• Title/Summary/Keyword: dark adaptation

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Vision and Aging

  • Kim, In Suk;Hilz, Rudolf
    • Journal of Korean Ophthalmic Optics Society
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    • v.7 no.1
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    • pp.9-13
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    • 2002
  • It is well known that the maximum amplitude of accommodation decreases with increasing age.(Presbyopia). With single vision lenses presbyopia can be corrected only for one viewing distance. With progressive power lenses presbyopia can be corrected for all viewing distances. But there are some other changes in the visual system with age which can not be corrected by spectacle lenses. Pupillary diameter decreases and the light transmission of the ocular media decreases. Therefore old people need more light, they need better illumination. Cone density in the retina decreases, this is only one example for changes in the sensory system. These changes in the visual system cause changes in visual functions. At the age of 80 visual acuity has decreased to half. Contrast sensitivity for gratings decreases mainly for high spatial frequencies very important is the increase of stray light in the ocular media and therefore the increase of glare. Veiling luminance increases by a multiple of approximately 4, Dark adaptation gets slower and light sensitivity is approximately 2 log units (factor 100) less when the eye is completely dark adapted. Also colour vision gets worse, especially at low luminances. Elderly people have problems with visual tasks which require divided attention between foveal and peripheral vision. An example is the measurement of the useful field of view. This useful field of view be expanded (improved) by visual training.

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Breeding Process and Characteristics of Gopoong, a New Variety of Panax ginseng C.A. Meyer. (인삼(Panax ginseng C.A. Meyer) 신품종 고풍의 육성경과 및 생육특성)

  • Kwon, Woo-Saeng;Lee, Jang-Ho;Park, Chan-Soo;Yang, Deok-Chun
    • Journal of Ginseng Research
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    • v.27 no.2
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    • pp.86-91
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    • 2003
  • To develop a new ginseng variety with good quality and high yielding, a lot of individual ginseng plant were selected in the farmers'fields in 1968. Among them, a promising line,680-83-4, has been developed through comparative cultivation of several lines selected with pure line separation from local races in KT&C Central Research Institute, preliminary and advanced yield trials were performed fir 8 years.680-83-4 was designated as KG103, which was then registered as a new variety “Gopoong” with the regional yield and adaptation trials for 10 years (1981-1990) on December 27,2000 in Korea. Gopoong has different phenotype of a dark violet stem and dark red fruit and inverted triangle shape of berries cluster as compared with other varieties. Taproot of Gopoong was longer than local race Jakyungjong, and root yield was 4.5% higher than local race Jakyungjong. In red ginseng quality, the rates of Chun-Jeesam grade(Chun and Jee means 1 st and 2nd grade, respectively) were 16.6% and 9.4% for Gopoong and Jakyungjong, respectively. In these results, it was that Gopoong was superior ginseng line with good quality far manufacture of red ginseng.

A Study on the Circadian Rhythm of Opiate Receptor in Rat Brain (백서 뇌내 Opiate 수용체의 일주기 변동에 대한 연구)

  • Lee, Moo-Suck;Kim, Ki-Won;Cho, Kyu-Park
    • The Korean Journal of Pharmacology
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    • v.20 no.2
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    • pp.23-34
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    • 1984
  • To investigate diurnal variations of opiate receptor binding and its modification by experimental condition or treatment of various centrally-acting drugs, the amount of maximum $^3H-morphine$ binding in rat midbrain homogenates was measured at 4 hour intervals for 24 hours. Animals were conditioned under the controlled L : D, 12 : 12 cycle or D: D, 12 : 12 cycle, for 3 weeks and treated with 0.5 ml of physiological saline or drugs for 2 weeks. A highly significant diurnal rhythm with peak at 22 hour of early dark phase with an amplitude$(0.68{\pm}0.06\;pmole/mg\;protein)$ of +51.1% and nadir $(0.33{\pm}0.03\;mole/mg\;prtein)$ at 18 hour of late light phase with an amplitude of -26.6% was found in control group. 24 tour mean of $^3H-morphine$ binding was $0.45{\pm}0.03\;pmole/mg$ protein respectively. Constant dark adaptation or treatment of reserpine, pargyline, imipramine, amphetamine and chlorpromazine modified the diurnal rhythm in the time of peak and nadir binding shape, phase, amplitude of the diurnal curve and 24 hour mean of $^3H-morphine$ binding. However, Kd values were not changed in all experimental groups : Statistical analysis at times of least and great binding indicates that the differences in $^3H-morphine$ binding were due to changes not in the affinity, but in the number of binding sites. The results are interpreted with regard to the diurnal rhythm of opiate receptor finding. The modes of action of psychoactive drugs are closely related to postulated changes of receptor sensitivity in neuropharmacological aspects.

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Breeding of a Seedless Table Grape Cultivar 'Heukisul' (Vitis sp.) with High Quality (고품질 무핵 포도 품종 '흑이슬' 육성)

  • Park, Sung-Min
    • Horticultural Science & Technology
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    • v.29 no.5
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    • pp.507-509
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    • 2011
  • 'Heukisul' (3x) a cross made in 2000 between 'Kyoho' (4x, Vitis sp.) and 'Thompson Seedless' (2x, Vitis vinifera L.) in a seedless grape breeding program, was preliminarily selected in 2004. After regional adaptation testing under the name of 'KTS014' at two sites during 2004-2005, it was finally selected in 2006. 'Heukisul' showed low incidence of berry shattering, resulting in a good berry set compared to 'King Dela'. 'Heukisul' had budburst on April 23, flowering on in June 9, and fruit maturation in September 29 (almost the same as 'King Dela' at Chuncheon), and it was considered a midseason cultivar. The mean berry weight was 4.0 g, about 0.7 g heavier than 'King Dela', and mean soluble solids were $21.9\;^{\circ}Brix$, about $2.7\;^{\circ}Brix$ higher than 'King Dela'. The skin color was dark violet with abundant bloom and the flesh was very firm. Although the cluster was compact, it required no cluster thinning. Also the incidence of berry cracking was very low.

Physiological Studies on Adaptation of Tilapia(Oreochromis miloticus) in the Various Salinities I. Endocrine Changes (틸라피아의 해수순치에 관한 생리학적 연구 I. 내분비학적 변화)

  • 윤종만;조갑민;박홍양
    • Korean Journal of Animal Reproduction
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    • v.16 no.4
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    • pp.353-361
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    • 1993
  • This study was taken to examine external changes, behavioral changes, and endocrine changes such as estradiol-17$\beta$, progesterone, T4 and T3 of female Oreochromis niloticus living in 0$\textperthousand$, 10$\textperthousand$, 20$\textperthousand$, and 30$\textperthousand$ salt concentrations, respectively. The results obtained in these experiments were summarized as follows. In seawater obtained in these experiments were summarized as follows. In seawater challenge test, any fish didn't die in each group such as 10$\textperthousand$, 20$\textperthousand$ and 30$\textperthousand$. When fish were adapted from 0$\textperthousand$ to 10$\textperthousand$, 20$\textperthousand$ and 30$\textperthousand$, external body color of fish changed from dark-striped to light-grey color. At the same time, thyroxine and triiodothyronine concentrations significantly(P<0.05) increased, and then were at the highest level in 30 salinity. When fish were adapted from 0$\textperthousand$ to 10$\textperthousand$, feed intake of fish started from the fourth day. From 0$\textperthousand$ to 10$\textperthousand$, 20$\textperthousand$ and 30$\textperthousand$, estradiol-17$\beta$ levels were increased gradually. When fish was adapted from 0$\textperthousand$ to 10$\textperthousand$, 20$\textperthousand$ and 30$\textperthousand$, the levels of each progesterone didn't show significant change, and especially showed the lowest peak in 20$\textperthousand$. The greatest thyroxine activity(T4) was observed in 30$\textperthousand$. The levels of and triiodothyronine(T3) significantly changed in all salinities, and its level was at the highest peak in 30$\textperthousand$ salinity. Correlation coefficients between serum progesterone and triiodothyronine in 10$\textperthousand$ and 30$\textperthousand$ were +0.677 and +0.843, respectively. Correlation coefficient of serum thyroxine(T4) and triiodothyronine(T3) individuals in 10$\textperthousand$ was +0.768, and +0.843, respectively.

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Diel Horizontal Migration of the Two Mysids Archaeomysis kokuboi and Acanthomysis sp. in the Sandy Shore Surf Zone of Yongil Bay, Eastern Korea (동해 영일만의 모래해변 쇄파대에 사는 곤쟁이류 Archaeomysis kokuboi와 Acanthomysis sp. 두 종의 주야 수평이동)

  • Suh, Hae-Lip;Jo, Soo-Gun;Kim, Kwang-Young
    • 한국해양학회지
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    • v.30 no.6
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    • pp.523-528
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    • 1995
  • The mysids, Archaeomysis kokuboi and Acanthomysis sp., clearly exhibited the diel patterns of interspecific horizontal migration in the surf zone at a sandy shore in Yongil Bay, eastern Korea. Shoreward migration of Acanthomysis sp. at sunset resulted in the presence of significantly high numbers of mysids after dark at the bottom of 1 m depth. At first light, Acanthomysis sp. moved back to deeper water of>1 m depth in conjunction with a reverse migration by A. kokuboi. In the afternoon, A. kokuboi moved to offshore, then these species remained there. Although A. kokuboi has been considered an intertidal species in the exposed beaches with strong wave action, this is not the case in a sandy beach of Yongil Bay. We suggest that evidence for behavioral adaptation comes from the response of k. kokuboi to the sheltered beaches with weak wave action. The habitat shifts presumably provide this species with high availability of food materials in the surf zone.

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Synergism Between Zinc and Taurine in the Visual Sensitivity of the Bullfrog's Eye

  • Kim, Hyun-Jung;Kim, You-Young
    • Journal of Photoscience
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    • v.7 no.3
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    • pp.115-121
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    • 2000
  • Although there are high concentrations of zinc and taurine in ocular tissue, their exact role and correlation in the visual process are not clear. The purpose of present study was to clarity this point using electroretinogram (ERG) recording and spectrophotometer measurements before and after zinc and taurine treatment in bullfrog's eye. The optimal zinc concentration used in this study was 10$^{-2}$ M ZnCl$_2$120 ${mu}ell$/12$m\ell$ ringer solution while the optimal turine concentration was 10$^{-2}$ M taurine 12${mu}ell$/12$m\ell$ ringer solution. For the effects of zinc and taurine on the retinal function, the changes of ERG parameters (especially threshold and b-wave) and absorption spectra were observed before and after treatment. It is noteworthy that high concentrations of zinc and taurine present in the retinal pigment epithelium and the retina. Our results indicate that dark-adapted ERG threshold became elevated and the peak amplitude of b-wave was increased with zinc and taurine treatment. Furthermore there are some synergism effects between zinc and taurine as a result of co-treatment. In spectral scan, absorbance increment due to zinc and taurine treatment was shown over the whole range of spectral range (300-750 nm) with some differences in absorbance increment depending on the case of treatment. As the results of above we believe that zinc and taurine, which are abundant in the retinal pigment epithelium and the retina particularly, may be essential factors for visual process, have some synergism with each other and be required to improve the visual sensitivity during visual adaptation.

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Illustration of Origin of Modern American Society through Coen Brothers: Focused on (코엔형제가 그린 미국 현대사회의 기원: <더 브레이브>를 중심으로)

  • Yoon, Soo-In
    • The Journal of the Korea Contents Association
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    • v.17 no.8
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    • pp.654-666
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    • 2017
  • is a 1968 western novel by Charles Portis. The novel was adapted for screenplay of the 1969 movie of the same name directed by Henry Hathaway. In 2010, Coen brothers directs, writes, and produces the second adaptation of Portis's novel writing most of the script. Of nineteen films directed by Coen brothers, only and are adapted from novel. (released as in Korea), is the only remake of an existing film by Coen brothers. The story plot of the novel or the 1969 or 2010 do not differ greatly, however by emphasizing on different subjects, the character development is slightly altered and in the end, all three are perceived as unique. By comparing what each story is trying to emphasis, examining different cinematic devices, and how it relates to previous worldviews of modern America seen through Coen brothers, portrays a dark society continuously consuming and while illustrating origin of problematic American society.

The Effects of Drugs, including Alcohol, on Ocular Health and Contact Lens Wear (약물과 알코올이 눈과 콘택트렌즈에 미치는 영향)

  • Kim, Jae-Min
    • Journal of Korean Ophthalmic Optics Society
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    • v.5 no.1
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    • pp.73-81
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    • 2000
  • This review on ocular toxicology concentrates on the effects on ocular health and contact lens wear induced by systemically used drugs, including alcohol. Many systemically administered drugs produce ocular adverse effects. Fortunately, relatively few are capable of causing significant, irreversible visual impairment. The visual symptoms of acute intoxication are as follows : Drop in vision/visual acuity, diplopia, poor dark adaptation, increase in time for glare recovery, early cataract, decreased depth perception, blue-yellow or red-green colour defect and visual hallucinations. Blinking pattern, tear production, and discoloration of contact lenses can be affected by some systemic or local ocular medications. The cornea, conjunctiva, or eyelids may react to some systemic medications and to some preservatives used in contact lens solutions. The hydrogel contact lens act as a drug reservoir that emits the drug over time. I discuss management of contact lens-induced infectious and inflammatory conditions.

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Comparison of Shade Changes According to Dry/Wet Condition of Tooth using Intra-Oral Colorimeter (건조정도에 따른 자연치아의 색조비교)

  • Choi, Mee-Ra
    • Journal of Dental Rehabilitation and Applied Science
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    • v.26 no.3
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    • pp.265-271
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    • 2010
  • One of the most important aspect of esthetic dentistry is shade selection. Alterations to perception of color can occur as a result of numerous factors, including light source, tooth surface texture, observer's ability, surrounding colors, the angle of observation, light and dark adaptation and others. During the clinical procedures, tooth might be in dry or semi-dry condition. The purpose of this study was to compare the shade changes in wet and dry conditions of natural tooth. Groups of measurement are an initial wet condition as control, dry in 10seconds, 1 minute, 5minutes and 30seconds air dry. Using Shadeeye, color difference(${\Delta}E$) between measurements were analyzed and there were significant differences between groups. But most of the differneces were <3.7 ${\Delta}E$ unit. Such differences are below the threshold for perceivable color mismathces in intraoral condition. Shade selection with an intraoral colorimeter could be changes in dry and wet condition but there might be no significant differences in visual color mathing.