Signal processing based method for modeling and solving inverse scattering problems

A mature and difficult problem, still preoccupying many research communities in different application areas, is the recovery of a quantitative image of some unknown penetrable strongly scattering object. In most fields, such as ground penetrating radar, seismic and medical applications, the problem is compounded by the availability of only limited angle and noisy data. One of the more common approximate solution methods is based on diffraction tomography that relies on the first Born approximation method, which limits applications to weakly scattering situations. More sophisticated methods are typically iterative in nature, computationally intense and may not converge. We have studied an alternative nonlinear filtering approach and developed a new way to implement it, as well as evaluating different filter functions to find an optimal form. We have applied this approach to a number of classes of objects and developed a user- friendly scattered field simulator as a resource for this and related inverse scattering problems. We also re-investigated the widely accepted limitations of the first Born approximation and found that when close to a scattering resonance, the first Born approximation can yield a good estimate of the object’s scattering cross section. Tied to all of these imaging applications is the issue of limited data: how many sources and how many receivers are required for a given quality and reliability of the resulting image. We took a fundamental look at this issue in terms of the number of degrees of freedom of the entire source-measurement domain and deduced clear guidelines on the minimum data sets necessary that should be measured, in order to expect a reasonable image

An examination of the institutional character and organizational ethos at Seventh-Day Adventist colleges in the United States

The purpose of this study was to examine the institutional character and organizational ethos at Seventh-day Adventist (SDA) colleges in the United States. Given the problem of a scarcity of published information about SDA colleges, this study has served to investigate an otherwise un-researched facet of American higher education. Six Seventh-day Adventist colleges participated in this study. A modified version of the Institutional Functioning Inventory (I.F.I.), which utilized six of its scales, was used for collecting data. The survey instrument was presented to 528 faculty members at the six colleges and 245 responses were received. A college's institutional mean score on the I.F.I, scales was the basis for the description of the institutional culture of each participating college. An ANOVA was performed, designating each college as the independent variable and each I.F.I. scale, in turn, as a dependent variable. The findings allow for certain generalizations to be made about SDA colleges. The participants, collectively, scored very high on measures of faculty morale and commitment to a shared sense of purpose while, at the same time, faculty reported generally low levels of personal and academic freedom. There was a generally high level of concern for undergraduate learning with the academic environments reported to be modestly interesting places for work and study

CIVIC LEARNING IN ONLINE COURSES: THE EXPERIENCE OF EMERGING ADULTS AT THE COMMUNITY COLLEGE

Civic learning is an important part of the mission of higher learning. The community college is a unique and integral part of the system of higher education in the United States. Digital technology has increased the options for students to take classes at a distance in a fully online format. Many of the students in online classes at the community college are in a life stage known as emerging adulthood. While there has been considerable research on each of the four topics of civic learning, the community college, emerging adulthood, and online learning, there remains a substantial gap in the literature where these topics intersect. Instructors, administrators, and designers of online courses need more information with which to best plan and deliver civic learning opportunities to emerging adults in online classes at the public community college. Qualitative research is an appropriate methodology for areas of study with little extant literature. This study used the phenomenological method in order to better understand how emerging adults enrolled in asynchronous online classes at the public community college perceive civic responsibility, civic engagement, and the experience of civic learning in their online classes. The study produced findings that highlighted the importance of respect for diversity, civil discourse, nurturing of a social learning community and instructor presence. Implications for an online pedagogy to promote civic learning are included

Views of addiction neuroscientists and clinicians on the clinical impact of a ‘Brain Disease Model of Addiction’

Addiction is increasingly described as a "chronic and relapsing brain disease". The potential impact of the brain disease model on the treatment of addiction or addicted individuals' treatment behaviour remains uncertain. We conducted a qualitative study to examine: (i) the extent to which leading Australian addiction neuroscientists and clinicians accept the brain disease view of addiction; and (ii) their views on the likely impacts of this view on addicted individuals' beliefs and behaviour. Thirty-one Australian addiction neuroscientists and clinicians (10 females and 21 males; 16 with clinical experience and 15 with no clinical experience) took part in 1 h semi-structured interviews. Most addiction neuroscientists and clinicians did not uncritically support the use of brain disease model of addiction. Most were cautious about the potential for adverse impacts on individuals' recovery and motivation to enter treatment. While some recognised the possibility that the brain disease model of addiction may provide a rationale for addicted persons to seek treatment and motivate behaviour change, Australian addiction neuroscientist and clinicians do not assume that messages about "diseased brains" will always lead to increased treatment-seeking and reduced drug use. Research is needed on how neuroscience research could be used in ways that optimise positive outcomes for addicted persons

NFATc1 controls the cytotoxicity of CD8+ T cells

NFAT nuclear translocation has been shown to be required for CD8+ T cell cytokine production in response to viral infection. Here the authors show NFATc1 controls the cytotoxicity and metabolic switching of activated CD8+ T cells required for optimal response to bacteria and tumor cells

Current strategies for treatment of intervertebral disc degeneration: substitution and regeneration possibilities

Background: Intervertebral disc degeneration has an annual worldwide socioeconomic impact masked as low back pain of over 70 billion euros. This disease has a high prevalence over the working age class, which raises the socioeconomic impact over the years. Acute physical trauma or prolonged intervertebral disc mistreatment triggers a biochemical negative tendency of catabolic-anabolic balance that progress to a chronic degeneration disease. Current biomedical treatments are not only ineffective in the long-run, but can also cause degeneration to spread to adjacent intervertebral discs. Regenerative strategies are desperately needed in the clinics, such as: minimal invasive nucleus pulposus or annulus fibrosus treatments, total disc replacement, and cartilaginous endplates decalcification. Main Body: Herein, it is reviewed the state-of-the-art of intervertebral disc regeneration strategies from the perspective of cells, scaffolds, or constructs, including both popular and unique tissue engineering approaches. The premises for cell type and origin selection or even absence of cells is being explored. Choice of several raw materials and scaffold fabrication methods are evaluated. Extensive studies have been developed for fully regeneration of the annulus fibrosus and nucleus pulposus, together or separately, with a long set of different rationales already reported. Recent works show promising biomaterials and processing methods applied to intervertebral disc substitutive or regenerative strategies. Facing the abundance of studies presented in the literature aiming intervertebral disc regeneration it is interesting to observe how cartilaginous endplates have been extensively neglected, being this a major source of nutrients and water supply for the whole disc. Conclusion: Severalinnovative avenues for tackling intervertebral disc degeneration are being reported â from acellular to cellular approaches, but the cartilaginous endplates regeneration strategies remain unaddressed. Interestingly, patient-specific approaches show great promise in respecting patient anatomy and thus allow quicker translation to the clinics in the near future.The authors would like to acknowledge the support provided by the Portuguese Foundation for Science and Technology (FCT) through the project EPIDisc (UTAP-EXPL/BBBECT/0050/2014), funded in the Framework of the “International Collaboratory for Emerging Technologies, CoLab”, UT Austin|Portugal Program. The FCT distinctions attributed to J. Miguel Oliveira (IF/00423/2012 and IF/01285/ 2015) and J. Silva-Correia (IF/00115/2015) under the Investigator FCT program are also greatly acknowledged.info:eu-repo/semantics/publishedVersio

A correlative and quantitative imaging approach enabling characterization of primary cell-cell communication: Case of human CD4+ T cell-macrophage immunological synapses

Cell-to-cell communication engages signaling and spatiotemporal reorganization events driven by highly context-dependent and dynamic intercellular interactions, which are difficult to capture within heterogeneous primary cell cultures. Here, we present a straightforward correlative imaging approach utilizing commonly available instrumentation to sample large numbers of cell-cell interaction events, allowing qualitative and quantitative characterization of rare functioning cell-conjugates based on calcium signals. We applied this approach to examine a previously uncharacterized immunological synapse, investigating autologous human blood CD4+ T cells and monocyte-derived macrophages (MDMs) forming functional conjugates in vitro. Populations of signaling conjugates were visualized, tracked and analyzed by combining live imaging, calcium recording and multivariate statistical analysis. Correlative immunofluorescence was added to quantify endogenous molecular recruitments at the cell-cell junction. By analyzing a large number of rare conjugates, we were able to define calcium signatures associated with different states of CD4+ T cell-MDM interactions. Quantitative image analysis of immunostained conjugates detected the propensity of endogenous T cell surface markers and intracellular organelles to polarize towards cell-cell junctions with high and sustained calcium signaling profiles, hence defining immunological synapses. Overall, we developed a broadly applicable approach enabling detailed single cell- and population-based investigations of rare cell-cell communication events with primary cells

Structuring effect of tools conceptualized through initial goal fixedness for work activity

Analysis of work activities in nuclear industry has highlighted a new psycho-cognitive phenomenon: the structuring effect of tools (SET) sometimes leading to unexpected operating deviations; the subject is unable to perform a task concerning object A using or adapting a tool designed and presented to perform the same task concerning object B when object A is expected by the subject. Conditions to isolate and identify the SET were determined and reproduced in experiments for further analysis. Students and seven professional categories of adults (N = 77) were involved in three experimental conditions (control group, group with prior warning, group with final control) while individually performing a task with similar characteristics compared to real operating conditions and under moderate time-pressure. The results were: (1) highest performance with prior warning and (2) demonstration that academic and professional training favor the SET. After discussing different cognitive processes potentially related to the SET, we described (3) the psycho-cognitive process underlying the SET: Initial Goal Fixedness (IGF), a combination of the anchoring of the initial goal of the activity with a focus on the features of the initial goal favored by an Einstellung effect. This suggested coping with the negative effect of the SET by impeding the IGF rather than trying to increase the subjects’ awareness at the expense of their health. Extensions to other high-risk industries were discussed

DADOS-Survey: an open-source application for CHERRIES-compliant Web surveys

BACKGROUND: The Internet has been increasingly utilized in biomedical research. From online searching for literature to data sharing, the Internet has emerged as a primary means of research for many physicians and scientists. As a result, Web-based surveys have been employed as an alternative to traditional, paper-based surveys. We describe DADOS-Survey, an open-source Web-survey application developed at our institution that, to the best of our knowledge, is the first to be compliant with the Checklist for Reporting Results of Internet E-Surveys (CHERRIES). DADOS-Survey was designed with usability as a priority, allowing investigators to design and execute their own studies with minimal technical difficulties in doing so. RESULTS: To date, DADOS-Survey has been successfully implemented in five Institutional Review Board-approved studies conducted by various departments within our academic center. Each of these studies employed a Web-survey design as their primary methodology. Our initial experience indicates that DADOS-Survey has been used with relative ease by each of the investigators and survey recipients. This has been further demonstrated through formal and field usability testing, during which time suggestions for improvement were incorporated into the software design. CONCLUSION: DADOS-Survey has the potential to have an important role in the future direction of Web-survey administration in biomedical research. This CHERRIES-compliant application is tailored to the emerging requirements of quality data collection in medicine