High-spectral resolution data for determining leaf water content

Abstract

Background: Cognitive Muscular TherapyTM (CMT) is an integrated behavioural intervention developed for knee osteoarthritis. CMT teaches patients to reconceptualise the condition, integrates muscle biofeedback and aims to reduce muscle overactivity, both in response to pain and during daily activities. This nested qualitative study explored patient and physiotherapist perspectives and experiences of CMT.Methods: Five physiotherapists were trained to follow a well-defined protocol and then delivered CMT to at least two patients with knee osteoarthritis. Each patient received seven individual clinical sessions and was provided with access to online learning materials incorporating animated videos. Semi-structured interviews took place after delivery/completion of the intervention and data were analysed at the patient and physiotherapist level.Results: Five physiotherapists and five patients were interviewed. All described a process of changing beliefs throughout their engagement with CMT. A framework with three phases was developed to organise the data according to how osteoarthritis was conceptualised and how this changed throughout their interactions with CMT. Firstly, was an identification of pain beliefs to be challenged and recognition of how current beliefs can misalign with daily experiences. Secondly was a process of challenging and changing beliefs, validated through new experiences. Finally, there was an embedding of changed beliefs into self-management to continue with activities. Conclusion:This study identified a range of psychological changes which occur during exposure to CMT. These changes enabled patients to reconceptualise their condition, develop a new understanding of their body, understand psychological processes, and make sense of their knee pain.

Leaf Equivalent Water Thickness assessment using reflectance at optimum wavelengths

“…It is believed that the variation in leaf structure causes the magnitude of leaf reflectance to change irrespective of the leaf water content. However, the relative "depths" of the water absorption features in the reflectance spectra seem not be affected by leaf structure (Danson et al 1992). As the depth of an absorption feature increases, the slopes on the edges of the feature also increase.…”

“…The linear correlation analysis showed that there exists a statistically significant correlation between water content parameters and leaf reflectance at 1,450, 1,650 and 2,250 nm, however, this correlation was not seen at 975 and 1,175 nm absorption bands. The study of Danson et al (1992) showed that when the leaf internal structure varies, the first derivative of leaf reflectance is superior to the original reflectance data for the estimation of leaf water content. It is believed that the variation in leaf structure causes the magnitude of leaf reflectance to change irrespective of the leaf water content.…”

“…Riaño et al (2005b) specified that 1,400-2,500 nm range provides the highest correlation with EWT. Danson et al (1992) used six water absorption bands centred on 975; 1,175; 1,450; 1,650; 1,950 and 2,250 nm for leaf water content estimation. The linear correlation analysis showed that there exists a statistically significant correlation between water content parameters and leaf reflectance at 1,450, 1,650 and 2,250 nm, however, this correlation was not seen at 975 and 1,175 nm absorption bands.…”

“…From different indexes for measurement of leaf water content available in the literature (Ceccato et al 2001, Danson et al 1992, Wang et al 2009), two of them, i.e. Full Moisture Content (FMC) and Equivalent Water Thickness (EWT) are more often addressed.…”

Remote Sensing of Cropland Agriculture

“…Danson et al (1992) showed that the first derivatives of reflectance associated with the slopes of the lines near water-absorption bands were highly correlated with leaf water content. Gitelson et al (2003a) developed a technique based upon remote sensing that accounted for more than 90 percent of the variability in mid-day canopy photosynthesis of irrigated corn.…”