scholarly journals The Spectral Reflectance Response of ‘Riviera’ Common Bermudagrass to Increasing Saline Irrigation Concentrations

2020 ◽  
pp. 1-6
Author(s):  
Lakshmy Gopinath ◽  
Matthew Barton ◽  
Justin Quetone Moss
Keyword(s):  
Salinity Stress ◽  
Spectral Reflectance ◽  
Linear Regression Analysis ◽  
Limited Area ◽  
Visual Response ◽  
Salinity Treatment ◽  
Visual Responses ◽  
Saline Irrigation ◽  
Measuring Device ◽  
Common Bermudagrass

The availability of freshwater is a growing concern throughout the world as it is an increasingly valuable and limited resource. Alternative water resources such as recycled water low in quality and high in salinity are now frequently used to irrigate turfgrass. However, irrigating with highly saline water can affect the growth, performance, appearance, and quality of turfgrass. Bermudagrass (Cynodon sp.) is the most commonly used turfgrass throughout the southern United States. In this study, the spectral reflectance and visual response of ‘Riviera’ common bermudagrass (Cynodon dactylon) were evaluated by consecutively irrigating with 12 salinity concentrations (4–48 dS·m−1) in increments of 4 dS·m−1 via manual overhead irrigation for 30 days. The experiment was replicated in time in a controlled environment with four replications for each salinity treatment and control. ‘Riviera’ maintained a leaf firing (LF) value above 5 (rated on a scale from 1 to 9) when irrigated with 28 dS·m−1 for 30 days. Also, the LF value did not fall below 2 when irrigated with a salinity concentration of 48 dS·m−1 for 30 days, suggesting high salinity tolerance of ‘Riviera’. However, in this study, the normalized difference vegetation index (NDVI) had a lower ability to detect the increase in salinity stress due to the limited area measured by the NDVI measuring device used. An increase in sodium ion concentration was observed in the shoot with increasing salinity concentrations. The NDVI was highly correlated (r = 0.93) to LF, indicating the usefulness of NDVI as a tool to measure the magnitude of salinity stress. The multiple linear regression analysis revealed that the data showed a linear response to salinity stress with LF (r2 = 0.86) and NDVI (r2 = 0.76) decreasing linearly as the salinity concentration and days of treatment increased. This study provides an accurate depiction of the spectral and visual responses of ‘Riviera’ when exposed to multiple salinity concentrations with narrow increments.

scholarly journals Exogenous Putrescine Enhances Salt Tolerance and Ginsenosides Content in Korean Ginseng (Panax ginseng Meyer) Sprouts

Plants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1313
Author(s):  
Md. Jahirul Islam ◽  
Byeong Ryeol Ryu ◽  
Md. Obyedul Kalam Azad ◽  
Md. Hafizur Rahman ◽  
Md. Soyel Rana ◽  
...  
Keyword(s):  
Panax Ginseng ◽  
Salinity Stress ◽  
Soluble Sugar ◽  
Principal Component ◽  
Total Soluble Protein ◽  
Soluble Carbohydrate ◽  
Guaiacol Peroxidase ◽  
Salinity Treatment ◽  
Total Soluble Sugar ◽  
Biochemical Processes

The effect of exogenously applied putrescine (Put) on salt stress tolerance was investigated in Panax ginseng. Thirty-day-old ginseng sprouts were grown in salinized nutrient solution (150 mM NaCl) for five days, while the control sprouts were grown in nutrients solution. Putrescine (0.3, 0.6, and 0.9 mM) was sprayed on the plants once at the onset of salinity treatment, whereas control plants were sprayed with water only. Ginseng seedlings tested under salinity exhibited reduced plant growth and biomass production, which was directly interlinked with reduced chlorophyll and chlorophyll fluorescence due to higher reactive oxygen species (hydrogen peroxide; H2O2) and lipid peroxidation (malondialdehyde; MDA) production. Application of Put enhanced accumulation of proline, total soluble carbohydrate, total soluble sugar and total soluble protein. At the same time, activities of antioxidant enzymes like superoxide dismutase, catalase, ascorbate peroxidase, guaiacol peroxidase in leaves, stems, and roots of ginseng seedlings were increased. Such modulation of physio-biochemical processes reduced the level of H2O2 and MDA, which indicates a successful adaptation of ginseng seedlings to salinity stress. Moreover, protopanaxadiol (PPD) ginsenosides enhanced by both salinity stress and exogenous Put treatment. On the other hand, protopanaxatriol (PPT) ginsenosides enhanced in roots and reduced in leaves and stems under salinity stress condition. In contrast, they enhanced by exogenous Put application in all parts of the plants for most cases, also evidenced by principal component analysis. Collectively, our findings provide an important prospect for the use of Put in modulating salinity tolerance and ginsenosides content in ginseng sprouts.

scholarly journals Visual response of ventrolateral prefrontal neurons and their behavior-related modulation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Stefano Rozzi ◽  
Marco Bimbi ◽  
Alfonso Gravante ◽  
Luciano Simone ◽  
Leonardo Fogassi
Keyword(s):  
Visual Cues ◽  
Visual Stimuli ◽  
Visual Response ◽  
Visual Responses ◽  
Action Execution ◽  
Natural Behavior ◽  
Large Sector ◽  
Small Set ◽  
Early Passive ◽  
Task Conditions

AbstractThe ventral part of lateral prefrontal cortex (VLPF) of the monkey receives strong visual input, mainly from inferotemporal cortex. It has been shown that VLPF neurons can show visual responses during paradigms requiring to associate arbitrary visual cues to behavioral reactions. Further studies showed that there are also VLPF neurons responding to the presentation of specific visual stimuli, such as objects and faces. However, it is largely unknown whether VLPF neurons respond and differentiate between stimuli belonging to different categories, also in absence of a specific requirement to actively categorize or to exploit these stimuli for choosing a given behavior. The first aim of the present study is to evaluate and map the responses of neurons of a large sector of VLPF to a wide set of visual stimuli when monkeys simply observe them. Recent studies showed that visual responses to objects are also present in VLPF neurons coding action execution, when they are the target of the action. Thus, the second aim of the present study is to compare the visual responses of VLPF neurons when the same objects are simply observed or when they become the target of a grasping action. Our results indicate that: (1) part of VLPF visually responsive neurons respond specifically to one stimulus or to a small set of stimuli, but there is no indication of a “passive” categorical coding; (2) VLPF neuronal visual responses to objects are often modulated by the task conditions in which the object is observed, with the strongest response when the object is target of an action. These data indicate that VLPF performs an early passive description of several types of visual stimuli, that can then be used for organizing and planning behavior. This could explain the modulation of visual response both in associative learning and in natural behavior.

Effect of longer periods of dark rearing on NMDA receptors in cat visual cortex

1994 ◽  
Vol 72 (3) ◽  
pp. 1220-1226 ◽  
Author(s):  
D. Czepita ◽  
S. N. Reid ◽  
N. W. Daw
Keyword(s):  
Visual Cortex ◽  
Nmda Receptor ◽  
Firing Rate ◽  
Spontaneous Activity ◽  
Visual Response ◽  
Visual Responses ◽  
Level Of Activity ◽  
Direction Of Movement ◽  
Excitatory Drive ◽  
Dark Rearing

1. Cats were reared in the dark to 3, 5, and 11 mo. We studied the N-methyl-D-aspartate (NMDA) receptor contribution to the visual response in the cortex, defined as the percentage reduction in visual response after application of 2-amino-5-phosphonovaleric acid (APV). We also studied the firing rate in response to the optimal visual stimulus and the spontaneous activity. We made comparisons of all these properties between light-reared and dark-reared animals. 2. The NMDA receptor contribution to the visual response in layers IV, V, and VI of dark-reared animals was substantially above that in light-reared animals at all ages tested. 3. The specificity of receptive field properties in dark-reared animals showed some degeneration between 6 wk and 3 mo of age. At > or = 3 mo, almost no cells were specific for orientation and direction of movement. 4. Firing rate was lower in dark-reared animals at all ages, suggesting a decrease in excitatory drive to the visual cortex. 5. Spontaneous activity was equal in dark- and light-reared animals, suggesting that the overall level of activity (including visual responses as well as spontaneous activity) in light-reared animals is higher than in dark-reared animals. This should tend to upregulate glutamate receptors in general in dark-reared animals.

scholarly journals Landmark-Centered Coding in Frontal Cortex Visual Responses

2020 ◽  
Author(s):  
Adrian Schütz ◽  
Vishal Bharmauria ◽  
Xiaogang Yan ◽  
Hongying Wang ◽  
Frank Bremmer ◽  
...  
Keyword(s):  
Frontal Cortex ◽  
Visual Space ◽  
List Type ◽  
Visual Response ◽  
Visual Responses ◽  
Visual Landmarks ◽  
Specific Target ◽  
Visual Coding ◽  
The Gaze ◽  
Landmark Configuration

SummaryVisual landmarks influence spatial cognition [1–3], navigation [4,5] and goal-directed behavior [6–8], but their influence on visual coding in sensorimotor systems is poorly understood [6,9–11]. We hypothesized that visual responses in frontal cortex control gaze areas encode potential targets in an intermediate gaze-centered / landmark-centered reference frame that might depend on specific target-landmark configurations rather than a global mechanism. We tested this hypothesis by recording neural activity in the frontal eye fields (FEF) and supplementary eye fields (SEF) while head-unrestrained macaques engaged in a memory-delay gaze task. Visual response fields (the area of visual space where targets modulate activity) were tested for each neuron in the presence of a background landmark placed at one of four oblique configurations relative to the target stimulus. 102 of 312 FEF and 43 of 256 SEF neurons showed spatially tuned response fields in this task. We then fit these data against a mathematical continuum between a gaze-centered model and a landmark-centered model. When we pooled data across the entire dataset for each neuron, our response field fits did not deviate significantly from the gaze-centered model. However, when we fit response fields separately for each target-landmark configuration, the best fits shifted (mean 37% / 40%) toward landmark-centered coding in FEF / SEF respectively. This confirmed an intermediate gaze / landmark-centered mechanism dependent on local (configuration-dependent) interactions. Overall, these data show that external landmarks influence prefrontal visual responses, likely helping to stabilize gaze goals in the presence of variable eye and head orientations.HighlightsPrefrontal visual responses recorded in the presence of visual landmarksResponse fields showed intermediate gaze / landmark-centered organizationThis influence depended on specific target-landmark configurations

scholarly journals Effects of 1-aminocyclopropane-1-carboxylate-deaminase–Producing Bacteria on Perennial Ryegrass Growth and Physiological Responses to Salinity Stress

2016 ◽  
Vol 141 (3) ◽  
pp. 233-241 ◽  
Author(s):  
Liang Cheng ◽  
Ning Zhang ◽  
Bingru Huang
Keyword(s):  
Salinity Stress ◽  
Perennial Ryegrass ◽  
Photochemical Efficiency ◽  
Acc Deaminase ◽  
Nutrition Status ◽  
Shoot Biomass ◽  
Leaf Water Content ◽  
Salinity Treatment ◽  
Plant Tolerance ◽  
Water Control

The accumulation of 1-aminocyclopropane-1-carboxylate (ACC), which is a precursor for ethylene production, in plant roots exposed to salinity stress can be detrimental to plant growth. The objectives of this study were to determine whether inoculating roots with bacteria containing deaminase enzymes that break down ACC (ACC-deaminase) could improve plant tolerance to salinity in perennial ryegrass (Lolium perenne) and to examine growth and physiological factors, as well as nutrition status of plants affected by the ACC-deaminase bacteria inoculation under salinity stress. Plants of perennial ryegrass (cv. Pangea) were inoculated with either Burkholderia phytofirmans PsJN or Burkholderia gladioli RU1 and irrigated with either fresh water (control) or a 250 mm NaCl solution to induce salinity stress. The bacterium-inoculated plants had less ACC content in shoots and roots under both nonstressed and salinity conditions. Salinity stress inhibited root and shoot growth, but the bacterium-inoculated plants exhibited higher visual turf quality (TQ), tiller number, root biomass, shoot biomass, leaf water content, and photochemical efficiency, as well as lower cellular electrolyte leakage (EL) under salinity stress. Plants inoculated with bacteria had lower sodium content and higher potassium to sodium ratios in shoots under salinity stress. Shoot and root nitrogen content and shoot potassium content increased, whereas shoot and root calcium, magnesium, iron, and aluminum content all decreased due to bacterial inoculation under salinity treatment. ACC-deaminase bacteria inoculation of roots was effective in improving salinity tolerance of perennial ryegrass and could be incorporated into turfgrass maintenance programs in salt-affected soils.

scholarly journals PATTERNS OF CHANGES IN FLUORESCENCE OF NADH AND FAD COENZYMES AND THEIR RELATIONSHIP IN SKELETAL MUSCLE IN EARLY POST-MORTEM PERIOD (EXPERIMENTAL STUDY)

2020 ◽  
Author(s):  
Anastasia S. Babkina
Keyword(s):  
Skeletal Muscle ◽  
Mathematical Models ◽  
Fluorescence Intensity ◽  
Statistical Significance ◽  
Linear Regression Analysis ◽  
Post Mortem ◽  
Redox Ratio ◽  
Measuring Device ◽  
Nadh Fluorescence ◽  
The Relationship

Abstract. The paper presents changes and mathematical models of autofluorescence of reduced nicotinamide adenine dinucleotide (NADH) and flavin adenine dinucleotide (FAD) and their redox ratio (RR) in the rat skeletal muscle during the first 24 hours after death. Aim. To establish a pattern of change in the fluorescence intensity of NADH and FAD coenzymes, as well as their relationship in the skeletal muscle during the first 24 hours after death using mathematical modeling. Material and methods. The experiment was performed on Sprague Dawley rats. The fluorescence intensity of FAD and NADH coenzymes in skeletal muscle was measured in situ in living rats under general anesthesia, 5 minutes after euthanasia, and at intervals of 1.5-3 h during the 24-hour postmortem period. To estimate the fluorescence intensity of NADH and FAD coenzymes and to calculate the RR, the Lasma MC-3 fluorescence measuring device with special software was used. The obtained data were analyzed by non-linear regression analysis. The summary, accuracy estimation and significance of the regression equation coefficients were assessed using SigmaPlot 10.0 software. The significance of the regression model was tested using the Fisher F-criterion. Results. During the first 3 hours of the postmortem period, an increase in the mean values of RR and NADH fluorescence was detected, starting from 4.5 and till 24 hours post-mortem their gradual decrease was observed. The relationship between NADH, RR and time after death is characterized by the Weibull equation. The statistical significance of NADH and RR models, based on the obtained equations was considered high. Conclusion. The analysis of the obtained data allowed to create mathematical models describing the relationship between RR and NADH fluorescence intensity and time after death, which confirms non-randomness and regularity of the discovered patterns.time of death; NADH; FAD; auto-fluorescence; redox ratio; early post-mortem changes

scholarly journals Accumulation of Phenylpropanoids in Tartary Buckwheat (Fagopyrum tataricum) under Salt Stress

Agronomy ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 739 ◽  
Author(s):  
Nam Su Kim ◽  
Soon-Jae Kwon ◽  
Do Manh Cuong ◽  
Jin Jeon ◽  
Jong Seok Park ◽  
...  
Keyword(s):  
Salinity Stress ◽  
Ion Homeostasis ◽  
Tartary Buckwheat ◽  
Anthocyanin Content ◽  
Salinity Treatment ◽  
Fagopyrum Tataricum ◽  
Time Treatment ◽  
Nacl Concentration ◽  
Ion Imbalance

Salinity stress affects plants by reducing the water potential and causing ion imbalance or disturbances in ion homeostasis and toxicity. Salinity stress frequently causes both osmotic and ionic stress in plants, resulting in the increase or decrease of certain secondary metabolites in plants. In this study, the effect of NaCl treatment on the nutritional quality of tartary buckwheat plants was studied by conducting an HPLC analysis of phenylpropanoid and anthocyanin content. It was observed that there was no significant change of color in tartary buckwheat during salt treatment. The accumulation of most phenylpropanoid compounds increased slightly in response to the NaCl concentration. The total phenylpropanoid content in tartary buckwheat was the highest at 100 mM NaCl treatment. Seven-day-old wheat plantlets treated with 100 mM NaCl for 2, 4, 6, and 8 days showed the highest accumulation of total phenylpropanoids at day 8 after treatment, while the content of most phenylpropanoids was higher than that in the control during this period. Although the development of tartary buckwheat slightly decreased with NaCl treatment and the accumulation of anthocyanin compounds did not change in plants with a diffident NaCl concentration and time treatment, the results suggest that the salinity treatment of tartary buckwheat causes antioxidant activity improvement by inducing an accumulation of flavonoid and phenolic compounds. However, since the anthocyanin content did not increase, the antioxidant effect of the treatment is not expected to be significant.

The functional influence of nicotinic cholinergic receptors on the visual responses of neurones in the superficial superior colliculus

2000 ◽  
Vol 17 (2) ◽  
pp. 283-289 ◽  
Author(s):  
K.E. BINNS ◽  
T.E. SALT
Keyword(s):  
Superior Colliculus ◽  
Nicotinic Receptors ◽  
Visual Stimulation ◽  
Glutamate Release ◽  
Drug Application ◽  
Receptor Activation ◽  
Visual Input ◽  
Visual Response ◽  
Visual Responses ◽  
Parabigeminal Nucleus

In the rat, the superficial gray layer (SGS) of the superior colliculus receives glutamatergic projections from the contralateral retina and from the visual cortex. A few fibers from the ipsilateral retina also directly innervate the SGS, but most of the ipsilateral visual input is provided by cholinergic afferents from the opposing parabigeminal nucleus (PBG). Thus, visual input carried by cholinergic afferents may have a functional influence on the responses of SGS neurones. When single neuronal extracellular recording and iontophoretic drug application were employed to examine this possibility, cholinergic agonists were found to depress responses to visual stimulation. Lobeline and 1-acetyl-4-methylpiperazine both depressed visually evoked activity and had a tendency to reduce the background firing rate of the neurones. Carbachol depressed the visual responses without any significant effect on the ongoing activity, while the muscarinic receptor selective agonist methacholine increased the background activity of the neurones and reduced their visual responses. Lobeline was chosen for further studies on the role of nicotinic receptors in SGS. Given that nicotinic receptors are associated with retinal terminals in SGS, and that the activation of presynaptic nicotinic receptors normally facilitates transmitter release (in this case glutamate release), the depressant effects of nicotinic agonists are intriguing. However, many retinal afferents contact inhibitory neurones in SGS; thus it is possible that the increase in glutamate release in turn facilitates the liberation of GABA which goes on to inhibit the visual responses. We therefore attempted to reverse the effects of lobeline with GABA receptor antagonists. The depressant effects of lobeline on the visual response could not be reversed by the GABAA antagonist bicuculline, but the GABAB antagonist CGP 35348 reduced the effects of lobeline. We hypothesize that cholinergic drive from the parabigeminal nucleus may activate presynaptic nicotinic receptors on retinal terminals, thereby facilitating the release of glutamate onto inhibitory neurones. Consequently GABA is released, activating GABAB receptors, and thus the ultimate effect of nicotinic receptor activation is to depress visual responses.

Dependence of retinogeniculate transmission in cat on NMDA receptors

1990 ◽  
Vol 63 (2) ◽  
pp. 347-355 ◽  
Author(s):  
A. M. Sillito ◽  
P. C. Murphy ◽  
T. E. Salt ◽  
C. I. Moody
Keyword(s):  
Nmda Receptor ◽  
Nmda Receptors ◽  
Dorsal Lateral Geniculate Nucleus ◽  
Visual Response ◽  
Visual Responses ◽  
Receptor Agonists ◽  
Selective Blockade ◽  
X And Y Cells ◽  
X 24 ◽  
Y Cells

1. We have examined the possibility that N-methyl-D-aspartate (NMDA) receptors may be involved in the visual response of relay cells in the cat dorsal lateral geniculate nucleus (dLGN). The selective NMDA receptor antagonists D-2-amino-5-phosphonovalerate (APV) and 3-[(+/-)-2-carboxypiperazin-4-yl]-propyl-1-phosphonic acid (CPP) have been iontophoretically applied to X and Y cells in the dLGN and their effects on the visual response to a light spot flashed within the receptive field center determined. 2. The antagonist effects were assessed at ejection current levels producing a selective blockade of the responses to iontophoretically applied NMDA with respect to those elicited by the non-NMDA receptor agonists quisqualate and kainate. These selective effects were determined in an experimental paradigm where the visual response and responses to NMDA and the non-NMDA receptor agonists were compared in the same test run. The data refer to a total population of 52 cells (28 X, 24 Y). 3. Application of APV abolished or greatly reduced the visual responses of both X and Y cells. The mean percentage reduction in the visual response for the X cells studied was 59 +/- 10% (SE; n = 7) and for the Y cells 66 +/- 8% (SE; n = 11). Both the early onset transient and the sustained component of the visual response to the flashed stimulus were equally affected. 4. The antagonist CPP produced a similar pattern of effect to APV, substantially reducing or abolishing the visual response in both X and Y cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of passive eye movement on retinogeniculate transmission in the cat

1990 ◽  
Vol 63 (3) ◽  
pp. 523-538 ◽  
Author(s):  
R. Lal ◽  
M. J. Friedlander
Keyword(s):  
Firing Rate ◽  
Spontaneous Activity ◽  
Eye Movement ◽  
Visual Stimulus ◽  
Action Potentials ◽  
Visual Stimuli ◽  
Dorsal Lateral Geniculate Nucleus ◽  
Visual Response ◽  
Visual Responses ◽  
Movement Effect

1. The nature and time window of interaction between passive phasic eye movement signals and visual stimuli were studied for dorsal lateral geniculate nucleus (LGNd) neurons in the cat. Extracellular recordings were made from single neurons in layer A of the left LGNd of anesthetized paralyzed cats in response to a normalized visual stimulus presented to the right eye at each of several times of movement of the left eye. The left eye was moved passively at a fixed amplitude and velocity while varying the movement onset time with respect to the visual stimulus onset in a randomized and interleaved fashion. Visual stimuli consisted of square-wave modulated circular spots of appropriate contrast, sign, and size to elicit an optimal excitatory response when placed in the neurons' receptive-field (RF) center. 2. Interactions were analyzed for 78 neurons (33 X-neurons, 43 Y-neurons, and 2 physiologically unclassified neurons) on 25-65 trials of identical visual stimuli for each of eight times of eye movement. 3. Sixty percent (47/78) of the neurons tested had a significant eye movement effect (ANOVA, P less than 0.05) on some aspect of their visual response. Of these 47 neurons, 42 (89%) had a significant (P less than 0.05) effect of an appropriately timed eye movement on the number of action potentials, 36 (77%) had a significant effect on the mean peak firing rate, and 31 (66%) were significantly affected as evaluated by both criteria. 4. The eye movement effect on the neurons' visual responses was primarily facilitatory. Facilitation was observed for 37 (79%) of the affected neurons. For 25 of these 37 neurons (68%), the facilitation was significant (P less than 0.05) as evaluated by both criteria (number of action potentials and mean peak firing rate). Ten (21%) of the affected neurons had their visual response significantly inhibited (P less than 0.05). 5. Sixty percent (46/78) of the neurons were tested for the effect of eye movement on both visually elicited activity (visual stimulus contrast = 2 times threshold) and spontaneous activity (contrast = 0). Eye movement significantly affected the visual response of 23 (50%) of these neurons. However, spontaneous activity was significantly affected for only nine (20%) of these neurons. The interaction of the eye movement and visual signals was nonlinear. 6. Nine of 12 neurons (75%) tested had a directionally selective effect of eye movement on the visual response, with most (8/9) preferring the temporal ward direction.(ABSTRACT TRUNCATED AT 400 WORDS)

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