The Lifting Properties of A-Homotopy Theory

In classical homotopy theory, two spaces are homotopy equivalent if one space can be continuously deformed into the other. This theory, however, does not respect the discrete nature of graphs. For this reason, a discrete homotopy theory that recognizes the difference between the vertices and edges of a graph was invented, called A-homotopy theory [1-5]. In classical homotopy theory, covering spaces and lifting properties are often used to compute the fundamental group of the circle. In this paper, we develop the lifting properties for A-homotopy theory. Using a covering graph and these lifting properties, we compute the fundamental group of the 5-cycle , giving an alternate approach to [4].Comment: 27 pages, 3 figures, updated version. Minor changes to the introduction and clarification that the computation of the fundamental group of the 5-cycle originally appeared in [4]. Title changed from "Computing A-Homotopy Groups Using Coverings and Lifting Properties" to "The Lifting Properties of A-Homotopy Theory

Measuring inequity: a systematic review of methods used to quantify structural racism

Abstract Objective: To summarize the ways in which researchers have quantified measures of structural racism for the purposes of empirical, quantitative investigation of its associations with physical and mental health outcomes. Methods: Systematic review of literature published January 1, 2007-June 30, 2017. We searched PubMed and EMBASE databases for studies including at least one of the following search terms in the title or abstract: “structural racism”, “systemic racism”, “institutional racism”, “institutionalized racism”. Excluded studies were not original research, not US based, did not quantify an explicitly named indicator of structural racism, or were qualitative designs. Data from full text articles were abstracted and synthesized. Results: Twenty articles met the final inclusion criteria. Articles included measures of structural racism within the following domains: residential neighborhood/housing, perceived racism in social institutions, immigration and border enforcement, political participation, socioeconomic status, criminal justice, and workplace environment. Conclusions: A burgeoning body of work suggest ways to operationalize and measure structural racism in US society for the purposes of exploring its impacts on individual and population health inequities

From a Place of Love: The Experiences of Birthing in a Black-Owned Culturally-Centered Community Birth Center

Introduction: Racial and ethnic disparities in perinatal health outcomes are among the greatest threats to population health in the United States. Black birthing communities are most impacted by these inequities due to structural racism throughout society and within health care settings. Although multiple studies have shown that structural racism and the disrespect associated with this system of inequity are the root causes of observed perinatal inequities, little scholarship has centered the needs of Black birthing communities to create alternative care models. Leaning on reproductive justice and critical race theoretical frameworks, this study explores good birth experiences as described by Black birthing people. Methods: Thematic analysis of two focus groups and three one-on-one interviews conducted with clients at a Black-owned free-standing culturally-centered birth center (n=10). Results: We found that Black birthing persons’ concerns centered on three main themes: agency, historically- and culturally-safe birthing experiences, and relationship-centered care. Many participants pointed directly to past experiences of medical mistreatment and obstetric racism when defining their ideal birth experience. Conclusion: Black birthing people seeking care from culturally-informed providers often do so because they have been mistreated, disregarded, and neglected within traditional care settings. The needs articulated by our study participants provide a powerful framework for understanding alternative patient-centered models of care that can be developed to improve the care experiences of Black birthing people in the pursuit of birth equity

Effects of the COVID-19 associated United Kingdom lockdown on physical activity in older adults at high risk of cardiovascular disease: a mixed methods perspective from the MedEx-UK multicenter trial

Introduction: Physical inactivity and sedentary behaviour are linked to increased risk of cardiovascular disease, infections and dementia, as well as placing a significant economic burden on healthcare systems. The implementation of COVID-19pandemic lockdown measures aimed at reducing virus transmission posed challenges to the opportunity to be physically active. This study investigates how the first UK COVID-19 lockdown affected objectively measured physical activity in older adults at higher risk of cardiovascular disease.Methods: We studied 48 individuals aged 55-74 years (81.3% female) with self-reported PA levels &lt; 90 min/week and a QRISK2 score ≥ 10 (indicative of a ≥ 10% risk of a major cardiovascular event in the next 10 years) without mild cognitive impairment or dementia. Physical activity data was collected using objective wrist-based activity monitors and analysed across three time periods, usual activity (pre-pandemic), the precautionary phase when the UK began advising on limiting social contact and finally during the first UK lockdown period was collected (27 January 2020 and 07 June 2020).Data was analysed using linear mixed effects model was used to investigate PA levels over the measured 12-weekperiod. Effects of BMI, age, deprivation score and baseline PA levels on PA across the three measurement periods were also examined. Focus-group and individual interviews were conducted, and data were thematically analysed.Results: Average daily step count (−34% lower, p &lt; 0.001) and active energy expenditure (−26% lower, p &lt;0.001) were significantly lower during the precautionary period compared with the usual activity period. Physical activity remained low during the UK lockdown period. Participants with a lower BMI engaged in significantly more (+45% higher daily steps p &lt; 0.001) physical activity and those over 70 years old were more physically active than those under 70years across the 12-week period (+23% higher daily steps p &lt; 0.007).The risk of COVID-19 infection and restrictions because of lockdown measures meant some individuals had to find alternative methods to staying physical active. Participants described a lack of access to facilities and concerns over health related to COVID-19 as barriers to engaging in physical activity during lockdown. For some, this resulted in a shift towards less structured activities such as gardening or going for a walk.Discussion: The data presented shows that lockdown measures during the COVID-19 pandemic significantly reduced physical activity among older individuals at risk of cardiovascular disease, particularly those with a higher body mass index. To support this population group in staying active during future lockdowns, a multifaceted strategy is needed, emphasizing psychosocial benefits and home-based physical activity. The MedEx-UK study was pre-registered with ClinicalTrials.gov (NCT03673722).</p

Intravital FRAP imaging using an E-cadherin-GFP mouse reveals disease- and drug-dependent dynamic regulation of cell-cell junctions in live tissue

E-cadherin-mediated cell-cell junctions play a prominent role in maintaining the epithelial architecture. The disruption or deregulation of these adhesions in cancer can lead to the collapse of tumor epithelia that precedes invasion and subsequent metastasis. Here we generated an E-cadherin-GFP mouse that enables intravital photobleaching and quantification of E-cadherin mobility in live tissue without affecting normal biology. We demonstrate the broad applications of this mouse by examining E-cadherin regulation in multiple tissues, including mammary, brain, liver, and kidney tissue, while specifically monitoring E-cadherin mobility during disease progression in the pancreas. We assess E-cadherin stability in native pancreatic tissue upon genetic manipulation involving Kras and p53 or in response to anti-invasive drug treatment and gain insights into the dynamic remodeling of E-cadherin during in situ cancer progression. FRAP in the E-cadherin-GFP mouse, therefore, promises to be a valuable tool to fundamentally expand our understanding of E-cadherin-mediated events in native microenvironments

Feasibility and acceptability of a multi-domain intervention to increase Mediterranean diet adherence and physical activity in older UK adults at risk of dementia: Protocol for the MedEx-UK randomised controlled trial

Introduction Dementia prevalence continues to increase, and effective interventions are needed to prevent, delay or slow its progression. Higher adherence to the Mediterranean diet (MedDiet) and increased physical activity (PA) have been proposed as strategies to facilitate healthy brain ageing and reduce dementia risk. However, to date, there have been no dementia prevention trials in the UK focussed on combined dietary and PA interventions. This study aims to: (1) assess feasibility and acceptability of a theory-underpinned digital and group-based intervention for dementia risk reduction in an 'at risk' UK cohort; (2) evaluate behaviour change responses to the intervention; and, (3) provide information on cognitive, neurological, vascular and physiological outcomes to inform the design of a follow-on, full-scale efficacy trial. Methods One hundred and eight participants aged 55 to 74 years with a QRISK2 score of ≥10% will be recruited to take part in this 24-week multi-site study. Participants will be randomised into three parallel arms: (1) Control; (2) MedDiet; and, (3) MedDiet+PA. The study will evaluate a personalised website, group session and food delivery intervention to increase MedDiet adherence and PA in older adults at risk of dementia. Diet and PA will be monitored prior to, during and following the intervention. Feasibility, acceptability and hypothesised mediators will be assessed in addition to measures of cognitive function, brain structure/perfusion (MRI), vascular function and metabolic markers (blood, urine and faecal) prior to, and following, the intervention. Discussion This trial will provide insights into the feasibility, acceptability and mechanism of effect of a multi-domain intervention focussed on the MedDiet alone and PA for dementia risk reduction in an 'at risk' UK cohort. Ethics and dissemination The study has received NHS REC and HRA approval (18/NI/0191). Findings will be disseminated via conference presentations, public lectures, and peer-reviewed publications. Trial registration details ClinicalTrials.gov NCT03673722

Computing A-Homotopy Groups of Graphs Using Coverings and Lifting Properties

In classical homotopy theory, two spaces are homotopy equivalent if one space can be continuously deformed into the other. This theory, however, does not respect the discrete nature of graphs. For this reason, a discrete homotopy theory that recognizes the difference between the vertices and edges of a graph was invented, called A-homotopy theory. In classical homotopy theory, covering spaces and lifting properties are often used to compute the fundamental group of a space. In this thesis, we develop the lifting properties for A-homotopy theory. Using a covering graph and these lifting properties, we compute the fundamental group of the cycle C_5 and use this computation to show that C_5 is not contractible in this theory, even though the cycles C_3 and C_4 are contractible

Community Health Workers in the Midwest: Understanding and Developing the Workforce

The American Cancer Society seeks to promote the use of community health workers throughout their midwest region. Wilder Research conducted an assessment designed to increase understanding of the community health worker workforce in four states: Iowa, Minnesota, South Dakota, and Wisconsin. WR also conducted a study to demonstrate the economic value of investing in cancer outreach via community health workers