The effect of nonlinearities on the dynamic response of a large shuttle payload

The STS Centaur was designed to be a high energy upper stage for use with the Space Shuttle. Two versions were designed under development when the program was cancelled. The first version, designated G-prime, was for planetary missions. The second version, designated G, was to place spacecraft in geosynchronous orbit. As a part of the STS Centaur finite-element model verification effort, test articles of both versions were subjected to a series of static tests. In addition the Centaur G-prime test article was subjected to a series of dynamic tests including a modal survey. Both the static and dynamic tests showed that nonlinearities existed in the Centaur and its support system. The support system included flight-like latches. The nonlinearities were particularly apparent in tests that loaded the forward support structure of the Centaur. These test results were used to aid in the development of two improved finite-element models. The first was a linear model, while the second contained nonlinear elements at the boundaries. Results from both models were compared with the transient response obtained from a step-relaxation or twang test. The linear model was able to accurately match the low frequency response found in the test data. However, only the nonlinear model was able to match higher frequency response that was present in some of the test data. In addition the nonlinear model was able to predict other nonlinear behavior such as the dynamic jump that occurs in systems with nonlinear stiffness

Informatics Metrics and Measures for a Smart Public Health Systems Approach: Information Science Perspective

Public health informatics is an evolving domain in which practices constantly change to meet the demands of a highly complex public health and healthcare delivery system. Given the emergence of various concepts, such as learning health systems, smart health systems, and adaptive complex health systems, health informatics professionals would benefit from a common set of measures and capabilities to inform our modeling, measuring, and managing of health system “smartness.” Here, we introduce the concepts of organizational complexity, problem/issue complexity, and situational awareness as three codependent drivers of smart public health systems characteristics. We also propose seven smart public health systems measures and capabilities that are important in a public health informatics professional’s toolkit

Microbial Ecogenomics and Forensic Archaeology: New Methods for Investigating Clandestine Gravesites

In the mid-1990s, the crime scene toolkit was revolutionised by the introduction of DNA-based analyses such as the polymerase chain reaction, low copy number DNA analysis, short-tandem repeat typing, pulse-field gel electrophoresis and variable number tandem repeat. Since then, methodological advances in other disciplines, especially molecular microbial ecology, can now be adapted for cutting-edge applications in forensic contexts. Despite several studies and discussions, there is, however, currently very little evidence of these techniques’ adoption at the contemporary crime scene. Consequently, this article discusses some of the popular ‘omics’ and their current and potential exploitations in the ‘forensic ecogenomics’ of body decomposition in a crime scene. Thus, together with published supportive findings and discourse, knowledge gaps are identified. These then justify the need for more comprehensive, directed, concerted and global research towards state-of-the-art microecophysiology method application and/or adaptation for subsequent successful exploitations in this additional context of microbial forensics

An Organizational Informatics Analysis of Colorectal, Breast, and Cervical Cancer Screening Clinical Decision Support and Information Systems within Community Health Centers

Indiana University-Purdue University Indianapolis (IUPUI)A study design has been developed that employs a dual modeling approach to identify factors associated with facility-level cancer screening improvement and how this is mediated by the use of clinical decision support. This dual modeling approach combines principles of (1) Health Informatics, (2) Cancer Prevention and Control, (3) Health Services Research, and (4) Organizational Change/Theory. The study design builds upon the constructs of a conceptual framework developed by Jane Zapka, namely, (1) organizational and/or practice settings, (2) provider characteristics, and (3) patient population characteristics. These constructs have been operationalized as measures in a 2005 HRSA/NCI Health Disparities Cancer Collaborative inventory of 44 community health centers. The first, statistical models will use: sequential, multivariable regression models to test for the organizational determinants that may account for the presence and intensity-of-use of clinical decision support (CDS) and information systems (IS) within community health centers for use in colorectal, breast, and cervical cancer screening. A subsequent test will assess the impact of CDS/IS on provider reported cancer screening improvement rates. The second, computational models will use a multi-agent model of network evolution called CONSTRUCT® to identify the agents, tasks, knowledge, groups, and beliefs associated with cancer screening practices and CDS/IS use to inform both CDS/IS implementation and cancer screening intervention strategies. This virtual experiment will facilitate hypothesis-generation through computer simulation exercises. The outcome of this research will be to identify barriers and facilitators to improving community health center facility-level cancer screening performance using CDS/IS as an agent of change. Stakeholders for this work include both national and local community health center IT leadership, as well as clinical managers deploying IT strategies to improve cancer screening among vulnerable patient populations

The 2017 Vermont Opioid Prescribing Rules: Prescriber Attitudes

Introduction. In July of 2017, Vermont enacted new rules on acute opioid pre- scribing to reduce misuse, addiction, and overdose associated with prescription opioids. The new rules include requirements of non-opioid therapy use when possible, querying VPMS, patient education and informed consent, and co-prescription of naloxone. Our study objective was to gain insight into the perspectives of opioid prescribers on the new rules. Methods. The 17-item survey included closed and open-ended questions addressing prescriber perceptions about the new rules as well as demographic information about respondents. The survey was sent to Vermont-based opioid prescribers via email, to multiple healthcare organizations and professional societies, and through personal contacts. Open-ended responses were categorized using paired reviewers and group consensus, using a grounded theory approach. Results. A total of 431 responses were obtained, with MD/DOs accounting for 65%, APRNs- 14%, DDS/DMD- 7%, PAs-13%, and NDs- 1%. Of the respondents, 75% thought that more restrictive opioid prescribing rules were necessary, 74% felt the new rules would have some positive effect on the opioid crisis, but only 48% were in favor of the new rules. Barriers to implementation included co-prescribing naloxone (50% were unsuccessful), justifying exceptions to rules in medical record (46% unsuc- cessful), considering non-pharmacologic therapies (39% unsuccessful), and adhering to prescription limits (31% unsuccessful). Conclusions. Roll-out of the new rules has been criticized for implementation issues, overall reducing favorability among prescribers. Feedback obtained may be utilized by the Vermont Health Department and by other states to improve current models of opioid prescribing.https://scholarworks.uvm.edu/comphp_gallery/1264/thumbnail.jp

Infrared Spectroscopy of H-Bonded Bridges Stretched across the cis-Amide Group: II. Ammonia and Mixed Ammonia/Water Bridges

Clusters of two model cis amides, oxindole and 3,4-dihydro-2(IH)-quinolinone, containing one and two ammonia molecules have been studied in the IR hydride stretch region using resonant ion-dip IR spectroscopy. The spectra confirm that ammonia is able to form hydrogen-bonded bridges across the adjacent amide N-H and C=O sites in a manner very similar to that of water. Such bridged structures require that ammonia assume the role of a hydrogen bond donor. Further similarities of the hydrogen bonding capabilities of ammonia and water have been revealed by investigations of ternary clusters containing an amide, one ammonia, and one water molecule. Experimentally, two species are observed having IR spectra consistent with a hydrogen-bonded bridge structure. The two species differ only in the relative positions of the ammonia and water molecules within the bridge. These experimental results are well supported by optimized structures, vibrational frequencies, and IR intensities calculated using density functional theory with the Becke3LYP functional. Additionally, the characteristic features of the hydride stretch fundamentals in a hydrogen-bond-donating ammonia molecule can be readily understood using a simple model for the coupled NH oscillators in which the hydrogen-bonded NH has its force constant lowered and its dipole derivative increased, much like in other hydrogen-bonded XH groups

Infrared Spectroscopy Of H-bonded Bridges Stretched Across The Cis-amide Group: I. Water Bridges

The water-containing clusters of oxindole (OI) and 3,4-dihydro-2(1H)-quinolinone (DQ) have been studied in the hydride stretch region of the infrared by the technique of resonant ion-dip infrared spectroscopy (RIDIRS). Both OI and DQ are constrained cis-amides with adjacent N-H and C=O groups between which water can form H-bonded bridges. The hydride stretch fundamentals of OI-W-n with n = 1-3 and DQ-W-n with n = 1, 2 without exception divide up into free OH stretch fundamentals near 3700 cm(-1) and a set of H-bonded bridge fundamentals in the 3200-3450 cm(-1) region. The bridge fundamentals show a distribution of intensities that reflects strong coupling among the XH oscillators in the bridge. When more than one water is involved in the bridge, the bridge fundamentals are unusually broad, with widths of 50-80 cm(-1) full width at half-maximum. Minimum-energy structures, binding energies, vibrational frequencies, and infrared intensities have been calculated by density functional theory with a Becke3LYP functional and a 6-31+G* basis set. The calculated infrared spectra match experiment well, confirming the bridge structures for the clusters. The form of the calculated normal modes provides insight into the nature of the bridge fundamentals

The Infrared and Ultraviolet Spectra of Individual Conformational Isomers of Biomolecules: Tryptamine

Resonant ion-dip infrared (RIDIR) and UV-UV hole-burning spectroscopies are used to record the hydride stretch infrared spectra and S 1 rS 0 ultraviolet spectra of each of seven conformational isomers of tryptamine free from interference from one another. The different conformations of the ethylamine side chain produce unique S 1 rS 0 vibronic spectra, which can serve as the basis for RIDIR spectroscopy. The seven conformers possess unique spectral signatures in the alkyl CH stretch region of the infrared, which aid in the assignment of the observed transitions in the ultraviolet. Density functional theory (DFT) calculations of the structures, relative energies, and harmonic vibrational frequencies of nine low-energy minima are compared with the present and previous experimental data on tryptamine to assign the spectra of all seven conformers, all of which point the R carbon out of the plane of the indole ring. The nine conformers consist of all combinations of the three minimum-energy amino group positions (anti, gauche toward the phenyl side, and gauche toward the pyrrole side of indole) and three amino group orientations (180°, (60°) at each position. All three anti conformers are observed experimentally, whereas only the two lowest-energy of the three orientational conformers at each gauche position are observed. The dominant factor in determining the form of the CH stretch infrared spectrum is the orientation of the amino group, with the amino group position playing a secondary role. The frequencies of the S 1 rS 0 origin transitions, on the other hand, are most sensitive to the position of the amino group, whether it is anti, gauche phenyl, or gauche pyrrole. The prospects for using these methods more generally to characterize the conformations and energetics of flexible biomolecules are discussed

Hypothesis Generation Using Network Structures on Community Health Center Cancer-Screening Performance

RESEARCH OBJECTIVES: Nationally sponsored cancer-care quality-improvement efforts have been deployed in community health centers to increase breast, cervical, and colorectal cancer-screening rates among vulnerable populations. Despite several immediate and short-term gains, screening rates remain below national benchmark objectives. Overall improvement has been both difficult to sustain over time in some organizational settings and/or challenging to diffuse to other settings as repeatable best practices. Reasons for this include facility-level changes, which typically occur in dynamic organizational environments that are complex, adaptive, and unpredictable. This study seeks to understand the factors that shape community health center facility-level cancer-screening performance over time. This study applies a computational-modeling approach, combining principles of health-services research, health informatics, network theory, and systems science. METHODS: To investigate the roles of knowledge acquisition, retention, and sharing within the setting of the community health center and to examine their effects on the relationship between clinical decision support capabilities and improvement in cancer-screening rate improvement, we employed Construct-TM to create simulated community health centers using previously collected point-in-time survey data. Construct-TM is a multi-agent model of network evolution. Because social, knowledge, and belief networks co-evolve, groups and organizations are treated as complex systems to capture the variability of human and organizational factors. In Construct-TM, individuals and groups interact by communicating, learning, and making decisions in a continuous cycle. Data from the survey was used to differentiate high-performing simulated community health centers from low-performing ones based on computer-based decision support usage and self-reported cancer-screening improvement. RESULTS: This virtual experiment revealed that patterns of overall network symmetry, agent cohesion, and connectedness varied by community health center performance level. Visual assessment of both the agent-to-agent knowledge sharing network and agent-to-resource knowledge use network diagrams demonstrated that community health centers labeled as high performers typically showed higher levels of collaboration and cohesiveness among agent classes, faster knowledge-absorption rates, and fewer agents that were unconnected to key knowledge resources. Conclusions and research implications: Using the point-in-time survey data outlining community health center cancer-screening practices, our computational model successfully distinguished between high and low performers. Results indicated that high-performance environments displayed distinctive network characteristics in patterns of interaction among agents, as well as in the access and utilization of key knowledge resources. Our study demonstrated how non-network-specific data obtained from a point-in-time survey can be employed to forecast community health center performance over time, thereby enhancing the sustainability of long-term strategic-improvement efforts. Our results revealed a strategic profile for community health center cancer-screening improvement via simulation over a projected 10-year period. The use of computational modeling allows additional inferential knowledge to be drawn from existing data when examining organizational performance in increasingly complex environments