scholarly journals Independent and Opposing Associations of Habitual Exercise and Chronic PM 2.5 Exposures on Hypertension Incidence

Circulation ◽  
2020 ◽  
Vol 142 (7) ◽  
pp. 645-656
Author(s):  
Cui Guo ◽  
Yiqian Zeng ◽  
Ly-yun Chang ◽  
Zengli Yu ◽  
Yacong Bo ◽  
...  
Keyword(s):  
Lower Risk ◽  
Cox Regression ◽  
Screening Program ◽  
Fine Particulate Matter ◽  
Positive Association ◽  
Mean Value ◽  
Spatiotemporal Model ◽  
Wide Range ◽  
The Mean ◽  
Joint Associations

Background: We investigated the joint associations of habitual physical activity (PA) and long-term exposure to fine particulate matter (PM 2.5 ) with the development of hypertension in a longitudinal cohort in Taiwan. Methods: We selected 140 072 adults (≥18 years of age) without hypertension who joined a standard medical screening program with 360 905 medical examinations between 2001 and 2016. PM 2.5 exposure was estimated at each participant’s address using a satellite data-based spatiotemporal model with 1 km 2 resolution. Information on habitual PA and a wide range of covariates was collected using a standard self-administered questionnaire. We used the Cox regression model with time-dependent covariates to examine the joint associations. Results: The mean age of all observations was 41.7 years, and 48.8% were male. The mean value for systolic and diastolic blood pressure was 112.5 and 68.7mm Hg, respectively. Approximately 34.2% of all observations were inactive (0 metabolic equivalence values-hours), 29.8% had moderate-PA (median [interquartile range]; 3.75 [3.38 to 4.38] metabolic equivalence values-hours), and 36.0% had high-PA (15.7 [10.3 to 24.8] metabolic equivalence values-hours). The mean±SD of PM 2.5 was 26.1±7.3 μg/m 3 . The prevalence of cardiovascular disease, diabetes mellitus, and cancer was 2.1%, 2.9%, and 1.5%, respectively. After adjusting for a wide range of covariates (including a mutual adjustment for PA or PM 2.5 ), a higher PA level was associated with a lower risk of hypertension (hazard ratio [HR] for the moderate- and high-PA was 0.93 [95% CI, 0.89–0.97] and 0.92 [95% CI, 0.88–0.96], respectively, as compared with the inactive-PA), whereas a higher level of PM 2.5 was associated with a higher risk of hypertension (HR for the moderate- and high-PM 2.5 was 1.37 [95% CI, 1.32–1.43] and 1.92 [95% CI, 1.81–2.04], respectively, as compared with the low-PM 2.5 group]. No significant interaction was observed between PA and PM 2.5 (HR 1.01 [95% CI, 1.00–1.02]). Conclusions: A high-PA and low PM 2.5 exposure were associated with a lower risk of hypertension. The negative association between PA and hypertension remained stable in people exposed to various levels of PM 2.5 , and the positive association between PM 2.5 and hypertension was not modified by PA. Our results indicated that PA is a suitable hypertension prevention strategy for people residing in relatively polluted regions.

A Comparison of Physiological Demand between Self-Propelled and Motorized Treadmill Exercise

2018 ◽  
Vol 7 (4) ◽  
pp. 13-21
Author(s):  
Todd Backes ◽  
Charlene Takacs
Keyword(s):  
Respiratory Exchange Ratio ◽  
Treadmill Exercise ◽  
Cardiopulmonary Exercise Testing ◽  
Mean Value ◽  
The Self ◽  
Mixing Chamber ◽  
Wide Range ◽  
The Subject ◽  
The Mean ◽  
Computer Controlled

There are a wide range of options for individuals to choose from in order to engage in aerobic exercise; from outdoor running to computer controlled and self-propelled treadmills. Recently, self-propelled treadmills have increased in popularity and provide an alternative to a motorized treadmill. Twenty subjects (10 men, 10 women) ranging in age from 19-23 with a mean of 20.4 ± 0.8 SD were participants in this study. The subjects visited the laboratory on three occasions. The purpose of the first visit was to familiarize the subject with the self-propelled treadmill (Woodway Curve 3.0). The second visit, subjects were instructed to run on the self-propelled treadmill for 3km at a self-determined pace. Speed data were collected directly from the self-propelled treadmill. The third visit used speed data collected during the self-propelled treadmill run to create an identically paced 3km run for the subjects to perform on a motorized treadmill (COSMED T150). During both the second and third visit, oxygen consumption (VO2) and respiratory exchange ratio (R) data were collected with COSMED’s Quark cardiopulmonary exercise testing (CPET) metabolic mixing chamber system. The VO2 mean value for the self-propelled treadmill (44.90 ± 1.65 SE ml/kg/min) was significantly greater than the motorized treadmill (34.38 ± 1.39 SE ml/kg/min). The mean R value for the self-propelled treadmill (0.91 ± 0.01 SE) was significantly greater than the motorized treadmill (0.86 ± 0.01 SE). Our study demonstrated that a 3km run on a self-propelled treadmill does elicit a greater physiological response than a 3km run at on a standard motorized treadmill. Self-propelled treadmills provide a mode of exercise that offers increased training loads and should be considered as an alternative to motorized treadmills.

The Mode of Excretion of Ammonia and Urea in Xenopus Laevis

1961 ◽  
Vol 38 (4) ◽  
pp. 695-705
Author(s):  
J. B. BALINSKY ◽  
E. BALDWIN
Keyword(s):  
Xenopus Laevis ◽  
Blood Concentration ◽  
Concentration Ratio ◽  
Ammonia Excretion ◽  
Ammonia Concentration ◽  
Mean Value ◽  
Urea Excretion ◽  
Wide Range ◽  
Glomerular Filtrate ◽  
The Mean

1. Eighty-two single determinations of ammonia and urea excretion by Xenopus laevis indicated that the percentage of ammonia varied from 40 to 80%, with a mean value of 62%. 2. Measurements of excretion on successive days after feeding showed that a large amount of ammonia was produced soon after feeding, but that ammonia excretion declined rapidly. Urea excretion, not so high initially, remained more or less constant until the third or fourth day, often exceeding ammonia excretion at that time. Thereafter, it also declined and the excretion of both substances reached a constant starvation level by the fifteenth day. 3. Both ammonia and urea excretion were equally affected by temperature. The Q10's were near 2 in the range 20-30° C., but greater in the range 10-20° C. 4. At least 86% of ammonia, and 81% of urea were excreted through the cloaca. 5. The mean 24 hr. urine output of Xenopus at 20% C. was 23.6 ml. per 100 g. body weight. 6. Although the blood ammonia concentration did not appear to be zero, the urine/blood concentration ratio of ammonia was greater than 100. The urine/blood concentration ratio of urea was not significantly different from unity, and constant over a very wide range of concentrations. 7. The above result is interpreted to indicate passive glomerular filtration of urea, and little or no tubular reabsorption of water. 8. It is suggested that ammonia is formed in the kidney, and actively secreted into the glomerular filtrate.

scholarly journals Estimating the Young Generation’s Willingness to Pay (WTP) for PM2.5 Control in Daegu, Korea, and Beijing, China

2019 ◽  
Vol 11 (20) ◽  
pp. 5704
Author(s):  
Ning ◽  
Lee
Keyword(s):  
Willingness To Pay ◽  
Fine Particulate Matter ◽  
Control Measures ◽  
Young Generation ◽  
Explanatory Variables ◽  
Wide Range ◽  
Air Quality Improvement ◽  
The Mean ◽  
The One ◽  
Beijing China

This research aimed to examine the willingness to pay (WTP) of the young generation (the age group from 18 to 29) for the participatory solutions and actions on fine particulate matter (PM2.5) pollution control and abatement in Daegu, Korea, and Beijing, China. This study found out that Korean respondents and Chinese respondents shared a wide range of similarities, both in terms of socio-demographic characters like age, family size, and house/apartment ownership, as well as a number of perceptions related to environmental and social responsibilities. Around one-third of the Korean respondents and one-fifth of the Chinese respondents expressed negative WTP due to primary reasons such as lack of trust in the effectiveness of PM2.5 control measures (Korea) and limitation of budget (China). The mean estimated values of WTP with and without explanatory variables in Korea were merely slightly higher than those in China. The mean WTP without control variables in Korea was 11,882.97 KRW/month (10.61 USD/month) and the one in China was 65.09 CNY/month (9.48 USD/month). The mean WTP with explanatory variables for Daegu, Korea, was KRW 11,982.33 (USD 10.70) per person per month, and the one for Beijing, China, was CNY 64.84 (USD 9.40) per person per month. The annual total WTP for Daegu, Korea, was assessed around KRW 47572 million (USD 42.45 million), whereas the estimated total WTP for Beijing, China, was around CNY 3260.14 million (USD 474.94 million) per year. Based on the results and the findings, this study proposes to further strengthen the comprehensive cooperation between China and Korea in the field of air quality improvement, with a particular focus on PM2.5 control and abatement and cooperation in academic circles and among the general public.

Effects of left atrial pressure on the pulmonary vascular response to hypoxic ventilation

1991 ◽  
Vol 70 (5) ◽  
pp. 1991-1995 ◽  
Author(s):  
S. A. Gu ◽  
J. Ducas ◽  
U. Schick ◽  
R. M. Prewitt
Keyword(s):  
Arterial Pressure ◽  
Left Atrial ◽  
Pulmonary Arterial Pressure ◽  
Mean Value ◽  
Atrial Pressure ◽  
Left Atrial Pressure ◽  
Vascular Response ◽  
Wide Range ◽  
Pulmonary Arterial ◽  
The Mean

We investigated the effects of hypoxic ventilation on the pulmonary arterial pressure- (P) flow (Q) relationship in an intact canine preparation. Mean pulmonary P-Q coordinates were obtained during hypoxic ventilation and during ventilation with 100% O2 at normal and at increased left atrial pressure. Specifically, we tested the hypothesis that, over a wide range, changes in left atrial pressure would alter the effects of hypoxic ventilation on pulmonary P-Q characteristics. Seven dogs were studied. When left atrial pressure was normal (5 mmHg), the mean value of the extrapolated intercept (PI) of the linear P-Q relationship was 10.9 mmHg and the slope (incremental vascular resistance, IR) of the P-Q relationship was 2.2 mmHg.l-1.min. Hypoxic ventilation increased PI to 18 mmHg (P less than 0.01) but did not affect IR. Subsequently, during ventilation with 100% O2, when left atrial pressure was increased to 14 mmHg by inflation of left atrial balloon, PI increased to 18 mmHg. IR was 1.6 mmHg.l-1.min. Again, hypoxic ventilation caused an isolated change in PI. Hypoxia increased PI from 18 to 28 mmHg (P less than 0.01). As in the condition of normal left atrial pressure, hypoxic ventilation did not affect IR. We conclude that, in an anesthetized intact canine preparation, hypoxic ventilation causes an isolated increase in the extrapolated pressure intercept of the pulmonary P-Q relationship. Furthermore the effects of hypoxic ventilation on pulmonary P-Q characteristics are not affected by the resting left atrial pressure.

scholarly journals Early Risk of Stroke in Patients Undergoing Acute Versus Elective Cardioversion for Atrial Fibrillation

2021 ◽  
Author(s):  
Tomas Forslund ◽  
Frieder Braunschweig ◽  
Martin J. Holzmann ◽  
Anwar J. Siddiqui
Keyword(s):  
Atrial Fibrillation ◽  
Lower Risk ◽  
Cox Regression ◽  
Oral Anticoagulants ◽  
Regression Analyses ◽  
Regional Health ◽  
European Guidelines ◽  
Regional Health Care ◽  
The Mean ◽  
First Time

Background Electrical cardioversion (ECV) is routinely used to restore sinus rhythm in patients with symptomatic atrial fibrillation. The European guidelines have been updated in recent years. Current information on differences in the risk for stroke after acute versus elective ECV is lacking. Methods And Results All patients with a first‐time acute or elective ECV in the Stockholm regional health care data warehouse from 2011 to 2018 were included. Cox regression analyses were performed evaluating ischemic or unspecified stroke within 30 days after ECV with adjustments for the CHA 2 DS 2 ‐VASc score, medical treatment, and year of inclusion. The study included 9139 patients, 3094 after acute and 6045 after elective ECV. The mean age was 65.9±11.3 years, 69.5% were men, and the mean CHA 2 DS 2 ‐VASc score was 2.4±1.7. Before the intervention, 49.6% of patients with an acute ECV and 96.4% of those with an elective ECV had claimed an oral anticoagulant prescription. Ischemic or unspecified stroke occurred in 26 (0.28%) patients within 30 days. The unadjusted risk was higher after acute compared with elective ECV (hazard ratio [HR], 2.29; 95% CI, 1.06–4.96), whereas there was no difference after multivariable adjustments (adjusted HR, 0.99; 95% CI, 0.36–2.72). Both non–vitamin K oral anticoagulants (adjusted HR, 0.28; 95% CI, 0.08–0.98) and warfarin (adjusted HR, 0.17; 95% CI, 0.05–0.53) were associated with a lower risk for stroke compared with no anticoagulation. Conclusions Acute ECV was associated with a higher unadjusted risk for stroke than elective ECV, but the risk was similar after adjustment for anticoagulant treatment. This study indicates the importance of anticoagulation before ECV according to recent European guidelines.

scholarly journals Progress towards clover cyst nematode resistant white clover

1996 ◽  
pp. 237-241
Author(s):  
J. Van den Bosch ◽  
C.F. Mercer
Keyword(s):  
White Clover ◽  
Trifolium Repens ◽  
Egg Production ◽  
First Generation ◽  
Control Method ◽  
Dry Weight ◽  
Mean Value ◽  
Cyst Nematode ◽  
Wide Range ◽  
The Mean

Clover cyst nematode (Heterodera trifolii) reduces growth and nutrient uptake of white clover (Trifolium repens) in New Zealand, and breeding resistant cultivars is the preferred control method for ecological and economic reasons. Resistant and susceptible selections were taken from a wide range of white clover seedlines. Selected plants were intercrossed and reselected over two cycles of selection. Cysts per gram of root dry weight (cysts/ g) was the measure of resistance used, with low cysts/g plants being more resistant. The mean cysts/ g value of the progenies from resistant parents was 69% of the mean value of the progenies from susceptible parents in the first generation, and 38% in the second generation. Root weights were similar, while the resistant selections had 58% and 34% (first and second generations respectively) of the number of cysts in the susceptible selections. There were no immune plants (0 cysts) in the first generation and only two in the second. Counts were made of cysts, eggs per cyst and eggs per plant on clones of two resistant and two susceptible genotypes. The resistant genotypes had lower counts than the susceptible genotypes in terms of cysts per plant (means of 6 cf. 108), eggs per cyst (11 cf. 21) and eggs per plant (35 cf. 1650). The differences in numbers of cysts between resistant and susceptible lines increased during two generations of selection, supporting earlier results that indicated that progress in breeding for resistance was possible. Furthermore, the resistance is also acting on clover cyst nematode egg production which would further reduce recruitment to later generations of clover cyst nematode. Keywords: breeding, Heterodera trifolii, resistance, screening, selection, Trifolium repens

scholarly journals PRODUCTIVIDAD PRIMARIA EN LA CIENAGA GRANDE DE SANTA MARTA, COLOMBIA

2016 ◽  
Vol 19 ◽  
Author(s):  
Carlos A. Hernández J. ◽  
Klaus Gocke
Keyword(s):  
Primary Productivity ◽  
Coastal Lagoon ◽  
Mean Value ◽  
High Concentration ◽  
Water Turbidity ◽  
High Particle Concentration ◽  
High Particle ◽  
Wide Range ◽  
The Mean ◽  
The Caribbean

Between January 1987 and January 1988 the primary productivity and related parameters were studied in the Ciénaga Grande de Santa Marta. The Ciénaga is a coastal lagoon with an area of 423 km'2 and mean depth of 1.6 m, which is located at the Caribbean coast of Colombia. The salinity fluctuates seasonally within a wide range. The system is characterized by a high concentration of seston and a great primary productivity. The concentration of chlorophyll " a " ranged from 5.6to 181 ug Ii , the mean value was 59 ug I i . The concentration of proteins was within the extremes of 0.9 and 9.5 mg I"i f the mean value was 4.2 mg I ] . The gross primary productivity in the central part of the Ciénaga amounted to 1690 g C m*2 per year. Considering the temporal fluctuation in the whole system the lowest and highest values were 1.40 and 16.3 g C rrr2 per day. Highest productivity values were encountered when the salinity was low. The primary productivity is controlled by water turbidity and availability of nutrients, thus, seasonal continental waters. The photosynthetic laver ¡s restricted to less than 1.5 m due to the high particle concentration. The mean N: P relation was 4:1 which indicates that the nitrogen compounds are the limiting nutrientes. The high primary productivity sustains an important local fishery. The coastal area in the vicinity of the Ciénaga Grande is benefitted by the export of particulated and dissolved organic matter produced in excess within the coastal lagoon.

scholarly journals Clinical Impact of the Maximum Mean Value of Home Blood Pressure on Cardiovascular Outcomes: A Novel Indicator of Home Blood Pressure Variability

Hypertension ◽  
2021 ◽  
Author(s):  
Takeshi Fujiwara ◽  
Satoshi Hoshide ◽  
Hiroshi Kanegae ◽  
Kazuomi Kario
Keyword(s):  
Blood Pressure ◽  
Coronary Heart Disease ◽  
Heart Disease ◽  
Cox Regression ◽  
Mean Value ◽  
Home Blood Pressure ◽  
Antihypertensive Medications ◽  
Unique Identifier ◽  
Cox Regression Analysis ◽  
The Mean

We assessed the relationship between maximum mean home blood pressure (HBP) and incident cardiovascular disease risks in the general practice population of the J-HOP study (Japan Morning Surge-Home Blood Pressure), which recruited 4231 patients with cardiovascular risk factors (mean [SD] age: 65 [11] years; 53% women; 79% on antihypertensive medications) who measured their HBP in the morning and evening for 14 days. The first day’s HBPs were excluded. The average of morning and evening (the average of morning and evening value [MEave]) BP was defined as the average of all HBP values. The maximum mean HBP was defined as the highest value of mean HBP on one occasion. The variability independent of the mean of MEave BP was assessed. The MEave BP was 134/76 mm Hg; the maximum mean HBP was 156/88 mm Hg. Over a median 3.9-year follow-up (16 762 person-years), 72 stroke, and 76 coronary heart disease events occurred. A Cox regression analysis showed that the hazard ratios of a 1-SD increase in maximum mean home systolic BP (SBP; 95% CI) for incident stroke events were (1) 1.89 (1.23–2.89) including MEave SBP and (2) 1.68 (1.33–2.14) including the variability independent of the mean of MEave SBP. These significant associations were not observed for coronary heart disease events. Adding the maximum mean home SBP to the stroke prediction model significantly improved the discrimination: (1) MEave SBP: C statistics difference (95% CI), 0.019 (0.002–0.038); and (2) variability independent of the mean of MEave SBP: 0.031 (0.008–0.056). The maximum mean HBP could be a useful marker for evaluating the stroke risk of patients. REGISTRATION: URL: https://upload.umin.ac.jp ; Unique identifier: UMIN000000894

scholarly journals Potassium isotopic variability and implications for <sup>40</sup>K-based geochronology

2020 ◽  
Author(s):  
Leah E. Morgan
Keyword(s):  
Neutron Fluence ◽  
Radioactive Decay ◽  
Mean Value ◽  
Decay Constants ◽  
Wide Range ◽  
The Mean ◽  
Precision And Accuracy ◽  
Ar Geochronology ◽  
Isotopic Measurements ◽  
Silicate Materials

Abstract. 40Ar/39Ar and K-Ar geochronology assume that 40K/K values are invariant among the sample of interest, the co-irradiated neutron fluence monitor (standard), and the material used to measure decay constants. Until recently, this assumption was reasonable due to the small K isotope (41K, 40K, 39K) variability found in many terrestrial samples and the negligible effect of any variation relative to the precision of the determined age. The recent discovery of measurable δ41K variability in terrestrial samples now questions this assumption. Although δ41K values for some neutron fluence monitors have now been reported, potassium isotopes are not routinely measured on samples dated by the 40Ar/39Ar method even though a wide range of silicate materials were found to vary by > 2.5 ‰. Further, the 40K decay constants used in 40Ar/39Ar geochronology are based on activity counting of radioactive decay in K-rich salts. These salts have not been measured for δ41K, yet evaporites have been shown to vary by > 1 ‰ from the mean value of silicates. The potential effects of δ41K variability on 40Ar/39Ar ages are illustrated using the case of the ca. 28.2 Ma Fish Canyon sanidine (FCs) and the ca. 99 Ma Mt. Dromedary Biotite (GA-1550). If the two standards have δ41K values as measured and the material used to determine decay constants is appropriately represented by δ41K of evaporites, the age of FCs is underestimated by ca. 7 ka (0.25 ‰). Although this is a small effect, such bias is becoming important as the analytical precision and accuracy of isotopic measurements and calculation of 40Ar/39Ar ages continue to improve.

scholarly journals Enzyme-Linked Immunosorbent Assay for Measurement of Cytomegalovirus Glycoprotein B Antibody in Serum

2010 ◽  
Vol 17 (5) ◽  
pp. 836-839 ◽  
Author(s):  
Daniel J. Hackett ◽  
Changpin Zhang ◽  
Carla Stefanescu ◽  
Robert F. Pass
Keyword(s):  
Immunosorbent Assay ◽  
Geometric Mean ◽  
Mean Value ◽  
Glycoprotein B ◽  
Enzyme Linked Immunosorbent Assay ◽  
Igg Antibody ◽  
Negative Results ◽  
Wide Range ◽  
The Mean ◽  
Antibody Levels

ABSTRACT Measurement of antibody to cytomegalovirus (CMV) glycoprotein B (gB) is valuable in the assessment of the antibody response to infection and to gB-containing vaccines. For this purpose, an enzyme-linked immunosorbent assay (ELISA) with a recombinant CMV gB molecule as the antigen was evaluated. Sera from 168 anti-CMV IgG-positive and 100 seronegative subjects were used to evaluate the anti-gB antibody assay. A cutoff optical density (OD) that would distinguish gB antibody-positive from -negative sera was established. Titers of antibody to gB determined by endpoint dilution were compared with those calculated using regression analysis. The run-to-run and interoperator reproducibilities of results were measured. The mean OD + 5 standard deviations from 50 anti-CMV IgG antibody-negative sera (0.2472) was used as the cutoff between anti-gB antibody-positive and -negative results. All sera from 100 anti-CMV IgG-seronegative subjects were negative for antibody to gB. All but 1 of 168 sera from seropositive subjects were positive for antibody to gB. Observed antibody levels based on titration to the endpoint were very similar to results calculated using linear regression. The run-to-run consistency of endpoints was excellent, with 38 runs from one operator and 48 runs from another all giving results within 1 dilution of the mean value for each of three anti-CMV IgG antibody-positive serum pools. The geometric mean titer of antibody to gB for 99 sera from seropositive blood donors was 1/10,937. This ELISA gives accurate and reproducible results for the relative quantity of anti-CMV gB IgG in serum over a wide range of antibody levels.

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