Relationship Between Structure and Functional Connectivity Within the Default Mode Network

We proposed a novel measure of conceptualizing dynamic functional network connectivity (FNC) in the human brain using flexibility of functional connectivity (fFC), which captures the variance of functional connectivity across time. In task-free fMRI scans (N = 122), this measure was demonstrated to correspond to the underlying structural connectivity (SC) within the default mode network (DMN), while static functional connectivity (sFC) did so to a relatively low degree. As SC likely does not develop to facilitate task-free brain function, but rather to integrate information during cognitive engagement, we argue that fFC can estimate the potential functional connectivity exhibited outside of the task-free setting to a greater degree than sFC, and is better suited for examining behavioral correlates of FNC. In support of this, we showed that SC-fFC coupling was related to intelligence levels, while SC-sFC coupling was not. Further, we found that the DMN existed in a functionally disconnected state during a large portion of the scan, raising questions about whether sFC is a meaningful quantifier of functional connectivity in the absence of a task, and scrutinizing its extrapolative power to real-world, cognitively engaging scenarios. Given that fFC is based on FNC variability across time rather than its average, it is largely unaffected by such contaminants

Low-Power Architecture for an Optical Life Gas Analyzer

Analog and digital electronic control architecture has been combined with an operating methodology for an optical trace gas sensor platform that allows very low power consumption while providing four independent gas measurements in essentially real time, as well as a user interface and digital data storage and output. The implemented design eliminates the cross-talk between the measurement channels while maximizing the sensitivity, selectivity, and dynamic range for each measured gas. The combination provides for battery operation on a simple camcorder battery for as long as eight hours. The custom, compact, rugged, self-contained design specifically targets applications of optical major constituent and trace gas detection for multiple gases using multiple lasers and photodetectors in an integrated package

In Situ Aerosol Detector

An affordable technology designed to facilitate extensive global atmospheric aerosol measurements has been developed. This lightweight instrument is compatible with newly developed platforms such as tethered balloons, blimps, kites, and even disposable instruments such as dropsondes. This technology is based on detection of light scattered by aerosol particles where an optical layout is used to enhance the performance of the laboratory prototype instrument, which allows detection of smaller aerosol particles and improves the accuracy of aerosol particle size measurement. It has been determined that using focused illumination geometry without any apertures is advantageous over using the originally proposed collimated beam/slit geometry (that is supposed to produce uniform illumination over the beam cross-section). The illumination source is used more efficiently, which allows detection of smaller aerosol particles. Second, the obtained integral scattered light intensity measured for the particle can be corrected for the beam intensity profile inhomogeneity based on the measured beam intensity profile and measured particle location. The particle location (coordinates) in the illuminated sample volume is determined based on the information contained in the image frame. The procedure considerably improves the accuracy of determination of the aerosol particle size

Optical Multi-Gas Monitor Technology Demonstration on the International Space Station

The International Space Station (ISS) employs a suite of portable and permanently located gas monitors to insure crew health and safety. These sensors are tasked with functions ranging from fixed mass spectrometer based major constituents analysis to portable electrochemical sensor based combustion product monitoring. An all optical multigas sensor is being developed that can provide the specificity of a mass spectrometer with the portability of an electrochemical cell. The technology, developed under the Small Business Innovation Research program, allows for an architecture that is rugged, compact and low power. A four gas version called the Multi-Gas Monitor was launched to ISS in November 2013 aboard Soyuz and activated in February 2014. The portable instrument is comprised of a major constituents analyzer (water vapor, carbon dioxide, oxygen) and high dynamic range real-time ammonia sensor. All species are sensed inside the same enhanced path length optical cell with a separate vertical cavity surface emitting laser (VCSEL) targeted at each species. The prototype is controlled digitally with a field-programmable gate array/microcontroller architecture. The optical and electronic approaches are designed for scalability and future versions could add three important acid gases and carbon monoxide combustion product gases to the four species already sensed. Results obtained to date from the technology demonstration on ISS are presented and discussed

Dual modality fluorescence confocal and spectral-domain optical coherence tomography microendoscope

Optical biopsy facilitates in vivo disease diagnoses by providing a real-time in situ view of tissue in a clinical setting. Fluorescence confocal microendoscopy and optical coherence tomography (OCT) are two methods that have demonstrated significant potential in this context. These techniques provide complementary viewpoints. The high resolution and contrast associated with confocal systems allow en face visualization of sub-cellular details and cellular organization within a thin layer of biological tissue. OCT provides cross-sectional images showing the tissue micro-architecture to a depth beyond the reach of confocal systems. We present a novel design for a bench-top imaging system that incorporates both confocal and OCT modalities in the same optical train allowing the potential for rapid switching between the two imaging techniques. Preliminary results using simple phantoms show that it is possible to realize both confocal microendoscopy and OCT through a fiber bundle based imaging system

Фактор неопределенности в современных сообществах Крайнего Севера РФ: методологические подходы к изучению

The article introduces readers to work on a new research project “Overcoming Uncertainty in Interaction with the Physical and Social Environment in the Russian Arctic” by describing its conceptual and theoretical approach and premises as well as the steps of designing it. It opens with an analysis of the concept of risk, which is currently popular in the Arctic Social Studies and which is sometimes claimed to be the central concept in the field. It proceeds by describing the new approach, which is based on the concept of uncertainty, both natural and social, which constantly accompanies human life in the Far North. The inhabitants of the North know from experience that uncertainty cannot be ruled out, but one can be constantly prepared for it by planning one’s behavior with this factor in mind. Furthermore, one can suggest that the effects of ecological, economic and social changes are experienced by these inhabitants first and foremost as shifts in the level and kind of uncertainty. Therefore, the concept of uncertainty can replace the concept of risk in the studies of the effects of change on northern communities; in fact, “uncertainty” is preferable because its conceived nature is obvious, while in many risk studies, risk is still perceived as something objective. The main questions that a study of uncertainty can answer are: what is the role of natural and social uncertainty in the everyday life of the permanent population of the Arctic? What are the action strategies of the people in the face of uncertainty, including discursive strategies to explain the growing uncertainty? What is the role of state authorities, industrial companies, local organizations, urban and rural communities in overcoming the negative consequences of natural and social uncertainties? How are social connections and networks involved in dealing with situations of uncertainty? The paper demonstrates how these questions can be answered on the basis of anthropological fieldwork. It also uses examples from the Komi Republic (Vorkuta), Yakutia (Chersky settlement), and Magadan area to demonstrate the sort of problems the uncertainty-based approach can contribute to solving. A review of the existing literature in Russian and English is presented in order to give the reader useful insights into the field of uncertainty studies and outline the main directions of research that a study of uncertainty can takeСтатья знакомит читателей с работой Центра социальных исследований Севера Европейского университета в Санкт-Петербурге по исследовательскому проекту «Преодоление неопределенности при взаимодействии с физической и социальной средой в Российской Арктике». Основные вопросы, на которые призвано ответить исследование: какова роль природной и социальной неопределенности в жизненных ситуациях постоянного населения Арктики? Каковы стратегии действий населения в условиях неопределенности? Какова роль различных акторов в преодолении негативных последствий природных и социальных неопределенностей? Дается обзор теоретических и методологических основ проекта и литературы по объекту на русском и английском языках