Comparison of alternate scoring of variables on the performance of the frailty index

Background: The frailty index (FI) is used to measure the health status of ageing individuals. An FI is constructed as the proportion of deficits present in an individual out of the total number of age-related health variables considered. The purpose of this study was to systematically assess whether dichotomizing deficits included in an FI affects the information value of the whole index. Methods: Secondary analysis of three population-based longitudinal studies of community dwelling individuals: Nova Scotia Health Survey (NSHS, n = 3227 aged 18+), Survey of Health, Ageing and Retirement in Europe (SHARE, n = 37546 aged 50+), and Yale Precipitating Events Project (Yale-PEP, n = 754 aged 70+). For each dataset, we constructed two FIs from baseline data using the deficit accumulation approach. In each dataset, both FIs included the same variables (23 in NSHS, 70 in SHARE, 33 in Yale-PEP). One FI was constructed with only dichotomous values (marking presence or absence of a deficit); in the other FI, as many variables as possible were coded as ordinal (graded severity of a deficit). Participants in each study were followed for different durations (NSHS: 10 years, SHARE: 5 years, Yale PEP: 12 years). Results: Within each dataset, the difference in mean scores between the ordinal and dichotomous-only FIs ranged from 0 to 1.5 deficits. Their ability to predict mortality was identical; their absolute difference in area under the ROC curve ranged from 0.00 to 0.02, and their absolute difference between Cox Hazard Ratios ranged from 0.001 to 0.009. Conclusions: Analyses from three diverse datasets suggest that variables included in an FI can be coded either as dichotomous or ordinal, with negligible impact on the performance of the index in predicting mortality.Fernando G Peña, Olga Theou, Lindsay Wallace, Thomas D Brothers, Thomas M Gill, Evelyne A Gahbauer, Susan Kirkland, Arnold Mitnitski and Kenneth Rockwoo

Self-degradable Cementitious Sealing Materials

A self-degradable alkali-activated cementitious material consisting of a sodium silicate activator, slag, Class C fly ash, and sodium carboxymethyl cellulose (CMC) additive was formulated as one dry mix component, and we evaluated its potential in laboratory for use as a temporary sealing material for Enhanced Geothermal System (EGS) wells. The self-degradation of alkali-activated cementitious material (AACM) occurred, when AACM heated at temperatures of {ge}200 C came in contact with water. We interpreted the mechanism of this water-initiated self-degradation as resulting from the in-situ exothermic reactions between the reactants yielded from the dissolution of the non-reacted or partially reacted sodium silicate activator and the thermal degradation of the CMC. The magnitude of self-degradation depended on the CMC content; its effective content in promoting degradation was {ge}0.7%. In contrast, no self-degradation was observed from CMC-modified Class G well cement. For 200 C-autoclaved AACMs without CMC, followed by heating at temperatures up to 300 C, they had a compressive strength ranging from 5982 to 4945 psi, which is {approx}3.5-fold higher than that of the commercial Class G well cement; the initial- and final-setting times of this AACM slurry at 85 C were {approx}60 and {approx}90 min. Two well-formed crystalline hydration phases, 1.1 nm tobermorite and calcium silicate hydrate (I), were responsible for developing this excellent high compressive strength. Although CMC is an attractive, as a degradation-promoting additive, its addition to both the AACM and the Class G well cement altered some properties of original cementitious materials; among those were an extending their setting times, an increasing their porosity, and lowering their compressive strength. Nevertheless, a 0.7% CMC-modified AACM as self-degradable cementitious material displayed the following properties before its breakdown by water; {approx}120 min initial- and {approx}180 min final-setting times at 85 C, and 1825 to 1375 psi compressive strength with 51.2 to 55.0% porosity up to 300 C

Development in the Gulf of Maine: Avoiding Geohazards and Embracing Opportunities

Mapping for marine-spatial planning is crucial if Maine is to safely develop its offshore resources, espe­cially wind and tidal energy. The authors focus on shallow natural gas (methane) deposits, an important and widespread geohazard in Maine’s seafloor. They describe the origin, occur­rence, and identification of natural gas in Maine’s seafloor; explain the hazards associated with these deposits and how to map them; and discuss what Maine can learn from European nations that have already developed their offshore wind resources. Because the U.S. gives states a central role in coastal management, Maine has the chance to be proactive in delineating coastal resources and demarcating potential seafloor hazards

Just Like The Will O\u27 The Wisp

Illustration of woman\u27s face in bubble emerging from fountain; Fountain design with men and women holding bowl; Roses around fountain with many bubbles emerginghttps://scholarsjunction.msstate.edu/cht-sheet-music/7807/thumbnail.jp

Central Blood Pressure and Peripheral Reactive Vasodilation in Plant-Based and Typical Dieting African Americans

African American individuals (AA) face higher mortality rates from cardiovascular disease than Americans from other racial/ethnic backgrounds. The cause of this health disparity is multifactorial and is in part related to impaired vascular function as well as other variables including diet and numerous socioeconomic factors. Diets rich in whole plant foods and low in animal products may protect blood vessels through their high antioxidant capacity and low inflammatory load. PURPOSE: The purpose of this study was to test the hypothesis that AA adhering to a 100% plant-based (vegan) diet (PBD) would have a more favorable dietary intake of several key nutrients and more optimal blood cholesterol, which would contribute to better blood pressure and peripheral reactive vasodilation relative to AA following a typical American diet (TAD). METHODS: Seventeen AA participated in the study. Of them, 8 (5 female; age: 25±2 years; BMI: 23.4±1.4 kg/m2) were following a PBD for 2.5±0.3 years and 9 (5 female; age: 21±1 years; BMI: 25.3±2.1 kg/m2) were following a TAD. A fasting venous blood draw was performed to assess blood lipids. Participants completed a comprehensive diet questionnaire (DHQIII, NIH). Peripheral and central blood pressures were measured via the SphygmoCor system (AtCor Medical). Brachial artery flow-mediated dilation (FMD) and reactive hyperemia (RH) were assessed via well-established procedures. Briefly, 2 min baseline measurements of brachial artery diameter and blood velocity were taken via Doppler ultrasound before a forearm cuff was inflated to 220 mmHg for 5 min. Post-occlusion data were recorded for 3 min. Measurement of baseline to peak post-occlusion brachial artery diameter and blood velocity were performed by pairing a video capture system (Elgato) with edge-detection and blood velocity-tracking software (Quipu). RESULTS: PBD AA consumed more dark green vegetables and whole grains and less cholesterol than TAD AA (p\u3c.05 for all). Consumption of sodium, potassium, and vitamins C & E was not different between groups (p\u3e.05 for all). Total (TC) and low-density lipoprotein (LDL-C) blood cholesterol concentrations were lower in PBD AA relative to TAD AA (TC: 136±9 vs. 174±12 mg/dl; LDL-C: 77±6 vs. 106±11 mg/dl; respectively; p\u3c.05 for both). Resting brachial (b) and central (c) mean arterial blood pressures (MAP) were lower in PBD AA relative to TAD AA (bMAP: 85±2 vs. 91±2 mmHg; cMAP: 80±2 vs. 87±2 mmHg; respectively; p\u3c.05 for both). There were no differences between groups in FMD nor RH (p\u3e.05 for all). FMD and FMD/shear rate were 7.7±0.8% and 0.33±0.05 au in PBD AA and 6.2±0.9% and 0.27±0.03 au in TAD AA, respectively. For RH, the percentage change in blood velocity and flow were 1441±479% and 1425±466% in PBD AA and 707±495% and 671±76% in TAD AA, respectively. CONCLUSION: These preliminary data suggest that a diet rich in whole plant foods but devoid of animal products may be associated with healthier blood cholesterol and peripheral and central blood pressures in AA but that these differences may not yet be translating to differences in peripheral reactive vasodilation

A feedback loop links brownification to anoxia in a temperate, shallow lake

This study examines a natural, rapid, fivefold increase in dissolved organic carbon (DOC) concentrations in a temperate shallow lake, describing the processes by which increased DOC resulted in anoxic conditions and altered existing carbon cycling pathways. High precipitation for two consecutive years led to rising water levels and the flooding of adjacent degraded peatlands. Leaching from the flooded soils provided an initial increase in DOC concentrations (from a 2010 mean of 12 ± 1 mg L−1 to a maximum concentration of 53 mg L−1 by June 2012). Increasing water levels, DOC, and phytoplankton concentrations reduced light reaching the sediment surface, eliminating most benthic primary production and promoting anoxia in the hypolimnion. From January to June 2012 there was a sudden increase in total phosphorus (from 57 µg L−1 to 216 µg L−1), DOC (from 24.6 mg L−1 to 53 mg L−1), and iron (from 0.12 mg L−1 to 1.07 mg L−1) concentrations, without any further large fluxes in water levels. We suggest that anoxic conditions at the sediment surface and flooded soils produced a dramatic release of these chemicals that exacerbated brownification and eutrophication, creating anoxic conditions that persisted roughly 6 months below a water depth of 1 m and extended periodically to the water surface. This brownification-anoxia feedback loop resulted in a near-complete loss of macroinvertebrate and fish populations, and increased surface carbon dioxide (CO2) emissions by an order of magnitude relative to previous years

Infant cortex responds to other humans from shortly after birth

A significant feature of the adult human brain is its ability to selectively process information about conspecifics. Much debate has centred on whether this specialization is primarily a result of phylogenetic adaptation, or whether the brain acquires expertise in processing social stimuli as a result of its being born into an intensely social environment. Here we study the haemodynamic response in cortical areas of newborns (1–5 days old) while they passively viewed dynamic human or mechanical action videos. We observed activation selective to a dynamic face stimulus over bilateral posterior temporal cortex, but no activation in response to a moving human arm. This selective activation to the social stimulus correlated with age in hours over the first few days post partum. Thus, even very limited experience of face-to-face interaction with other humans may be sufficient to elicit social stimulus activation of relevant cortical regions