THE EFFECTS OF PHYSICAL STIMULI ON THE LARVAL STAGE OF TERRANOVA DECIPIENS: III. ELECTROMAGNETIC SPECTRUM AND GALVANOTAXIS

1963 ◽  
Vol 41 (2) ◽  
pp. 197-217 ◽  
Author(s):  
Keith Ronald
Keyword(s):  
Latent Period ◽  
Direct Current ◽  
Larval Stage ◽  
Fish Muscle ◽  
Electromagnetic Spectrum ◽  
Light Radiation ◽  
Directional Response ◽  
Low Level ◽  
Physical Stimuli ◽  
Directional Stimulus

Various frequencies in the range of 25.9 kc to approximately 100 mmmc were used as a source of stimuli to the larval stage of the nematode Terranova decipiens. Larvae exposed to 650 kc ultrasound were killed in 4 minutes, while those exposed to 25.9 and 1000 kc were killed in 30 and 270 minutes respectively. The larvae were not affected by radiation produced either in the radio- or the micro-wave frequencies. Light radiation of less than 280 mμ had no effect on the nematode, while fish muscle insulated the larvae from the limited effects of radiations between 253.7 to 900 mμ. The larvae showed no photo tactic response. When exposed to 4 million roentgen equivalent physical, the larvae died immediately (LD50); however, after a latent period of 288 hours a much lower dose (400,000 rep) will bring about death. The larvae were stimulated by low-level direct current applied intermittently, but exhibited no directional response to any level of alternating or direct current. The low resistance offered by the fish muscle habitat of the nematode excludes any application of directional stimulus.

scholarly journals A three-dimensional laser interferometer gravitational-wave detector

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Mengxu Liu ◽  
Biping Gong
Keyword(s):  
Gravitational Wave ◽  
Laser Interferometer ◽  
Three Dimensional ◽  
Electromagnetic Emission ◽  
Laser Interferometry ◽  
Electromagnetic Spectrum ◽  
Spherically Symmetric ◽  
Directional Response ◽  
Wave Detector ◽  
The Universe

Abstract The gravitational wave (GW) has opened a new window to the universe beyond the electromagnetic spectrum. Since 2015, dozens of GW events have been caught by the ground-based GW detectors through laser interferometry. However, all the ground-based detectors are L-shaped Michelson interferometers, with very limited directional response to GW. Here we propose a three-dimensional (3-D) laser interferometer detector in the shape of a regular triangular pyramid, which has more spherically symmetric antenna pattern. Moreover, the new configuration corresponds to much stronger constraints on parameters of GW sources, and is capable of constructing null-streams to get rid of the signal-like noise events. A 3-D detector of kilometer scale of such kind would shed new light on  the joint search of GW and electromagnetic emission.

The Glare Effect Does Not Give Rise to a Longer-Lasting Afterimage

Perception ◽  
10.1068/p5484 ◽  
2006 ◽  
Vol 35 (5) ◽  
pp. 701-707 ◽  
Author(s):  
Hongjing Lu ◽  
Daniele Zavagno ◽  
Zili Liu
Keyword(s):  
Low Level ◽  
Physical Stimuli ◽  
Glare Effect

The glare effect is an illusion in which a region appears self-luminous when flanked by gradients that decrease in luminance with distance from the region (Zavagno, 1999 Perception28 835–838). This region also appears brighter than a surface of the same luminance. We investigated, using the paradigm of afterimages, whether a low-level mechanism at the level of the retina or LGN could account for this apparent brighter sensation. We first replicated the result from the literature that brighter and longer-lasting physical stimuli generate longer-lasting afterimages. We then compared the glare-effect stimuli with their counterpart controls, and found that the glare-effect stimuli did not give rise to longer-lasting afterimages. This suggests that the apparent brighter sensation of the glare effect is not due to a retinal or LGN mechanism, but must have a cortical origin.

Low-Level Experimental Selenite Additions Decrease Mercury in Aquatic Food Chains and Fish Muscle but Increase Selenium in Fish Gonads

2013 ◽  
Vol 66 (1) ◽  
pp. 32-40 ◽  
Author(s):  
Mariah Mailman ◽  
R. A. Bodaly ◽  
Michael J. Paterson ◽  
Shirley Thompson ◽  
Robert J. Flett
Keyword(s):  
Fish Muscle ◽  
Food Chains ◽  
Low Level ◽  
Aquatic Food ◽  
Fish Gonads

Investigation of the effect of low power laser used in photodynamic therapy for treatment of psoriasis

2012 ◽  
Vol 1 (4) ◽  
Author(s):  
Nafie A. Almuslet ◽  
Abdelmoniem E. Osman
Keyword(s):  
Photodynamic Therapy ◽  
Low Power ◽  
Plaque Psoriasis ◽  
Continuous Wave ◽  
Diode Lasers ◽  
Electromagnetic Spectrum ◽  
Power Laser ◽  
Chronic Plaque Psoriasis ◽  
Low Level ◽  
Level Laser

AbstractThe objective of this study was to investigate the effect of power on low-level lasers used in photodynamic therapy (PDT) to treat chronic plaque psoriasis in a group of Sudanese patients.Twenty-four patients with chronic plaque psoriasis were randomly selected to enter this study from a total of 100 patients who attended the Khartoum Dermatology Teaching Hospital between 2010 and 2011. The lasers used for PDT were three continuous wave diode lasers in the red portion of the electromagnetic spectrum (671–675 nm) with output powers of 16, 50 and 100 mW to activate the chemical photosensitizer (LevulanThis study showed that 62% of the patients treated with 100 mW achieved complete clearance compared with 25% for those treated with 50 mW and 0% for those treated with 16 mW.The results showed that increasing the power of low-level laser in PDT increased the clearance of plaque psoriasis. PDT can be used as an alternative method for treatment of psoriasis.

scholarly journals Conversion of differentiation inducer resistance to differentiation inducer sensitivity in erythroleukemia cells.

1990 ◽  
Vol 10 (7) ◽  
pp. 3535-3540 ◽  
Author(s):  
J Michaeli ◽  
Y B Lebedev ◽  
V M Richon ◽  
Z X Chen ◽  
P A Marks ◽  
...  
Keyword(s):  
Latent Period ◽  
Constitutive Expression ◽  
Beta Activity ◽  
Potent Inducer ◽  
Low Level ◽  
A Cells ◽  
Erythroleukemia Cells ◽  
Murine Erythroleukemia ◽  
Kinetics Of ◽  
Differentiation Inducer

Hexamethylene bisacetamide (HMBA) is a potent inducer of differentiation of murine erythroleukemia cells (MELC). Commitment, the irreversible initiation of the program of terminal-cell differentiation, is first detected in HMBA-sensitive DS19-SC9 MELC in culture after 10 to 12 h of exposure to HMBA. Vincristine (VC)-resistant MELC derived from the DS19-SC9 MELC line display increased sensitivity to HMBA and become committed with little or no latent period. In the present study, we showed that the MELC line R1, which is resistant to HMBA-mediated differentiation, became sensitive to inducer if selected for a low level of VC resistance (less than 10 ng of VC per ml). Four independently derived VC-resistant cell lines from HMBA-resistant R1 cells, designated R1[VCR]a to R1[VCR]d, acquired sensitivity to HMBA and the accelerated kinetics of commitment that are characteristic of VC-resistant MELC derived from the parental DS19-SC9 cells. The calcium channel blocker verapamil suppresses the VC resistance of R1[VCR] cells but does not alter the accelerated response to HMBA. In R1[VCR] cells there was no detectable increase in the level of the 140-kilodalton P-glycoprotein. Transient inhibition of protein synthesis during the latent period delays inducer-mediated commitment of VC-sensitive DS19-SC9 MELC but does not alter the accelerated commitment kinetics of R1[VCR]a cells. Previously, we have reported evidence that protein kinase C beta (PKC beta) plays a role in HMBA-induced MELC differentiation and that compared with DS19-SC9 cells, R1 cells have a relatively low level and R1[VCR]a cells have a high level of PKC beta. These findings suggest that (i) acquisition of VC resistance overcomes the block acquired by R1 cells to HMBA-mediated differentiation; (ii) the accelerated kinetics of HMBA-induced commitment of VC-resistant MELC is not dependent on the verapamil-sensitive transport channel that is responsible, at least in part, for resistance to VC; (iii) in VC-resistant MELC, there is constitutive expression or accumulation of a protein required for HMBA-induced differentiation; and (iv) an elevated level of PKC beta activity may play a role in the altered response of R1[VCR] and other VC-resistant MELC to HMBA.

Antitumor Effect of Externally Applied Low-Level Direct Current on Fibrosarcoma Tumor Model

1993 ◽  
Vol 11 (1) ◽  
pp. 22-23
Author(s):  
Lojze Vodovnik ◽  
Stojan Plesnicar ◽  
Stanislav Rebersek ◽  
Damijan Miklavcic ◽  
Gregor Sersa ◽  
...  
Keyword(s):  
Direct Current ◽  
Antitumor Effect ◽  
Tumor Model ◽  
Low Level

scholarly journals Uji Kinerja Modul Pelatihan Motor Penunjang Mata Kuliah Mekatronika

2017 ◽  
Vol 3 (3) ◽  
pp. 127
Author(s):  
Anwar Mujadin ◽  
Dwi Astharini
Keyword(s):  
Direct Current ◽  
Duty Cycle ◽  
Pulse Width ◽  
Pulse Width Modulation ◽  
Dc Motor ◽  
Stepper Motor ◽  
Servo Motor ◽  
Low Level ◽  
Time Period ◽  
Angle Rotation

<p><em>Abstrak – </em><strong>Teknis pemberian pulse width modulation (PWM) menjadi sangat penting terutama dalam pengendalian motor seperti pada motor direct current (motror DC), motor stepper maupun motor servo. Lebar pulsa duty cycle dalam satu perioda waktu  PWM akan menentukan tingkat keakuratan kecepatan maupun sudut. PWM diatur memggunakan program (assembly),  kemudian kecepatanya diamati menggunakan alat ukur laser tachometer sedangkan tingkat kepersisian sudutnya diukur menggunakan pola kertas (template). Untuk mendapatkan performa independensi setiap motor, maka motor dikendalikan dan diujicobakan tanpa menggunakan beban  (tidak ada uji torsi).</strong></p><p><strong><em> </em></strong></p><p><strong><em>Kata kunci</em></strong><em>- pulse width modulation mekatronika motor traineer.</em></p><p> </p><p><em>Abstract – </em><strong>the pulse width modulation (PWM) is especially inportant for motor controlling such as in DC motor, stepper motor and servo motor. The width of duty cycle in time period will determine speed and angle accurately. PWM wil be generated by using low level programm code of microcontroller (assembler), then speed of motor observed by laser tachometer and angle rotation observed by paper patern template. To get the performance independence of each motor, the motor is controlled and tested without the use of loads (no test of torque).</strong></p><p><em> </em></p><p><strong><em>Keywords</em></strong> – <em>pulse width modulation motor traineer for mechatronic modules.</em></p>

Sign in / Sign up

Export Citation Format

Share Document