Separation of Receptor and Lamina Potentials in the Electroretinogram of Normal and Mutant Drosophila

1971 ◽  
Vol 55 (1) ◽  
pp. 85-100 ◽  
Author(s):  
MARTIN HEISENBERG
Keyword(s):  
Light Intensity ◽  
High Intensity ◽  
Receptor Potential ◽  
High Light Intensity ◽  
Pass Filter ◽  
High Stimulus ◽  
The Difference ◽  
Behavioural Experiments ◽  
Extracellular Resistance ◽  
High Pass

1. In Drosophila the retinula cells and the cells in the lamina ganglionaris contribute to the ERG. This is due to extracellular resistance barriers across these cells ; one of these is situated near the proximal ends of the rhabdomeres separating the retinula cell layer from the rest of the fly, the other is situated either within several layers or homogeneously distributed throughout the lamina. Because of their different origin, two components of the ERG, the receptor potential and the lamina potential can be separated experimentally. 2. At high light intensity the receptor potential is larger than the lamina potential. However, under stimulus conditions where the receptor potential is very small (a) at low light intensity, (b) at high intensity but low flash contrast (ΔI/I), (c) at high frequency of stimulation, the lamina potential exceeds the receptor potential. It is suggested that these properties reflect summation and adaptation of the sensory input within the lamina. The shape of the lamina potential has, under these conditions, the characteristics of a high-pass filter and may improve the fly's response to high stimulus frequencies. 3. The ERGS of the mutants ebony, tan and opm 2 have normal or nearly normal receptor potentials but at the same time demonstrate severe defects in the lamina potentials. In ebony a fast on-effect at high intensity, and in tan a delayed off-effect at high intensity, are still present. The mutant opm 2 shows very little lamina activity at all. The difference of the defects in the three mutants argues against non-specific current leaks in or around the lamina. Therefore it is most likely that the lamina properties of summation, adaptation, and high-pass filtering, are largely lost in the three mutants. This is supported by behavioural experiments.

scholarly journals PENGARUH INTENSITAS CAHAYA TERHADAP KETERTARIKAN GEROMBOLAN IKAN PELAGIS KECIL PADA MINI PURSE SEINE DI PERAIRAN PEMALANG JAWA TENGAH

2017 ◽  
Vol 13 (2) ◽  
pp. 125
Author(s):  
Erfind Nurdin ◽  
Mohammad Natsir ◽  
Hufiadi Hufiadi
Keyword(s):  
Light Intensity ◽  
Significant Influence ◽  
High Intensity ◽  
Purse Seine ◽  
North Coast ◽  
Fish School ◽  
The Third ◽  
Small Intensity ◽  
The Difference ◽  
Fishing Practices

Penggunaan intensitas cahaya pada unit penangkapan light fishing cenderung meningkat. Hal ini, didasari atas persepsi bahwa intensitas cahaya yang tinggi akan meningkatkan hasil tangkapan. Fenomena ini dijadikan suatu penelitian yang dilakukan selama 3 minggu pada bulan September 2004 di perairan Pemalang Jawa Tengah. Alat tangkap pukat cincin mini (mini purse seine) di pantai utara Jawa pada operasi penangkapan selain menggunakan rumpon juga mengggunakan cahaya sebagai alat bantu penangkapan. Pengukuran nilai intensitas lampu dilakukan dengan meggunakan LI COR 250 quantum meter (μmol sɹ mɲ) pada jumlah lampu yang berbeda, dan digunakan pula akustik EY 500 untuk memperoleh data sebaran dan gerombolan ikan yang berada dalam pengaruh cahaya lampu. Pada deteksi awal (A) ikan cenderung mengelompok pada lahan intensitas tinggi, deteksi ke 2 (B) pengelompokkan mulai terkonsentrasi dekat kapal, deteksi ke-3 (C) pengelompokkan ikan bertambah banyak, dan deteksi ke-4 (D) kelompok ikan berada pada lahan yang sangat memungkinkan untuk ditangkap. Dari hasil penelitian diperoleh laju tangkap (catch rate) 125,7 kg per tawur. Perbedaan jumlah lampu yang sedikit tidak menunjukkan pengaruh yang terlalu besar terhadap hasil tangkapan. The influence of light intensity to the light fishing practices commonly tends to increase. Fishermen believe that with the higher intensity of light the bigger catch they have. This phenomenon stimulated us to a research that during was done three weeks on September 2004 in Pemalang West Java. Mini purse seine is conduct at north coast of Java use payaos and light artificial for fish attractive. LI COR 250 quantum metre (μmol sɹ mɲ) was used for light intencity at different lamps amount and EY 500 acoustic to obtain the data of fish school in influence of lamp light. At the first detecting (A) fish school was concentrated in high intensity area, the second detecting (B) the concentration was closer to the ship, the third detecting (C) fish school increased, and the forth detecting (D) fish school was consentrated in catchable area. The results show that the cath rate was 125.7 kg per setting. The difference of lamps amount with a small intensity did not show significant influence to the catch haul.

Effect of Climatic Conditions on Phytotoxicity of Terbutryn

Weed Science ◽  
1972 ◽  
Vol 20 (1) ◽  
pp. 60-63 ◽  
Author(s):  
L. F. Figuerola ◽  
W. R. Furtick
Keyword(s):  
Light Intensity ◽  
Dry Weight ◽  
High Light Intensity ◽  
Climatic Conditions ◽  
High Light ◽  
Controlled Environment ◽  
Low Light ◽  
Carbon Dioxide Uptake ◽  
Low Light Intensity ◽  
The Difference

Phytotoxicity of 2-(tert-butylamino)-4-(ethylamino)-6-(methylthio)-s-triazine (terbutryn) on winter wheat (Triticum aestivum Vill. ‘Host’) was investigated in a controlled environment. Highly significant differences in foliage dry weight were caused by different light intensities and rates of terbutryn. Injury symptoms appeared much earlier in plants under high light intensity. Carbon dioxide uptake by wheat plants was reduced by terbutryn at high light intensity. At low light intensity the reduction was less severe and developed later. Respiration (CO2 evolved in the dark) was reduced only by the highest rates. Terbutryn was significantly less toxic to wheat than 2-chloro-4,6-bis(ethylamino)-s-triazine (simazine). The difference was more noticeable at low rates under high light intensity. At low light intensity no injury was observed with terbutryn.

scholarly journals The effect of flooding and light competition on the planting success of degraded tropical peatland

Jurnal Galam ◽  
2021 ◽  
Vol 1 (2) ◽  
pp. 123-140
Author(s):  
Dony Rachmanadi ◽  
◽  
Eny Faridah ◽  
Sumardi Sumardi ◽  
Peter van der Meer ◽  
...  
Keyword(s):  
Survival Rate ◽  
Light Intensity ◽  
Environmental Conditions ◽  
Field Testing ◽  
High Light Intensity ◽  
Light Competition ◽  
Tropical Peatland ◽  
The Difference ◽  
The Right ◽  
Two Stages

Planting was done as a rehabilitation effort at degraded tropical peatland. Understanding the characteristics of the species and environmental conditions that affect plant growth will determine the success of the planting. This study aims to determine the main environmental factors that affect plants in the field so that the right species can be determined. This study used a randomized completely blocked design which was conducted in two stages, namely field testing and verification under controlled conditions in the nursery. The research treatments consisted of inundation conditions and competition with understorey. The competition factor is interpreted by the difference in light intensity at the verification stage. The species used are meranti (Shorea pallidfolia), gerunggang (Cratoxylum glaucum), terentang (Campnosperma coreacea) dan tumih (Combretocarpus rotundatus). The results showed that the inundation conditions had an effect on the survival of meranti and gerunggang species where the survival rate was 8.3%—96.3%, but it did not affect the terentang and tumih with the survival rate reaching > 80%. The growth of meranti and gerunggang tends to decrease in line with the inundation conditions, while the growth of terentang and tumih tends to increase. Meranti growth requires understorey as protection from high light intensity. The tumih and terentang show better growth without competition with understorey. The trends in the field are consistent with observations during the verification stage. The difference in the response of plants to environmental conditions determines the presence of these species in the succession stage. Keywords: rehabilitation, flooding, drainage, succession, sequen

A V-Band Two Pole High-Pass Filter for Frequency Quadrupler Design

2016 ◽  
Vol 6 (1) ◽  
pp. 56
Author(s):  
Maryam Abata ◽  
Mahmoud Mehdi ◽  
Said Mazer ◽  
Moulhime El Bekkali ◽  
Catherine Algani
Keyword(s):  
Pass Filter ◽  
High Pass Filter ◽  
V Band ◽  
High Pass

Novel Compact High-Pass Filter with Sharp Attenuation Slope Using Cross-Coupling in the Multi-Layer Structure

2012 ◽  
Vol E95-C (2) ◽  
pp. 313-316
Author(s):  
Takenori YASUZUMI ◽  
Tomoki UWANO ◽  
Osamu HASHIMOTO
Keyword(s):  
Layer Structure ◽  
Cross Coupling ◽  
Pass Filter ◽  
High Pass Filter ◽  
High Pass

Characteristics of Photosynthesis in Different Wheat Cultivars under High Light Intensity and High Temperature Stresses

2009 ◽  
Vol 34 (12) ◽  
pp. 2196-2201 ◽  
Author(s):  
Xue-Li QI ◽  
Lin HU ◽  
Hai-Bin DONG ◽  
Lei ZHANG ◽  
Gen-Song WANG ◽  
...  
Keyword(s):  
High Temperature ◽  
Light Intensity ◽  
High Light Intensity ◽  
High Light ◽  
Wheat Cultivars ◽  
Temperature Stresses

Baseline-free sensor fault detection for piezoelectric array

2021 ◽  
pp. 1045389X2110188
Author(s):  
Qibo Mao ◽  
Yuande Wang ◽  
Shizuo Huang
Keyword(s):  
Prior Knowledge ◽  
Frequency Response Function ◽  
Sensor Array ◽  
Piezoelectric Element ◽  
Piezoelectric Sensor ◽  
Steel Beam ◽  
Sensor Fault ◽  
Pass Filter ◽  
Sensor Fault Detection ◽  
High Pass

In this study, a new methodology is presented to detect the sensor fault for piezoelectric array based on the filtered frequency response function (FRF) shapes. The proposed method does not require prior knowledge about healthy piezoelectric array. First, the imaginary parts of FRFs from the piezoelectric array during vibration are measured and normalized to obtain the FRF shapes in different frequencies. Then the irregularities in these FRF shapes are extracted by using high-pass filter with properly chosen cut-off frequency. These abnormal irregularities on the filtered FRF shape curves indicate the location of the faulty sensor, due to the irregularity of FRF shapes introduced by the faulty piezoelectric element. The proposed sensor fault method is experimentally demonstrated on a clamped-clamped steel beam mounted with piezoelectric buzzer array. Two common piezoelectric sensor fault types including sensor breakage and debonding are evaluated. The experimental results indicate that the proposed method has great potential in the detection of the sensor fault for piezoelectric array as it is simple and does not require the FRF data of the healthy sensor array as a baseline.

scholarly journals In search of the spectral composition of an effective light trap for the mushroom pest Lycoriella ingenua (Diptera: Sciaridae)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sándor Kecskeméti ◽  
András Geösel ◽  
József Fail ◽  
Ádám Egri
Keyword(s):  
Light Intensity ◽  
Spectral Sensitivity ◽  
Fungal Pathogens ◽  
Light Trap ◽  
Spectral Composition ◽  
Wavelength Dependence ◽  
Crop Damage ◽  
Photon Flux ◽  
Compound Eyes ◽  
Behavioural Experiments

AbstractCertain fungus gnats, like Lycoriella ingenua are notorious pests in agriculture, especially in mushroom production. While larvae cause mainly direct crop damage, adults are vectors of several dangerous fungal pathogens. To promote the development of pesticide-free management methods, such as light trapping, we measured the spectral sensitivity of L. ingenua compound eyes with electroretinography and performed two different behavioural experiments to reveal the wavelength dependence of phototaxis in this species. The spectral sensitivity of the compound eyes is bimodal with peaks at 370 nm (UV) and 526 nm (green). Behavioural experiments showed that attraction to light as a function of wavelength depends on light intensity. In our first experiment, where the minimal photon flux (105–109 photons/cm2/s) needed for eliciting a phototactic response was determined wavelength by wavelength, phototaxis was strongest in the green spectral range (~526 nm). In the other behavioural experiment, where wavelength preference was tested under a higher but constant light intensity (~1013 photons/cm2/s), the highest attraction was elicited by UV wavelengths (398 nm). Our results suggest that both UV and green are important spectral regions for L. ingenua thus we recommend to use both UV (~370-398 nm) and green (~526 nm) for trapping these insects.

scholarly journals Towards an optimum silicon heterojunction solar cell configuration for high temperature and high light intensity environment

2017 ◽  
Vol 124 ◽  
pp. 331-337 ◽  
Author(s):  
Amir Abdallah ◽  
Ounsi El Daif ◽  
Brahim Aïssa ◽  
Maulid Kivambe ◽  
Nouar Tabet ◽  
...  
Keyword(s):  
Solar Cell ◽  
High Temperature ◽  
Light Intensity ◽  
High Light Intensity ◽  
High Light ◽  
Heterojunction Solar Cell ◽  
Cell Configuration ◽  
Silicon Heterojunction Solar Cell

High light intensity stress as the limiting factor in micropropagation of sugar maple (Acer saccharum Marsh.)

2017 ◽  
Vol 129 (2) ◽  
pp. 209-221 ◽  
Author(s):  
Amritpal S. Singh ◽  
A. Maxwell P. Jones ◽  
Mukund R. Shukla ◽  
Praveen K. Saxena
Keyword(s):  
Light Intensity ◽  
Acer Saccharum ◽  
Sugar Maple ◽  
High Light Intensity ◽  
High Light ◽  
Limiting Factor ◽  
Intensity Stress
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