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Transport connectivity is essential to sustain inclusive growth in developing countries, where many rural populations and businesses are still considered to be unconnected to the domestic, regional, or global market. The Rural Access Index is among the most important global indicators for measuring people's transport accessibility in rural areas where the majority of the poor live. A new method to calculate the Rural Access Index was recently developed using spatial data and techniques. The characteristics of subnational Rural Access Index estimates were investigated in eight countries: Bangladesh, Ethiopia, Kenya, Mozambique, Nepal, Tanzania, Uganda, and Zambia. It was found that for the countries in Africa, road density and road condition are important determinants of the Rural Access Index. For the South Asian countries, improvement of road condition is particularly relevant. The evidence suggests that significant resources are likely to be required to achieve universal access through rehabilitating the existing road network and expanding the road network.

Rural Access --- Transport Connectivity

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General anesthesia is a standard medical procedure in today's hospital practice. Although in most cases the administration of anesthetics does not affect severely the patients health, side effects of anesthesia are well-known, such as nausea or cognitive impairment. Moreover 1-2 out of 1000 patients under surgery report a partial wake up from anesthesia during the operation. The reason for such a partial lack of control of depth of anesthesia is that medical procedures are highly optimized based on experience but the neural dynamics during general anesthesia is far from being understood. One reason for this lack of understanding is both the complex neural interactions of neurons on different spatial and temporal scales and the poorly understood action of anesthetics on neural populations. For instance, anesthetic agents act on synaptic receptors on a microscopic scale essentially evoking a macroscopic change of population activity, such as Local Field Potentials, EEG/MEG or resulting change of cerebral blood flow. This population effect then triggers the loss of consciousness in patients. This Research Topic aims to address recent theoretical and experimental advances in the field. The theoretical and experimental studies represent a good overview over the current state of research in the field and provides a deeper insight into the underlying neural mechanisms. Each article in the issue focusses on a specific current research topic in general anesthesia research and several articles introduce to the topic in a pedagogical way. The issue covers various types of anaesthesia and the most important topics in the field, such as (but not limited to) recent advances in theoretical models and states of consciousness reflected in experimental data, the connectivity changes observed during anesthesia or effects of specific drugs on brain activity. The introduction style of the papers facilitates the reader to understand the background of the research aspect and even allows readers not familiar with general anesthesia research to enter the research domain. Hence the Research Topic aims to provide on one hand an overview of the current state of the art and on the other hand a good starting point for new researchers in the field.

functional connectivity --- Consciousness --- coherence --- EEG --- Burst-suppression

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We obtain a complete description of the planar cubic Cayley graphs, providing an explicit presentation and embedding for each of them. This turns out to be a rich class, comprising several infinite families. We obtain counterexamples to conjectures of Mohar, Bonnington and Watkins. Our analysis makes the involved graphs accessible to computation, corroborating a conjecture of Droms.

Cayley graphs --- Graph connectivity --- Graph theory

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Rural access is among the most important infrastructure elements to stimulate economic growth in rural and remote areas. The sustainability of feeder road maintenance is a challenge in many developing countries. Many feeder roads are unpaved and need to be maintained frequently, but they are often neglected under budget pressure. Output- and performance-based road contracts are an instrument to ensure the sustainability of road maintenance. Contractors are required not only to improve roads, but also to maintain them. Using micro data from household surveys in Zambia, the paper examines the impacts of output- and performance-based road contracts on agricultural production. It shows that the contracts have a significant impact on crop production, especially maize and groundnuts, two major crops grown in the study area. The paper also finds that the measured impacts are associated with actual road maintenance works, regardless of contractual methods. Any road work can improve people's connectivity, even if it is not an output- and performance-based road contracts. The impact of the contracts is catalytic: more road works were implemented on contract roads than non-contract roads, holding everything else constant. This is an important contribution to the sustainability of road maintenance. Finally, road improvement works are found to facilitate farmers' market participation, but the impact seems weak. There may be other constraints. Transport service costs are found to have a negative impact on farmers' market sales. Thus, although roads are improved, transport services may be not available or too expensive, which still hamper farmers' market participation.

Agricultural Production --- Rural Access --- Transport Connectivity

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There is a growing appreciation that many psychiatric (and neurological) conditions can be understood as functional disconnection syndromes – as reflected in aberrant functional integration and synaptic connectivity. This Research Topic considers recent advances in understanding psychopathology in terms of aberrant effective connectivity – as measured noninvasively using functional magnetic resonance imaging (fMRI). Recently, there has been increasing interest in inferring directed connectivity (effective connectivity) from fMRI data. Effective connectivity refers to the influence that one neural system exerts over another and quantifies the directed coupling among brain regions – and how they change with pathophysiology. Compared to functional connectivity, effective connectivity allows one to understand how brain regions interact with each other in terms of context sensitive changes and directed coupling – and therefore may provide mechanistic insights into the neural basis of psychopathology. Established models of effective connectivity include psychophysiological interaction (PPI), structural equation modeling (SEM) and dynamic causal modelling (DCM). DCM is unique because it explicitly models the interaction among brain regions in terms of latent neuronal activity. Moreover, recent advances in DCM such as stochastic and spectral DCM, make it possible to characterize the interaction between different brain regions both at rest and during a cognitive task.

brain connectivity --- Granger causality analysis --- fMRI --- effective connectivity --- psychophysiological interaction --- dynamic causal modeling