scholarly journals Spectral tuning by opsin coexpression in retinal regions that view different parts of the visual field

2014 ◽  
Vol 281 (1797) ◽  
pp. 20141980 ◽  
Author(s):  
Brian E. Dalton ◽  
Ellis R. Loew ◽  
Thomas W. Cronin ◽  
Karen L. Carleton
Keyword(s):  
Visual Field ◽  
Visual Pigment ◽  
Cichlid Fish ◽  
Visual Pigments ◽  
Colour Discrimination ◽  
Spectral Tuning ◽  
Trade Off ◽  
Opsin Genes ◽  
First Time ◽  
Different Parts

Vision frequently mediates critical behaviours, and photoreceptors must respond to the light available to accomplish these tasks. Most photoreceptors are thought to contain a single visual pigment, an opsin protein bound to a chromophore, which together determine spectral sensitivity. Mechanisms of spectral tuning include altering the opsin, changing the chromophore and incorporating pre-receptor filtering. A few exceptions to the use of a single visual pigment have been documented in which a single mature photoreceptor coexpresses opsins that form spectrally distinct visual pigments, and in these exceptions the functional significance of coexpression is unclear. Here we document for the first time photoreceptors coexpressing spectrally distinct opsin genes in a manner that tunes sensitivity to the light environment. Photoreceptors of the cichlid fish, Metriaclima zebra , mix different pairs of opsins in retinal regions that view distinct backgrounds. The mixing of visual pigments increases absorbance of the corresponding background, potentially aiding the detection of dark objects. Thus, opsin coexpression may be a novel mechanism of spectral tuning that could be useful for detecting prey, predators and mates. However, our calculations show that coexpression of some opsins can hinder colour discrimination, creating a trade-off between visual functions.

Status of Family Fissidentaceae in Gujarat

2016 ◽  
Vol 1 (1) ◽  
Author(s):  
D.G. Shah ◽  
D.N. Mehta ◽  
R.V. Gujar
Keyword(s):  
Distinct Species ◽  
The State ◽  
The Other ◽  
Land Plants ◽  
Reproductive Structures ◽  
The Family ◽  
The Status ◽  
Vegetative Characters ◽  
First Time ◽  
Different Parts

Bryophytes are the second largest group of land plants and are also known as the amphibians of the plant kingdom. 67 species of bryophytes have been reported from select locations across the state of Gujrat. The status of family fissidentaceae which is a large moss family is being presented in this paper. Globally the family consists of 10 genera but only one genus, Fissidens Hedw. has been collected from Gujarat. Fissidens is characterized by a unique leaf structure and shows the presence of three distinct lamina, the dorsal, the ventral and the vaginant lamina. A total of 8 species of Fissidens have been reported from the state based on vegetative characters as no sporophyte stages were collected earlier. Species reported from the neighboring states also showed the absence of sporophytes. The identification of different species was difficult due to substantial overlap in vegetative characters. Hence a detailed study on the diversity of members of Fissidentaceae in Gujarat was carried out between November 2013 and February 2015. In present study 8 distinct species of Fissidens have been collected from different parts of the state. Three species Fissidens splachnobryoides Broth., Fissidens zollingerii Mont. and Fissidens curvato-involutus Dixon. have been identified while the other five are still to be identified. Fissidens zollingerii Mont. and Fissidens xiphoides M. Fleisch., which have been reported as distinct species are actually synonyms according to TROPICOS database. The presence of sexual reproductive structures and sporophytes for several Fissidens species are also being reported for the first time from the state.

“Quelques misérables places à remplir”Locating Shaped Painting in Eighteenth-Century France

2017 ◽  
Vol 80 (4) ◽  
pp. 544-571
Author(s):  
David Pullins
Keyword(s):  
Eighteenth Century ◽  
Visual Field ◽  
Decorative Arts ◽  
Relationship Of ◽  
First Time ◽  
The Relationship

Abstract This article addresses in depth for the first time the irregularly shaped canvases known as tableaux chantournés (cut-out paintings) that were produced in vast numbers by leading academicians between the 1730s and 1750s and occupy a tenuous place between fine and applied or decorative arts. Through an examination of the term’s first uses in regard to painting and eighteenth-century critics’ responses to these works, tableaux chantournés are positioned as a means of rethinking the extraction of painting from a richer visual field and the relationship of this medium-specific agenda to the historiography of the rococo.

Shilpakar Mahasabha in Colonial Uttarakhand: Subjective Representation of Collective Self

2021 ◽  
pp. 2455328X2110267
Author(s):  
Isha Tamta
Keyword(s):  
Caste System ◽  
Educational Institutions ◽  
Mutual Aid ◽  
British Raj ◽  
Collective Self ◽  
Lower Castes ◽  
Colonial Government ◽  
First Time ◽  
Subjective Representation ◽  
Different Parts

The caste system in India got transformed as a consequence of the policies of the British Raj. The introduction of the census under the colonial government, among other things, made the most direct impact because for the first time the castes have been enumerated with great details. As a result, castes immediately not only organized themselves but also formed caste associations in order to get their status recorded in the way they thought was honourable to them. Caste associations emerged over the period to pressurize the colonial administration to improve their rank in the census. This process was especially prevalent among the lower castes in different parts of India. Shilpakar Mahashaba was a case in point in Uttarakhand. Shilpakar Mahasabha claimed new advantages from the state like reservations (quotas) in educational institutions and in the civil service. Subsequently, they also became mutual aid structures. Shilpakar Mahasabha founded schools and hostels for the children of Shilpakars and led a sort of co-operative movement. Some have argued that caste associations acted like a collective enterprise with economic, social and political objectives for their caste.

Examination of the field of vision in pregnant women

1926 ◽  
Vol 22 (3) ◽  
pp. 333-335
Author(s):  
N. A. Popova
Keyword(s):  
Visual Field ◽  
Pregnant Women ◽  
International Congress ◽  
Field Of Vision ◽  
First Time

In a report to the International Congress of Ophthalmologists in America, in 1922, Finlay reported for the first time that when examining the eyes of one woman who was in the last month of pregnancy, he accidentally stumbled upon a sharp bilateral temporal narrowing of the visual field, and since there were no he could not detect the phenomenon of moments, he suggested that this narrowing of the field of vision depends on the hypertrophy of the cerebral appendage occurring during pregnancy.

Profesorowie Uniwersytetu Jagiellońskiego: Władysław Chłopicki i Władysław Reiss oraz ich powiązania rodowe, czyli o Krupniczej nieco inaczej

2021 ◽  
Author(s):  
Maria Przybyszewska
Keyword(s):  
Military Leaders ◽  
Family Ties ◽  
Politics And Science ◽  
Tenement House ◽  
The Family ◽  
History Of ◽  
Individual Decisions ◽  
First Time ◽  
Different Parts

The history of the inhabitants of the house at 5 Krupnicza Street in Krakow inspired to write this book, the aim of which is to present the history of two families who came to Krakow from different parts of Poland. The „Pod Matką Boską” tenement house, which has become a life haven for so many generations of Reiss and Chłopicki, including medical professors associated with the Jagiellonian University, is the basis of a much wider story about the intertwining of human lives. Thanks to these circumstances, we restore memory, and we often realise for the first time how far fates of families intertwine and connect with each other. Reaching deeply into the family roots, we not only find numerous family ties, but also appreciate their importance. We also understand better how history influences the course of life and how individual decisions can influence the course of events. The pages of this book will include wellknown and distinguished figures, who have their place in the history of politics and science, as well as doctors, military leaders, politicians. There will be also room for those who cared about family and public matters without publicity, serving current and everyday matters, but without whom great things could not have been fulfiled.

scholarly journals ISLAM DAN TRADISI LOKAL DI NUSANTARA (Telaah Kritis Terhadap Tradisi Pelet Betteng Pada Masyarakat Madura dalam Perspektif Hukum Islam)

2017 ◽  
Vol 13 (2) ◽  
pp. 229
Author(s):  
Buhori Buhori
Keyword(s):  
Islamic Law ◽  
Trade Off ◽  
Islamic Jurisprudence ◽  
Local Tradition ◽  
First Time

Abstract Religion and culture are main elements in an interconnected society. When a religion enters a community, there will be a trade-off between the religion and culture e.g. when Islam is descended at Arab which has old tradition. Tradition is part of culture, for that it is not a surprise that every country has tradition including Indonesia. One of Indonesian local tradition is madurese tradition: Pelet Betteng or Pelet Kandhung or Peret Kandung or Salamenddhen Kandhungan which constitutes a pregnancy ritual. It is held by making du’a and giving alms in the fourth or seventh month of pregnancy period of a woman who is pregnant for the first time (seriyang). According to sharia perspective, Islam presents without ignoring Arabian tradition (`adah) and convention. They are even considered as sources of Islamic jurisprudence with particular limitations. Therefore, the term of `adat which has a similar meaning to `uruf, has become a basic of istinbath hukm.Keywords: Islam, Local Tradition, Islamic Law.  Abstrak Agama dan budaya merupakan dua unsur penting dalam masyarakat yang saling mempengaruhi. Ketika ajaran agama masuk dalam sebuah komunitas yang berbudaya, akan terjadi tarik menarik antara kepentingan agama di satu sisi dengan kepentingan budaya di sisi lain. Demikian juga halnya dengan agama Islam yang diturunkan di tengah-tengah masyarakat Arab yang memiliki adat-istiadat dan tradisi secara turun-temurun. Tradisi merupakan bagian dari budaya. Salah satu tradisi lokal yang melekat erat dalam kehidupan masyarakat Indonesia, khususnya suku Madura adalah Pelet Betteng,atau terkadang dikenal dengan sebutan Pelet Kandhung atau Peret Kandung atau Salameddhen Kandhungan, yangsecara sederhana diartikan sebagai pijat kandungan atau selamatan kehamilan. Tradisi ini merupakan upacara selamatan yang dilakukan dengan cara pembacaan do`a-do`a dan sedekah, ketika seorang wanita tengah mengandung pertama kalinya (Madura: seriyang) pada saat usia kehamilan mencapai empat bulanatau tujuh bulan.Dalam persepektif hukum Islam, ternyata ajaran Islam sangat memperhatikan tradisi (Arab: `adah) dan konvensi masyarakat untuk dijadikan sumber bagi jurisprudensi hukum Islam dengan penyempurnaan dan batasan-batasan tertentu.Terma `adat yang memiliki kesamaan makna dengan `uruf telahmenjadi salah satu landasan dalam istinbat hukum Islam.Kata Kunci: Islam, Tradisi Lokal, Hukum Islam.

Spectral absorbance, structure, and population density of photoreceptors in the retina of the lake sturgeon (Acipenser fulvescens)

2007 ◽  
Vol 85 (4) ◽  
pp. 584-587 ◽  
Author(s):  
A.J. Sillman ◽  
E.K. Ong ◽  
E.R. Loew
Keyword(s):  
Visual Pigment ◽  
Visual Pigments ◽  
Lake Sturgeon ◽  
Acipenser Fulvescens ◽  
Long Wavelength ◽  
Rods And Cones ◽  
The North ◽  
Spectral Absorbance ◽  
Dim Light ◽  
Scanning Electron

Lake sturgeon ( Acipenser fulvescens Rafinesque, 1817) photoreceptors were studied with scanning electron microscopy and microspectrophotometry. The retina contains both rods and cones, with cones estimated composing about 30% of the photoreceptor population. Only large single cones were identified and they are similar to those found in other species of the order Acipenseriformes. The rods are large, with long, broad outer segments, and are similar to the dominant rod found in other sturgeons and the North American paddlefish ( Polyodon spathula (Walbaum, 1792)). Mean (SD) rod packing density at 22 624 ± 3 509 rods/mm2 is low compared with those of other animals that function primarily in dim light. The visual pigment of the rods has a mean (SD) peak absorbance (λmax) at 541 ± 2 nm. Three different cone populations were identified: a long wavelength sensitive cone containing a visual pigment with λmax at 619 ± 3 nm; middle wavelength sensitive cone with λmax at 538 ± 1 nm; and short wavelength sensitive cone with λmax at 448 ± 1 nm. All the visual pigments are based on the vitamin A2 chromophore.

Molecular identification of cyst-forming nematodes (Heteroderidae) from Iran and a phylogeny based on ITS-rDNA sequences

Nematology ◽  
2003 ◽  
Vol 5 (1) ◽  
pp. 99-111 ◽  
Author(s):  
Zahra Tanha Maafi ◽  
Sergei Subbotin ◽  
Maurice Moens
Keyword(s):  
Phylogenetic Analyses ◽  
Species Level ◽  
Its Rdna ◽  
Heterodera Avenae ◽  
Published Data ◽  
Rdna Sequences ◽  
First Time ◽  
Group Species ◽  
High Support ◽  
Different Parts

Abstract RFLP and sequences of ITS-rDNA of 45 populations of cyst-forming nematodes collected from different parts of Iran were analysed and identified as representatives of 21 species. Eight enzymes generated RFLP for all studied populations. Comparison of RFLP profiles and sequences of the ITS regions with published data confirmed the presence of Heterodera avenae, H. filipjevi, H. glycines, H. hordecalis, H. latipons, H. schachtii and H. trifolii in Iran. RFLP patterns and ITS sequences for H. elachista, H. turcomanica, H. mothi and C. cacti were obtained for the first time in this study. Heterodera humuli, H. goettingiana, H. fici, H. elachista, H. turcomanica and Cactodera cacti are recorded for the first time in Iran. These results correspond with morphological and morphometric identification of the populations. Several populations were not identified at the species level and are attributed to Heterodera sp.; some of these may correspond to new species. Twenty-one new sequences from Iranian cyst-forming nematodes and 36 known sequences were used for the phylogenetic analyses. The cyst-forming nematodes formed several clades corresponding to their morphological features. Heterodera mothi and H. elachista clustered with high support with other Cyperi group species and H. turcomanica formed a moderately to highly supported clade with the Humuli group.

The photoreceptors and visual pigments in the retina of the white sturgeon, Acipenser transmontanus

1990 ◽  
Vol 68 (7) ◽  
pp. 1544-1551 ◽  
Author(s):  
A. J. Sillman ◽  
M. D. Spanfelner ◽  
E. R. Loew
Keyword(s):  
Vitamin A ◽  
Visual Pigment ◽  
Visual Pigments ◽  
Spectrophotometric Analysis ◽  
White Sturgeon ◽  
Acipenser Transmontanus ◽  
Light Regimen ◽  
Cone Pigment ◽  
Spectral Absorbance

The photoreceptors in the retina of the white sturgeon, Acipenser transmontanus (Chondrostei), were studied by means of scanning electron microscopy, in situ microspectrophotometry, and spectrophotometric analysis of visual pigment extracts. The white sturgeon retina is simple in that it contains only two morphologically distinct photoreceptors. The retina is dominated by rods with large outer segments, but there is a substantial population (40%) of single cones. Evidence was found for only one rod visual pigment and one cone visual pigment. Peak spectral absorbance (λmax) of the rod pigment is near 539 nm, whereas λmax of the cone pigment is near 605 nm. Both visual pigments are porphyropsin types with chromophores based on vitamin A2. No detectable rhodopsin based on vitamin A1 is ever present, regardless of season or light regimen. The results are discussed in terms of the sturgeon's behavior, as well as the implications for the evolution of color vision.

Sign in / Sign up

Export Citation Format

Share Document