The synergy of microplastics with the heavy metal zinc has resulted in reducing the toxic effects of zinc on lentil () seed germination and seedling growth.

There is growing recognition of the impact of the rising presence of microplastics (MPs) on terrestrial plant growth and, in general, the terrestrial ecosystem. Simultaneously, there is growing heavy metal accumulation in agricultural lands at an astonishing rate owing to the overwhelming use of chemical fertilizers, herbicides, and weedicides. Thus, there is a need to investigate the synergetic effect of MPs along with heavy metals on the inducing combined toxicity.

Effects of microplastics on lentil (Lens culinaris) seed germination and seedling growth.

Widespread use of plastics and mishandling has resulted in severe environmental issues affecting seed germination and seedling growth. This study investigates the effect of polyethylene microplastics (740-4990 nm PEMPs) on lentil (Lens culinaris) seed germination and seedling growth using Biospeckle Optical Coherence Tomography (bOCT), a technique that we successfully demonstrated earlier in visualizing the internal activity of plants. Lentil seeds were exposed to PEMPs bioassay for seven days with 10, 50, and 100 mg L concentrations.

Demonstration of laser biospeckle method for speedy in vivo evaluation of plant-sound interactions with arugula.

In recent years, it is becoming clearer that plant growth and its yield are affected by sound with certain sounds, such as seedling of corn directing itself toward the sound source and its ability to distinguish stuttering of larvae from other sounds. However, methods investigating the effects of sound on plants either take a long time or are destructive. Here, we propose using laser biospeckle, a non-destructive and non-contact technique, to investigate the activities of an arugula plant for sounds of different frequencies, namely, 0 Hz or control, 100 Hz, 1 kHz, 10 kHz, including rock and classical music.

Nanometer accuracy statistical interferometric technique in monitoring the short-term effects of exogenous plant hormones, auxin and gibberellic acid, on rice plants.

Statistical interferometric technique (SIT) is a highly sensitive, high speed non-contact, and non-destructive optical technique developed by our group capable of measuring instantaeoues sub-nanometer displacements. SIT applied to plant leaf elongation revealed nanometric intrinsic fluctuaitons (NIF) that are robust and sensitive to variations in the environment making NIF as a measure of healthiness of the plants. In this study, exogenous plant hormones, auxin (2,4-dichlorophenoxyacetic acid-2,4-D), and gibberellic acid (GA), along with an auxin transport inhibitor 2,3,5-triiodobenzoic acid-TIBA, that affect plant growth were used to investigate their effects on NIF.

Biospeckle optical coherence tomography in speedy visualizing effects of foliar application of plant growth hormone to Chinese chives leaves.

Objective: The aim of this study is to demonstrate the potential of applying the contrast of the speckles obtained as noise in optical coherence tomography (OCT) images to monitor short term activity changes during foliar application of phytohormones to a plant leaf. Plant growth hormone, gibberellic acid (GA) was sprayed onto the leaf of Chinese chives and after 60 min, OCT images (1 frame: 512 × 2048 pixels) were recorded at ten frames per second for a few tens of seconds.

Results: Contrast across the temporal axis was calculated for each pixel of the structural images and biospeckle OCT contrast images were obtained under the conditions of before and after application of GA for different concentrations 0, 40, and 100 μM.

Fractal based complexity analysis of wheat root system under different heavy metals.

In this study, fractal geometry was applied to characterize the complexity of the root system morphology of wheat plants under the exposure of heavy metals, namely cadmium (Cd), copper (Cu) and zinc (Zn). We proposed a measure called, relative complexity index (RCI), a ratio based on fractal dimension (FD) before and after exposure to heavy metals. FDs were calculated by box-counting method with digitized and skeletonized images of roots of wheat plants cultivated in hydroculture system.

Highly sensitive optical interferometric technique reveals stress-dependent instantaneous nanometric growth fluctuations of Chinese chive leaf under heavy metal stress.

Plant growth apart from being a complex and highly dynamic is dependent on its immediate environment. Leaf expansion measurements using Statistical Interferometry Technique, a sensitive interferometric technique at nanometric accuracy and at sub-second levels revealed the presence of characteristic nanometric intrinsic fluctuations [Plant Biotechnology 31, 195 (2014)]. In this paper, we demonstrate that the nanometric intrinsic fluctuations are sensitive enough that they change under exposure of heavy metals, essential micronutrient zinc and non-essential element cadmium, at relatively low concentrations in the leaves of Chinese chive (Allium tuberosum).

Functional optical coherence tomography of rat olfactory bulb with periodic odor stimulation.

In rodent olfactory bulb (OB), optical intrinsic signal imaging (OISI) is commonly used to investigate functional maps to odorant stimulations. However, in such studies, the spatial resolution in depth direction (z-axis) is lost because of the integration of light from different depths. To solve this problem, we propose functional optical coherence tomography (fOCT) with periodic stimulation and continuous recording.

Nanometer-scale elongation rate fluctuations in the Myriophyllum aquaticum (Parrot feather) stem were altered by radio-frequency electromagnetic radiation.

The emission of radio-frequency electromagnetic radiation (EMR) by various wireless communication base stations has increased in recent years. While there is wide concern about the effects of EMR on humans and animals, the influence of EMR on plants is not well understood. In this study, we investigated the effect of EMR on the growth dynamics of Myriophyllum aquaticum (Parrot feather) by measuring the nanometric elongation rate fluctuation (NERF) using a statistical interferometry technique.

An optical interferometric technique for assessing ozone induced damage and recovery under cumulative exposures for a Japanese rice cultivar.

Exposure to ozone (O3) causes reduction both in the growth and yield of rice (Oriza sativa L.). Commonly used Chlorophyll fluorescent measurements are not sensitive enough for short term exposure of O3 aiming an immediate assessments.

Swept source optical coherence tomography as a tool for real time visualization and localization of electrodes used in electrophysiological studies of brain in vivo.

In studies of in vivo extracellular recording, we usually penetrate electrodes almost blindly into the neural tissue, in order to detect the neural activity from an expected target location at a certain depth. After the recording, it is necessary for us to determine the position of the electrodes precisely. Generally, to identify the position of the electrode, one method is to examine the postmortem tissue sample at micron resolution.

In vivo layer visualization of rat olfactory bulb by a swept source optical coherence tomography and its confirmation through electrocoagulation and anatomy.

Here, we report in vivo 3-D visualization of the layered organization of a rat olfactory bulb (OB) by a swept source optical coherence tomography (SS-OCT). The SS-OCT operates at a wavelength of 1334 nm with respective theoretical depth and lateral resolutions of 6.7 μm and 15.

Expansion of the dynamic range of statistical interferometry and its application to extremely short- to long-term plant growth monitoring.

In this study, we propose a method to expand the dynamic range of expansion or strain measurement using statistical interferometry. Statistical interferometry is a very accurate interferometric technique that is applicable to practical rough surface objects [Opt. Lett.

Use of dynamic electronic speckle pattern interferometry with the Hilbert transform method to investigate thermal expansion of a joint material.

A dynamic electronic speckle pattern interferometry method is applied to investigate thermal expansion of a joint material (ceramic-stainless steel) as a practical industrial object. The speckle interference signal is considered in the temporal domain and the phase is analyzed by the Hilbert transform method. Errors caused by the bias and modulation variations over the phase values are first examined by numerical simulation.

Dynamic electronic speckle pattern interferometry (DESPI) phase analyses with temporal Hilbert transform.

In this study, we propose the Hilbert transform (HT) method for phase analysis of a Dynamic ESPI signal. The data processing is performed in the temporal domain, using the temporal history of the interference signal at every single pixel. The final results give a temporal development of the two-dimensional deformation field.