1,650 research outputs found
Age and Prostate-Specific Antigen Level Prior to Diagnosis Predict Risk of Death from Prostate Cancer.
A single early prostate-specific antigen (PSA) level has been correlated with a higher likelihood of prostate cancer diagnosis and death in younger men. PSA testing in older men has been considered of limited utility. We evaluated prostate cancer death in relation to age and PSA level immediately prior to prostate cancer diagnosis. Using the Veterans Affairs database, we identified 230,081 men aged 50-89 years diagnosed with prostate cancer and at least one prior PSA test between 1999 and 2009. Prostate cancer-specific death over time was calculated for patients stratified by age group (e.g., 50-59 years, through 80-89 years) and PSA range at diagnosis (10 ranges) using Kaplan-Meier methods. Risk of 10-year prostate cancer mortality across age and PSA was compared using log-rank tests with a Bonferroni adjustment for multiple testing. 10.5% of men diagnosed with prostate cancer died of cancer during the 10-year study period (mean follow-up = 3.7 years). Higher PSA values prior to diagnosis predict a higher risk of death in all age groups (p < 0.0001). Within the same PSA range, older age groups are at increased risk for death from prostate cancer (p < 0.0001). For PSA of 7-10 ng/mL, cancer-specific death, 10 years after diagnosis, increased from 7% for age 50-59 years to 51% for age 80-89 years. Men older than 70 years are more likely to die of prostate cancer at any PSA level than younger men, suggesting prostate cancer remains a significant problem among older men (even those aged 80+) and deserves additional study
Is There a Relationship Between Mathematics Background and Conception of Proof?
To invest in the future of mathematics education is to invest in our future teachers. Equipping such individuals should be the utmost priority, for they will communicate mathematics to our students. Research shows that the way we work with and explain mathematics is consequential to our proof scheme; that is, the proof schemes we hold are the proof schemes we will inevitably teach. This study explores the possible proof schemes and mindsets held by ten university students studying mathematics education at Lee University--six enrolled in a geometry course and four in an algebra course. Through interviews and critical thinking exercises, we analyzed the future students\u27 proof schemes and views on mathematics. Our analysis found that participants who had encountered proof-based mathematics courses had a tendency to approach problems analytically, which implied the existence of an association between their definitions of proof and methods of problem-solving. This relationship perhaps has implications about teacher preparation and development prior to entering the classroom, thus revealing its significance to student success
The Heparan Sulfate Proteoglycans Dally-like and Syndecan Have Distinct Functions in Axon Guidance and Visual-System Assembly in Drosophila
SummaryHeparan sulfate proteoglycans (HSPGs), a class of glycosaminoglycan-modified proteins, control diverse patterning events via their regulation of growth-factor signaling and morphogen distribution [1]. In C. elegans, zebrafish, and the mouse, heparan sulfate (HS) biosynthesis is required for normal axon guidance [2–4], and mutations affecting Syndecan (Sdc), a transmembrane HSPG, disrupt axon guidance in Drosophila embryos [5, 6]. Glypicans, a family of glycosylphosphatidylinositol (GPI)-linked HSPGs, are expressed on axons and growth cones in vertebrates, but their role in axon guidance has not been determined [7, 8]. We demonstrate here that the Drosophila glypican Dally-like protein (Dlp) is required for proper axon guidance and visual-system function. Mosaic studies revealed that Dlp is necessary in both the retina and the brain for different aspects of visual-system assembly. Sdc mutants also showed axon guidance and visual-system defects, some that overlap with dlp and others that are unique. dlp+ transgenes were able to rescue some sdc visual-system phenotypes, but sdc+ transgenes were ineffective in rescuing dlp abnormalities. Together, these findings suggest that in some contexts HS chains provide the biologically critical component, whereas in others the structure of the protein core is also essential
How and when to end the COVID-19 lockdown: an optimization approach
Countries around the world are in a state of lockdown to help limit the spread of SARS-CoV-2. However, as the number of new daily confirmed cases begins to decrease, governments must decide how to release their populations from quarantine as efficiently as possible without overwhelming their health services. We applied an optimal control framework to an adapted Susceptible-Exposure-Infection-Recovery (SEIR) model framework to investigate the efficacy of two potential lockdown release strategies, focusing on the UK population as a test case. To limit recurrent spread, we find that ending quarantine for the entire population simultaneously is a high-risk strategy, and that a gradual re-integration approach would be more reliable. Furthermore, to increase the number of people that can be first released, lockdown should not be ended until the number of new daily confirmed cases reaches a sufficiently low threshold. We model a gradual release strategy by allowing different fractions of those in lockdown to re-enter the working non-quarantined population. Mathematical optimization methods, combined with our adapted SEIR model, determine how to maximize those working while preventing the health service from being overwhelmed. The optimal strategy is broadly found to be to release approximately half the population 2–4 weeks from the end of an initial infection peak, then wait another 3–4 months to allow for a second peak before releasing everyone else. We also modeled an “on-off” strategy, of releasing everyone, but re-establishing lockdown if infections become too high. We conclude that the worst-case scenario of a gradual release is more manageable than the worst-case scenario of an on-off strategy, and caution against lockdown-release strategies based on a threshold-dependent on-off mechanism. The two quantities most critical in determining the optimal solution are transmission rate and the recovery rate, where the latter is defined as the fraction of infected people in any given day that then become classed as recovered. We suggest that the accurate identification of these values is of particular importance to the ongoing monitoring of the pandemic
The Relationship between Aerobic Capacity and Bone Health in Young Women
International Journal of Exercise Science 9(1): 56-63, 2016. The purpose of the present investigation was to examine the relationship between maximal oxygen consumption (VO2max) and bone health in young women. Eighty-three participants (age=21.0±2.2 years; BMI=22.4±3.0 kg/m2) reported for testing on two occasions separated by 48 hours. During visit 1 body composition assessment via dual-energy X-ray absorptiometry (DXA) and during visit 2, a VO2max test performed on a motorized treadmill. Weak correlations were found between absolute VO2max (L/min) and whole-body bone mineral density (WB-BMD: r=0.24, p=0.031) and whole-body bone mineral content (WB-BMC: r=0.37, p\u3c0.001). No relation between variables were observed when VO2max was expressed relative to body mass (mL/kg/min). Moderate correlations were observed between bone variables and body mass (WB-BMD: r=0.36, p\u3c0.001; WB-BMC: r=0.62, p\u3c0.001), fat-free mass (WB-BMD: r=0.45, p\u3c0.001; WB-BMC: r=0.54, p\u3c0.001), and fat mass (WB-BMD: r=0.31, p=0.004; WB-BMC: r=0.60, p\u3c0.001). Body mass, regardless of composition, was a stronger predictor of bone health than aerobic capacity in this sample of young women
Understanding how children are coping with climate change anxiety by exploring coping strategies and supportive interventions.
Climate change presents a significant threat to both the planet and human prosperity which impacts our physical health and mental well-being. There is an imminent requirement for
significant global action. This means (a) our children have been born into unprecedented times and (b) as future adults, they will find themselves facing the major consequences of climate change. These can negatively affect their mental health and well-being. This paper reports the effect of climate anxiety on this population group through an exploration of coping strategies and supportive interventions. Empowering children to engage in climate action has been identified as a coping strategy. Whilst equipping them with knowledge and resources on climate change and providing safe spaces and experiences in nature are identified as supportive interventions. However, further empirical research evidence is needed to determine the next steps to address the extent of the impact of climate anxiety and prepare our children for the future
Patient engagement with antibiotic messaging in secondary care: a qualitative feasibility study of the ‘review & revise’ experience
Background: We aimed to investigate and optimise the acceptability and usefulness of a patient leaflet about antibiotic prescribing decisions made during hospitalisation, and to explore individual patient experiences and preferences regarding the process of antibiotic prescription ‘review & revise’ which is a key strategy to minimise antibiotic overuse in hospitals.
Methods: In this qualitative study, run within the feasibility study of a large, cluster-randomised stepped wedge trial of 36 hospital organisations, a series of semi-structured, think-aloud telephone interviews were conducted and data were analysed using thematic analysis. Fifteen adult patients who had experienced a recent acute medical hospital admission during which they had been prescribed antimicrobials and offered a patient leaflet about antibiotic prescribing were recruited to the study.
Results: Participants reacted positively to the leaflet, reporting that it was both an accessible and important source of information which struck the appropriate balance between informing and reassuring. Participants all valued open communication with clinicians, and were keen to be involved in antibiotic prescribing decisions, with individuals reporting positive experiences regarding antibiotic prescription changes or stopping. Many participants had prior experience or knowledge of antibiotics and resistance, and generally welcomed efforts to reduce antibiotic usage. Overall, there was a feeling that healthcare professionals (HCPs) are trusted experts providing the most appropriate treatment for individual patient conditions.
Conclusions: This study offers novel insights into how patients within secondary care are likely to respond to messages advocating a reduction in the use of antibiotics through the ‘review & revise’ approach. Due to the level of trust that patients place in their care provider, encouraging HCPs within secondary care to engage patients with greater communication and information provision could provide great advantages in the drive to reduce antibiotic use. It may also be beneficial for HCPs to view patient experiences as cumulative events that have the potential to impact future behaviour around antibiotic use. Finally, pre-testing messages about antibiotic prescribing and resistance is vital to dispelling any misconceptions either around effectiveness of treatment for patients, or perceptions of how messages may be received
National Pharmacare in Canada: Equality or Equity, Accessibility or Affordability; Comment on “Universal Pharmacare in Canada: A Prescription for Equity in Healthcare”
Canada’s federal government intends to take steps to implement national pharmacare so that all Canadians have prescription drug coverage they need at an affordable price. Relatively limited funds have so far been pledged to support national pharmacare, which raises the question: what kind of program is envisioned? Since the government has already introduced regulations intended to reduce new drug prices drastically, national pharmacare seems likely to be a basic system designed to assist low-income Canadians with accessing primary care medicines. What Canadians actually need is a system that provides access to the medicine considered appropriate by the patient and their healthcare provider for the patient’s specific condition. Equitable national pharmacare will not be achieved if patients are denied access to new high-cost specialized medicines that can improve or extend their lives, any more than if patients who cannot afford basic drugs are not helped
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