities within contemporary urban theory and practice in the 21st century. The underlying theoretical supposition in this special feature1 is that what have been labelled con- tested cities have growing similarities to less polarized cities similarities found in the expansion of ethnic, racial and class conflicts that revolve around issues of housing, infrastructure, participation and identity. In this sense, Jerusalem represents a rather exceptional case study and demonstrates a powerful spatio-political urban pattern in the field of urban studies. The examination of Jerusalem can advance our understanding of the relationship between planning conflicts and urban geopolitics in a growing number of cities worldwide

Plant Growth-Promoting Rhizobacteria: Context, Mechanisms of Action, and Roadmap to Commercialization of Biostimulants for Sustainable Agriculture

Microbes of the phytomicrobiome are associated with every plant tissue and, in combination with the plant form the holobiont. Plants regulate the composition and activity of their associated bacterial community carefully. These microbes provide a wide range of services and benefits to the plant; in return, the plant provides the microbial community with reduced carbon and other metabolites. Soils are generally a moist environment, rich in reduced carbon which supports extensive soil microbial communities. The rhizomicrobiome is of great importance to agriculture owing to the rich diversity of root exudates and plant cell debris that attract diverse and unique patterns of microbial colonization. Microbes of the rhizomicrobiome play key roles in nutrient acquisition and assimilation, improved soil texture, secreting, and modulating extracellular molecules such as hormones, secondary metabolites, antibiotics, and various signal compounds, all leading to enhancement of plant growth. The microbes and compounds they secrete constitute valuable biostimulants and play pivotal roles in modulating plant stress responses. Research has demonstrated that inoculating plants with plant-growth promoting rhizobacteria (PGPR) or treating plants with microbe-to-plant signal compounds can be an effective strategy to stimulate crop growth. Furthermore, these strategies can improve crop tolerance for the abiotic stresses (e.g., drought, heat, and salinity) likely to become more frequent as climate change conditions continue to develop. This discovery has resulted in multifunctional PGPR-based formulations for commercial agriculture, to minimize the use of synthetic fertilizers and agrochemicals. This review is an update about the role of PGPR in agriculture, from their collection to commercialization as low-cost commercial agricultural inputs. First, we introduce the concept and role of the phytomicrobiome and the agricultural context underlying food security in the 21st century. Next, mechanisms of plant growth promotion by PGPR are discussed, including signal exchange between plant roots and PGPR and how these relationships modulate plant abiotic stress responses via induced systemic resistance. On the application side, strategies are discussed to improve rhizosphere colonization by PGPR inoculants. The final sections of the paper describe the applications of PGPR in 21st century agriculture and the roadmap to commercialization of a PGPR-based technology

Coding Efficiency of Fly Motion Processing Is Set by Firing Rate, Not Firing Precision

To comprehend the principles underlying sensory information processing, it is important to understand how the nervous system deals with various sources of perturbation. Here, we analyze how the representation of motion information in the fly's nervous system changes with temperature and luminance. Although these two environmental variables have a considerable impact on the fly's nervous system, they do not impede the fly to behave suitably over a wide range of conditions. We recorded responses from a motion-sensitive neuron, the H1-cell, to a time-varying stimulus at many different combinations of temperature and luminance. We found that the mean firing rate, but not firing precision, changes with temperature, while both were affected by mean luminance. Because we also found that information rate and coding efficiency are mainly set by the mean firing rate, our results suggest that, in the face of environmental perturbations, the coding efficiency is improved by an increase in the mean firing rate, rather than by an increased firing precision

Extracting regulator activity profiles by integration of de novo motifs and expression data: characterizing key regulators of nutrient depletion responses in Streptomyces coelicolor

Determining transcriptional regulator activities is a major focus of systems biology, providing key insight into regulatory mechanisms and co-regulators. For organisms such as Escherichia coli, transcriptional regulator binding site data can be integrated with expression data to infer transcriptional regulator activities. However, for most organisms there is only sparse data on their transcriptional regulators, while their associated binding motifs are largely unknown. Here, we address the challenge of inferring activities of unknown regulators by generating de novo (binding) motifs and integrating with expression data. We identify a number of key regulators active in the metabolic switch, including PhoP with its associated directed repeat PHO box, candidate motifs for two SARPs, a CRP family regulator, an iron response regulator and that for LexA. Experimental validation for some of our predictions was obtained using gel-shift assays. Our analysis is applicable to any organism for which there is a reasonable amount of complementary expression data and for which motifs (either over represented or evolutionary conserved) can be identified in the genome

Segregation, mobility and encounters in Jerusalem: The role of public transport infrastructure in connecting the ‘divided city’

This paper assesses ways in which urban segregation is shaped and transformed by Jerusalem’s public transport network, enhancing mobility and potential group encounters. We suggest that segregation should be understood as an issue of mobility and co-presence in public space, rather than the static residential-based segregation that continues to be a central focus of debate in urban studies. We explore public transport infrastructures, considering how their implementation reflects the variety of ways that transport can have impact: segmenting populations, linking populations and/or creating spaces for interaction or conflict between the city’s Jewish Israeli and Arab Palestinian populations. Space syntax network analysis suggests that in the case of Jerusalem, access to public transport is multi-dimensional: as well as providing access to resources, it shapes opportunities for spatial mobility that may either overcome or reinforce area-based housing segregation. We discuss these opportunities in the light of Jerusalem’s on-going ethno-national division in an increasingly fractured urban reality