scholarly journals DERIVED PHOTOSENSITIVE PIGMENTS FROM INVERTEBRATE EYES

1943 ◽  
Vol 26 (4) ◽  
pp. 361-367 ◽  
Author(s):  
Alfred F. Bliss
Keyword(s):  
Absorption Spectrum ◽  
Spectral Sensitivity ◽  
Blue Crab ◽  
Horseshoe Crab ◽  
Light Sensitivity ◽  
Red Pigment ◽  
Difference Absorption Spectrum ◽  
Light Stability ◽  
The Difference ◽  
Difference Absorption

The red pigment in the eyes of the squid, blue crab, and horseshoe crab becomes photosensitive when treated with formalin, and bleaches in the light. The resulting change in density is approximately symmetrical around a maximum at 480 mµ in the blue green. This difference absorption spectrum is in rough agreement with the spectral sensitivity of the cephalopod eye and differs only slightly from the difference absorption spectrum of vertebrate visual purple. The formalin-sensitized pigment is not melanoid. Its bleaching in squid retinas releases large quantities of retinene. It is suggested that the light sensitivity of the normal squid photopigment may be independent of its light stability.

Electroretinographic Determination of Spectral Sensitivity in Albino and Pigmented Brook Trout (Salvelinus fontinalis, Mitchill)

1971 ◽  
Vol 49 (12) ◽  
pp. 1030-1037 ◽  
Author(s):  
H. Kobayashi ◽  
M. A. Ali
Keyword(s):  
Absorption Spectrum ◽  
Spectral Sensitivity ◽  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Narrow Band ◽  
Visible Spectrum ◽  
The Difference

A technique for recording electroretinograms from the unpunctured eyes in situ of living, anesthetized fish is described. This technique permits the use of the same fish in a number of experiments over a period of weeks, months, or years. Using this technique the spectral sensitivity of dark-adapted (scotopic) and light-adapted (photopic) fish was measured at 13 bands of the visible spectrum. The scotopic curves of albino and pigmented trout thus obtained in the winter have their maxima around 525 nm which differ from that of the absorption spectrum of the scotopic pigment in situ and in vitro of older fish obtained in the summer. The photopic curve of the pigmented fish is a broad one with humps around 425 nm, 545 nm, and 595 nm. The albino's curve has a relatively narrow band with a peak around 630 nm and a shoulder at about 550 nm. The difference between the shapes of the two curves may be ascribed to the increase in the intensity of light of longer wavelengths within the eyeball of the albino, due to reflection from blood vessels and sclera caused by the absence of pigmentation.

scholarly journals The Luminosity Curve of the Deuteranomalous Fovea

1968 ◽  
Vol 52 (5) ◽  
pp. 738-749 ◽  
Author(s):  
Mathew Alpern ◽  
Shuko Torii
Keyword(s):  
Absorption Spectrum ◽  
Spectral Sensitivity ◽  
Short Wave ◽  
Dilute Solution ◽  
Red Pigment ◽  
Two Alternatives

Analogous to protans, the two types of deutan color-defectives—the dichromats (deuteranopes) and the anomalous trichromats (deuteranomalous)—do not differ in spectral sensitivity in the red-green range at threshold (either in the dark or against bright colored backgrounds). However, luminosity curves obtained by heterochromatic brightness matching show the latter to be slightly more sensitive in the blue-green, and slightly less so in the red, than the former. Experiment proves that these differences are due (at least in part) to contributions of cones containing the deuteranomalous anomalous pigment which are missing from the deuteranope's eye. The absorption spectrum of the anomalous pigment can be inferred with assumptions (analogous to those already made with protanomalous trichromats) about how the different cone mechanisms pool their responses to yield luminosity. Two alternatives thus revealed are (a) the normal red pigment in dilute solution or (b) a spectrum very similar to that of the normal red pigment but shifted slightly toward the short wave end of the spectrum. Since the spectrum inferred by (a) has the same λmax as the normal red pigment, (a) predicts that deuteranomalous observers will require a negative red primary when matching monochromatic lights of wavelengths near the λmax. This is not observed.

Optical Fiber CO Concentration Measurement Prism of the Gas Chamber Variable Optical Path Automatic Adjustment System Research

2011 ◽  
Vol 109 ◽  
pp. 237-243
Author(s):  
Hong Xiu Zhu ◽  
Hao Zheng ◽  
Hong Bo Zhang ◽  
Xin Wang ◽  
Bo Xi Yang ◽  
...  
Keyword(s):  
Absorption Spectrum ◽  
Optical Fiber ◽  
Light Sensitivity ◽  
Concentration Measurement ◽  
Harmonic Detection ◽  
Feedback Type ◽  
Detection Technology ◽  
Co Concentration ◽  
Adjustment System ◽  
Gas Chamber

According to the absorption spectrum, combined with CO distribution feedback type laser diode (DFB-LD) light source, we selected R a center for 1567.3 nm as the wavelength of the absorption spectrum line. Comprehensively using of prism of gas chamber and harmonic detection technology, we constructed the optical fiber CO concentration measurement system. Through the stepping motor regulation height, it changes indoor prism gas effective absorption process, adjusts the light sensitivity system.

scholarly journals Assessment of Conformational Changes in Low-Sulphur S-Carboxymethylkerateine from Wool

1967 ◽  
Vol 20 (4) ◽  
pp. 827 ◽  
Author(s):  
GM Bhatnagar ◽  
WG Crewther
Keyword(s):  
Absorption Spectrum ◽  
Conformational Changes ◽  
Guanidine Hydrochloride ◽  
Ultraviolet Absorption Spectrum ◽  
Spectral Measurements ◽  
Characteristic Difference ◽  
Concentrated Solutions ◽  
Difference Spectra ◽  
The Difference ◽  
Negative Difference

The effects of urea and guanidine hydrochloride on the ultraviolet absorption spectrum of the low-sulphur S-carboxymethylkerateine fraction of wool have been measured. In concentrated solutions of urea characteristic difference spectra were obtained with maxima of negative absorbance at 288, 280, and 240 miL. The addition of guanidine hydrochloride or an increase in temperature gave similar negative difference maxima at the higher wavelengths. Calculation of the extent of unfolding of the protein chains from the difference in absorbance at all three maxima showed that the unfolding was 50% complete at a urea concentration of about 1� 8M whereas a urea concep.tration of about 4� 3M was required to decrease the helix content by 50%. Similar measurements on components 7 and 8, the two major constituents of SCMKA, showed that a 50% decrease in helix content was obtained with 2�8M and O� 8M urea respectively whereas the corresponding values for 50 % unfolding assessed from difference spectral measurements were 2� 2M and 1� 2M urea respectively. It is suggested that the helical regions of components 7 and 8 aggregate specifically and that spectral measurements relate largely to non-helical portions of the chains.

Light-evoked contraction of red absorbing cones in the Xenopus retina is maximally sensitive to green light

1992 ◽  
Vol 8 (3) ◽  
pp. 243-249 ◽  
Author(s):  
Joseph C. Besharse ◽  
Paul Witkovsky
Keyword(s):  
Xenopus Laevis ◽  
Spectral Sensitivity ◽  
Red Light ◽  
Green Light ◽  
Sensitivity Function ◽  
Direct Mechanism ◽  
Sensitivity Experiments ◽  
Light Stimuli ◽  
The Difference ◽  
Spectral Sensitivity Function

AbstractTo test the hypothesis that light-evoked cone contraction in eye cups from Xenopus laevis is controlled through a direct mechanism initiated by the cone's own photopigment, we conducted spectral-sensitivity experiments. We estimate that initiation of contraction of red absorbing cones (611 nm) is 1.5 log units more sensitive to green (533 nm) than red (650 nm) light stimuli. The difference is comparable to that predicted from the spectral-sensitivity function of the green absorbing, principal rod (523 nm). Furthermore, 480-nm and 580-nm stimuli which are absorbed nearly equally by the principal rod have indistinguishable effects on cone contraction. We also found that light blockade of nighttime cone elongation is much more sensitive to green than to red light stimuli. Our observations are inconsistent with the hypothesis tested, and suggest that light-regulated cone motility is controlled through an indirect mechanism initiated primarily by the green absorbing, principal rod.

scholarly journals Estimasi Produk Degradasi Ekstrak Kasar Pigmen Alga Merah Kappaphycus alvarezii (Doty) Doty Varian Merah, Coklat, dan Hijau: Telaah Perbedaan Spektrum Serapan

2012 ◽  
Vol 17 (1) ◽  
pp. 31
Author(s):  
Helly De Fretes ◽  
A.B. Susanto ◽  
Budi Prasetyo ◽  
Heriyanto Heriyanto ◽  
Tatas H.P. Brotosudarmo ◽  
...  
Keyword(s):  
Light Intensity ◽  
Absorption Spectra ◽  
Degradation Products ◽  
Kappaphycus Alvarezii ◽  
Red Alga ◽  
Before And After ◽  
Heating Treatment ◽  
Pigment Extract ◽  
The Difference ◽  
Difference Absorption

Penelitian ini bertujuan untuk mengestimasi produk degradasi pigmen ekstrak kasar alga merah Kappaphycus alvarezii (Doty) Doty varian merah, coklat dan hijau yang terbentuk selama perlakuan iradiasi dan pemanasan, melalui perbedaan spektrum serapannya. Ketiga varian diekstraksi menggunakan 100% metanol. Uji fotostabilitas ekstrak pigmen dilakukan dengan iradiasi menggunakan lampu Volpi intralux 4100 pada intensitas cahaya 39300 lux, 56700 lux dan 76400 lux.  Lama waktu penyinaran 0, 5, 10, 15, dan 20 menit. Sedangkan uji termostabilitas  dilakukan pada suhu 25 dan 90 ° C selama 0, 3, 6 24, dan 48 jam. Pola spektra diukur pada panjang gelombang 300-800 nm sebelum dan sesudah perlakuan dengan spektrofotometer UV-Tampak Shimadzu 1700. Data dianalisis dengan SPINA Versi 3, untuk memperoleh intensitas maksimum dan perbedaan spektra serapan. Hasil penelitian menunjukkan bahwa produk degradasi pigmen ekstrak kasar alga merah K. alvarezii dapat diidentifikasi melalui spektrum serapan dan hasil perbedaan spektra serapan. Isomer cis karotenoid, karotenoid tidak berwarna, dan feofitin a diestimasi sebagai produk degradasi yang terbentuk selama perlakuan iradiasi dengan intensitas cahaya 76400 lux dan perlakuan pemanasan pada suhu 90°C selama 48 jam. Penurunan intensitas warna larutan pigmen juga mengindikasikan terbentuknya produk degradasi selama perlakuan. Kata kunci: Kappaphycus alvarezii, perbedaan spektrum serapan, produk degradasi The aims of this study were to estimate the degradation products of crude pigment extracts from red, brown, and green varieties of red alga Kappaphycus alverezii (Doty) Doty that formed during irradiation and heating treatment from their difference absorption spectra. All three variants were extracted using 100% methanol. The photostability assay of crude pigment extracts was conducted by irradiating the crude pigment extracts with a day light lamp (Volpi, Intralux 4100) at 39300 lux, 56700 lux and 76400 lux light intensity during 0, 5, 10, 15, and 20 minutes treatment, whereas the thermostability assay was performed at 25 and 90 °C for 0, 3, 6 24, and 48 hours. The absorption spectra of the crude pigment extract before and after each treatment were monitored successively at 300-800 nm using MultiSpec 1501 UV-VIS spectrophotometer. Data were analyzed with spina Version 3, to obtain maximum intensity and the difference absorption spectra. The results showed that the  degradation products of crude pigment extracts from red alga K. alvarezii could be identified by absorption spectra and difference absorption spectra. Cis isomers carotenoids, colorless carotenoids, and feofitin-a were estimated as degradation product formed during the irradiation treatment with 76400 lux of light intensity and heating treatment at a temperature of 90 ° C for 48 hours. Decrease in the intensity of the color of pigment solution also indicates the formation of degradation products during treatment.Key words: Kappaphycus alvarezii, difference absorption spectra, degradation products

scholarly journals Changes in thick filament length in Limulus striated muscle.

1977 ◽  
Vol 75 (2) ◽  
pp. 366-380 ◽  
Author(s):  
M M Dewey ◽  
B Walcott ◽  
D E Colflesh ◽  
H Terry ◽  
R J Levine
Keyword(s):  
Horseshoe Crab ◽  
Striated Muscle ◽  
Thick Filament ◽  
Filament Length ◽  
Thin Filaments ◽  
Thick Filaments ◽  
Wide Range ◽  
The Difference

Here we describe the change in thick filament length in striated muscle of Limulus, the horseshoe crab. Long thick filaments (4.0 microns) are isolated from living, unstimulated Limulus striated muscle while those isolated from either electrically or K+-stimulated fibers are significantly shorter (3.1 microns) (P less than 0.001). Filaments isolated from muscle glycerinated at long sarcomere lengths are long (4.4 microns) while those isolated from muscle glycerinated at short sarcomere lengths are short (2.9 microns) and the difference is significant (P less than 0.001). Thin filaments are 2.4 microns in length. The shortening of thick filaments is related to the wide range of sarcomere lengths exhibited by Limulus telson striated muscle.

Horseshoe crabs as potential sentinel species for coastal health: juvenile haemolymph quality and relationship to habitat conditions

2018 ◽  
Vol 69 (6) ◽  
pp. 894 ◽  
Author(s):  
Billy K. Y. Kwan ◽  
Virginia K. Y. Un ◽  
S. G. Cheung ◽  
Paul K. S. Shin
Keyword(s):  
Horseshoe Crab ◽  
Anthropogenic Activities ◽  
Monitoring Program ◽  
Significant Negative Correlation ◽  
Sentinel Species ◽  
Crab Species ◽  
Horseshoe Crabs ◽  
The Difference ◽  
Lead Nickel ◽  
Further Development

As an interface between terrestrial and marine environments, coastal and estuarine areas are particularly prone to various pollution stresses. Identification of sentinel species is, therefore, essential to provide precautionary information on coastal health conditions. Given their significant ecological roles in estuarine ecosystems, horseshoe crabs are a potential species to indicate the general health status of coastal habitats. The present study demonstrated that the changes in haemolymph composition pattern of two Asian juvenile horseshoe crab species (Tachypleus tridentatus and Carcinoscorpius rotundicauda) are sensitive to reflect heavy metal (lead, nickel and iron) and nutrient (nitrate and ammonia) concentrations of intertidal sediments. In particular, a significant negative correlation was found for the amebocyte viability and ratio of granular–spherical to granular–flattened and degranulated dendritic-like morphological states of amebocytes in juvenile haemolymph with nitrate and lead concentrations respectively. There were also significantly higher concentrations of haemolymph haemocyanin and plasma protein in juvenile C. rotundicauda than in T. tridentatus on the same shore, possibly being related to the difference in foraging habitats of these two horseshoe crab species. Such non-lethal sampling of haemolymph from juvenile horseshoe crabs can be useful for a further development of the monitoring program in assessing potential environmental impacts by anthropogenic activities.

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