Protostellar Disk Evolution Over Million-Year Timescales with a Prescription for Magnetized Turbulence

Magnetorotational instability (MRI) is the most promising mechanism behind accretion in low-mass protostellar disks. Here we present the first analysis of the global structure and evolution of non-ideal MRI-driven T-Tauri disks on million-year timescales. We accomplish this in a 1+1D simulation by calculating magnetic diffusivities and utilizing turbulence activity criteria to determine thermal structure and accretion rate without resorting to a 3-D magnetohydrodynamical (MHD) simulation. Our major findings are as follows. First, even for modest surface densities of just a few times the minimum-mass solar nebula, the dead zone encompasses the giant planet-forming region, preserving any compositional gradients. Second, the surface density of the active layer is nearly constant in time at roughly 10 g/cm2, which we use to derive a simple prescription for viscous heating in MRI-active disks for those who wish to avoid detailed MHD computations. Furthermore, unlike a standard disk with constant-alpha viscosity, the disk midplane does not cool off over time, though the surface cools as the star evolves along the Hayashi track. The ice line is firmly in the terrestrial planet-forming region throughout disk evolution and can move either inward or outward with time, depending on whether pileups form near the star. Finally, steady-state mass transport is a poor description of flow through an MRI-active disk. We caution that MRI activity is sensitive to many parameters, including stellar X-ray flux, grain size, gas/small grain mass ratio and magnetic field strength, and we have not performed an exhaustive parameter study here.Comment: Accepted for publication in Astrophysical Journal. 19 pages, including 8 figure

Do Employees From Less-Healthy Communities Use More Care and Cost More? Seeking to Establish a Business Case for Investment in Community Health.

INTRODUCTION: Few studies have examined the impact of community health on employers. We explored whether employed adults and their adult dependents living in less-healthy communities in the greater Philadelphia region used more care and incurred higher costs to employers than employees from healthier communities. METHODS: We used a multi-employer database to identify adult employees and dependents with continuous employment and mapped them to 31 zip code regions. We calculated community health scores at the regional level, by using metrics similar to the Robert Wood Johnson Foundation (RWJF) County Health Rankings but with local data. We used descriptive analyses and multilevel linear modeling to explore relationships between community health and 3 outcome variables: emergency department (ED) use, hospital use, and paid claims. Business leaders reviewed findings and offered insights on preparedness to invest in community health improvement. RESULTS: Poorer community health was associated with high use of ED services, after controlling for age and sex. After including a summary measure of racial composition at the zip code region level, the relationship between community health and ED use became nonsignificant. No significant relationships between community health and hospitalizations or paid claims were identified. Business leaders expressed interest in further understanding health needs of communities where their employees live. CONCLUSION: The health of communities in which adult employees and dependents live was associated with ED use, but similar relationships were not seen for hospitalizations or paid claims. This finding suggests a need for more primary care access. Despite limited quantitative evidence, business leaders expressed interest in guidance on investing in community health improvement

Paced to perfection: Exploring the potential impact of WaveLight Technology in athletics

Athletics is in the midst of a technological revolution, which has had a major impact on endurance running performance. Since 2016, most men’s and women’s world records, from the 5000 m to the Marathon have been broken, while the all-time list of fastest performances has been recalibrated. While much emphasis has been placed on the introduction of the so-called ‘super-shoe’ technology, other innovations may have contributed to these improvements. For instance, when Eliud Kipchoge completed the marathon in under 2-hours in 2019, his race-kit and the course were carefully designed (i.e., long-straight sections and minimal undulations/ curves), but a lesser appreciated innovation was the pacing device that was used. The use of pacing lights represented a key factor in Kipchoge’s performance, and this approach to pacing was translated to international track athletics during 2020. This translation of technology coincided with world record performances in the Men’s 5000 m and 10000 m, and the Women’s 5000 m

\u27Ice in the Family\u27: Exploring the experiences of close family members when another family member is using methamphetamine: A longitudinal qualitative study

Objective: To explore the experiences of close family members when another family member is using methamphetamine and how the family member responds over time. Background: Methamphetamine use has widespread implications and harms for both people who use the drug and those that live with them. While there is a significant representation in the literature relating to family members of people who use drugs or alcohol, there are limited studies specifically considering family members experiences of methamphetamine use. Families have been shown to have both positive and negative impacts on people using drugs, but less is known on the impact on the family members themselves. Study design and methods: Multiple semistructured qualitative interviews were conducted with 11 families (17 individual participants) from regional and metropolitan Western Australia over a 12-month period. Interpretative Phenomenological Analysis was used in data collection and analysis. Results: Four main themes were identified: 1. The New Lifeguard describes family members’ unplanned insertion into a new role and their rapidly changing experience of the person using methamphetamine. 2. Hit by the Wave demonstrates participants’ experience of repeated and unpredictable impacts on their lives. 3. Life in the Ocean describes the groundlessness associated with changes to goals and family structure. 4. Learning to Surf illuminates the changing strategies employed over time, moving away from trying to fix the person, to participants managing their own wellbeing. Discussion: This study identified common aspects within the lived experience of close family members of people using methamphetamine and ascertained a commonality in the process of this experience. Significant impacts to all areas of life were reported, and distress was fluctuating and unpredictable in line with the cyclical nature of the drug use. Participant responses to these changes varied over time between resentment and trying to fix things, and acceptance and resilience, while gaining or maintaining like-minded supports. Conclusion: Understanding the issues faced by families around this unique drug is vital in providing informed interventions for this group. Family members experience a broad range of financial, social and health impacts and harms over a protracted length of time. They are often not the focus of available support and in adapting to these issues, will themselves seek support away from treatment services for the person using methamphetamine. Implications for practice: Understanding the complex journey of families has a broad range of implications (and opportunities) for a variety of areas such as criminal justice, family support and child protection. There is an opportunity for these areas to consider broader and more specific supports and approaches, and to develop more appropriate, bespoke, and inclusive treatment for families of people using methamphetamine. What is already known about the topic? Methamphetamine is recognised worldwide as a harmful drug with few effective treatments for methamphetamine dependence. Few studies exist exploring the specific impact of methamphetamine on family members. Fewer studies explore the experiences over time. What this paper adds: Family members with a relative who is using methamphetamine experience a range of harms in many areas of their lives. The impact of methamphetamine use is unpredictable and takes place over long periods of time, affecting both individual family members and impacting on the overall structure of the family unit. Families and family members adapt their approach over time, from attempting to fix the situation, to stepping back and seeking support from others who they perceive to be in similar circumstances

Risk and the importance of absent symptoms in constructions of the ‘cancer candidate’

Cancer is a disease that is imbued with notions of risk, with individuals expected to avoid ‘risky’ behaviours and act swiftly when symptoms indicating a risk of cancer emerge. Cancer symptoms, however, are often ambiguous and indicative of a number of other conditions, making it difficult for people to assess when symptoms may, or may not, be the result of cancer. Here, we discuss interview data from a study examining the symptom appraisal and help-seeking experiences of patients referred for assessment of symptoms suspicious of a lung or colorectal cancer in the North-East of England. We explore how individuals draw upon ideas about cancer risks to assess whether cancer may be a possible explanation for their symptoms and to inform their decisions about help-seeking. In our analysis, we applied the concept of candidacy to the data, to highlight how lay epidemiology shapes people’s perceptions of cancer risk, and their subsequent responses to it. We found that participants appraised their symptoms, and the likelihood that they may have cancer, in light of relevant information on risk. These sources of information related to lifestyle factors, family history of cancer, environmental factors, and importantly, the symptomatic experience itself, including the absence of symptoms that participants associated with cancer. The importance of experienced, and absent, symptoms was a core element of participants’ everyday constructions of the ‘cancer candidate’, which informed symptom appraisal and subsequent help-seeking decision-making

Augmented Reality-based Feedback for Technician-in-the-loop C-arm Repositioning

Interventional C-arm imaging is crucial to percutaneous orthopedic procedures as it enables the surgeon to monitor the progress of surgery on the anatomy level. Minimally invasive interventions require repeated acquisition of X-ray images from different anatomical views to verify tool placement. Achieving and reproducing these views often comes at the cost of increased surgical time and radiation dose to both patient and staff. This work proposes a marker-free "technician-in-the-loop" Augmented Reality (AR) solution for C-arm repositioning. The X-ray technician operating the C-arm interventionally is equipped with a head-mounted display capable of recording desired C-arm poses in 3D via an integrated infrared sensor. For C-arm repositioning to a particular target view, the recorded C-arm pose is restored as a virtual object and visualized in an AR environment, serving as a perceptual reference for the technician. We conduct experiments in a setting simulating orthopedic trauma surgery. Our proof-of-principle findings indicate that the proposed system can decrease the 2.76 X-ray images required per desired view down to zero, suggesting substantial reductions of radiation dose during C-arm repositioning. The proposed AR solution is a first step towards facilitating communication between the surgeon and the surgical staff, improving the quality of surgical image acquisition, and enabling context-aware guidance for surgery rooms of the future. The concept of technician-in-the-loop design will become relevant to various interventions considering the expected advancements of sensing and wearable computing in the near future

Simultaneous clustering of gene expression data with clinical chemistry and pathological evaluations reveals phenotypic prototypes

BACKGROUND: Commonly employed clustering methods for analysis of gene expression data do not directly incorporate phenotypic data about the samples. Furthermore, clustering of samples with known phenotypes is typically performed in an informal fashion. The inability of clustering algorithms to incorporate biological data in the grouping process can limit proper interpretation of the data and its underlying biology. RESULTS: We present a more formal approach, the modk-prototypes algorithm, for clustering biological samples based on simultaneously considering microarray gene expression data and classes of known phenotypic variables such as clinical chemistry evaluations and histopathologic observations. The strategy involves constructing an objective function with the sum of the squared Euclidean distances for numeric microarray and clinical chemistry data and simple matching for histopathology categorical values in order to measure dissimilarity of the samples. Separate weighting terms are used for microarray, clinical chemistry and histopathology measurements to control the influence of each data domain on the clustering of the samples. The dynamic validity index for numeric data was modified with a category utility measure for determining the number of clusters in the data sets. A cluster's prototype, formed from the mean of the values for numeric features and the mode of the categorical values of all the samples in the group, is representative of the phenotype of the cluster members. The approach is shown to work well with a simulated mixed data set and two real data examples containing numeric and categorical data types. One from a heart disease study and another from acetaminophen (an analgesic) exposure in rat liver that causes centrilobular necrosis. CONCLUSION: The modk-prototypes algorithm partitioned the simulated data into clusters with samples in their respective class group and the heart disease samples into two groups (sick and buff denoting samples having pain type representative of angina and non-angina respectively) with an accuracy of 79%. This is on par with, or better than, the assignment accuracy of the heart disease samples by several well-known and successful clustering algorithms. Following modk-prototypes clustering of the acetaminophen-exposed samples, informative genes from the cluster prototypes were identified that are descriptive of, and phenotypically anchored to, levels of necrosis of the centrilobular region of the rat liver. The biological processes cell growth and/or maintenance, amine metabolism, and stress response were shown to discern between no and moderate levels of acetaminophen-induced centrilobular necrosis. The use of well-known and traditional measurements directly in the clustering provides some guarantee that the resulting clusters will be meaningfully interpretable

Thermal Control Method for High-Current Wire Bundles by Injecting a Thermally Conductive Filler

A procedure was developed to inject thermal filler material (a paste-like substance) inside the power wire bundle coming from solar arrays. This substance fills in voids between wires, which enhances the heat path and reduces wire temperature. This leads to a reduced amount of heat generated. This technique is especially helpful for current and future generation high-power spacecraft (1 kW or more), because the heat generated by the power wires is significant enough to cause unacceptable overheating to critical components that are in close contact with the bundle

The Clinical Ultrasonography Elective in Clerkship (CUSEC): A pilot elective for senior clerkship students at the University of Saskatchewan

We created a clinical ultrasound (CUS) elective in clerkship, which gave medical students the opportunity to enhance their knowledge and technical skills while refining their CUS-related clinical decision making. This elective uniquely allowed medical students to integrate their CUS knowledge and skills into real patient care within the clinical environment (discipline) of their choice. As such, beyond supporting increasing technical competence, students learned to advocate for appropriate use of CUS, an important skill for trainees to develop.&nbsp