Gauging the Relationship between Contextual Growth and Structural Neglect

Population and land use out-migrations from urban to peripheral areas can result in non-functional, unmaintained historic structures which deteriorate to the point where removal is cheaper than removal – or demolition by neglect. The increasing rate of neglected historic structures is a growing concern. There is a need for research investigating connections between urban growth management and its effect on neglect. This paper applies Newman’s (2013) conceptual model of measuring neglect to Geographic Information Systems, comparing rates of neglect in historic Doylestown, Quakertown, and Bristol boroughs in Pennsylvania, USA utilizing different amounts of peripheral agricultural preservation. Comparisons are made examining descriptive statistics on existing conditions, a Polychoric correlation evaluating relationships between drivers of neglect, and a cross-comparative GIS spatial analysis. Results indicate as amounts of peripheral preserved farmlands increase, neglect can be lowered

Gauging the Relationship Between Contextual Growth and Structural Neglect

Population and land use out-migrations from urban to peripheral areas can result in non-functional, unmaintained historic structures which deteriorate to the point where removal is cheaper than removal – or demolition by neglect. The increasing rate of neglected historic structures is a growing concern. There is a need for research investigating connections between urban growth management and its effect on neglect. This paper applies Newman\u27s (2013) conceptual model of measuring neglect to Geographic Information Systems, comparing rates of neglect in historic Doylestown, Quakertown, and Bristol boroughs in Pennsylvania, USA utilizing different amounts of peripheral agricultural preservation. Comparisons are made examining descriptive statistics on existing conditions, a Polychoric correlation evaluating relationships between drivers of neglect, and a cross-comparative GIS spatial analysis. Results indicate as amounts of peripheral preserved farmlands increase, neglect can be lowered

The aortic-femoral arterial stiffness gradient demonstrates good between-day reliability

In a healthy cardiovascular system, arterial stiffness progressively increases from the elastic aorta to the muscular conduit arteries of the periphery. This stiffness gradient permits a gradual attenuation of the forward pressure wave into a smooth consistent blood flow and prevents the transmission of pulsatile forces to the microcirculation and endorgans [1]. However, aging and lifestyle factors may disrupt these beneficial phenomena [2]. In particular, the aorta tends to stiffen, whereas changes in lower-limb arterial stiffness, for example, are less marked [2]. These differential changes in stiffness lead to a reversal of the stiffness gradient, increasing forward pressure transmission, and contributing to end-organ damage [1, 3]. A recent study reported that the stiffness gradient between aortic and lower-limb arterial stiffness provided prognostic information beyond the carotid-femoral pulse-wave velocity (cfPWV), a criterion measure of arterial health [4]. This measure provides a promising opportunity to gain meaningful insight into the hemodynamic integration of the vascular system. However, a measurement must have acceptable precision (reliability) to be of value in clinical and research settings. Therefore, the objective of this study was to estimate the between-day reliability of the aortic-femoral arterial stiffness gradient (af-SG)

The Aortic-Femoral Arterial Stiffness Gradient: An Atherosclerosis Risk in Communities (ARIC) Study

Background: The aortic to femoral arterial stiffness gradient (af-SG) may be a novel measure of arterial health and cardiovascular disease (CVD) risk, but its association with CVD risk factors and CVD status, and whether or not they differ from the referent measure, carotid-femoral pulse-wave velocity (cfPWV), is not known. Method: Accordingly, we compared the associations of the af-SG and cfPWV with (i) age and traditional CVD risk factors and (ii) CVD status. We evaluated 4183 older-aged (75.2 ± 5.0 years) men and women in the community-based Atherosclerosis Risk in Communities (ARIC) Study. cfPWV and femoral-ankle PWV (faPWV) were measured using an automated cardiovascular screening device. The af-SG was calculated as faPWV divided by cfPWV. Associations of af-SG and cfPWV with age, CVD risk factors (age, BMI, blood pressure, heart rate, glucose and blood lipid levels) and CVD status (hypertension, diabetes, coronary heart disease, heart failure, stroke) were determined using linear and logistic regression analyses. Results: (i) the af-SG and cfPWV demonstrated comparable associations with age and CVD risk factors, except BMI. (ii) a low af-SG was associated with diabetes, coronary heart disease, heart failure and stroke, whilst a high cfPWV was only associated with diabetes. Conclusion: Although future studies are necessary to confirm clinical utility, the af-SG is a promising tool that may provide a unique picture of hemodynamic integration and identification of CVD risk when compared with cfPWV

Associations of lower-limb atherosclerosis and arteriosclerosis with cardiovascular risk factors and disease in older adults:The Atherosclerosis Risk in Communities (ARIC) study

BACKGROUND & AIMS Atherosclerosis and arteriosclerosis contribute to vascular aging and cardiovascular disease (CVD) risk. Both processes can be assessed simply in the lower-limbs and reflect systemic pathology. However, only atherosclerosis is routinely assessed, typically via ankle-brachial index (ABI). Arteriosclerosis can be assessed using femoral-ankle pulse wave velocity (faPWV), but no studies have identified whether ABI and faPWV similarly associate with overt CVD and risk factors, nor whether faPWV confers additional information. The aims of this study were to, (i) Compare associations of ABI and faPWV with traditional CVD risk factors, including age, sex, systolic blood pressure (SBP), high-density lipoprotein (HDL), total cholesterol (TC), smoking, and diabetes; and, ii) Determine the independent and additive associations of ABI and faPWV with a composite measure of prevalent CVD. METHODS We evaluated ABI and faPWV in 4,330 older-aged (75.3±5.0 years) adults using an oscillometric screening device. Associations between ABI and faPWV with CVD risk factors and CVD were determined using mixed-model linear- and logistic-regression. RESULTS ABI and faPWV were associated with age, HDL, and smoking. ABI was associated with sex, TC, diabetes. faPWV was associated with SBP. Both ABI and faPWV were inversely associated with CVD. Low ABI (≤0.9 vs. >0.9) and low faPWV (≤9.94 vs. >9.94) increased the odds of CVD by 2.41-fold (95% CI:1.85,3.17) and 1.46-fold (95% CI:1.23,1.74), respectively. The inverse association between faPWV and CVD was independent of ABI and CVD risk factors. CONCLUSION ABI and faPWV, measures of lower-limb atherosclerosis and arteriosclerosis, are independently associated with CVD risk factors and prevalent CVD. Assessment of faPWV may confer additional risk information beyond ABI

Exploration of cerebral hemodynamic pathways through which large artery function affects neurovascular coupling in young women

Background The interactions between large artery function and neurovascular coupling (NVC) are emerging as important contributors to cognitive health. Women are disproportionally affected by Alzheimer's disease and related dementia later in life. Understanding large artery correlates of NVC in young women may help with preservation of cognitive health with advancing age. Purpose To explore the association between large artery function, NVC and cognitive performance in young women. Methods Vascular measurements were made in 61 women (21 ± 4 yrs) at rest and during a cognitive challenge (Stroop task). Transcranial Doppler was used to measure left middle cerebral artery (MCA) maximum velocity (Vmax), mean velocity (Vmean), and pulsatility index (PI). NVC was determined as MCA blood velocity reactivity to the Stroop task. Large artery function was determined using carotid-femoral pulse wave velocity (cfPWV) as a proxy measure of aortic stiffness and carotid ultrasound-derived measures of compliance and reactivity (diameter change to the Stroop task). Cognitive function was assessed separately using a computerized neurocognitive battery that included appraisal of response speed, executive function, information processing efficiency, memory, attention/concentration, and impulsivity. Results MCA Vmax reactivity was positively associated with executive function (β = 0.26, 95% CI 0.01–0.10); MCA Vmean reactivity was negatively associated with response speed (β = −0.33, 95% CI −0.19 to −0.02) and positively with memory score (β = 0.28, 95% CI 0.01–0.19). MCA PI reactivity was negatively associated with attention performance (β = −0.29, 95% CI −14.9 to −1.0). Path analyses identified significant paths (p < 0.05) between carotid compliance and carotid diameter reactivity to select domains of cognitive function through MCA reactivity. Conclusions NVC was associated with cognitive function in young women. Carotid artery function assessed as carotid compliance and carotid reactivity may contribute to optimal NVC in young women through increased blood flow delivery and reduced blood flow pulsatility

Galaxy and Mass Assembly (GAMA): the stellar mass budget of galaxy spheroids and discs

We build on a recent photometric decomposition analysis of 7506 Galaxy and Mass Assembly (GAMA) survey galaxies to derive stellar mass function fits to individual spheroid and disc component populations down to a lower mass limit of log(M*/M⊙) = 8. We find that the spheroid/disc mass distributions for individual galaxy morphological types are well described by single Schechter function forms. We derive estimates of the total stellar mass densities in spheroids (ρspheroid = 1.24 ± 0.49 × 108 M⊙ Mpc -3h0.7) and discs (ρdisc = 1.20 ± 0.45 × 108 M⊙ Mpc -3h0.7), which translates to approximately 50 per cent of the local stellar mass density in spheroids and 48 per cent in discs. The remaining stellar mass is found in the dwarf 'little blue spheroid' class, which is not obviously similar in structure to either classical spheroid or disc populations. We also examine the variation of component mass ratios across galaxy mass and group halo mass regimes, finding the transition from spheroid to disc mass dominance occurs near galaxy stellar mass ~1011 M⊙ and group halo mass ~1012.5 M⊙h-1. We further quantify the variation in spheroid-to-total mass ratio with group halo mass for central and satellite populations as well as the radial variation of this ratio within groups.Publisher PDFPeer reviewe

Targeting Sedentary Behavior in Minority Populations as a Feasible Health Strategy during and beyond COVID-19: On Behalf of ACSM-EIM and HL-PIVOT

Increased sedentary behavior has been an unintended consequence of social and physical distancing restrictions needed to limit transmission of SARS-CoV-2, the novel coronavirus that causes COVID-19. Sedentary behavior is defined as any waking behavior characterized by an energy expenditure ≤1.5 METs while in a sitting, reclining, or lying posture. These restrictions negatively affect peoples’ cardiometabolic and mental health and disproportionately affect certain sectors of the population, including racial/ethnic minorities. In part, the higher risk for complications of COVID-19 could be the result of an increased prevalence of comorbid diseases. Further, regular participation and adherence to current physical activity guidelines, defined as at least 150 min·wk−1 of moderate-intensity physical activity or muscle strengthening activities on 2 or more days a week, is challenging for many and may be especially difficult to achieve during the COVID-19 pandemic. A practical strategy to promote health and well-being during COVID-19 is reducing sedentary behavior. Reducing sedentary behaviors (e.g., breaking up periods of prolonged sitting with light-intensity physical activity) may be more easily achieved than physical activity for all individuals, including individuals of racial/ethnic decent, as it does not require purchasing equipment nor require compromising the physical restrictions necessary to slow the spread of COVID-19. The purpose of this commentary is to argue that sedentary behavior is a feasible, independent target to modify during COVID-19, particularly in minority populations, and to address this behavior we need to consider individual, environmental, and policy-level factors.N/

Galaxy And Mass Assembly (GAMA) : trends in galaxy colours, morphology, and stellar populations with large-scale structure, group, and pair environments

We explore trends in galaxy properties with Mpc-scale structures using catalogues of environment and large-scale structure from the Galaxy And Mass Assembly (GAMA) survey. Existing GAMA catalogues of large-scale structure, group, and pair membership allow us to construct galaxy stellar mass functions for different environmental types. To avoid simply extracting the known underlying correlations between galaxy properties and stellar mass, we create a mass matched sample of galaxies with stellar masses within 9.5 ≤ log M*/h−2 M⊙ ≤ 11 for each environmental population. Using these samples, we show that mass normalized galaxies in different large-scale environments have similar energy outputs, u − r colours, luminosities, and morphologies. Extending our analysis to group and pair environments, we show that galaxies that are not in groups or pairs exhibit similar characteristics to each other regardless of broader environment. For our mass controlled sample, we fail to see a strong dependence of Sérsic index or galaxy luminosity on halo mass, but do find that it correlates very strongly with colour. Repeating our analysis for galaxies that have not been mass controlled introduces and amplifies trends in the properties of galaxies in pairs, groups, and large-scale structure, indicating that stellar mass is the most important predictor of the galaxy properties we examine, as opposed to environmental classifications.Publisher PDFPeer reviewe