scholarly journals Determination of Loline Alkaloids and Mycelial Biomass in Endophyte-Infected Schedonorus pratensis by Near-Infrared Spectroscopy and Chemometrics

2020 ◽  
Vol 8 (5) ◽  
pp. 776
Author(s):  
Giovanni Cagnano ◽  
Beatriz R. Vázquez-de-Aldana ◽  
Torben Asp ◽  
Niels Roulund ◽  
Christian S. Jensen ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
High Performance ◽  
Near Infrared ◽  
Fungal Endophyte ◽  
Mycelial Biomass ◽  
In Planta ◽  
Meadow Fescue ◽  
Nondestructive Technique ◽  
Loline Alkaloids

Near infrared spectroscopy (NIRS) is an accurate, fast and nondestructive technique whose use in predicting forage quality has become increasingly relevant in recent decades. Epichloë-infected grass varieties are commonly used in areas with high pest pressure due to their better performances compared to endophyte-free varieties. The insect resistance of Epichloë-infected grasses has been associated with four main groups of endophyte secondary metabolites: ergot alkaloids, indole-diterpenes, lolines and peramine. Concentrations of these alkaloids are usually measured with high performance liquid chromatography or gas chromatography analysis, which are accurate methods but relatively expensive and laborious. In this paper, we developed a rapid method based on NIRS to detect and quantify loline alkaloids in wild accessions of Schedonorus pratensis infected with the fungal endophyte Epichloë uncinata. The quantitative NIR equations obtained by modified partial least squares algorithm had coefficients of correlation of 0.90, 0.78, 0.85, 0.90 for N-acetylloline, N-acetylnorloline and N-formylloline and the sum of the three, respectively. The acquired NIR spectra were also used for developing an equation to predict in planta fungal biomass with a coefficient of correlation of 0.75. These results showed that the use of NIRS and chemometrics allows the quantification of loline alkaloids and mycelial biomass in a heterogeneous set of endophyte-infected meadow fescue samples.

scholarly journals PHYSIOLOGICAL CORRELATES OF ALMOST LOSS OF CONSCIOUSNESS (A-LOC) DURING DYNAMIC FLIGHT SIMULATION (DFS) ON HUMAN CENTRIFUGE: A CASE REPORT

2020 ◽  
Vol 25 (2) ◽  
pp. 38-43
Author(s):  
Anna Przewodzka ◽  
◽  
Stefan P. Gaździński ◽  
Michał Janewicz ◽  
Krzysztof Kowalczuk ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
High Performance ◽  
Near Infrared ◽  
Vital Signs ◽  
Flight Simulation ◽  
Loss Of Consciousness ◽  
Brain Oxygenation ◽  
Medicine Research ◽  
High Level

Introduction: G-LOC is still a threat for aircrew of high performance aircrafts. It is evoked by a high level of +Gz acceleration causing a deficit of brain oxygenation. Although near-infrared spectroscopy (NIRS) was used to identify brain oxygenation decreases preceding G-LOC, it is not used regularly in aero-medicine research in Poland. Here, we report the physiological correlates of Almost Loss of Consciousness (A-LOC) that occurred during a research project. Method: During Dynamic Flight Simulation training on a human centrifuge one pilot experienced momentaneous confusion which was recorded on a camera. We post-hoc reviewed his vital signs, stroke volumes (SV), cardiac output (CO) obtained with bioimpedance rheography, and brain oxygenation (OX) measures with near-infrared spectroscopy on the forehead. Finally, we reviewed the recording of his eye movements obtained with video-oculography. Results: SV and CO measures were confounded by artefacts induced by anti-G straining manoeuvres (AGSM). However, OX measures demonstrated decreased brain oxygenation that lasted several seconds after the incident. Following the incident, the pilot’s pulse remained decreased for several seconds. Discussion: NIRS methodology seems to be resistant to artefacts created by muscles during AGSM. NIRS systems with a probing rate of 0.1 second might help detect upcoming A-LOC or G-LOC.

Oil and Fat Classification by Selected Bands of Near-Infrared Spectroscopy

2000 ◽  
Vol 54 (8) ◽  
pp. 1168-1174 ◽  
Author(s):  
Pierre Hourant ◽  
Vincent Baeten ◽  
Maria T. Morales ◽  
Marc Meurens ◽  
Ramon Aparicio
Keyword(s):  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
High Performance ◽  
Near Infrared ◽  
Discriminant Functions ◽  
Linear Discriminant ◽  
High Oleic ◽  
Infrared Spectral ◽  
Filter Type ◽  
Different Sources

One hundred and four edible oil and fat samples from 18 different sources, either vegetable (Brazil nut, coconut, corn, sunflower, walnut, virgin olive, peanut, palm, canola, soybean, sunflower) or animal (tallow and hydrogenated fish), have been analyzed by high-performance gas chromatography (HPGC) and near-infrared spectroscopy (NIRS). Fatty acids were quantified by HPGC. The near-infrared spectral features of the most noteworthy bands were studied and discussed to design a filter-type NIR instrument. An arborescent structure, based on stepwise linear discriminant analysis (SLDA), was built to classify the samples according to their sources. Seven discriminant functions permitted a successive discrimination of saturated fats, corn, soybean, sunflower, canola, peanut, high oleic sunflower, and virgin olive oils. The discriminant functions were based on the absorbance values, between three and five, from the 1700–1800 and 2100–2400 nm regions. Chemical explanations are given in support of the selected wavelengths. The arborescent structure was then checked with a test set, and 90% of the samples were correctly classified.

Measurement of cerebral blood volume using near-infrared spectroscopy and indocyanine green elimination

1999 ◽  
Vol 87 (5) ◽  
pp. 1981-1987 ◽  
Author(s):  
P. Hopton ◽  
T. S. Walsh ◽  
A. Lee
Keyword(s):  
Infrared Spectroscopy ◽  
Indocyanine Green ◽  
Blood Volume ◽  
Near Infrared Spectroscopy ◽  
High Performance ◽  
Near Infrared ◽  
Cerebral Blood Volume ◽  
Mean Value ◽  
Cerebral Tissue ◽  
Adult Head

Methods for measuring cerebral blood volume (CBV) have traditionally used radioisotopes. More recently, near-infrared spectroscopy (NIRS) has been used to measure CBV by using a technique involving O2 desaturation of cerebral tissue, where the observed change in the concentration of oxygenated hemoglobin is a marker of the volume of blood contained within the brain. A new integration method employing NIRS is described by using indocyanine green (ICG) as the intravascular marker. After bolus injection, concentration-time integrals of cerebral tissue ICG concentration ([ICG]tissue) measured by NIRS are compared with corresponding integrals of the cerebral blood ICG concentrations ([ICG]blood) estimated by high-performance liquid chromatography of peripheral blood samples with allowance for cerebral-to-large-vessel hematocrit ratio. It is shown that[Formula: see text] Measurements in 10 adult volunteers gave a mean value of 1.1 ± 0.39 (SD) ml/100 g illuminated tissue. This result, although lower than previous NIRS estimations, is consistent with the long extracerebral path of light in the adult head. Scaling of results is required to take into account this component of the optical pathlength.

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