Connectivity Pathways Research Articles

Path, place, and pace in mid-Ming Suzhou landscape painting

Path, place, and pace in mid-Ming Suzhou landscape painting

Graph theory reveals amygdala modules consistent with its anatomical subdivisions

Similarities on the cellular and neurochemical composition of the amygdaloid subnuclei suggests their clustering into subunits that exhibit unique functional organization. The topological principle of community structure has been used to identify functional subnetworks in neuroimaging data that reflect the brain effective organization. Here we used modularity to investigate the organization of the amygdala using resting state functional magnetic resonance imaging (rsfMRI) data. Our goal was to determine whether such topological organization would reliably reflect the known neurobiology of individual amygdaloid nuclei, allowing for human imaging studies to accurately reflect the underlying neurobiology. Modularity analysis identified amygdaloid elements consistent with the main anatomical subdivisions of the amygdala that embody distinct functional and structural properties. Additionally, functional connectivity pathways of these subunits and their correlation with task-induced amygdala activation revealed distinct functional profiles consistent with the neurobiology of the amygdala nuclei. These modularity findings corroborate the structure–function relationship between amygdala anatomical substructures, supporting the use of network analysis techniques to generate biologically meaningful partitions of brain structures.

A Multilayered Approach to Public Diplomacy Evaluation: Pathways of Connection

This article presents a multilayered framework, called pathways of connection, as an approach to public diplomacy evaluation. It is well established both in the study and practice of public diplomacy that evaluation is a daunting task, mostly due to the complex and convoluted nature of the concept. To overcome such obstacles, the proposed framework first defines public diplomacy as a foreign policy tool. This definition is then used to state that the only success criterion for a public diplomacy project is its contribution to advancing national interests, regardless of the type of the project or the practitioner country. Second, three layers on which the outcomes of public diplomacy projects can be observed are described by incorporating mainstream international relations theories in the practice of public diplomacy. Third, pathways of connection are introduced to explain how the changes in target audiences contribute to the advancement of national interests.

Sensing coral reef connectivity pathways from space

Coral reefs rely on inter-habitat connectivity to maintain gene flow, biodiversity and ecosystem resilience. Coral reef communities of the Red Sea exhibit remarkable genetic homogeneity across most of the Arabian Peninsula coastline, with a genetic break towards the southern part of the basin. While previous studies have attributed these patterns to environmental heterogeneity, we hypothesize that they may also emerge as a result of dynamic circulation flow; yet, such linkages remain undemonstrated. Here, we integrate satellite-derived biophysical observations, particle dispersion model simulations, genetic population data and ship-borne in situ profiles to assess reef connectivity in the Red Sea. We simulated long-term (>20 yrs.) connectivity patterns driven by remotely-sensed sea surface height and evaluated results against estimates of genetic distance among populations of anemonefish, Amphiprion bicinctus, along the eastern Red Sea coastline. Predicted connectivity was remarkably consistent with genetic population data, demonstrating that circulation features (eddies, surface currents) formulate physical pathways for gene flow. The southern basin has lower physical connectivity than elsewhere, agreeing with known genetic structure of coral reef organisms. The central Red Sea provides key source regions, meriting conservation priority. Our analysis demonstrates a cost-effective tool to estimate biophysical connectivity remotely, supporting coastal management in data-limited regions.

Climate Change Impacts on Water Scarcity and Food Security in Tropical Environments: The Case of Caribbean Regionultivars

The potential impacts of climate change on water scarcity and food security are a major area of concern for researchers and policy makers around the world, especially in tropical regions. Tropical regions are highly vulnerable to climate change, which poses increased threats to water and food security. While precipitation is the major source of freshwater in tropical regions, the agricultural sector and food production are under threat due to the impact of climate change. Recent downscaled regional data using the Representative Connection Pathway (RCPs) emission scenarios on precipitation shows a trend of decreasing precipitation in some tropical regions and Small Island Developing States (SIDS) to the year 2100.

Photosynthetic pigment-protein complexes as highly connected networks: implications for robust energy transport.

Photosynthetic pigment-protein complexes (PPCs) are a vital component of the light-harvesting machinery of all plants and photosynthesizing bacteria, enabling efficient transport of the energy of absorbed light towards the reaction centre, where chemical energy storage is initiated. PPCs comprise a set of chromophore molecules, typically bacteriochlorophyll species, held in a well-defined arrangement by a protein scaffold; this relatively rigid distribution leads to a viewpoint in which the chromophore subsystem is treated as a network, where chromophores represent vertices and inter-chromophore electronic couplings represent edges. This graph-based view can then be used as a framework within which to interrogate the role of structural and electronic organization in PPCs. Here, we use this network-based viewpoint to compare excitation energy transfer (EET) dynamics in the light-harvesting complex II (LHC-II) system commonly found in higher plants and the Fenna-Matthews-Olson (FMO) complex found in green sulfur bacteria. The results of our simple network-based investigations clearly demonstrate the role of network connectivity and multiple EET pathways on the efficient and robust EET dynamics in these PPCs, and highlight a role for such considerations in the development of new artificial light-harvesting systems.

Education for sustainable development: Connecting the dots for sustainability

Critical pedagogy, practitioner experience and a regulatory perspective are employed to scrutinize the notion of Education for Sustainable Development (ESD) as it occurs in the literature. They promote understanding of the challenges impeding the completion of unfinished ESD businesses. In response to practitioner-expressed needs, this paper innovatively proposes a Sustainable Development-compliant National Qualifications and Credit Framework (SD-NQCF) as the instrument to finally connect isolated ESD ‘dots’ and scaffold their sustainability.Informed by a systems approach, this framework encourages repositioning educational activities within the UN Agenda 21 to ensure the suffusion of SD principles. ESD becomes the backbone of NQCFs, while critical pedagogy provides the adequate instrument to foster 21st Century sustainability competencies that are embedded into curricula as learning outcomes. The SD-compliant framework resolves tensions between formal, non-formal and informal education. It provides connecting bridges and pathways to sustainably suffusing socio-economic fabrics with SD principles that will shift paradigms.

Image quality transfer and applications in diffusion MRI

This paper introduces a new computational imaging technique called image quality transfer (IQT). IQT uses machine learning to transfer the rich information available from one-off experimental medical imaging devices to the abundant but lower-quality data from routine acquisitions. The procedure uses matched pairs to learn mappings from low-quality to corresponding high-quality images. Once learned, these mappings then augment unseen low quality images, for example by enhancing image resolution or information content. Here, we demonstrate IQT using a simple patch-regression implementation and the uniquely rich diffusion MRI data set from the human connectome project (HCP). Results highlight potential benefits of IQT in both brain connectivity mapping and microstructure imaging. In brain connectivity mapping, IQT reveals, from standard data sets, thin connection pathways that tractography normally requires specialised data to reconstruct. In microstructure imaging, IQT shows potential in estimating, from standard “single-shell” data (one non-zero b-value), maps of microstructural parameters that normally require specialised multi-shell data. Further experiments show strong generalisability, highlighting IQT's benefits even when the training set does not directly represent the application domain. The concept extends naturally to many other imaging modalities and reconstruction problems.

Mapping conservation priorities and connectivity pathways under climate change for tropical ecosystems

Climate change and land use conversion are global threats to biodiversity. Protected areas and biological corridors have been historically implemented as biodiversity conservation measures and suggested as tools within planning frameworks to respond to climate change. However, few applications to national protected areas systems considering climate change in tropical countries exist. Our goal is to define new priority areas for biodiversity conservation and biological corridors within an existing protected areas network. We aim at preserving samples of all biodiversity under climate change and facilitate species dispersal to reduce the vulnerability of biodiversity. The analysis was based on a three step strategy: i) protect representative samples of various levels of terrestrial biodiversity across protected area systems given future redistributions under climate change, ii) identify and protect areas with reduced climate velocities where populations could persist for relatively longer periods, and iii) ensure species dispersal between conservation areas through climatic connectivity pathways. The study was integrated into a participatory planning approach for biodiversity conservation in Costa Rica. Results showed that there should be an increase of 11 % and 5 % on new conservation areas and biological corridors respectively. Our approach integrates climate change into the design of a network of protected areas for tropical ecosystems and can be applied to other biodiversity rich areas to reduce the vulnerability of biodiversity to global warming.

The requirement of intra village pathways for roadway technology adoption: A rural survey in Nador village, Madhya Pradesh, India

Over decades, rural development has assumed global attention especially among the developing nations like India. In rural India, Intra village pathways are the major channels for intra village conveyance means. As the benefits derived from the rural roads construction are reflected throughout the economy of the village, similarly, there are lots of welfare derived from construction of rural pathways for the improvement of the social conditions of rural population. This paper explores the present conditions of connecting pathways and requisite of technology interventions for their development inside the Nador village under CSIR-800 activity and their socio-economic impacts on rural life. Findings of household survey data from the village via transient walkthrough indicates a large proportion (approx.80.5%) of village population disconsolated with the existing conditions of intra village pathways. Various troubles due to disagreeable conditions of connecting pathways are reported. The key message from the findings include there is requisite of proper channel of intra village pathways in Indian villages along with scientific and technological initiatives to improve the substandard and unsatisfactory conditions of connecting pathways inside the village. The paper concludes that geopolymerization technology could resolve the pathway related problems in rural areas by the aid of optimum utilization of the available resources and raw materials to produce simple, energy-efficient and environment-friendly construction material for rural India. Ultimately this study will benefit the rural environments in terms of intra village pathway advancement with the adoption of geopolymerization technology.

The right hippocampus leads the bilateral integration of gamma-parsed lateralized information

It is unclear whether the two hippocampal lobes convey similar or different activities and how they cooperate. Spatial discrimination of electric fields in anesthetized rats allowed us to compare the pathway-specific field potentials corresponding to the gamma-paced CA3 output (CA1 Schaffer potentials) and CA3 somatic inhibition within and between sides. Bilateral excitatory Schaffer gamma waves are generally larger and lead from the right hemisphere with only moderate covariation of amplitude, and drive CA1 pyramidal units more strongly than unilateral waves. CA3 waves lock to the ipsilateral Schaffer potentials, although bilateral coherence was weak. Notably, Schaffer activity may run laterally, as seen after the disruption of the connecting pathways. Thus, asymmetric operations promote the entrainment of CA3-autonomous gamma oscillators bilaterally, synchronizing lateralized gamma strings to converge optimally on CA1 targets. The findings support the view that interhippocampal connections integrate different aspects of information that flow through the left and right lobes.

Production of Bacillus amyloliquefaciens OG and its metabolites in renewable media: valorisation for biodiesel production and p-xylene decontamination.

Biosurfactants are important in many areas; however, costs impede large-scale production. This work aimed to develop a global sustainable strategy for the production of biosurfactants by a novel strain of Bacillus amyloliquefaciens. Initially, Bacillus sp. strain 0G was renamed B. amyloliquefaciens subsp. plantarum (syn. Bacillus velezensis) after analysis of the gyrA and gyrB DNA sequences. Growth in modified Landy's medium produced 3 main recoverable metabolites: surfactin, fengycin, and acetoin, which promote plant growth. Cultivation was studied in the presence of renewable carbon (as glycerol) and nitrogen (as arginine) sources. While diverse kinetics of acetoin production were observed in different media, similar yields (6-8 g·L-1) were obtained after 72 h of growth. Glycerol increased surfactin-specific production, while arginine increased the yields of surfactin and fengycin and increased biomass significantly. The specific production of fengycin increased ∼10 times, possibly due to a connecting pathway involving arginine and ornithine. Adding value to crude extracts and biomass, both were shown to be useful, respectively, for the removal of p-xylene from contaminated water and for biodiesel production, yielding ∼70 mg·g-1 cells and glycerol, which could be recycled in novel media. This is the first study considering circular bioeconomy to lower the production costs of biosurfactants by valorisation of both microbial cells and their primary and secondary metabolites.

Ex-Situ 3D Nano-Ptychography of Ni-YSZ SOFC Anode during Redox Cycling

Solid oxide cells (SOC) are used for efficient and cost-effective conversion of a wide variety of fuels (SOFC) for power generation or for energy storage via electrolysis (SOEC). However, SOC lifetime under harsh operating conditions is limited by electrode microstructure durability. In particular, the state of the art anode electrodes are composed of a porous cermet of nickel and yttria stabilized zirconia (YSZ). Electrochemical reactions occur where the ion and electron conducting phases meet the pores at the triple phase boundaries (TPB). Thus, the electrochemical activity of the electrode is strongly dependent on the density of TPBs and the quality of the connecting pathways through each phase1. Despite nickel remaining stable under reducing environments, nickel oxidation can occur in the electrode due to air leakage in the fuel system or by mechanical failure of the electrolyte. During operation, redox cycles can impact the lifetime of the electrode thus tracking their effect on the microstructure in 3D provides valuable information. 3D characterization of a Ni-YSZ electrode was first achieved in 20062 using focused ion beam scanning electron microscope (FIB-SEM) nanotomography and it has been routinely performed for the last decade followed by the development of near edge X-ray nano-tomography3 and most recently holotomography4. Near edge X-ray nano-tomography and FIB-SEM has been used to study the effects of oxidation on Ni-YSZ electrodes3 X-ray Ptychography is a scanning based technique in which a set of several local far-field scattering patterns is obtained by scanning the sample with a coherent micrometer-size X-ray beam. When used in tomography mode, ptychography provides a quantitative measurement of the local electron density of materials in 3D. Over the years, ptychography has demonstrated high sensitivity to mass density changes and the highest resolution among the X-ray imaging techniques5. As a proof of concept, we report the first results of ptycho-nanotomography applied to an “ex-situ” redox experiment performed at the cSAXS beamline at the Swiss Light Source (PSI). In the experiment the same Ni-YSZ anode microstructure is first analyzed in its pristine state, then oxidized and finally reduced again at 850°C in air and in 4%H2-96%N2 respectively. A specimen containing both Ni-YSZ electrode and YSZ electrolyte was created using a high precision mechanical polishing procedure followed by FIB ion milling. The “ex-situ” treatments were carried out in a small custom made tube furnace between each ptychography scan at the beamline. Datasets typically 20x20x12 µm in size were quantified to have a 3D spatial resolution of 55 nm using the Fourier shell correlation method5. The high mass density sensitivity of ptychography, resulted in high phase contrast between Ni, YSZ, NiO and pore, enabled us to effectively resolve all the phases present in the electrode (figure 1a,b,c). Therefore, an accurate segmentation procedure could be applied minimizing the associated geometrical errors of calculated microstructural parameters. Here we describe the major microstructural changes which can be noticed in the microstructure showing the evolution of the nickel particle size distribution, connectivity and tortuosity in this recent experiment. Moreover, the morphological changes in the YSZ phase are also discussed with emphasis on the observed micro-cracks (figure 1d) and their effect on the overall connectivity.

A Hedonism Hub in the Human Brain.

Human values are abstract ideals that motivate behavior. The motivational nature of human values raises the possibility that they might be underpinned by brain structures that are particularly involved in motivated behavior and reward processing. We hypothesized that variation in subcortical hubs of the reward system and their main connecting pathway, the superolateral medial forebrain bundle (slMFB) is associated with individual value orientation. We conducted Pearson's correlation between the scores of 10 human values and the volumes of 14 subcortical structures and microstructural properties of the medial forebrain bundle in a sample of 87 participants, correcting for multiple comparisons (i.e.,190). We found a positive association between the value that people attach to hedonism and the volume of the left globus pallidus (GP).We then tested whether microstructural parameters (i.e., fractional anisotropy and myelin volume fraction) of the slMFB, which connects with the GP, are also associated to hedonism and found a significant, albeit in an uncorrected level, positive association between the myelin volume fraction within the left slMFB and hedonism scores. This is the first study to elucidate the relationship between the importance people attach to the human value of hedonism and structural variation in reward-related subcortical brain regions.

The role of transforming growth factor-β1/connective tissue growth factor signaling pathway in paraquat-induced pulmonary fibrosis

Objective: To investigate the effects of Paraquat on human embryonic lung fibroblasts (MRC5) and explore the role of transforming growth factor-β1/connective tissue growth factor signaling pathway in paraquat-induced pulmonary fibrosis. Methods: MRC5 cells were cultured with different concentration of PQ (0, 12.5, 25, 50, 100, 200, 400 μmol/L) for 24 h. The viability of cells was measured by MTT. The protein level of TGF-β1 were analyzed by ELISA after PQ treatment (0, 25, 50, 100 μmol/L) . To examine whether TGF-β1/CTGF signaling pathway was involved in paraquat-induced cytotoxicity, cells was divided into 6 groups: (1) control; (2) 25 μmol/L PQ group; (3) 50 μmol/L PQ group; (4) 100 μmol/L PQ group; (5) TGF-β1 positive control group (50 μmol/L rhTGF-β1) ; (6) stimulate group (100 μmol/L PQ+50 μmol/L TGF-β1) . The protein levels of p-Smad2, p-Smad3 and CTGF were assayed by western blot. The mRNA level of CTGF was assayed by real time RT-PCR. Results: MTT showed that cell viability decreased with increasing PQ concentration (P<0.05) . The protein expression of TGF-β1 treated with PQ (25, 50, 100 μmol/L) significantly increased compared with control in a dose-independent manner (P<0.05) . Exposure to PQ (25, 50, 100 μmol/L) induced increase of protein levels of p-Smad2 and p-Smad3. Noteworthy, the expression of p-Smad2 and p-Smad3 were dramatically increased following PQ plus TGF-β1 stimulation (P<0.05) . Exposure to PQ (50, 100μmol/L) induced increase of CTGF protein expression and similar greatly increase following PQ plus TGF-β1 stimulation (P<0.05) . Real time RT-PCR showed CTGF mRNA in all groups also significantly up-regulated compared with control (P<0.05) . Conclusion: TGF-β1 regulates the expression of target gene CTGF to exhibit its pro-fibrogenic effects by activating TGF-β1/Smad signaling pathway in PQ-induced pulmonary fibrosis.

Dynamic Multiscale Modes of Resting State Brain Activity Detected by Entropy Field Decomposition.

The ability of functional magnetic resonance imaging (FMRI) to noninvasively measure fluctuations in brain activity in the absence of an applied stimulus offers the possibility of discerning functional networks in the resting state of the brain. However, the reconstruction of brain networks from these signal fluctuations poses a significant challenge because they are generally nonlinear and nongaussian and can overlap in both their spatial and temporal extent. Moreover, because there is no explicit input stimulus, there is no signal model with which to compare the brain responses. A variety of techniques have been devised to address this problem, but the predominant approaches are based on the presupposition of statistical properties of complex brain signal parameters, which are unprovable but facilitate the analysis. In this article, we address this problem with a new method, entropy field decomposition, for estimating structure within spatiotemporal data. This method is based on a general information field-theoretic formulation of Bayesian probability theory incorporating prior coupling information that allows the enumeration of the most probable parameter configurations without the need for unjustified statistical assumptions. This approach facilitates the construction of brain activation modes directly from the spatial-temporal correlation structure of the data. These modes and their associated spatial-temporal correlation structure can then be used to generate space-time activity probability trajectories, called functional connectivity pathways, which provide a characterization of functional brain networks.

Wandering mussels: using natural tags to identify connectivity patterns among Marine Protected Areas

Knowledge of connectivity pathways in the marine environment is crucial for understanding the spatial structure of populations and for developing appropriate monitoring and management strategies. Here, we used the mussel Mytilus galloprovincialis as a model species to investigate connectivity patterns within the Berlengas and Arrabida Marine Protected Areas (MPAs) along the central Portuguese west coast. We generated an atlas of location-specific environmental markers based on the microchemistry of bivalve larval shells (using laser ablation inductively coupled plasma mass spectrometry). This atlas was then employed to trace the natal origins of newly settled mussels and generate connectivity matrices among populations. Our results reflected 3 distinctive chemical signatures in larval shells, corresponding to 3 regions: Estremadura, Cascais and Arrabida. Linear discriminant analyses allowed for a high reclassification success (average of 79.5% of jackknifed cross-validated cases correctly assigned) based on 8 of the 16 trace elements analyzed (B, P, Co, Cu, Zn, Ce, Pb and U). The population connectivity matrix identified different dispersal pathways for mussel larvae, in particular a predominantly northward dispersion pattern in July 2013. This pattern was consistent with simultaneous environmental physical data, which confirmed an extended period of wind reversal and upwelling relaxation. The Arrabida MPA was an important source population for the other 2 regions and showed high rates of self-recruitment but limited connectivity to the Berlengas MPA. These direct measures of demographic connectivity can be a powerful tool to inform policymakers on the conservation and management of ecologically coherent networks of protected areas in coastal marine ecosystems.

Combining systemic and stereotactic MEMRI to detect the correlation between gliosis and neuronal connective pathway at the chronic stage after stroke.

BackgroundThe early dysfunction and subsequent recovery after stroke, characterized by the destruction and remodeling of connective pathways between cortex and subcortical regions, is associated with neuroinflammation. As major components of the inflammatory process, reactive astrocytes have double-edged effects on pathological progression. The temporal patterns of astrocyte and neuronal pathway activity can be revealed by systemic and stereotactic manganese-enhanced magnetic resonance imaging (MEMRI), respectively. In the present study, we aimed to detect an association between astrocyte activity and recovery of neuronal connective pathways by combining systemic with stereotactic MEMRI.MethodsFifty adult rats, divided into two groups, underwent a 60-min occlusion of the middle cerebral artery. The groups were given either a systemic administration or stereotactic injection of MnCl2 at 1, 3, 7, and 14 days after stroke and underwent MRI 4 and 2 days later, respectively. Immunofluorescence (IF) of group 1 was conducted to corroborate the results. Repetitive behavioral testing was also performed with all rats at 1, 3, 7, and 14 days to obtain a functional score.ResultsRing- or crescent-shaped enhancements formed in the striatal peri-infarct regions (STR) at 11 and 18 days. This was concurrent with the activity of glial fibrillary acidic protein (GFAP)-positive astrocytes, which mainly localized at the peri-infarct region and significantly increased in number at 11 and 18 days after stroke. Microglia/macrophages, detected by IF, mainly localized in the lesion core, rather than in the region of enhancement. The ipsilateral substantia nigra (SN) revealed Mn-related signal enhancement reduction and subsequent signs of the recovery process at 3 to 5 days and 9 to 16 days, respectively. Behavioral testing showed that sensorimotor functions were initially disturbed, but subsequently recovered at 7 and 14 days.ConclusionsWe found a positive temporal correlation between astrogliosis and the recovery of neuronal connective pathways at the chronic stage by using the in vivo method of MEMRI. Our results highlighted the potential contribution of astrocytes to the neuronal recovery of these connective pathways.Electronic supplementary materialThe online version of this article (doi:10.1186/s12974-016-0622-7) contains supplementary material, which is available to authorized users.

Latent Variable Graphical Model Selection using Harmonic Analysis: Applications to the Human Connectome Project (HCP).

A major goal of imaging studies such as the (ongoing) Human Connectome Project (HCP) is to characterize the structural network map of the human brain and identify its associations with covariates such as genotype, risk factors, and so on that correspond to an individual. But the set of image derived measures and the set of covariates are both large, so we must first estimate a 'parsimonious' set of relations between the measurements. For instance, a Gaussian graphical model will show conditional independences between the random variables, which can then be used to setup specific downstream analyses. But most such data involve a large list of 'latent' variables that remain unobserved, yet affect the 'observed' variables sustantially. Accounting for such latent variables is not directly addressed by standard precision matrix estimation, and is tackled via highly specialized optimization methods. This paper offers a unique harmonic analysis view of this problem. By casting the estimation of the precision matrix in terms of a composition of low-frequency latent variables and high-frequency sparse terms, we show how the problem can be formulated using a new wavelet-type expansion in non-Euclidean spaces. Our formulation poses the estimation problem in the frequency space and shows how it can be solved by a simple sub-gradient scheme. We provide a set of scientific results on ~500 scans from the recently released HCP data where our algorithm recovers highly interpretable and sparse conditional dependencies between brain connectivity pathways and well-known covariates.

Living in cities, naturally.

Natural features, settings, and processes in urban areas can help to reduce stress associated with urban life. In this and other ways, public health benefits from, street trees, green roofs, community gardens, parks and open spaces, and extensive connective pathways for walking and biking. Such urban design provisions can also yield ecological benefits, not only directly but also through the role they play in shaping attitudes toward the environment and environmental protection. Knowledge of the psychological benefits of nature experience supports efforts to better integrate nature into the architecture, infrastructure, and public spaces of urban areas.