Evaluation of the bank stability and toe erosion model (BSTEM) for predicting lateral retreat on composite streambanks

Streambank erosion is known to be a major source of sediment in streams and rivers. The Bank Stability and Toe Erosion Model (BSTEM) was developed in order to predict streambank retreat due to both fluvial erosion and geotechnical failure. However, few, if any, model evaluations using long-term streambank retreat data have been performed. The objectives of this research were to (1) monitor long-term composite streambank retreat during a hydraulically active period on a rapidly migrating stream, (2) evaluate BSTEM’s ability to predict the measured streambank retreat, and (3) assess the importance of accurate geotechnical, fluvial erosion, and near-bank pore-water pressure properties. The Barren Fork Creek in northeastern Oklahoma laterally eroded 7.8 to 20.9 m along a 100-m length of stream between April and October 2009 based on regular bank location surveys. The most significant lateral retreat occurred in mid- to late-May and September due to a series of storm events, and not necessarily the most extreme events observed during the monitoring period. BSTEM (version 5.2) was not originally programmed to run multiple hydrographs iteratively, so a subroutine was written that automatically input the temporal sequence of stream stage and to lag the water table in the near-bank ground water depending on user settings. Eight BSTEM simulations of the Barren Fork Creek streambank were performed using combinations of the following input data: with and without a water table lag; default BSTEM geotechnical parameters (moderate silt loam) versus laboratory measured geotechnical parameters based on direct shear tests on saturated soil samples; and default BSTEM fluvial erosion parameters versus field measured fluvial erosion parameters from submerged jet tests. Using default BSTEM input values underestimated the actual erosion that occurred. Lagging the water table predicted more geotechnical failures resulting in greater streambank retreat. Using measured fluvial and geotechnical parameters and a water table lag also under predicted retreat (approximately 3.3 m), but did predict the appropriate timing of streambank collapses. The under prediction of retreat was hypothesized to be due to over predicting the critical shear stress of the non-cohesive gravel, under predicting the erodibility of the non-cohesive gravel, and/or under predicting the imposed shear stress acting on the streambank. Current research improving our understanding of shear stress distributions, streambank pore-water pressure dynamics, and methods for estimating excess shear stress parameters for noncohesive soils will be critical for improving BSTEM and other streambank stability models

Evaluation of the bank stability and toe erosion model (BSTEM) for predicting lateral retreat on composite streambanks

Streambank erosion is known to be a major source of sediment in streams and rivers. The Bank Stability and Toe Erosion Model (BSTEM) was developed in order to predict streambank retreat due to both fluvial erosion and geotechnical failure. However, few, if any, model evaluations using long-term streambank retreat data have been performed. The objectives of this research were to (1) monitor long-term composite streambank retreat during a hydraulically active period on a rapidly migrating stream, (2) evaluate BSTEM’s ability to predict the measured streambank retreat, and (3) assess the importance of accurate geotechnical, fluvial erosion, and near-bank pore-water pressure properties. The Barren Fork Creek in northeastern Oklahoma laterally eroded 7.8 to 20.9 m along a 100-m length of stream between April and October 2009 based on regular bank location surveys. The most significant lateral retreat occurred in mid- to late-May and September due to a series of storm events, and not necessarily the most extreme events observed during the monitoring period. BSTEM (version 5.2) was not originally programmed to run multiple hydrographs iteratively, so a subroutine was written that automatically input the temporal sequence of stream stage and to lag the water table in the near-bank ground water depending on user settings. Eight BSTEM simulations of the Barren Fork Creek streambank were performed using combinations of the following input data: with and without a water table lag; default BSTEM geotechnical parameters (moderate silt loam) versus laboratory measured geotechnical parameters based on direct shear tests on saturated soil samples; and default BSTEM fluvial erosion parameters versus field measured fluvial erosion parameters from submerged jet tests. Using default BSTEM input values underestimated the actual erosion that occurred. Lagging the water table predicted more geotechnical failures resulting in greater streambank retreat. Using measured fluvial and geotechnical parameters and a water table lag also under predicted retreat (approximately 3.3 m), but did predict the appropriate timing of streambank collapses. The under prediction of retreat was hypothesized to be due to over predicting the critical shear stress of the non-cohesive gravel, under predicting the erodibility of the non-cohesive gravel, and/or under predicting the imposed shear stress acting on the streambank. Current research improving our understanding of shear stress distributions, streambank pore-water pressure dynamics, and methods for estimating excess shear stress parameters for noncohesive soils will be critical for improving BSTEM and other streambank stability models

The effect of fibre cell remodelling on the power and optical quality of the lens.

Vertebrate eye lenses are uniquely adapted to form a refractive index gradient (GRIN) for improved acuity, and to grow slowly in size despite constant cell proliferation. The mechanisms behind these adaptations remain poorly understood. We hypothesize that cell compaction contributes to both. To test this notion, we examined the relationship between lens size and shape, refractive characteristics and the cross-sectional areas of constituent fibre cells in mice of different ages. We developed a block-face imaging method to visualize cellular cross sections and found that the cross-sectional areas of fibre cells rose and then decreased over time, with the most significant reduction occurring in denucleating cells in the adult lens cortex, followed by cells in the embryonic nucleus. These findings help reconcile differences between the predictions of lens growth models and empirical data. Biomechanical simulations suggested that compressive forces generated from continuous deposition of fibre cells could contribute to cellular compaction. However, optical measurements revealed that the GRIN did not mirror the pattern of cellular compaction, implying that compaction alone cannot account for GRIN formation and that additional mechanisms are likely to be involved

Hypercomplex quantum mechanics

The fundamental axioms of the quantum theory do not explicitly identify the algebraic structure of the linear space for which orthogonal subspaces correspond to the propositions (equivalence classes of physical questions). The projective geometry of the weakly modular orthocomplemented lattice of propositions may be imbedded in a complex Hilbert space; this is the structure which has traditionally been used. This paper reviews some work which has been devoted to generalizing the target space of this imbedding to Hilbert modules of a more general type. In particular, detailed discussion is given of the simplest generalization of the complex Hilbert space, that of the quaternion Hilbert module.Comment: Plain Tex, 11 page

Conversion From Tacrolimus to Belatacept to Prevent the Progression of Chronic Kidney Disease in Pancreas Transplantation: Case Report of Two Patients

Belatacept is a novel immunosuppressive agent that may be used as an alternative to calcineurin inhibitors (CNI) in immunosuppression (IS) regimens. We report two cases of pancreas transplant that were switched from tacrolimus (TAC) to belatacept. Case 1: 38‐year‐old female with pancreas transplant alone maintained on TAC‐based IS regimen whose serum creatinine (SCr) slowly deteriorated from 0.6 mg/dL at baseline to 2.2 mg/dL, 16 months posttransplant. A native kidney biopsy performed showed CNI toxicity. The patient was started on belatacept and TAC was eliminated. Case 2: 49‐year‐old female with simultaneous pancreas–kidney transplant, maintained on TAC‐based regimen where the SCr worsened over an initial 3‐month period from a baseline of 1.0 to 3.0 mg/dL. Belatacept was started and TAC was lowered. Due to persistent graft dysfunction and kidney transplant biopsy still showing changes consistent with CNI toxicity, the TAC was then discontinued. At >1 year postbelatacept and off TAC follow‐up, kidney function as measured by SCr remains stable at 1.0 ± 0.2 mg/dL in both recipients. Neither patient developed rejection following the switch, and pancreas allograft function remains stable in both recipients

Mii and MiiBump: Supporting pregnant women to continue or commence an active lifestyle

The purpose of this study was to investigate how women perceive exercising during pregnancy and whether existing technologies could be used to support active behaviours. Information for pregnant women who wish to continue or start exercising is limited and not readily offered. With the ever growing capability and accessibility to technologies research is warranted to investigate whether it could be used to help support exercising during pregnancy. An interpretative phenomenological approach was used to conduct in-depth interviews with five women, via purposive sampling. The data revealed that the participants perceived a number of barriers to active behaviours, such as the lack of a pregnant buddy with which to exercise. A lack of provided information was evident with the women claiming to have sought appropriate information themselves. Findings highlighted the potential for existing technologies to be utilised in order to support and enhance exercise behaviours during pregnancy

Adherence of internet-based cancer risk assessment tools to best practices in risk communication: Content analysis

BACKGROUND: Internet-based risk assessment tools offer a potential avenue for people to learn about their cancer risk and adopt risk-reducing behaviors. However, little is known about whether internet-based risk assessment tools adhere to scientific evidence for what constitutes good risk communication strategies. Furthermore, their quality may vary from a user experience perspective. OBJECTIVE: This study aims to understand the extent to which current best practices in risk communication have been applied to internet-based cancer risk assessment tools. METHODS: We conducted a search on August 6, 2019, to identify websites that provided personalized assessments of cancer risk or the likelihood of developing cancer. Each website (N=39) was coded according to standardized criteria and focused on 3 categories: general website characteristics, accessibility and credibility, and risk communication formats and strategies. RESULTS: Some best practices in risk communication were more frequently adhered to by websites. First, we found that undefined medical terminology was widespread, impeding comprehension for those with limited health literacy. For example, 90% (35/39) of websites included technical language that the general public may find difficult to understand, yet only 23% (9/39) indicated that medical professionals were their intended audience. Second, websites lacked sufficient information for users to determine the credibility of the risk assessment, making it difficult to judge the scientific validity of their risk. For instance, only 59% (23/39) of websites referenced the scientific model used to calculate the user\u27s cancer risk. Third, practices known to foster unbiased risk comprehension, such as adding qualitative labels to quantitative numbers, were used by only 15% (6/39) of websites. CONCLUSIONS: Limitations in risk communication strategies used by internet-based cancer risk assessment tools were common. By observing best practices, these tools could limit confusion and cultivate understanding to help people make informed decisions and motivate people to engage in risk-reducing behaviors

Spontaneous self-affirmation is associated with psychological well-being: evidence from a US national adult survey sample

Emerging evidence suggests that individuals spontaneously self-affirm, by reflecting on values and strengths, in response to daily threats. We examined the prevalence and demographic and well-being correlates of spontaneous self-affirmation in the general population. Participants (n = 3185) completed the cross-sectional, nationally representative 2013 Health Information National Trends Survey (HINTS 4, Cycle 3), and answered questions about spontaneous self-affirmation, demographic factors, well-being, and affect. The majority of the population reported spontaneously self-affirming. Black and Hispanic respondents reported engaging in more spontaneous self-affirmation. Engaging in spontaneous self-affirmation was related to greater happiness, hopefulness, optimism, subjective health, and personal health efficacy, and less anger and sadness