The present study presents the bioactive profile of Polygala arillata Buch.-Ham ex D.Don using GC-MS. The phytochemical constituents of leaf and stem ethanolic extracts of Polygala arillata were investigated using Fisons Gas-chromatography – Mass spectrometry. The mass spectra of the compounds in the leaf and stem extracts was matched with National Institute of standards and Technology (NIST) L...

Plant leaves are studied by the analysis of the magnitude and phase spectra of their thickness mechanical resonances. These resonances appear at ultrasonic frequencies and have been excited and sensed using air-coupled ultrasounds. In spite of the complex leaf microstructure, the effective medium approach can be applied to solve the inverse problem, at least in the vicinity of the first thickne...

Thalassia testudinum (turtle grass) is the dominant and climax-successional seagrass species in the subtropical/tropical Atlantic and Caribbean region. Two die-offs of T. testudinum in Florida Bay, United States have raised concerns regarding the resilience of this species to environmental disturbances. Seedlings are important in recovery of T. testudinum, following disturbance events. Leaf spe...

The spectral signatures of crop canopies in the field provide much information relating morphological or quality characteristics of crops to their optical properties. This experiment was conducted using two winter-wheat (Triticum aestivum) cultivars, Jingdong8 (with erect leaves) and Zhongyou9507 (with horizontal leaves). We analysiced the relation between the direction spectral characteristics...

An experimental arrangement is described which enables high quality 31P NMR spectra of compressed spinach leaf pieces to be continuously recorded in which all the resonances observed (cytoplasmic and vacuolar Pi, glycerate-3-P, nucleotides) were sharp and well resolved. 31P NMR spectra obtained from intact chloroplasts showed a distinct peak of stromal Pi. An upfield shift of the stromal Pi res...

T h e PROSPECT leaf optical properties and SAIL canopy reflectance models were coupled and inverted using a set of 96 AVIRIS (Airborne Visible~Infrared Imaging Spectrometer) equivalent spectra gathered in afield experiment on sugar beet plots expressing a large range in leaf area index, chlorophyll concentration, and soil color. In a first attempt, the model accurately reproduced the spectral r...

The character of the electronic transitions in the ultraviolet-visible-near infrared (UV-vis-NIR) spectra of platinum-bis(alkynyl) bridged, bis-triarylamine mixed-valence systems trans-[Pt(C≡CC6H4NAr2)2 (PR3)2](n+) (R = ethyl, Ar = C6H4CH3-4 (1) or C6H4OCH3-4 (2); R = Ph, Ar = C6H4CH3-4 (3) or C6H4OCH3-4 (4), n = 0, 1, 2) has been determined from a combination of spectroscopic measurement and d...

When dhurrin [p-hydroxy-(S)-mandelonitrile-tJ-D-glucoside], the cyanogenic glucoside of sorghum [Sorghum bicolor (L.) Moench], is hydrolyzed by autoclaving, p-hydroxybenzaldehyde (P-HB) is released. The spectrophotometric determination of pHB concentration in autoclaved sorghum leaf extracts provides a measure of the hydrocyanic acid potential (HCN-p) of leaf tissue. Extracts of field-grown sor...

The conifer leaf model LIBERTY (Leaf Incorporating erties of individual leaves (Aber, 1994). Leaves are an Biochemistry Exhibiting Ref lectance and Transmittance important component of forest canopies, and it is the Yields) is an adaptation of radiative transfer theory for deconcentration of their biochemical constituents, namely, termining the optical properties of powders. LIBERTY pigments, w...