| 3 | Extrapolating plot-scale CO_(2) and ozone enrichment experimental results to novel conditions and scales using mechanistic modeling显示文摘Introduction:The Aspen-FACE experiment was an 11-year study of the effect of elevated CO_(2) and ozone(alone and in combination)on the growth of model aspen communities(pure aspen,aspen-birch,and aspen-maple)in the field in northern Wisconsin,USA.Uncertainty remains about how these short-term plotlevel responses might play out over broader temporal and spatial scales where climate change,competition,succession,and disturbances interact with tree-level responses.In this study,we used a new physiologybased approach(PnET-Succession v3.1)within the forest landscape model LANDIS-II to extrapolate the FACE results to broader temporal scales(and ultimately to landscape scale)by mechanistically accounting for the globally changing drivers of temperature,precipitation,CO_(2),and ozone.We added novel algorithms to the model to mechanistically simulate the effects of ozone on photosynthesis through ozone-induced impairment of stomatal control(i.e.,stomatal sluggishness)and damage of photosynthetic capacity at the chloroplast level.Results:We calibrated the model to empirical observations of competitive interactions on the elevated CO_(2) and O_(3) plots of the Aspen-FACE experiment and successfully validated it on the combined factor plots.We used the validated model to extend the Aspen-FACE experiment for 80 years.When only aspen clones competed,we found that clone 271 always dominated,although the ozone-tolerant clone was co-dominant when ozone was present.Under all treatments,when aspen clone 216 and birch competed,birch was always dominant or co-dominant,and when clone 216 and maple competed,clone 216 was dominant,although maple was able to grow steadily because of its shade tolerance.We also predicted long-term competitive outcomes for novel assemblages of taxa under each treatment and discovered that future composition and dominant taxa depend on treatment,and that short-term trends do not always persist in the long term.Conclusions:We identified the strengths and weaknesses of PnET-Succession v3.1 and conclude that it can generate potentially robust predictions of the effects of elevated CO_(2) and ozone at landscape scales because of its mechanistically motivated algorithms.These capabilities can be used to project forest dynamics under anticipated future conditions that have no historical analog with which to parameterize less mechanistic models. | Eric J.Gustafson Mark E.Kubiske Brian R.Miranda Yasutomo Hoshika Elena Paoletti | 2018 | Ecological Processes2018，7，1： | 0 |
| 4 | Exercise Catheterization for Hemodynamic Evaluation of Adults with Coarctation of the Aorta显示文摘Background: Coarctation of the aorta (CoA) is associated with a generalized arteriopathy and long-term complicationsdespite repair. Data on invasive exercise hemodynamics in this population are lacking. Accordingly, wereviewed adults with CoA undergoing exercise catheterization to assess 1. hemodynamic profile;2. feasibilityfor assessment of CoA severity. Methods: Twenty patients undergoing exercise cardiac catheterization (12 armadduction and 8 supine cycle ergometry) at a quaternary care center between 2004 and 2021 were identified. Restingand exercise hemodynamic data were abstracted from the procedure logs. Results: Mean age was 43.6 ±12.0 years. Eleven patients (55%) had resting pulmonary arterial wedge pressure (PAWP) >15 mmHg;amongthose undergoing arterial catheterization, left ventricular end-diastolic pressure was >15 mmHg in 63%. Elevenpatients (55%) had pulmonary hypertension: 7 (35%) combined and 4 (20%) isolated post-capillary. At peak exercise,ΔPAWP/Δcardiac output (CO) ≥2 and Δmean pulmonary artery pressure/ΔCO ≥3 mmHg/l/min were foundin 7 (78%) and 6 (67%) patients, respectively;the composite of exercise PAWP ≥25 mmHg or ΔPAWP/ΔCO>2 was seen in 12 (86%). CoA peak-to-peak gradients at baseline (n = 14) and during exercise (n = 9) were 12(3–16) and 16 mmHg (9–28), respectively. Only 2 patients had an increase in CoA gradient to >20 mmHg withexercise. Conclusions: Diastolic dysfunction and pulmonary hypertension were highly prevalent, with exerciseunmasking abnormal diastolic and pulmonary vascular reserve in some individuals. Most patients failed to showsignificant increases in CoA peak-to-peak gradients with exercise. Further studies are warranted to establish thebest diagnostic method for CoA severity assessment. | Irene Martin de Miguel C.Charles Jain Alexander C.Egbe Jason H.Anderson Heidi M.Connolly William R.Miranda | 2022 | Congenital Heart Disease2022，17，6： | 0 |
您所在的机构暂未开通此部分的功能，请联系管理员