Input-Output Model-Based Water Footprint Indicators to Support IWRM in the Irrigated Drylands of Uzbekistan, Central Asia

Author(s):  
Maksud Bekchanov ◽  
John P.A. Lamers ◽  
Anik Bhaduri ◽  
Manfred Lenzen ◽  
Bernhard Tischbein
2020 ◽  
Vol 268 ◽  
pp. 121925 ◽  
Author(s):  
Fang Luo ◽  
Yi Guo ◽  
Mingtao Yao ◽  
Wenqiu Cai ◽  
Meng Wang ◽  
...  

Author(s):  
Carlos Gregorio-Rodríguez ◽  
Luis Llana ◽  
Rafael Martínez-Torres

2020 ◽  
Vol 128 (2) ◽  
pp. 397-409
Author(s):  
Vasilis Z. Marmarelis ◽  
Dae C. Shin ◽  
Mareike Oesterreich ◽  
Martin Mueller

The study of dynamic cerebral autoregulation (DCA) in essential hypertension has received considerable attention because of its clinical importance. Several studies have examined the dynamic relationship between spontaneous beat-to-beat arterial blood pressure data and contemporaneous cerebral blood flow velocity measurements (obtained via transcranial Doppler at the middle cerebral arteries) in the form of a linear input-output model using transfer function analysis. This analysis is more reliable when the contemporaneous effects of changes in blood CO2 tension are also taken into account, because of the significant effects of CO2 dynamic vasomotor reactivity (DVR) upon cerebral flow. In this article, we extract such input-output predictive models from spontaneous time series hemodynamic data of 24 patients with essential hypertension and 20 normotensive control subjects under resting conditions, using the novel methodology of principal dynamic modes (PDMs) that achieves improved estimation accuracy over previous methods for relatively short and noisy data. The obtained data-based models are subsequently used to compute indexes and markers that quantify DCA and DVR in each subject or patient and therefore can be used to assess the effects of essential hypertension. These model-based DCA and DVR indexes were properly defined to capture the observed effects of DCA and VR and found to be significantly different ( P < 0.05) in the hypertensive patients. We also found significant differences between patients and control subjects in the relative contribution of three PDMs to the model output prediction, a finding that offers the prospect of identifying the physiological mechanisms affected by essential hypertension when the PDMs are interpreted in terms of specific physiological mechanisms. NEW & NOTEWORTHY This article presents novel model-based methodology for obtaining diagnostic indexes of dynamic cerebral autoregulation and dynamic vasomotor reactivity in hypertension.


2011 ◽  
Vol 70 (12) ◽  
pp. 2494-2502 ◽  
Author(s):  
Zhuoying Zhang ◽  
Hong Yang ◽  
Minjun Shi
Keyword(s):  

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