Melanocortin systems on pigment dispersion in fish chromatophores.

Science.gov (United States)

Kobayashi, Yuki; Mizusawa, Kanta; Saito, Yumiko; Takahashi, Akiyoshi

2012-01-01

α-Melanocyte-stimulating hormone (α-MSH) is responsible for pigment dispersion in the chromatophores of fish and other tetrapods such as amphibians and reptiles. Recently, we discovered that α-MSH did not always stimulate pigment dispersion because this hormonal peptide exerted no effects on the melanophores of flounders. We assumed that the reduction of α-MSH activity was related to the co-expression of different α-MSH receptor subtypes - termed melanocortin receptors (MCR) - a member of G-protein-coupled receptors (GPCR) - based on several reports demonstrating that GPCR forms heterodimers with various properties that are distinct from those of the corresponding monomers. In this review, we summarize the relationships between the pigment-dispersing activity of α-MSH-related peptides, molecular forms of α-MSH-related peptides, and mcr subtypes expressed in fish chromatophores.

Pigment dispersion syndrome: a clinical study.

Science.gov (United States)

Scheie, H G; Cameron, J D

1981-01-01

This study involved a group of 407 patients (799 eyes) with pigment dispersion syndrome gathered from a glaucoma population of 9200 patients. The sex distribution was equal. The majority (65%) of patients were myopic. The incidence of retinal detachment was 6.4%. No patients were black, but 5 were mulatto. Approximately one-quarter of the patients wih pigment dispersion syndrome (31% of the men, 19% of the women) had glaucoma. The average age of onset of glaucoma was 15 years less than in control patients with chronic simple glaucoma. When both eyes were affected by glaucoma, the glaucoma was consistently more severe in the eye with the more heavily pigmented angle. The degree of iris transillumination was found to be of no importance in predicting the presence of glaucoma or the severity of trabecular pigmentation. The pressure in 66% of the eyes with pigmentary glaucoma was controlled medically. A higher percentage of patients with pigmentary glaucoma required surgery than patients in the control group with chronic simple glaucoma. Men with pigmentary glaucoma required surgery at a much earlier age than women with pigmentary glaucoma. PMID:7236571

Corneal collagen crosslinking and pigment dispersion syndrome.

Science.gov (United States)

LaHood, Benjamin R; Moore, Sacha

2017-03-01

We describe the case of a keratoconus patient with pigment dispersion syndrome (PDS) who was treated for progressive corneal ectasia with corneal collagen crosslinking (CXL). Pigment dispersion syndrome has been shown to have associated morphologic changes of the corneal endothelium. Corneal CXL has the potential to cause toxicity to the corneal endothelium, and adjacent pigment might increase the likelihood of damage. In this case, the presence of PDS had no detrimental effect on the outcome of treatment, and no complications were observed at 12 months follow-up, indicating that it may be safe to perform corneal CXL in the setting of PDS. This is an important observation as the number of indications for corneal CXL grows. Copyright © 2017 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

Melanocortin systems on pigment dispersion in fish chromatophores

Directory of Open Access Journals (Sweden)

Yuki eKobayashi

2012-02-01

Full Text Available Alpha-Melanocyte-stimulating hormone (alpha-MSH is responsible for pigment dispersion in the chromatophores of fish and other tetrapods such as amphibians and reptiles. Recently, we discovered that alpha-MSH did not always stimulate pigment dispersion because this hormonal peptide exerted no effects on the melanophores of flounders. We assumed that the reduction of alpha-MSH activity was related to the co-expression of different alpha-MSH receptor subtypes—termed melanocortin receptors (MCR—a member of G-protein-coupled receptors (GPCR—based on several reports demonstrating that GPCR forms heterodimers with various properties that are distinct from those of the corresponding monomers. In this review, we summarize the relationships between the pigment-dispersing activity of alpha-MSH-related peptides, molecular forms of alpha-MSH-related peptides, and Mcr subtypes expressed in fish chromatophores.

The role of the lens in pigment dispersion syndrome.

Science.gov (United States)

Liu, Lance

2010-12-01

In patients with pigment dispersion syndrome, changes of the iris configuration can occur with accommodation, blinking, miotics, and following a laser iridotomy. This observational case series looks at the changes following cataract surgery in 3 eyes with signs of pigment dispersion, symptomatic cataracts, and no previous laser iridotomy that were imaged with optical coherence tomography. The iris was concave posteriorly in dark and light lighting conditions, and became flat following an uncomplicated cataract operation. This may be explained by the elimination of iridolenticular contact, which contributes to the mechanism of reverse pupil block. These iris changes suggest the lens plays an important role in the mechanism of pigment dispersion. Copyright 2010, SLACK Incorporated.

The pigmentation of powder coatings with the use of block copolymer dispersants

NARCIS (Netherlands)

Duivenvoorde, F.L.; Nostrum, van C.F.; Linde, van der R.

1999-01-01

The dispersing of pigments in powder coatings is a difficult and complicated process. The incomplete dispersion under standard extrusion conditions can be attributed to a combination of poor pigment wetting and insufficient disruption of the pigment agglomerates, as a result of the rheological

What is the risk of developing pigmentary glaucoma from pigment dispersion syndrome?

Science.gov (United States)

Siddiqui, Yasmin; Ten Hulzen, Richard D; Cameron, J Douglas; Hodge, David O; Johnson, Douglas H

2003-06-01

To determine the probability of converting from pigment dispersion syndrome to pigmentary glaucoma. Retrospective community-based study of all newly diagnosed cases of pigment dispersion syndrome or pigmentary glaucoma. Subjects were patients newly diagnosed with pigment dispersion syndrome or pigmentary glaucoma from 1976 to 1999 in Olmsted County, Minnesota. Criteria for pigment dispersion syndrome were two of three signs: midperipheral, radial iris transillumination defects; Krukenberg spindle; heavy trabecular meshwork pigmentation. Criteria for pigmentary glaucoma were pigment dispersion syndrome and two of three findings: intraocular pressure (IOP) greater than 21 mm, optic nerve damage, or visual field loss. Kaplan-Meier survival curves were used to determine the probability of conversion to pigmentary glaucoma. A total of 113 patients were newly diagnosed with pigment dispersion syndrome over the 24-year period. Of these, 9 persons developed pigmentary glaucoma or elevated IOP requiring therapy. The probability of converting to pigmentary glaucoma was 10% at 5 years and 15% at 15 years. An additional 23 patients were found to have pigmentary glaucoma at their initial examination. The mean age at diagnosis of pigmentary glaucoma was 42 +/- 12 years; 78% of patients were male, whereas 58% of patients with pigmentary dispersion syndrome glaucoma were male. The most significant risk factor for conversion to pigmentary glaucoma was an IOP greater than 21 mm Hg at initial examination, whereas age, refractive error, and family history of glaucoma were not correlated with conversion. The risk of developing pigmentary glaucoma from pigment dispersion syndrome was 10% at 5 years and 15% at 15 years. Young, myopic men were most likely to have pigmentary glaucoma. An IOP greater than 21 mm Hg at initial examination was associated with an increased risk of conversion.

Advanced pigment dispersion glaucoma secondary to phakic intraocular collamer lens implant

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Clara Ye

2018-06-01

Full Text Available Purpose: We report a case of pigment dispersion glaucoma secondary to uncomplicated phakic intraocular collamer lens (ICL (Visian ICL™, Staar Inc., Monrovia, CA implant that resulted in advanced visual field loss. Observations: A 50-year-old man presented for routine follow-up status post bilateral phakic intraocular collamer lens (ICL placement 8 years earlier. He was incidentally found to have a decline in visual acuity from an anterior subcapsular cataract and elevated intraocular pressure (IOP in the left eye. There were signs of pigment dispersion and no evidence of angle closure. Diffuse optic nerve thinning was consistent with advanced glaucomatous visual field defects. Pigment dispersion was also present in the patient's right eye, but without elevated IOP or visual field defects. The patient was treated with topical glaucoma medications and the phakic ICL in the left eye was removed concurrently with cataract surgery to prevent further visual field loss. Conclusions and importance: Pigment dispersion glaucoma is a serious adverse outcome after phakic ICL implantation and regular post-operative monitoring may prevent advanced visual field loss. Keywords: Phakic intraocular lens, Intraocular collamer lens, Pigment dispersion, Glaucoma

Intraocular pressure spike after YAG iridotomy in patients with pigment dispersion.

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Birt, Catherine M

2004-04-01

The role of laser peripheral iridotomy to break a suspected reverse pupil block in the long-term control of pigment dispersion is promising, but the usefulness of this procedure has not been completely established. The author examined whether patients with pigment dispersion are at higher risk for an intraocular pressure (IOP) spike after laser peripheral iridotomy due to possible compromise of trabecular meshwork function, compared with patients undergoing prophylactic peripheral iridotomy for an occludable angle. Data were collected prospectively on the first eye of 87 patients with occludable angles and 13 patients with pigment dispersion treated with peripheral laser iridotomy between November 1995 and October 1996 at the glaucoma service of a university-affiliated hospital in Toronto. All patients received one drop of 0.5% apraclonidine before the procedure. IOP was measured before and 1 and 24 hours after the procedure. There was no difference between the two groups in the distribution of right vs. left eyes, sex, race, the mean total energy required to produce a patent iridotomy, the mean number of medications used or the mean IOP before the procedure. The patients with pigment dispersion were significantly younger than those with occludable angles (mean age [and standard deviation (SD)] 40.5 [9.45] years vs. 66.4 [10.78] years) (p pigment dispersion group had an IOP spike greater than 2 mm Hg after the procedure (p = 0.001). Among these patients, the mean IOP (36.4 [SD 10.83] mm Hg vs. 30.3 [SD 7.04] mm Hg, p = 0.05) and the mean rise in IOP (14.0 [SD 10.63] mm Hg vs. 8.7 [SD 4.73] mm Hg, p = 0.04) were significantly higher in those with pigment dispersion than in those with occludable angles. Among the patients who used antiglaucoma medications before the procedure or had a prelaser IOP level greater than 22 mm Hg, those with pigment dispersion were more likely than those with occludable angles to have an IOP spike at 1 hour (p pigment dispersion

Mathematical modeling of pigment dispersion taking into account the full agglomerate particle size distribution

DEFF Research Database (Denmark)

Kiil, Søren

2017-01-01

The purpose of this work is to develop a mathematical model that can quantify the dispersion of pigments, with a focus on the mechanical breakage of pigment agglomerates. The underlying physical mechanism was assumed to be surface erosion of spherical pigment agglomerates. The full agglomerate pa.......g., in the development of novel dispersion principles and for analysis of dispersion failures. The general applicability of the model, beyond the three pigments considered, needs to be confirmed....

[Is prophylactic YAG iridotomy useful in pigment dispersion syndrome?].

Science.gov (United States)

Rosentreter, A; Schwenn, O; Funk, J; Dietlein, T

2013-04-01

Despite theoretical considerations concerning the advantage of iridotomy in eyes with pigment dispersion syndrome or early pigment glaucoma, there is a lack of clinical evidence that this procedure has a long-term effect in preventing glaucoma damage under these circumstances. However, several factors may contribute to this lack of evidence, e.g. the statistical problem of a low conversion rate from pigment dispersion syndrome to pigment glaucoma or the inclusion criteria in the studies treating patients older than 40 years or genetic dispositions in pigment glaucoma that are not yet fully clear. On the basis of current data the decision for YAG iridotomy should only be taken in patients younger than 40 years, if the midperipheral iris shows an inverse bowing and the intraocular pressure is normal or slightly increased with no progressive signs of optic nerve damage. In cases of insufficient intraocular pressure and visual defects due to glaucomatous optic nerve damage, incisional glaucoma surgery is usually necessary especially in younger patients with a long life expectancy.

Multispectral diagnostic imaging of the iris in pigment dispersion syndrome.

Science.gov (United States)

Roberts, Daniel K; Lukic, Ana; Yang, Yongyi; Wilensky, Jacob T; Wernick, Miles N

2012-08-01

To determine if wavelength selection with near infrared iris imaging may enhance iris transillumination defects (ITDs) in pigment dispersion syndrome. An experimental apparatus was used to acquire iris images in 6 African-American (AA) and 6 White patients with pigment dispersion syndrome. Light-emitting diode probes of 6 different spectral bands (700 to 950 nm) were used to project light into patients' eyes. Iris patterns were photographed, ITD regions of interest were outlined, and region of interest contrasts were calculated for each spectral band. Contrasts varied as a function of wavelength (Ppigmented eyes may be slightly longer than for less pigmented eyes.

A single gene causes an interspecific difference in pigmentation in Drosophila.

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Ahmed-Braimah, Yasir H; Sweigart, Andrea L

2015-05-01

The genetic basis of species differences remains understudied. Studies in insects have contributed significantly to our understanding of morphological evolution. Pigmentation traits in particular have received a great deal of attention and several genes in the insect pigmentation pathway have been implicated in inter- and intraspecific differences. Nonetheless, much remains unknown about many of the genes in this pathway and their potential role in understudied taxa. Here we genetically analyze the puparium color difference between members of the virilis group of Drosophila. The puparium of Drosophila virilis is black, while those of D. americana, D. novamexicana, and D. lummei are brown. We used a series of backcross hybrid populations between D. americana and D. virilis to map the genomic interval responsible for the difference between this species pair. First, we show that the pupal case color difference is caused by a single Mendelizing factor, which we ultimately map to an ∼11-kb region on chromosome 5. The mapped interval includes only the first exon and regulatory region(s) of the dopamine N-acetyltransferase gene (Dat). This gene encodes an enzyme that is known to play a part in the insect pigmentation pathway. Second, we show that this gene is highly expressed at the onset of pupation in light brown taxa (D. americana and D. novamexicana) relative to D. virilis, but not in the dark brown D. lummei. Finally, we examine the role of Dat in adult pigmentation between D. americana (heavily melanized) and D. novamexicana (lightly melanized) and find no discernible effect of this gene in adults. Our results demonstrate that a single gene is entirely or almost entirely responsible for a morphological difference between species. Copyright © 2015 by the Genetics Society of America.

Update on pigment dispersion syndrome and pigmentary glaucoma.

Science.gov (United States)

Okafor, Kingsley; Vinod, Kateki; Gedde, Steven J

2017-03-01

The present article reviews the clinical features and pathogenesis of pigment dispersion syndrome and pigmentary glaucoma and provides an update regarding their diagnosis and management. Newer imaging modalities including ultrasound biomicroscopy and anterior segment optical coherence tomography facilitate visualization of the iris concavity characteristic of eyes with pigment dispersion syndrome and pigmentary glaucoma. Patients with pigmentary glaucoma may be distinguished from those with other glaucoma types by the presence of typical symptoms, personality type, and patterns of diurnal intraocular pressure fluctuation. Although laser iridotomy has been shown to alter iris anatomy in pigmentary glaucoma, it is not proven to slow visual field progression. Multiple trials have validated the safety and efficacy of filtering surgery in treating pigmentary glaucoma, with fewer studies published on the role of micro-invasive glaucoma surgery. Literature from the review period has further defined the unique clinical characteristics of pigment dispersion syndrome and pigmentary glaucoma. Laser surgery has a limited role in the management of these entities, whereas trabeculectomy remains an acceptable first-line surgical treatment. Further studies are needed to define the potential application of the newer micro-invasive glaucoma procedures in pigmentary glaucoma.

Advanced pigment dispersion glaucoma secondary to phakic intraocular collamer lens implant.

Science.gov (United States)

Ye, Clara; Patel, Cajal K; Momont, Anna C; Liu, Yao

2018-06-01

We report a case of pigment dispersion glaucoma secondary to uncomplicated phakic intraocular collamer lens (ICL) (Visian ICL™, Staar Inc., Monrovia, CA) implant that resulted in advanced visual field loss. A 50-year-old man presented for routine follow-up status post bilateral phakic intraocular collamer lens (ICL) placement 8 years earlier. He was incidentally found to have a decline in visual acuity from an anterior subcapsular cataract and elevated intraocular pressure (IOP) in the left eye. There were signs of pigment dispersion and no evidence of angle closure. Diffuse optic nerve thinning was consistent with advanced glaucomatous visual field defects. Pigment dispersion was also present in the patient's right eye, but without elevated IOP or visual field defects. The patient was treated with topical glaucoma medications and the phakic ICL in the left eye was removed concurrently with cataract surgery to prevent further visual field loss. Pigment dispersion glaucoma is a serious adverse outcome after phakic ICL implantation and regular post-operative monitoring may prevent advanced visual field loss.

Properties of alginate fiber spun-dyed with fluorescent pigment dispersion.

Science.gov (United States)

Wang, Ping; Tawiah, Benjamin; Tian, Anli; Wang, Chunxia; Zhang, Liping; Fu, Shaohai

2015-03-15

Spun-dyed alginate fiber was prepared by the spun-dyeing method with the mixture of fluorescent pigment dispersion and sodium alginate fiber spinning solution, and its properties were characterized by SEM, TGA, DSC, and XRD. The results indicate that fluorescent pigment dispersion prepared with esterified poly (styrene-alt maleic acid) had excellent compatibility with sodium alginate fiber spinning solution, and small amount of fluorescent pigment could reduce the viscosity of spun-dyed spinning solutions. SEM photo of spun-dyed alginate fiber indicated that fewer pigment particles deposited on its surface. TGA, DSC, and XRD results suggested that thermal properties and crystal phase of spun-dyed alginate fibers had slight changes compared to the original alginate fibers. The fluorescence intensity of spun-dyed alginate fiber reached its maximum when the content of fluorescent pigment was 4%. The spun-dyed alginate fiber showed excellent rubbing and washing fastness. Copyright © 2014 Elsevier Ltd. All rights reserved.

Central posterior capsule pigmentation in a patient with pigment dispersion and previous ocular trauma: a case report.

Science.gov (United States)

Al-Mezaine, Hani S

2010-01-01

We report a 55-year-old man with unusually dense, unilateral central posterior capsule pigmentation associated with the characteristic clinical features of pigment dispersion syndrome, including a Krukenberg's spindle and dense trabecular pigmentation in both eyes. A history of an old blunt ocular trauma probably caused separation of the anterior hyaloid from the back of the lens, thereby creating an avenue by which pigment could reach the potential space of Berger's from the posterior chamber.

Pigment dispersion syndrome and pigmentary glaucoma--a major review.

Science.gov (United States)

Niyadurupola, Nuwan; Broadway, David C

2008-12-01

Pigment dispersion syndrome (PDS) is an interesting condition that can lead to secondary open angle glaucoma. Pigmentary glaucoma is primarily a disease of young people, myopes and men. PDS is characterized by the presence of Krukenberg spindles, iris trans-illumination defects, trabecular meshwork pigmentation and backward bowing of the iris. Posterior bowing of the iris causes rubbing of the pigmented iris epithelium against lens structures, liberation of pigment and trabecular meshwork changes that result in reduced aqueous outflow with the risk of glaucoma. Peripheral laser iridotomy can reverse backward bowing of the iris and may prevent progression of pigmentary glaucoma.

Ultraviolet Radiation Induces Dose-Dependent Pigment Dispersion in Crustacean Chromatophores

OpenAIRE

Gouveia, Glauce Ribeiro; Lopes, Thaís Martins; Neves, Carla Amorim; Nery, Luiz Eduardo Maia; Trindade, Gilma Santos

2004-01-01

Pigment dispersion in chromatophores as a response to UV radiation was investigated in two species of crustaceans, the crab Chasmagnathus granulata and the shrimp Palaemonetes argentinus. Eyestalkless crabs and shrimps maintained on either a black or a white background were irradiated with different UV bands. In eyestalkless crabs the significant minimal effective dose inducing pigment dispersion was 0.42 J/cm2 for UVA and 2.15 J/cm2 for UVB. Maximal response was achieved with 10.0 J/cm...

Synchronized Bilateral Synaptic Inputs to Drosophila melanogaster Neuropeptidergic Rest/Arousal Neurons

DEFF Research Database (Denmark)

McCarthy, E. V.; Wu, Y.; deCarvalho, T.

2011-01-01

Neuropeptide PDF (pigment-dispersing factor)-secreting large ventrolateral neurons (lLN(v)s) in the Drosophila brain regulate daily patterns of rest and arousal. These bilateral wake-promoting neurons are light responsive and integrate information from the circadian system, sleep circuits...

A genome-wide, fine-scale map of natural pigmentation variation in Drosophila melanogaster.

Directory of Open Access Journals (Sweden)

Héloïse Bastide

2013-06-01

Full Text Available Various approaches can be applied to uncover the genetic basis of natural phenotypic variation, each with their specific strengths and limitations. Here, we use a replicated genome-wide association approach (Pool-GWAS to fine-scale map genomic regions contributing to natural variation in female abdominal pigmentation in Drosophila melanogaster, a trait that is highly variable in natural populations and highly heritable in the laboratory. We examined abdominal pigmentation phenotypes in approximately 8000 female European D. melanogaster, isolating 1000 individuals with extreme phenotypes. We then used whole-genome Illumina sequencing to identify single nucleotide polymorphisms (SNPs segregating in our sample, and tested these for associations with pigmentation by contrasting allele frequencies between replicate pools of light and dark individuals. We identify two small regions near the pigmentation genes tan and bric-à-brac 1, both corresponding to known cis-regulatory regions, which contain SNPs showing significant associations with pigmentation variation. While the Pool-GWAS approach suffers some limitations, its cost advantage facilitates replication and it can be applied to any non-model system with an available reference genome.

A genome-wide, fine-scale map of natural pigmentation variation in Drosophila melanogaster.

Science.gov (United States)

Bastide, Héloïse; Betancourt, Andrea; Nolte, Viola; Tobler, Raymond; Stöbe, Petra; Futschik, Andreas; Schlötterer, Christian

2013-06-01

Various approaches can be applied to uncover the genetic basis of natural phenotypic variation, each with their specific strengths and limitations. Here, we use a replicated genome-wide association approach (Pool-GWAS) to fine-scale map genomic regions contributing to natural variation in female abdominal pigmentation in Drosophila melanogaster, a trait that is highly variable in natural populations and highly heritable in the laboratory. We examined abdominal pigmentation phenotypes in approximately 8000 female European D. melanogaster, isolating 1000 individuals with extreme phenotypes. We then used whole-genome Illumina sequencing to identify single nucleotide polymorphisms (SNPs) segregating in our sample, and tested these for associations with pigmentation by contrasting allele frequencies between replicate pools of light and dark individuals. We identify two small regions near the pigmentation genes tan and bric-à-brac 1, both corresponding to known cis-regulatory regions, which contain SNPs showing significant associations with pigmentation variation. While the Pool-GWAS approach suffers some limitations, its cost advantage facilitates replication and it can be applied to any non-model system with an available reference genome.

Secondary pigmentary glaucoma in patients with underlying primary pigment dispersion syndrome

OpenAIRE

Sivaraman, Kavitha R; Patel, Chirag G; Vajaranant, Thasarat S; Aref, Ahmad A

2013-01-01

Kavitha R Sivaraman, Chirag G Patel, Thasarat S Vajaranant, Ahmad A ArefDepartment of Ophthalmology and Visual Sciences, Illinois Eye and Ear Infirmary, University of Illinois at Chicago School of Medicine, Chicago, IL, USAAbstract: Primary pigment dispersion syndrome (PPDS) is a bilateral condition that occurs in anatomically predisposed individuals. PPDS may evolve into pigmentary glaucoma, but it is difficult to predict which patients will progress. Secondary pigment dispersion is more oft...

Central posterior capsule pigmentation in a patient with pigment dispersion and previous ocular trauma: A case report

Directory of Open Access Journals (Sweden)

Al-Mezaine Hani

2010-01-01

Full Text Available We report a 55-year-old man with unusually dense, unilateral central posterior capsule pigmentation associated with the characteristic clinical features of pigment dispersion syndrome, including a Krukenberg′s spindle and dense trabecular pigmentation in both eyes. A history of an old blunt ocular trauma probably caused separation of the anterior hyaloid from the back of the lens, thereby creating an avenue by which pigment could reach the potential space of Berger′s from the posterior chamber.

Iris coloboma in one eye and pigment dispersion syndrome in the fellow eye.

Science.gov (United States)

Galvis, Virgilio; Tello, Alejandro; Valarezo, Paul; Prada, Angélica M

2013-05-22

We report a case of a 43-year-old patient with coloboma of the iris, zonule, ciliary body, choroid and retina in the right eye and pigment dispersion syndrome in the left eye. Considering the hypothesis of the pigment dispersion syndrome pathogenesis in which a difference of pressures in the anterior and posterior chambers creates a posterior convexity of the iris leading to reverse pupillary block, iris touch and consequently causing pigment dispersion, we suggest that the presence of an iris coloboma, by equalising the pressures in the two chambers, prevented the onset of syndrome in that eye.

Pigment dispersion syndrome associated with spontaneous subluxation of crystalline lens

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Vikas Veerwal

2017-01-01

Full Text Available Pigment dispersion syndrome (PDS is an ocular condition characterized by a dispersion of iris pigment throughout the eye. This pigment is deposited in a characteristic manner on the corneal endothelium as Krukenberg's spindle, anterior surface of the iris, in the trabecular meshwork, on the lens and zonule and occasionally on the anterior hyaloid face. Even with deposition of pigment on zonular fibers, no zonular weakness, or zonular dehiscence has been reported in these cases. We report a unique case of PDS with bilateral spontaneous subluxation of crystalline lens. With characteristic findings of pigment distribution in both his eyes, the patient had concave iris configuration with heavily pigmented trabecular meshwork confirming the diagnosis of PDS. The patient had bilateral 180° temporal subluxation of crystalline lens in both his eyes. The usual cause of lens subluxation such as Marfan's Syndrome and Ehler's Danlos Syndrome was ruled out. The patient underwent right eye followed by left eye intracapsular cataract extraction with ab-interno technique with postoperative best-corrected visual acuity (BCVA of 6/9 in both eyes. Spontaneous subluxation of crystalline lens in isolated PDS is not known to occur and has been reported by means of this case. We recommend a thorough assessment of zonular status in all cases of PDS.

Pigment dispersion syndrome associated with spontaneous subluxation of crystalline lens.

Science.gov (United States)

Veerwal, Vikas; Goyal, Jawahar Lal; Jain, Parul; Arora, Ritu

2017-01-01

Pigment dispersion syndrome (PDS) is an ocular condition characterized by a dispersion of iris pigment throughout the eye. This pigment is deposited in a characteristic manner on the corneal endothelium as Krukenberg's spindle, anterior surface of the iris, in the trabecular meshwork, on the lens and zonule and occasionally on the anterior hyaloid face. Even with deposition of pigment on zonular fibers, no zonular weakness, or zonular dehiscence has been reported in these cases. We report a unique case of PDS with bilateral spontaneous subluxation of crystalline lens. With characteristic findings of pigment distribution in both his eyes, the patient had concave iris configuration with heavily pigmented trabecular meshwork confirming the diagnosis of PDS. The patient had bilateral 180° temporal subluxation of crystalline lens in both his eyes. The usual cause of lens subluxation such as Marfan's Syndrome and Ehler's Danlos Syndrome was ruled out. The patient underwent right eye followed by left eye intracapsular cataract extraction with ab-interno technique with postoperative best-corrected visual acuity (BCVA) of 6/9 in both eyes. Spontaneous subluxation of crystalline lens in isolated PDS is not known to occur and has been reported by means of this case. We recommend a thorough assessment of zonular status in all cases of PDS.

Pigment deposition on the central aspect of the posterior lens capsule in pigmentary dispersion.

Science.gov (United States)

Nagarajaiah, Shubha; Shun-Shin, Georges Adrien

2011-01-01

We describe a case of an increasing pigmentary plaque on the posterior surface of the lens during follow-up of a case of pigment dispersion syndrome and suggest that this is a new sign of pigment dispersion.

Pigment deposition on the central aspect of the posterior lens capsule in pigmentary dispersion

OpenAIRE

Nagarajaiah, Shubha; Shun-Shin, Georges Adrien

2011-01-01

We describe a case of an increasing pigmentary plaque on the posterior surface of the lens during follow-up of a case of pigment dispersion syndrome and suggest that this is a new sign of pigment dispersion.

Pigment dispersion syndrome associated with optic nerve melanocytoma.

Science.gov (United States)

Asorey-García, A; Méndez-Hernández, C D; Santos-Bueso, E; García-Feijoo, J

2015-10-01

A 60-year old patient was referred for cataract surgery. The examination showed retrokeratic pigment in the left eye, which had an intraocular pressure of 24 mm Hg. The funduscopy showed a brown lesion on the left optic disk, with adjacent vitreous seeding of pigment. The patient was thus diagnosed with secondary pigment dispersion syndrome due to optic disk melanocytoma. Although melanocytoma is most commonly a benign, stationary tumor, it may present with major complications leading to significant visual loss. A patient with melanocytoma of the optic disk should be examined periodically. Copyright © 2014 Sociedad Española de Oftalmología. Published by Elsevier España, S.L.U. All rights reserved.

Canine goniodysgenesis-related glaucoma: a morphologic review of 100 cases looking at inflammation and pigment dispersion.

Science.gov (United States)

Reilly, Christopher M; Morris, Rebecca; Dubielzig, Richard R

2005-01-01

To investigate the role of pigment dispersion and inflammation in the pathogenesis of goniodysgenesis-related glaucoma (GDRG). Cases of GDRG were selected when the duration of the disease was specified and there was not any confounding pathology. Cases were grouped into 7-day (chronic) durations, based on the time required to effect end-stage retinal damage. Acute cases were further divided into pigment dispersion: segmental loss of posterior iris pigment epithelium, clumping of posterior iris pigment epithelium, pigmented cells in the trabecular meshwork or anterior chamber and preferential settling of pigmented cells in the ventral aspect of the iridocorneal angle. Slides were also evaluated for the presence of neutrophils and/or lymphoplasmacytic cells in the trabecular meshwork (TM). Differences between groups were analyzed statistically. Of 100 cases evaluated, 34 were 7-days (chronic) in duration. Of all globes examined, 96% had at least one sign of pigment dispersion, with no significant difference between groups. Two or more signs of pigment dispersion were present in 76% of all globes. The 4-7-day group was significantly more likely than the 7-day groups. Neutrophils were present in the TM of 86% of 7-day cases to have neutrophils in the TM, with 65% and 17% [corrected] positive cases, respectively. Lymphoplasmacytic inflammation was present in 53% of all cases, with no significant difference between groups. Cases in the 7-day cases to have both types of inflammation. Our results indicate that both acute inflammation and pigment dispersion may be key factors in the pathogenesis of GDRG. Pigment dispersion is prevalent at all time points and increases during the first 7 days. The finding of iris pigment epithelial loss supports the theory that pupillary block associated with iris-lens touching may be important in the pathogenesis of GDRG.

Electrochromic coatings made of surface modified rutile and anatase pigments: Influence of trisilanol POSS dispersant on electrochromic effect

Energy Technology Data Exchange (ETDEWEB)

Mihelčič, Mohor [National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana (Slovenia); Francetič, Vojmir [Faculty of Chemistry and Chemical Technology, University of Ljubljani, Aškerčeva cesta 5, 1000 Ljubljana (Slovenia); Pori, Pavli [Chemcolor Sevnica d.o.o., Dolenje Brezovo 35, 8290 Sevnica (Slovenia); Gradišar, Helena [National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana (Slovenia); Kovač, Janez [Jožef Stefan Institute., Jamova 39, SI-1000 Ljubljana (Slovenia); Orel, Boris, E-mail: boris.orel@ki.si [National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana (Slovenia); CO-NOT, Hajdrihova 19, Ljubljana (Slovenia)

2014-09-15

Graphical abstract: - Highlights: • Transparent pigmented coatings were deposited from titania dispersions. • Trisilanol POSS was used as dispersant. • Surface modification of pigment particles was established from TEM, TG and IR. • IR spectra studies revealed covalent and H-bond dispersant/pigment interactions. • Electrochromic properties of titanina pigment coatings were shown and discussed. - Abstract: Polyhedral oligomeric silsesqioxanes (POSS) compounds consisting of [RSiO{sub 3/2}]{sub n} groups organized in the form of various polyhedra (T{sub n}, n = 3, 6, 8, 10, 12, ….) have not often been used as pigment surface modifiers. Their interactions with pigments are not known in detail and coatings deposited from pigments modified by POSS dispersants are rare. Identification of interactions between a dispersant and the surface of pigments is important from the point of view of obtaining stable pigment dispersions enabling the deposition of optical coatings with high pigment loading, low haze and mechanical integrity. Thin TiO{sub 2} (anatase) pigment coatings (70–260 nm) were deposited from pigment dispersions prepared by milling metatitanic acid (mTiA) powder agglomerates with trisilanol heptaisobutyl silsesquioxane dispersant (trisilanol POSS) in butanol and hexane. The results of TEM, EDAX and TG measurements confirmed the influence of trisilanol POSS dispersant on the formation of a dispersion with a uniform distribution of mTiA and rutile (mTiR) nanoparticles with a size of about 30 ± 5.0 nm and 90 ± 5.0 nm, respectively, as determined from dynamic light scattering (DLS) measurements. The mTiA/trisilanol POSS dispersions with added titanium tetraisopropoxide were deposited on fluorine-doped tin oxide (FTO) coated glass (spin-coating) and indium tin oxide coated polymeric substrate (ITO PET) (coil-coating) and thermally treated at 150 °C. UV–vis spectra, AFM and SEM results showed that the pigment coatings exhibited low haze (up to 6

Electrochromic coatings made of surface modified rutile and anatase pigments: Influence of trisilanol POSS dispersant on electrochromic effect

International Nuclear Information System (INIS)

Mihelčič, Mohor; Francetič, Vojmir; Pori, Pavli; Gradišar, Helena; Kovač, Janez; Orel, Boris

2014-01-01

Graphical abstract: - Highlights: • Transparent pigmented coatings were deposited from titania dispersions. • Trisilanol POSS was used as dispersant. • Surface modification of pigment particles was established from TEM, TG and IR. • IR spectra studies revealed covalent and H-bond dispersant/pigment interactions. • Electrochromic properties of titanina pigment coatings were shown and discussed. - Abstract: Polyhedral oligomeric silsesqioxanes (POSS) compounds consisting of [RSiO 3/2 ] n groups organized in the form of various polyhedra (T n , n = 3, 6, 8, 10, 12, ….) have not often been used as pigment surface modifiers. Their interactions with pigments are not known in detail and coatings deposited from pigments modified by POSS dispersants are rare. Identification of interactions between a dispersant and the surface of pigments is important from the point of view of obtaining stable pigment dispersions enabling the deposition of optical coatings with high pigment loading, low haze and mechanical integrity. Thin TiO 2 (anatase) pigment coatings (70–260 nm) were deposited from pigment dispersions prepared by milling metatitanic acid (mTiA) powder agglomerates with trisilanol heptaisobutyl silsesquioxane dispersant (trisilanol POSS) in butanol and hexane. The results of TEM, EDAX and TG measurements confirmed the influence of trisilanol POSS dispersant on the formation of a dispersion with a uniform distribution of mTiA and rutile (mTiR) nanoparticles with a size of about 30 ± 5.0 nm and 90 ± 5.0 nm, respectively, as determined from dynamic light scattering (DLS) measurements. The mTiA/trisilanol POSS dispersions with added titanium tetraisopropoxide were deposited on fluorine-doped tin oxide (FTO) coated glass (spin-coating) and indium tin oxide coated polymeric substrate (ITO PET) (coil-coating) and thermally treated at 150 °C. UV–vis spectra, AFM and SEM results showed that the pigment coatings exhibited low haze (up to 6%), low surface

New Yellow Synergist for Stable Pigment Dispersion of Inkjet Ink.

Science.gov (United States)

Song, Gihyun; Lee, Hayoon; Jung, Hyocheol; Kang, Seokwoo; Park, Jongwook

2018-02-01

Minimizing ink droplet and self-dispersed pigment mixture are becoming hot issues for high resolution of inkjet printing. New synergist including sulfonic acid group of PY-74 was suggested and synthesized. Pigment itself did not show water solubility but new synergist, SY-11 exhibited good solubility in water and organic solvents such as DMSO and DMF. When aqueous pigment ink was prepared with SY-11, storage stability of the ink has been remained for 7 days under periodically repeated heating and cooling conditions. Particle size of formulated ink was around 150 nm.

[Pigment dispersion and Artisan implants: crystalline lens rise as a safety criterion].

Science.gov (United States)

Baikoff, G; Bourgeon, G; Jodai, H Jitsuo; Fontaine, A; Vieira Lellis, F; Trinquet, L

2005-06-01

To validate the theoretical notion of a crystalline lens rise as a safety criterion for ARTISAN implants in order to prevent the development of pigment dispersion in the implanted eye. Crystalline lens rise is defined by the distance between the crystalline lens's anterior pole and the horizontal plane joining the opposite iridocorneal recesses. We analyzed the biometric measurements of 87 eyes with an Artisan implant. A comparative analysis of the crystalline lens rise was carried out on the nine eyes having developed pigment dispersion and 78 eyes with no problems. Among the modern anterior segment imaging devices (Artemis, Scheimpflug photography, optical coherence tomography, radiology exploration, magnetic resonance imaging, TDM), an anterior chamber optical coherence tomography (AC-OCT) prototype was used. This working hypothesis was confirmed by this study: the crystalline lens rise must be considered as a new safety criterion for implanting Artisan phakic lenses. Indeed, the higher the crystalline lens's rise, the greater the risk of developing pigment dispersion in the pupil area. This complication is more frequent in hyperopes than in myopes. We can consider that there is little or no risk of pigment dispersion if the rise is below 600 microm; however, at 600 microm or greater, there is a 67% rate of pupillary pigment dispersion. In certain cases, when the implant was loosely fixed, there was no traction on the iris root. This is a complication that can be avoided or delayed. The crystalline lens rise must be part of new safety criteria to be taken into consideration when inserting an Artisan implant. This notion must also be applied to other types of phakic implants. The distance remaining between the crystalline lens rise and a 600-micromm theoretical safety level allows one to calculate a safety time interval.

Two novel deletions (array CGH findings) in pigment dispersion syndrome.

Science.gov (United States)

Mikelsaar, Ruth; Molder, Harras; Bartsch, Oliver; Punab, Margus

2007-12-01

We report the first male with pigment dispersion syndrome and a balanced translocation t(10;15)(p11.1;q11.1). Cytogenetic analyses using Giemsa banding and FISH methods, and array CGH were performed. Array CGH analyses did not show altered DNA sequences in the breakpoints of the translocation, but revealed two novel deletions in 2q22.1 and 18q22.1. We suppose that the coexistence of t(10;15) and pigment dispersion syndrome in our patient is a coincidence. The deletion in 2q22.1, where the gene LRP1B has been located, may play a major role in the dysembryogenesis of the eye and cause the disorder.

Lattice degeneration of the retina and the pigment dispersion syndrome.

Science.gov (United States)

Weseley, P; Liebmann, J; Walsh, J B; Ritch, R

1992-11-15

Retinal detachment occurs more frequently in patients with pigment dispersion syndrome. We evaluated the incidence of peripheral retinal abnormalities known to predispose to rhegmatogenous retinal detachment in a consecutive series of 60 patients with pigment dispersion syndrome with or without glaucoma. Lattice degeneration was present in at least one eye of 12 patients (20%). Seven patients had bilateral lesions. Full-thickness retinal breaks were found in seven patients (11.7%) and two patients (3.3%) had asymptomatic rhegmatogenous retinal detachments that required scleral buckle procedures. The incidence of lattice degeneration and full-thickness retinal breaks appears to be increased in this group of patients, and may be responsible for the increased risk of rhegmatogenous detachment.

Pigment dispersion and Artisan phakic intraocular lenses: crystalline lens rise as a safety criterion.

Science.gov (United States)

Baïkoff, Georges; Bourgeon, Grégoire; Jodai, Horacio Jitsuo; Fontaine, Aline; Lellis, Fernando Viera; Trinquet, Laure

2005-04-01

To validate the theory that crystalline lens rise can be used as a safety criterion to prevent pigment dispersion in eyes with an Artisan phakic intraocular lens (IOL) (Ophtec BV). Monticelli Clinic, Marseilles, France. A comparative analysis of crystalline lens rise in 9 eyes with pigment dispersion and 78 eyes without dispersion was performed. All eyes had previous implantation of an Artisan IOL. Anterior segment imaging was done using an anterior chamber optical coherence tomography (AC OCT) prototype. Crystalline lens rise was defined by the distance between the anterior pole of the crystalline lens and the horizontal plane joining the opposite iridocorneal recesses. The study confirmed that crystalline lens rise can be considered a safety criterion for implantation of Artisan-type phakic IOLs. The higher the crystalline lens rise, the greater the risk for developing pigment dispersion in the area of the pupil. This complication occurred more frequently in hyperopic eyes than in myopic eyes. Results indicate there is little or no risk for pigment dispersion if the rise is less than 600 microm; 67% of eyes with a rise of 600 microm or more developed pupillary pigment dispersion. In some cases in which the IOL was loosely fixated, there was no traction on the iris root and dispersion was prevented or delayed. Crystalline lens rise should be considered a new safety criterion for Artisan phakic IOL implantation and should also be applied to other types of phakic IOLs. The distance remaining between the crystalline lens rise and a 600 microm theoretical safety level allows one to calculate how long the IOL can safely remain in the eye.

Clinical characteristics of pigment dispersion syndrome in Chinese patients.

Science.gov (United States)

Qing, G; Wang, N; Tang, X; Zhang, S; Chen, H

2009-08-01

To report clinical findings and characteristics of pigment dispersion syndrome (PDS) in Chinese patients. PDS suspects with any one of the following signs: corneal endothelial pigmentation, iris transillumination defects (ITDs), pigment granule dusting on anterior iris surface, posterior iris bowing, trabecular meshwork (TM) pigmentation, and lenticular or zonular pigmentation were evaluated for PDS at the glaucoma specialty clinic at Beijing Tongren Eye Centre. Diagnosis of PDS required at least two of the following signs: Krukenberg spindle, moderate-to-heavy TM pigmentation (>or=Scheie II) and any degree of lenticular and/or zonular pigmentation. Eighteen patients (12 males and six females) were identified as having PDS during a 1-year period, with mean age of 35.5+/-7.0 years (range, 22-49). All but two eyes from two patients had myopia of -0.5 D or greater, with mean spherical equivalent power of -5.20+/-5.80 D (range, -24.75+/-0.5). The average IOP at initial diagnosis was 33.7+/-10.5 mm Hg (range, 16-56). Fifteen patients (83.3%) were found to have pigmentary glaucoma at their initial diagnosis. All patients showed homogenous increased TM pigmentation as well as lenticular and/or zonular pigmentation. 61.1% of patients (11 of 18) had Krukenberg spindle. None of the patients exhibited spoke-like midperipheral ITDs except for trace-isolated transillumination in both eyes of the two patients. The most common clinical findings in Chinese PDS patients include homogeneous TM pigmentation and pigment granule dusting on lens zonules and/or posterior peripheral lens surface. ITDs are uncommon in Chinese patients with PDS.

Methods and principles of pigment dispersing to maximize ink opacity and performance

International Nuclear Information System (INIS)

Schaeffer, W.R.

1999-01-01

Four classes of oligomers were evaluated for their pigment dispersing capabilities. These include and aliphatic urethanes, epoxy acrylates, polyesters and a novel class of acrylated resins. This will show that surface tension and chemical structure are major factors influencing pigment and final ink performance properties

The characterisation of magnetic pigment dispersions using pulsed magnetic fields

International Nuclear Information System (INIS)

Blackwell, J.J.; O'Grady, K.; Nelson, N.K.; Sharrock, M.P.

2003-01-01

In this work, we describe the application of pulsed field magnetometry techniques for the characterisation of magnetic pigment dispersions. Magnetic pigment dispersions are important technological materials as in one form they are the material which are used to coat base film in order to make magnetic recording tape. It is these materials that have been evaluated. In this work, we describe the use of two pulsed field magnetometers, one being a low-field instrument with a maximum field of 750 Oe and the other a high-field instrument with a maximum field of 4.1 kOe. Using inductive sensing, the magnetisation is monitored in real time as the pulse is applied. We find that using these techniques we can successfully monitor the progress of the dispersion process, the effects of different resin systems and the effect of different processing conditions. We find that our results are consistent with rheological and other measurements

The characterisation of magnetic pigment dispersions using pulsed magnetic fields

Energy Technology Data Exchange (ETDEWEB)

Blackwell, J.J.; O' Grady, K. E-mail: kog1@york.ac.uk; Nelson, N.K.; Sharrock, M.P

2003-10-01

In this work, we describe the application of pulsed field magnetometry techniques for the characterisation of magnetic pigment dispersions. Magnetic pigment dispersions are important technological materials as in one form they are the material which are used to coat base film in order to make magnetic recording tape. It is these materials that have been evaluated. In this work, we describe the use of two pulsed field magnetometers, one being a low-field instrument with a maximum field of 750 Oe and the other a high-field instrument with a maximum field of 4.1 kOe. Using inductive sensing, the magnetisation is monitored in real time as the pulse is applied. We find that using these techniques we can successfully monitor the progress of the dispersion process, the effects of different resin systems and the effect of different processing conditions. We find that our results are consistent with rheological and other measurements.

Quantitative analysis of pigment dispersion taking into account the full agglomerate size distribution

OpenAIRE

Kiil, Søren

2017-01-01

This work concerns the development of simulation tools for mapping of pigment dispersion. Focus has been on the mechanical breakage of pigment agglomerates. The underlying physical mechanism was assumed to be surface erosion of spherical pigment agglomerates, and the full agglomerate particle size distribution was simulated. Data from previous experimental investigations with organic pigments were used for model validation.When the linear rate of agglomerate surface erosion was taken to be pr...

Traumatic glaucoma with features of unilateral pigment dispersion.

Science.gov (United States)

Bowler, Gordon; Ellul, Antony; Gouws, Pieter

2014-01-01

We report a patient with traumatic glaucoma with features of unilateral pigment dispersion. This rare form of secondary glaucoma has only been reported twice previously, with both patients demonstrating angle recession, indicating associated damage to the trabecular meshwork. To our knowledge, this is the first such case reported in which angle recession was absent.

Drosophila Vps16A is required for trafficking to lysosomes and biogenesis of pigment granules.

Science.gov (United States)

Pulipparacharuvil, Suprabha; Akbar, Mohammed Ali; Ray, Sanchali; Sevrioukov, Evgueny A; Haberman, Adam S; Rohrer, Jack; Krämer, Helmut

2005-08-15

Mutations that disrupt trafficking to lysosomes and lysosome-related organelles cause multiple diseases, including Hermansky-Pudlak syndrome. The Drosophila eye is a model system for analyzing such mutations. The eye-color genes carnation and deep orange encode two subunits of the Vps-C protein complex required for endosomal trafficking and pigment-granule biogenesis. Here we demonstrate that dVps16A (CG8454) encodes another Vps-C subunit. Biochemical experiments revealed a specific interaction between the dVps16A C-terminus and the Sec1/Munc18 homolog Carnation but not its closest homolog, dVps33B. Instead, dVps33B interacted with a related protein, dVps16B (CG18112). Deep orange bound both Vps16 homologs. Like a deep orange null mutation, eye-specific RNAi-induced knockdown of dVps16A inhibited lysosomal delivery of internalized ligands and interfered with biogenesis of pigment granules. Ubiquitous knockdown of dVps16A was lethal. Together, these findings demonstrate that Drosophila Vps16A is essential for lysosomal trafficking. Furthermore, metazoans have two types of Vps-C complexes with non-redundant functions.

Pigment dispersion syndrome and pigmentary glaucoma: a review and update.

Science.gov (United States)

Scuderi, Gianluca; Contestabile, Maria Teresa; Scuderi, Luca; Librando, Aloisa; Fenicia, Vito; Rahimi, Siavash

2018-05-02

Potential factors influencing stereopsis were investigated in patients with both refractive accommodative esotropia (RAE) and amblyopia. Pigment dispersion syndrome (PDS) is a condition where anomalous iridozonular contact leads to pigment dispersion throughout the anterior segment and the released pigment is abnormally deposited on various ocular structures. The clinical presentation of PDS is defined by the presence of pigmented cells on the corneal endothelium, an increase of pigmentation of the trabecular meshwork, and mid-periphery transillumination defects of the iris. This syndrome, more common in myopes, is usually bilateral and can be associated with ocular hypertension or glaucoma. Secondary open-angle pigmentary glaucoma (PG) can develop due to reduction of the outflow of aqueous humour and consequent increase in intraocular pressure leading to glaucomatous optic neuropathy. Diagnosis of PG is commonly between 40 and 50 years of age, occurring more frequently in men. The advent of ultrasound biomicroscopy and anterior segment optical coherence tomography has contributed to enhancing our knowledge on the condition. Typical alterations of the anterior segment are the posterior insertion of the iris and iris concavity. Treatment of PG should be initiated early to hinder disease progression, glaucomatous damage, and vision loss. Management is based on medical therapy, laser iridotomy, selective laser trabeculoplasty, and filtration procedures. The differential diagnosis of PDS with other disorders can be challenging and awareness of the condition together with meticulous ophthalmologic examination allows early diagnosis followed by appropriate management strategies. The present review is a comprehensive report on the clinical characteristics, pathogenesis, current management, and status quo of PDS and PG.

The influence of paint dispersion parameters on the spectral selectivity of black-pigmented coatings

Energy Technology Data Exchange (ETDEWEB)

Gunde, M.K.; Orel, Z.C. [National Institute of Chemistry, Ljubljana (Slovenia); Hutchins, M.G. [Oxford Brookes University, Oxford (United Kingdom). School of Engineering

2003-10-31

The optical properties of variously prepared black-pigmented solar absorbing paints were calculated in terms of their effective absorption and scattering abilities. The phenomenological two-parameter Kubelka-Munk effective medium theory was applied. Paints with the same composition were prepared for different degrees of pigment dispersion and characterized by the average size of pigment agglomerates present in the pigment/vehicle system. Prepared paints were applied to aluminium foil in two ways, by coil coating and by spraying. The size of coarse pigment particles and the paint application technique influence the spectral selectivity and thus determine the final performance of spectrally selective surfaces. (author)

Pigment-dispersing factor modulates pheromone production in clock cells that influence mating in Drosophila

NARCIS (Netherlands)

Krupp, Joshua J.; Billeter, Jean-Christophe; Wong, Amy; Choi, Charles; Nitabach, Michael N.; Levine, Joel D.

2013-01-01

Social cues contribute to the circadian entrainment of physiological and behavioral rhythms. These cues supplement the influence of daily and seasonal cycles in light and temperature. In Drosophila, the social environment modulates circadian mechanisms that regulate sex pheromone production and

Pupal development and pigmentation process of a polka-dotted fruit fly, Drosophila guttifera (Insecta, Diptera).

Science.gov (United States)

Fukutomi, Yuichi; Matsumoto, Keiji; Agata, Kiyokazu; Funayama, Noriko; Koshikawa, Shigeyuki

2017-06-01

Various organisms have color patterns on their body surfaces, and these color patterns are thought to contribute to physiological regulation, communication with conspecifics, and signaling with the environment. An adult fly of Drosophila guttifera (Insecta: Diptera: Drosophilidae) has melanin pigmentation patterns on its body and wings. Though D. guttifera has been used for research into color pattern formation, how its pupal development proceeds and when the pigmentation starts have not been well studied. In this study, we defined the pupal stages of D. guttifera and measured the pigment content of wing spots from the pupal period to the period after eclosion. Using a transgenic line which carries eGFP connected with an enhancer of yellow, a gene necessary for melanin synthesis, we analyzed the timing at which the yellow enhancer starts to drive eGFP. We also analyzed the distribution of Yellow-producing cells, as indicated by the expression of eGFP during pupal and young adult periods. The results suggested that Yellow-producing cells were removed from wings within 3 h after eclosion, and wing pigmentation continued without epithelial cells. Furthermore, the results of vein cutting experiments showed that the transport of melanin precursors through veins was necessary for wing pigmentation. These results showed the importance of melanin precursors transported through veins and of extracellular factors which were secreted from epithelial cells and left in the cuticle.

Pigment-Dispersing Factor-expressing neurons convey circadian information in the honey bee brain

Science.gov (United States)

Beer, Katharina; Kolbe, Esther; Kahana, Noa B.; Yayon, Nadav; Weiss, Ron; Menegazzi, Pamela; Bloch, Guy

2018-01-01

Pigment-Dispersing Factor (PDF) is an important neuropeptide in the brain circadian network of Drosophila and other insects, but its role in bees in which the circadian clock influences complex behaviour is not well understood. We combined high-resolution neuroanatomical characterizations, quantification of PDF levels over the day and brain injections of synthetic PDF peptide to study the role of PDF in the honey bee Apis mellifera. We show that PDF co-localizes with the clock protein Period (PER) in a cluster of laterally located neurons and that the widespread arborizations of these PER/PDF neurons are in close vicinity to other PER-positive cells (neurons and glia). PDF-immunostaining intensity oscillates in a diurnal and circadian manner with possible influences for age or worker task on synchrony of oscillations in different brain areas. Finally, PDF injection into the area between optic lobes and the central brain at the end of the subjective day produced a consistent trend of phase-delayed circadian rhythms in locomotor activity. Altogether, these results are consistent with the hypothesis that PDF is a neuromodulator that conveys circadian information from pacemaker cells to brain centres involved in diverse functions including locomotion, time memory and sun-compass orientation. PMID:29321240

Combined Laser Treatment in a Patient with Pigment Dispersion Secondary to a Large Iris Pigment Epithelial Cyst

Directory of Open Access Journals (Sweden)

Özlem Yıldırım

2012-09-01

Full Text Available We reported a case of bilateral extensive iris pigment epithelial cysts masquerading as pigment dispersion. A-30-year-old male patient presented with a dull pain in both eyes and a decreased visual acuity OD. He underwent a complete ophthalmic examination. OD was injected and the cells were graded as +3 and pigmented a +2, in the OS. Intraocular pressures (IOP were measured as 42 (OD and 22 (OS mmHg. Gonioscopy revealed a confluent accumulation of dense pigment in both eyes. Visual fields, peripapillary retinal nerve fiber layer thickness (Spectral OCT/SLO OTI-OPKO Health. Inc, Miami, FL and optic nerve head tomography (HRT-II Heidelberg Engineering, Heidelberg, Germany results were within normal limits. On ultrasound biomicroscopy (UBM, bilateral extensive cysts were identified in the midzonal portion of the iris and in the ciliary body. An, antiglaucomatous treatment was started. Then, we decided to perform both Nd:YAG laser iridocystotomyc and selective laser trabeculoplasty. Fourteen months after the combined therapy, the cysts had not recurred, and still apposed and the IOPs were under control without medication.

Combined laser treatment in a patient with pigment dispersion secondary to a large iris pigment epithelial cyst.

Science.gov (United States)

Aykan, Umit; Yıldırım, Ozlem

2012-09-01

We reported a case of bilateral extensive iris pigment epithelial cysts masquerading as pigment dispersion. A-30-year-old male patient presented with a dull pain in both eyes and a decreased visual acuity OD. He underwent a complete ophthalmic examination. OD was injected and the cells were graded as +3 and pigmented a +2, in the OS. Intraocular pressures (IOP) were measured as 42 (OD) and 22 (OS) mmHg. Gonioscopy revealed a confluent accumulation of dense pigment in both eyes. Visual fields, peripapillary retinal nerve fiber layer thickness (Spectral OCT/SLO OTI-OPKO Health. Inc, Miami, FL) and optic nerve head tomography (HRT-II Heidelberg Engineering, Heidelberg, Germany) results were within normal limits. On ultrasound biomicroscopy (UBM), bilateral extensive cysts were identified in the midzonal portion of the iris and in the ciliary body. An, antiglaucomatous treatment was started. Then, we decided to perform both Nd:YAG laser iridocystotomyc and selective laser trabeculoplasty. Fourteen months after the combined therapy, the cysts had not recurred, and still apposed and the IOPs were under control without medication.

Temporal evolution of intraocular pressure elevation after pupillary dilation in pigment dispersion syndrome.

Science.gov (United States)

Jewelewicz, Daniel A; Radcliffe, Nathan M; Liebmann, Jeffrey; Ritch, Robert

2009-03-01

To report 4 patients with pigment dispersion syndrome (PDS) who had delayed intraocular pressure (IOP) spikes after pharmacologic pupillary dilation. Four patients with a diagnosis of PDS with documented IOP spike after pharmacologic pupillary dilation were included. Study patients were examined before and after pupillary dilation. The amount of pigment present in the anterior chamber and the IOP were measured at hourly intervals. Although maximal pigment liberation occurred immediately after maximal dilation, the IOP continued to elevate for at least 1.5 hours. The increase in IOP after pupillary dilation may not occur simultaneously with maximal pigment liberation but may follow it after the pigment has settled out of the anterior chamber. This has implications for monitoring patients with PDS after dilation to detect and treat rises in IOP.

Improvement of Dispersion and Color Effect of Organic Pigments in Polymeric Films via Microencapsulation by the Miniemulsion Technique

Directory of Open Access Journals (Sweden)

Dongming Qi

2013-01-01

Full Text Available Three primary pigment/poly(n-butyl acrylate-co-styrene (P(BA+St nanocomposites were prepared via encapsulation of the corresponding organic pigments via the miniemulsion technique. The resulting latexes of the P(BA+St/pigment nanocomposites were filmed in a PTFE mould or printed onto cotton fabric. The morphology of the P(BA+St/pigment nanocomposites and the dispersion of pigment particles in the latex film and on the printed fabric surface, as well as the adhesion between pigment and adhesive film, were evaluated by transmission electron microscopy (TEM, field emission scanning electron microscopy (FESEM, 3D digital microscope system (3D-POM, and printing results tests. Attributing to the preprotection of adhesive polymer shell, the self-adhesive P(BA+St/pigment nanocomposites were homogeneously and firmly dispersed both in the thin latex film and in the adhesive layer on the fiber surface. As a result, the color strength, color fastness, and handle of the fabrics printed by the P(BA+St/pigment nanocomposites latex were significantly improved, compared to the fabrics printed by the conventional pigment blended latex.

Pigment dispersion and chronic intraocular pressure elevation after sulcus placement of 3-piece acrylic intraocular lens.

Science.gov (United States)

Almond, M Camille; Wu, Michael C; Chen, Philip P

2009-12-01

A 55-year-old man had phacoemulsification and implantation of a 3-piece acrylic intraocular lens (IOL) (AcrySof MA60AC) in the right eye. One month postoperatively, the intraocular pressure (IOP) was 48 mm Hg and peripheral transillumination defects were noted in the iris circumferentially, with the IOL optic edge visible as a silhouette. Gonioscopy showed dense pigmentation of the trabecular meshwork in the right eye, but in the left eye, only mild trabecular meshwork pigment was seen, along with a concave peripheral iris insertion. At 21 months, the right eye required 3 medications for IOP control. While pigment dispersion has been widely reported after placement of 1-piece acrylic IOLs in the ciliary sulcus, we conclude that in susceptible individuals with a concave peripheral iris insertion, pigment dispersion can occur with sulcus placement of a 3-piece acrylic model despite its thinner optic and angulated haptics.

A comparison of interocular differences in patients with pigment dispersion syndrome.

Science.gov (United States)

Yip, Leonard W; Sothornwit, Nisa; Berkowitz, Jonathan; Mikelberg, Frederick S

2009-01-01

Pigment dispersion syndrome (PDS) and pigmentary glaucoma (PG) are characterized by loss of iris pigment because of reverse pupillary block. The loss of iris pigment is manifested as transillumination defects. Differences in ocular anatomy have been found between subjects with PDS and controls. Our study aims to see if differences in interocular anatomic features are also related to differences in the quantity of transillumination defects between eyes. This is an observational case series of 30 eyes of 15 subjects with PDS/PG in at least 1 eye. Patients underwent refraction, exophthalmometry, corneal and anterior chamber analysis by Pentacam, biometry, A-scan, ultrasound biomicroscopy, and anterior segment digital photography. The Pentacam mean central radii of the posterior corneal surface (cornea back Rm), vertical central radius of curvature of the posterior corneal surface (cornea back Rv), and keratometric power deviation (influence of the posterior surface of the cornea on refractive power) were statistically different between eyes with greater pigment loss and eyes with lesser pigment loss. Eyes with greater pigment loss had a larger back radius of corneal curvature and a correspondingly numerically smaller keratometric power deviation. Other measurements of ocular anatomy were not statistically significant. A flatter curvature of the posterior corneal surface of the eye is associated with increased pigment loss in PDS and PG. The authors postulate that this could result in a difference in the biomechanical properties of the cornea, increased deformation with blinking, and a pumping action resulting in the reverse pupil block of PDS.

Visual and IOP outcomes after PRK in pigment dispersion syndrome.

Science.gov (United States)

Bower, Kraig S; Sia, Rose K; Ryan, Denise S; Mines, Michael J; Stutzman, Richard D; Kuzmowych, Chrystyna P; Eaddy, Jennifer B; Coe, Charles D; Wroblewski, Keith J

2011-09-01

To report the results of photorefractive keratectomy (PRK) in patients with pigment dispersion syndrome. The pre- and postoperative records of patients with pigment dispersion syndrome who underwent PRK between January 2002 and March 2009 were reviewed. Data for analysis included gender, age, ablation depth, surgical complications, manifest refraction spherical equivalent, uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), intraocular pressure (IOP), central corneal thickness (CCT), cup-to-disc (c/d) ratio, and postoperative complications. Thirty-seven eyes of 19 patients (17 men and 2 women) with a mean age of 37.5 ± 6.9 years were included for review. At final follow-up, mean 404.1±119.5 days postoperative, UDVA was 20/15 or better in 67.6%, 20/20 or better in 91.9%, and 20/25 or better in 100% of eyes; 94.6% of eyes were within 0.50 diopters (D) and 100% were within 1.00 D of emmetropia. Corrected distance visual acuity was unchanged from preoperative in 73% and improved by one line in 27% of eyes. No eye lost 1 or more lines of CDVA. When corrected for change in CCT and curvature, mean postoperative IOP was elevated from baseline (16.7 ± 3.8 mmHg) at 1 month (18.1 ± 4.9 mmHg, P =.044) but unchanged at any other time postoperatively. Two (11%) of 19 patients were steroid responders, requiring a single topical agent until completing the course of steroids. No significant change was noted in mean c/d ratio from baseline (0.35±0.12) to final postoperative (0.35 ± 0.13, P = .99). Although PRK in patients with pigment dispersion syndrome resulted in excellent UDVA, retention of CDVA, and low incidence of adverse effects 1 to 2 years after surgery, long-term safety and efficacy outcomes of PRK in this cohort remain speculative

Ultrastructural analysis of the pigment dispersion syndrome in DBA/2J mice.

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Schraermeyer, Mareike; Schnichels, Sven; Julien, Sylvie; Heiduschka, Peter; Bartz-Schmidt, Karl-Ulrich; Schraermeyer, Ulrich

2009-11-01

To characterise ocular pigment abnormalities associated with iris atrophy in DBA/2J mice as a model for human pigment dispersion syndrome. Immunohistochemistry, electron and light microscopy were performed to examine the eyes of DBA/2J mice ranging in age from 2.5 to 18 months old. The focus of our study was the description of the ultrastructural modifications in the irides of DBA/2J mice. The DBA/2J mice presented modifications in the melanosomes in all the pigmented parts of the eye, including the retinal pigment epithelial cells and choroidal melanocytes of the ciliary pigment epithelium. The extracellular matrix of the iris stroma disappeared with ageing. Pigmented cells detached from the iris and migrated into the trabecular meshwork exclusively on the anterior iris surface. These cells were identified as macrophages by immunohistochemistry and electron microscopy. There was no evidence that melanocytes or iris pigment epithelial cells migrated into the trabecular meshwork, but they became more and more depigmented. The aqueous outflow was blocked by pigment-laden cells, but not by cellular debris or melanosomes. No substantial amount of extracellular melanosomes was observed. The morphology of melanosomes is aberrant in all pigment cells in the eyes of DBA/2J mice. We conclude that the disease process begins with the transfer of both immature melanosomes from the iris pigment epithelium (IPE) and melanocytes to macrophages, which subsequently migrate into the trabecular meshwork. Accumulating macrophages cause a blockade of the chamber angle. As the disease progresses, the IPE, melanocytes and iris stroma, including blood vessels, disappear, leading to iris atrophy. It is speculated that the loss of these pigment cells is partly caused by reduction of the iris stroma.

Determination Of Association Of Pigmentary Glaucoma With Pigment Dispersion Syndrome.

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Shah, Imtiaz Ali; Shah, Shujaat Ali; Nagdev, Partab Rai; Abbasi, Safdar Ali; Abbasi, Naeem Ali; Katpar, Safdar Akhtar

2017-01-01

Pigment Dispersion Syndrome (PDS) is an autosomal dominant disorder of white males between 20 to 40 years of age characterized by deposition of pigment on the lens, zonules of lens, trabecular meshwork and corneal endothelium (Krukenberg's spindle) in addition to radial, spoke like transillumination defects in the mid peripheral iris. This study was conducted to determine the frequency of occurrence of Pigmentary Glaucoma in patients with Pigment Dispersion Syndrome (PDS). This longitudinal follow up study included patients presenting with Krukenberg's spindle on the endothelial side of cornea and pigmentation of angle of anterior chamber seen on slit lamp examination and gonioscopy. Seventy-two cases of PDS were included in the study, amongst them 63 (87.50%) were males. Mean age was 35.00±6.54 years (range 24-46 years). Forty-seven (65.28%) patients had an IOP in the range of 10-14 mmHg, 22 (30.56%) patients had an IOP in the range of 15-18 mmHg and 3 (4.17%) patients developed an IOP of greater than 19 mmHg. Fundoscopy showed myopic degeneration in 49 (68.06%) patients and optic disc cupping in 3 (4.17%) patients. Four (5.56%) patients had refractive error between +1D to +3D, 9 (12.50%) patients had refractive error between -1D to -4D, 21 (29.17%) patients had refractive error between -5 D to -8 D and 38 (52.78%) patients had refractive error between -9 D to -12 D. Our study showed that one patient having PDS developed glaucoma at 5 years of follow up and three patients developed glaucoma at 14 years of follow up. On the basis of this study we conclude that early onset primary open angle glaucoma associated with PDS or Juvenile glaucoma associated with PDS might have been mistaken as Pigmentary Glaucoma in Pakistani patients and a distinct entity in the form of Pigmentary Glaucoma may be non-existent.

Pigment dispersion syndrome associated with intraocular lens implantation: a new surgical technique.

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Canut Jordana, M Isabel; Pérez Formigó, Daniel; Abreu González, Rodrigo; Nadal Reus, Jeroni

2010-11-11

We report the case of a myopic patient who, after intraocular lens transplant in the posterior chamber, suffered elevated intraocular pressure due to pigment dispersion, with recurrent episodes of blurred vision. The patient was treated with a new surgical technique that can avoid potential iridolenticular contact. Complete ophthalmologic examination and optical coherence tomography (OCT) of the anterior segment were performed. Contact between the pigmentary epithelium and the iris with an intraocular lens was revealed by utrasound biomicroscopy and OCT. In this case, Nd:YAG laser iridotomy and laser iridoplasty were not effective for iridolenticular separation and control of the pigment dispersion. We propose a new technique: stitches on the surface of the iris to obtain good iridolenticular separation and good intraocular pressure control. Stitches on the iris surface should be considered as optional therapy in pigmentary glaucoma secondary to intraocular lens implantation. This surgical technique can avoid potential iridolenticular contacts more definitively.

5-HT receptor subtypes as key targets in mediating pigment dispersion within melanophores of teleost, Oreochromis mossambicus.

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Salim, Saima; Ali, Ayesha S; Ali, Sharique A

2013-02-01

The presence of distinct class of 5-HT receptors in the melanophores of tilapia (Oreochromis mossambicus) is reported. The cellular responses to 5-HT (5-hydroxytryptamine), 5-HT(1), and 5-HT(2), agonists on isolated scale melanophores were observed with regard to pigment translocation within the cells. It was found that 5-HT exerted rapid and strong concentration dependent pigment granule dispersion within the melanophores. The threshold pharmacological dose of 5-HT that could elicit a measurable response was as low as 4.7×10(-12) M/L. Selective 5-HT(1) and 5-HT(2) agonists, sumatriptan and myristicin were investigated and resulted in dose-dependent pigment dispersion. The dispersing effects were effectively antagonized by receptor specific antagonists. It is suggested that 5-HT-induced physiological effects are mediated via distinct classes of receptors that possibly participate in modulation of pigmentary responses of the fish. Copyright © 2012 Elsevier Inc. All rights reserved.

Synthesis and properties of amphiphilic hyperbranched polyethers as pigment dispersant

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Xu, Q.; Zhou, Y. J.; Long, S. J.; Liu, Y. G.; Li, J. H.

2018-01-01

Hyperbranched polymers possess prominent properties such as low viscosity, good solubility, high rheological property, environmental non-toxic, and so on, which have potential applications in coatings. In this study, the amphiphilic hyperbranched polyethers (AHPs) consisting of hydrophobic hyperbranched polyethers core and hydrophilic poly (ethylene glycol) arms with different degree of branching (DB) under various reaction temperatures was prepared by the cation ring-opening polymerization. Their structures were characterized by IR, 13CNMR and GPC. Their dispersion properties for pigment particles were investigated. The AHP47 with 0.47 DB was found to have good dispersion properties for Yellow HGR. This work would provide experimental data and theoretical foundation for the application of hyperbranched polyethers in environmental protection coating.

Solving intraocular lens-related pigment dispersion syndrome with repositioning of primary sulcus implanted single-piece IOL in the capsular bag.

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Kohnen, Thomas; Kook, Daniel

2009-08-01

We describe 2 cases of pigment dispersion syndrome (PDS) after uneventful phacoemulsification and implantation of a posterior chamber single-piece intraocular lens (IOL) with a sharp-edge design. In both cases, several days after IOL implantation, marked pigment dispersion was seen on the iris and in the trabecular meshwork, associated with an elevation in intraocular pressure (IOP). Thorough examination showed that the implanted IOL was in the ciliary sulcus. After surgical repositioning of both IOLs in the capsular bag, the pigment dispersion regressed and the IOP returned to normal limits. The 2 cases suggest that particularly in PDS patients, an IOL with an anterior sharp-edge design should be implanted in the capsular bag. Implantation in the ciliary sulcus should be avoided.

Circadian Rhythm Neuropeptides in Drosophila: Signals for Normal Circadian Function and Circadian Neurodegenerative Disease.

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He, Qiankun; Wu, Binbin; Price, Jeffrey L; Zhao, Zhangwu

2017-04-21

Circadian rhythm is a ubiquitous phenomenon in many organisms ranging from prokaryotes to eukaryotes. During more than four decades, the intrinsic and exogenous regulations of circadian rhythm have been studied. This review summarizes the core endogenous oscillation in Drosophila and then focuses on the neuropeptides, neurotransmitters and hormones that mediate its outputs and integration in Drosophila and the links between several of these (pigment dispersing factor (PDF) and insulin-like peptides) and neurodegenerative disease. These signaling molecules convey important network connectivity and signaling information for normal circadian function, but PDF and insulin-like peptides can also convey signals that lead to apoptosis, enhanced neurodegeneration and cognitive decline in flies carrying circadian mutations or in a senescent state.

Berberine-induced pigment dispersion in Bufo melanostictus melanophores by stimulation of beta-2 adrenergic receptors.

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Ali, Sharique A; Naaz, Ishrat; Choudhary, Ram Kumar

2014-02-01

Reduced production of melanin by decreased or the absence of melanocytes leads to various hypopigmentation disorders, and the development of melanogenetic agents for photoprotection and hypopigmentation disorders is one of the top priority areas of research. Hence, the present study was carried out to elucidate the ability of berberine, a principal active ingredient present in the roots of the herb Berberis vulgaris to stimulate pigment dispersion in the isolated skin melanophores of the toad Bufo melanostictus. In the present study, mean melanophore size index of the isolated skin melanophores of B. melanostictus was assayed after treating with various concentrations of berberine. A marked melanin dispersion response leading to skin darkening was observed in the isolated melanophores of toad in response to berberine, which was found to be mediated through beta-2 adrenergic receptors. The physiologically significant dose-related melanin dispersion effects of berberine per se were found to be completely abolished by propranolol, which is a specific beta-2 adrenergic receptor blocker. These per se melanin dispersal effects were also found to be markedly potentiated by isoprenaline, which is a specific beta-adrenoceptor agonist. The results indicate that berberine causes a tremendous, dose-dependent, physiologically significant pigment dispersing in the isolated skin melanophores of B. melanostictus.

Nitric oxide-dependent pigment migration induced by ultraviolet radiation in retinal pigment cells of the crab Neohelice granulata.

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Filgueira, Daza de Moraes Vaz Batista; Guterres, Laís Pereira; Votto, Ana Paula de Souza; Vargas, Marcelo Alves; Boyle, Robert Tew; Trindade, Gilma Santos; Nery, Luiz Eduardo Maia

2010-01-01

The purpose of this study was to verify the occurrence of pigment dispersion in retinal pigment cells exposed to UVA and UVB radiation, and to investigate the possible participation of a nitric oxide (NO) pathway. Retinal pigment cells from Neohelice granulata were obtained by cellular dissociation. Cells were analyzed for 30 min in the dark (control) and then exposed to 1.1 and 3.3 J cm(-2) UVA, 0.07 and 0.9 J cm(-2) UVB, 20 nmβ-PDH (pigment dispersing hormone) or 10 μm SIN-1 (NO donor). Histological analyses were performed to verify the UV effect in vivo. Cultured cells were exposed to 250 μm L-NAME (NO synthase blocker) and afterwards were treated with UVA, UVB or β-PDH. The retinal cells in culture displayed significant pigment dispersion in response to UVA, UVB and β-PDH. The same responses to UVA and UVB were observed in vivo. SIN-1 did not induce pigment dispersion in the cell cultures. L-NAME significantly decreased the pigment dispersion induced by UVA and UVB but not by β-PDH. All retinal cells showed an immunopositive reaction against neuronal nitric oxide synthases. Therefore, UVA and UVB radiation are capable of inducing pigment dispersion in retinal pigment cells of Neohelice granulata and this dispersion may be nitric oxide synthase dependent. © 2010 The Authors. Journal Compilation. The American Society of Photobiology.

Heterotrimeric Kinesin II Is the Microtubule Motor Protein Responsible for Pigment Dispersion in Xenopus Melanophores

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Tuma, M. Carolina; Zill, Andrew; Le Bot, Nathalie; Vernos, Isabelle; Gelfand, Vladimir

1998-01-01

Melanophores move pigment organelles (melanosomes) from the cell center to the periphery and vice-versa. These bidirectional movements require cytoplasmic microtubules and microfilaments and depend on the function of microtubule motors and a myosin. Earlier we found that melanosomes purified from Xenopus melanophores contain the plus end microtubule motor kinesin II, indicating that it may be involved in dispersion (Rogers, S.L., I.S. Tint, P.C. Fanapour, and V.I. Gelfand. 1997. Proc. Natl. Acad. Sci. USA. 94: 3720–3725). Here, we generated a dominant-negative construct encoding green fluorescent protein fused to the stalk-tail region of Xenopus kinesin-like protein 3 (Xklp3), the 95-kD motor subunit of Xenopus kinesin II, and introduced it into melanophores. Overexpression of the fusion protein inhibited pigment dispersion but had no effect on aggregation. To control for the specificity of this effect, we studied the kinesin-dependent movement of lysosomes. Neither dispersion of lysosomes in acidic conditions nor their clustering under alkaline conditions was affected by the mutant Xklp3. Furthermore, microinjection of melanophores with SUK4, a function-blocking kinesin antibody, inhibited dispersion of lysosomes but had no effect on melanosome transport. We conclude that melanosome dispersion is powered by kinesin II and not by conventional kinesin. This paper demonstrates that kinesin II moves membrane-bound organelles. PMID:9852150

Severe pigment dispersion after iris-claw phakic intraocular lens implantation.

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Galvis, Virgilio; Carreño, Néstor I; Tello, Alejandro; Laiton, Andrea N

2017-12-01

A 23-year-old female patient presented 3 months after the implantation of an Artisan® phakic intraocular lens with a severe depigmentation of the iris and peripheral anterior synechiae. Explantation of the intraocular lens and goniosynechialysis were performed. Eleven months after the explantation appearance of the iris significantly improved. There was no loss of lines of corrected distance visual acuity. Severe pigment dispersion after the implantation of an Artisan® phakic intraocular lens may happen and may require explantation of the lens. Iris depigmentation may improve with time.

Severe pigment dispersion after iris-claw phakic intraocular lens implantation

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Virgilio Galvis

2017-01-01

Full Text Available A 23-year-old female patient presented 3 months after the implantation of an Artisan® phakic intraocular lens with a severe depigmentation of the iris and peripheral anterior synechiae. Explantation of the intraocular lens and goniosynechialysis were performed. Eleven months after the explantation appearance of the iris significantly improved. There was no loss of lines of corrected distance visual acuity. Severe pigment dispersion after the implantation of an Artisan® phakic intraocular lens may happen and may require explantation of the lens. Iris depigmentation may improve with time.

Reverse pupillary block associated with pigment dispersion syndrome after in-the-bag intraocular lens implantation.

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Itagaki, Hideo; Kunikata, Toshio; Hiratsuka, Kentaro; Saito, Junichiro; Oshika, Tetsuro

2013-12-01

A 61-year-old man with high myopia who had received a systemic α1A-adrenoceptor antagonist had phacoemulsification and in-the-bag intraocular lens implantation in the right eye. One day postoperatively, marked pigment dispersion in the anterior chamber, posterior bowing of the iris, and iridodonesis were noted associated with a subsequent elevation in intraocular pressure (IOP). Pharmacological pupil dilation was effective in reducing pigment dispersion and IOP, and laser peripheral iridotomy was performed to alleviate posterior bowing of the iris. We hypothesize that dynamic changes in the aqueous humor flow by cataract surgery and latent flaccidity of the iris due to the systemic α1A-adrenoceptor antagonist caused reverse pupillary block. High myopia may be another risk factor for this complication. Copyright © 2013 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

Chronic Central Serous Chorioretinopathy in a Patient with Pigment Dispersion Syndrome: A Possible Correlation.

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Kourkoutas, Dimitrios; Tsakonas, George; Karamaounas, Aristotelis; Karamaounas, Nikolaos

2017-01-01

Chronic central serous chorioretinopathy (CSCR) is a progressive chorioretinopathy with widespread atrophic RPE abnormalities and serous retinal detachments (SRDs) present for 6 months or longer. We report a case of CSCR in a 38-year-old patient with Pigment Dispersion Syndrome (PDS). In the presented case of CSCR, the chronic course of the disease may in part be associated with an underlying generalized degenerative dysfunction of the pigmented cells of the eye on grounds of PDS. We suggest that a chronic course of disease may be suspected in the setting of CSCR with concurrent RPE pathology, such as what is found in PDS.

The genetics of pigment dispersion syndrome and pigmentary glaucoma.

Science.gov (United States)

Lascaratos, Gerassimos; Shah, Ameet; Garway-Heath, David F

2013-01-01

We review the inheritance patterns and recent genetic advances in the study of pigment dispersion syndrome (PDS) and pigmentary glaucoma (PG). Both conditions may result from combinations of mutations in more than one gene or from common variants in many genes, each contributing small effects. We discuss the currently known genetic loci that may be related with PDS/PG in humans, the role of animal models in expanding our understanding of the genetic basis of PDS, the genetic factors underlying the risk for conversion from PDS to PG and the relationship between genetic and environmental--as well as anatomical--risk factors. Copyright © 2013 Elsevier Inc. All rights reserved.

Three-dimensional characterization of pigment dispersion in dried paint films using focused ion beam-scanning electron microscopy.

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Lin, Jui-Ching; Heeschen, William; Reffner, John; Hook, John

2012-04-01

The combination of integrated focused ion beam-scanning electron microscope (FIB-SEM) serial sectioning and imaging techniques with image analysis provided quantitative characterization of three-dimensional (3D) pigment dispersion in dried paint films. The focused ion beam in a FIB-SEM dual beam system enables great control in slicing paints, and the sectioning process can be synchronized with SEM imaging providing high quality serial cross-section images for 3D reconstruction. Application of Euclidean distance map and ultimate eroded points image analysis methods can provide quantitative characterization of 3D particle distribution. It is concluded that 3D measurement of binder distribution in paints is effective to characterize the order of pigment dispersion in dried paint films.

Pigment Dispersion Syndrome Progression to Pigmentary Glaucoma in a Latin American Population.

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Gomez Goyeneche, Hector Fernando; Hernandez-Mendieta, Diana Patricia; Rodriguez, Diego Andres; Sepulveda, Ana Irene; Toledo, Jose Daniel

2015-01-01

To determine the progression of pigment dispersion syndrome (PDS) into pigmentary glaucoma (PG) in a population at the Central Military Hospital in Bogotá, Colombia. A retrospective study was conducted, based on a review of medical records of patients with PDS evaluated in the Glaucoma Clinic. Data were collected in a database in excel and subsequently analyzed with the software Statistical Package for the Social Sciences (SPSS), performing Chi-square test analysis and Spearman's rho test. Forty-eight eyes of 24 patients were included. Forty-two percent were women and 58% were men. Pigmentation of the trabecular meshwork was the most frequent clinical sign (100%), followed by Krukenberg's spindle (91.7%), the least frequent were the iris concavity and iris heterochromia (4.2%), the average of the spherical equivalent was of - 1.33 (SD 2.07). The rate of conversion of PDS to PG was 37.5%, after an average follow-up of 50.7 months. Having an intraocular pressure (IOP) greater than 21 mm Hg was statistically the only significant risk factor for conversion. We found several differences in frequency and clinical signs in these patients in contrast to previous data, probably due to different racial characteristics. The rate of progression is similar to previous reports despite of heterogeneity of these. Having IOP > 21 mm Hg was the only risk factor associated with progression in this sample. How to cite this article: Gomez Goyeneche HF, Hernandez-Mendieta DP, Rodriguez DA, Sepulveda AI, Toledo JD. Pigment Dispersion Syndrome Progression to Pigmentary Glaucoma in a Latin American Population. J Curr Glaucoma Pract 2015;9(3):69-72.

Pigment dispersion syndrome associated with intraocular lens implantation: a new surgical technique

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M Isabel Canut Jordana

2010-11-01

Full Text Available M Isabel Canut Jordana1, Daniel Pérez Formigó1, Rodrigo Abreu González2, Jeroni Nadal Reus11Barraquer Ophthalmology Centre, Barcelona, Spain; 2University Hospital of La Candelaria, Tenerife, SpainAims: We report the case of a myopic patient who, after intraocular lens transplant in the posterior chamber, suffered elevated intraocular pressure due to pigment dispersion, with recurrent episodes of blurred vision. The patient was treated with a new surgical technique that can avoid potential iridolenticular contact.Methods: Complete ophthalmologic examination and optical coherence tomography (OCT of the anterior segment were performed.Results: Contact between the pigmentary epithelium and the iris with an intraocular lens was revealed by utrasound biomicroscopy and OCT. In this case, Nd:YAG laser iridotomy and laser iridoplasty were not effective for iridolenticular separation and control of the pigment dispersion. We propose a new technique: stitches on the surface of the iris to obtain good iridolenticular separation and good intraocular pressure control.Conclusion: Stitches on the iris surface should be considered as optional therapy in pigmentary glaucoma secondary to intraocular lens implantation. This surgical technique can avoid potential iridolenticular contacts more definitively.Keywords: pigmentary glaucoma, intraocular lens, optical coherence tomography, laser

Chronic Central Serous Chorioretinopathy in a Patient with Pigment Dispersion Syndrome: A Possible Correlation

Directory of Open Access Journals (Sweden)

Dimitrios Kourkoutas

2017-01-01

Full Text Available Chronic central serous chorioretinopathy (CSCR is a progressive chorioretinopathy with widespread atrophic RPE abnormalities and serous retinal detachments (SRDs present for 6 months or longer. We report a case of CSCR in a 38-year-old patient with Pigment Dispersion Syndrome (PDS. In the presented case of CSCR, the chronic course of the disease may in part be associated with an underlying generalized degenerative dysfunction of the pigmented cells of the eye on grounds of PDS. We suggest that a chronic course of disease may be suspected in the setting of CSCR with concurrent RPE pathology, such as what is found in PDS.

Pigment Dispersion Syndrome Progression to Pigmentary Glaucoma in a Latin American Population

OpenAIRE

Gomez Goyeneche, Hector Fernando; Hernandez-Mendieta, Diana Patricia; Rodriguez, Diego Andres; Sepulveda, Ana Irene; Toledo, Jose Daniel

2016-01-01

ABSTRACT Objective: To determine the progression of pigment dispersion syndrome (PDS) into pigmentary glaucoma (PG) in a population at the Central Military Hospital in Bogot?, Colombia. Materials and methods: A retrospective study was conducted, based on a review of medical records of patients with PDS evaluated in the Glaucoma Clinic. Data were collected in a database in excel and subsequently analyzed with the software Statistical Package for the Social Sciences (SPSS), performing Chi-squar...

Circumferential Ciliary Body Cysts Presenting as Acute Pigment Dispersion and Ocular Hypertension.

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Sarıgül Sezenöz, Almila; Güngör, Sirel Gür; Kıratlı, Hayyam; Akman, Ahmet

2017-09-15

To report a case of circumferential neuroepithelial cyst of the ciliary body presenting with pigment dispersion (PD) and ocular hypertension. 48-year-old female patient presented with a complaint of pain in the left eye. On examination, visual acuity of the left eye was 0.9, and the intraocular pressure was 48 mmHg. Biomicroscopic anterior segment examination of the left eye revealed 4+ pigmented cells in the anterior chamber. Active PD from the pupillary region at 11 o'clock was noticed at the time of the examination. Ultrasound biomicroscopy demonstrated 360º cystic lesions of the ciliary body in the left eye. The patient was diagnosed as neuroepithelial cyst of the ciliary body. Our case is unique as it is the first case of circumferential neuroepithelial ciliary body cyst presenting with acute PD and ocular hypertension.

Impacts of Silver Nanoparticle Ingestion on Pigmentation and Developmental Progression in Drosophila

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S. Catherine Silver Key

2011-10-01

Full Text Available In recent years, the advent of nanomaterial use has increased exposure rates and raised health concerns. However, the toxicology profiles of many nanomaterials are far from complete for various reasons. In this study, Drosophila melanogaster, commonly called fruit flies, were exposed to one of the most widely used nanomaterials, silver nanopowder (Ag NP, to assess its toxicity and determine if D. melanogaster would be a good model organism for nanotoxicology studies. Comparison of developmental progression amongst groups of flies ingesting different Ag NP concentrations (0.05%/~90 ppm-5.0%/~9000 ppm, revealed that hatch rates were unaffected, but that larval progression was impeded at any dosage of Ag NP. At 0.3% Ag NP an approximate LD50 was observed. Additionally, a distinctive phenotype was observed among emergent adults (F1 generation that arose from larvae exposed to Ag NP which included reduced body pigmentation accompanied by shortened life span and abnormal climbing behavior. The phenotype prompted speculation that Ag NPs may affect the dopamine and/or the stress response pathway(s.

Non-aqueous pigmented inkjet inks

NARCIS (Netherlands)

DEROOVER, GEERT; Bernaerts, Katrien; HOOGMARTENS, IVAN

2009-01-01

A non-aqueous inkjet ink comprises a benzimidazolone pigment and a polymeric dispersant according to Formula (I): wherein, T represents hydrogen or a polymerization terminating group; Z represents theA non-aqueous inkjet ink comprises a benzimidazolone pigment and a polymeric dispersant according to

Role of laser peripheral iridotomy in pigmentary glaucoma and pigment dispersion syndrome: A review of the literature.

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Buffault, J; Leray, B; Bouillot, A; Baudouin, C; Labbé, A

2017-11-01

Pigment dispersion syndrome (PDS) is characterized by a structural abnormality of the posterior surface of the iris causing contact with the zonular fibers. It can lead to an open-angle glaucoma secondary to pigment dispersion into the trabecular meshwork. Laser peripheral iridotomy (PI) has been proposed as a treatment for pigmentary glaucoma (PG) and pigment dispersion syndrome (PDS) by reducing the dispersion of pigment. The goal of this review was to assess the effects of PI for PDS and PG. We included six randomized controlled trials and two cohort studies (286 eyes of 218 participants). Four trials included participants with PG, and 4 trials enrolled participants with PDS with or without elevated intraocular pressure (IOP). Among patients with PG, at an average of 9 months of follow-up, the mean difference in IOP between groups was 2.69mm Hg less in the PI group (95% CI: -6.05 to 0.67; 14 eyes). In patients with PDS, the average IOP was statistically lower after PI as compared to baseline (Student test t=11.49, P<0.01, 38 eyes). With regard to visual field progression in participants with PG, after an average follow-up of 28 months, the risk of progression was not influenced by PI (RR 1.00 95% CI: 0.16 to 6.25; 32 eyes). No trials that enrolled patients with PDS showed a diminution of the risk of glaucoma conversion at mid- and long-terms. PI decreases the biomechanical factor causing contact between the iris and zonular fibers and may lower IOP over the long-term. Nevertheless, the effects of PI on visual field changes or progression have not been established in PG and PDS. There is no scientific evidence as of yet to advocate PI as a treatment for PDS or PG. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Clinical Characteristics and Results of Laser Peripheral Iridotomy of Pigment Dispersion Syndrome

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Şerife Bayraktar

2017-12-01

Full Text Available Aims: To report the clinical findings, characteristics and the results of peripheral laser iridotomy in pigment dispersion syndrome (PDS patients.Methods: Medical records of 30 patients who had been diagnosed with PDS were evaluated retrospectively at Glaucoma Department of Istanbul Faculty of Medicine at Istanbul University.Results: Sixty eyes of these 30 patients enrolled in the study. 18 of them (60% were male and 12 (40% were female with mean age of 42.4 ±12.3 years (range: 22 to 73 years. Forty-six eyes of the 23 patients had myopia, 12 eyes of 6 patients had hyperopia, 2 eyes of 1 patient had emmetropia. All patients except 2 eyes of the 1 patient had (96.6% Krukenberg spindles. Homogeneous trabecular meshwork(TM pigmentation was seen in all patients. Thirty-two eyes of 17 patients (53.3 % had iris transillumination defects. Neodymium:yttrium–aluminum–garnet (Nd:YAG peripheral laser iridotomy was performed in 44 eyes of 60 eyes (73.3%.Conclusion: The most common clinical findings in Turkish PDS patients were Krukenberg spindles and homogeneous TM pigmentation. If PDS hasn’t advanced in pigmentary ocular hypertension or pigmentary glaucoma, progression can be stabilized by laser iridotomy and medical treatment.

An Overlap Syndrome of Pigment Dispersion and Pigmentary Glaucoma accompanied by Marfan Syndrome: Case Report with Literature Review.

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Chakravarti, Tutul; Spaeth, George

2013-01-01

'Overlap syndrome' describes the situation in which two or more 'independent' conditions are present, either one of which could cause a particular finding. This current presentation reports a case with bilateral pigment dispersion syndrome (PDS), advanced pigmentary glaucoma (PG), and the Marfan syndrome, with bilateral subluxation of the lenses, and large short-term and long-term fluctuations of intraocular pressure. It is interesting to consider whether the associated advanced glaucomatous nerve damage could be a manifestation of just the PDS, just the Marfan syndrome, or rather a combination of these two overlapping independent conditions. How to cite this article: Chakravarti T, George S. An Overlap Syndrome of Pigment Dispersion and Pigmentary Glaucoma accompanied by Marfan Syndrome: Case Report with Literature Review. J Current Glau Prac 2013;7(2):91-95.

A Case of Bilateral Pigment Dispersion Syndrome Following Many Years of Uninterrupted Treatment With Atropine 1% for Bilateral Congenital Cataracts.

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Gizzi, Corrado; Mohamed-Noriega, Jibran; Murdoch, Ian

2017-10-01

Describe an unusual case of bilateral pigment dispersion syndrome (PDS) following years of uninterrupted treatment with atropine 1% for bilateral congenital cataracts, speculate on potential mechanisms leading to this condition. This is a case report. A 45-year-old white patient on long-term treatment with atropine 1% ointment since his infancy for bilateral congenital cataracts developed PDS with secondary ocular hypertension. The patient showed all the hallmarks of PDS with secondary ocular hypertension. An anterior segment Swept-Source optical coherence tomography was obtained to review the iris profile. The patient showed good pressure response to topical prostaglandin therapy. This is the second case report of PDS in a patient with chronic use of topical atropine. The proposed mechanisms for pigment dispersion are discussed and the possibility raised of dispersion being a potential side effect of the drug.

[Role of laser peripheral iridotomy in pigmentary glaucoma and pigment dispersion syndrome: A review of the literature [French version

Science.gov (United States)

Buffault, J; Leray, B; Bouillot, A; Baudouin, C; Labbé, A

2017-12-01

Pigment dispersion syndrome (PSD) is characterized by a structural abnormality of the posterior surface of the iris causing contact with the zonular fibers. It can lead to an open-angle glaucoma secondary to pigment dispersion into the trabecular meshwork. Laser peripheral iridotomy (PI) has been proposed as a treatment for pigmentary glaucoma (PG) and pigment dispersion syndrome (PDS) by reducing the dispersion of pigment. The goal of this review was to assess the effects of PI for PSD and PG. We included six randomized controlled trials and two cohort studies (286 eyes of 218 participants). Four trials included participants with PG, and 4 trials enrolled participants with PSD with or without elevated intraocular pressure (IOP). Among patients with PG, at an average of 9 months of follow-up, the mean difference in IOP between groups was 2.69mmHg less in the PI group (95 % CI: -6.05 to 0.67; 14 eyes). In patients with PDS, the average IOP was statistically lower after PI as compared to baseline (Student test, t=11.49, P<0.01). With regard to visual field progression in participants with GP, after an average follow-up of 28 months, the risk of progression was not influenced by PI (RR 1.00 95 %: CI 0.16 to 6.25; 32 eyes). No trials that enrolled patients with PSD showed a diminution of the risk of glaucoma conversion at mid- and long-term. PI decreases the biomechanical factor causing contact between the iris and zonular fibers and may lower IOP over the long-term. Nevertheless, the effects of PI on visual field changes or progression have not been established in PG and PDS. There is no scientific evidence as of yet to advocate PI as a treatment for PDS or PG. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Pigmented striae of the anterior lens capsule and age-associated pigment dispersion of variable degree in a group of older African-Americans: an age, race, and gender matched study.

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Roberts, D K; Winters, J E; Castells, D D; Clark, C A; Teitelbaum, B A

2001-01-01

To investigate pigmented striae of the anterior lens capsule in African-Americans, a potential indicator of significant anterior segment pigment dispersion. A group of 40 African-American subjects who exhibited pigmented lens striae (PLS) were identified from a non-referred, primary eye care population in Chicago, IL, USA. These subjects were then compared to an age, race, and gender matched control group relative to refractive error and the presence or absence of diabetes and hypertension. The PLS subjects (mean age = 65.4 +/- 8.8 years, range = 50-87 years) consisted of 36 females and 4 males. PLS were bilateral in 36 (85%) of the 40 subjects. Among the eyes with PLS, 21 (55%) of 38 right eyes and 22 (61%) of 36 left eyes also had significant corneal endothelial pigment dusting, commonly in the shape of a Krukenberg's spindle. Ten (25%) of the PLS subjects had either glaucoma or ocular hypertension (7 bilateral, 3 unilateral). The presence of trabecular meshwork pigment varied from minimal to heavy. The mean +/- SD (range) refractive error of the PLS right eyes was +1.61 +/- 1.43D (-1.50 to +5.00D) and +1.77 +/- 1.37D (-1.00 to +5.00D) for the left eyes. Based on these data, the PLS right eyes were +1.63D (Student's t, p = 0.0001; 95% CI = +0.82 to +2.44D) more hyperopic on average than the control right eyes, and the PLS left eyes were +1.77D (p = 0.0001; 95% CI = +0.92 to +2.63D) more hyperopic on average than the control left eyes. Trend analysis showed a gradually increasing likelihood of PLS with increasing magnitude of hyperopia in both eyes (Mantel-Haenszel chi-square, p = 0.001). Among PLS subjects, 24 (60%) of 40 were hypertensive and 9 (23%) of 40 were diabetic. However, these proportions were not significantly different (two-tailed Fisher's exact test; hypertension: p = 0.30; diabetes: p = 0.70) from the randomly selected controls. Among our African-American group, which consisted predominately of females >50 years of age, the likelihood of PLS

Inhibiting roles of melanin-concentrating hormone for skin pigment dispersion in barfin flounder, Verasper moseri.

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Mizusawa, Kanta; Kobayashi, Yuki; Sunuma, Toshikazu; Asahida, Takashi; Saito, Yumiko; Takahashi, Akiyoshi

2011-03-01

Barfin flounders change their surface color pattern to match their background. We have reported evidence of the association between hormones and body color changes in this fish. First, bolus intraperitoneal injection with melanin-concentrating hormone (MCH) immediately turned the skin color pale, while injection with melanocyte-stimulating hormone (MSH) did not change the skin color. Second, gene expression levels of MCH change in response to background color, while those of MSH do not. We also reported the expression of an MCH receptor gene (Mch-r2) in the skin of this fish. In this study, we aimed to further evaluate the roles of MCH in skin color change. First, long-term adaptation of adult barfin flounder to black or white background colors induced significantly different pigment migration patterns in both melanophores and xanthophores (Ppigment-dispersing activity of MSH in a similar manner. Finally, we identified transcripts of Mch-r2 in cells isolated from both melanophores and xanthophores. Taken together, the evidence suggests that MCH aggregates pigments via MCH-R2 in concert with the nervous system by overcoming the melanin-dispersing activities of MSH in barfin flounder. Copyright © 2010 Elsevier Inc. All rights reserved.

In situ characterization of ancient plaster and pigments on tomb walls in Egypt using energy dispersive X-ray diffraction and fluorescence

International Nuclear Information System (INIS)

Uda, M.

2004-01-01

A portable type of energy dispersive X-ray diffraction and fluorescence (ED-XRDF) spectrometer was developed, whose operation mode is completely different from that of an X-ray diffractometer commercially available. The former is operated in energy dispersive mode but the latter in angle dispersive mode. The performance of the ED-XRDF spectrometer was tested in the field, i.e. in the tomb of Amenhotep III, built in 1364 B.C. or earlier in Egypt. The crystal structure and chemical composition of ancient plaster and pigments were successfully determined in the field using the spectrometer. The same areas investigated by the ED-XRDF spectrometer were also examined with an optical microscope. The plaster is found to be composed of anhydrite, calcite and quartz. White and yellow pigments were identified as huntite and orpiment, respectively. Egyptian blue and goethite were found in the green colored parts

A nanobody-based toolset to investigate the role of protein localization and dispersal in Drosophila.

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Harmansa, Stefan; Alborelli, Ilaria; Bieli, Dimitri; Caussinus, Emmanuel; Affolter, Markus

2017-04-11

The role of protein localization along the apical-basal axis of polarized cells is difficult to investigate in vivo, partially due to lack of suitable tools. Here, we present the GrabFP system, a collection of four nanobody-based GFP-traps that localize to defined positions along the apical-basal axis. We show that the localization preference of the GrabFP traps can impose a novel localization on GFP-tagged target proteins and results in their controlled mislocalization. These new tools were used to mislocalize transmembrane and cytoplasmic GFP fusion proteins in the Drosophila wing disc epithelium and to investigate the effect of protein mislocalization. Furthermore, we used the GrabFP system as a tool to study the extracellular dispersal of the Decapentaplegic (Dpp) protein and show that the Dpp gradient forming in the lateral plane of the Drosophila wing disc epithelium is essential for patterning of the wing imaginal disc.

Synthesis, Characterization, and NIR Reflectance of Highly Dispersed NiTiO3 and NiTiO3/TiO2 Composite Pigments

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Yuping Tong

2016-01-01

Full Text Available The highly dispersed nanostructured NiTiO3 pigments and NiTiO3/TiO2 composite pigments can be synthesized at relative low temperature. The activation energy of crystal growth of NiTiO3 during calcinations via salt-assistant combustion method is 9.35 kJ/mol. The UV-vis spectra results revealed that the absorbance decreased with the increasing of calcinations temperature due to small size effect of nanometer particles. The optical data of NiTiO3 nanocrystals were analyzed at the near-absorption edge. SEM showed that the obtained NiTiO3 nanocrystals and NiTiO3/TiO2 nanocomposite were composed of highly dispersed spherical-like and spherical particles with uniform size distribution, respectively. The chromatic properties and diffuse reflectance of samples were investigated. The obtained NiTiO3/TiO2 composite samples have higher NIR reflectance than NiTiO3 pigments.

75 FR 52930 - Carbazole Violet Pigment 23 From India: Preliminary Results of Antidumping Duty Changed...

Science.gov (United States)

2010-08-30

... of presscake and dry color. Pigment dispersions in any form (e.g., pigment dispersed in oleoresins... DEPARTMENT OF COMMERCE International Trade Administration [A-533-838] Carbazole Violet Pigment 23... order on carbazole violet pigment 23 from India to determine whether Meghmani Pigments (Meghmani) is the...

Or47b receptor neurons mediate sociosexual interactions in the fruit fly Drosophila melanogaster.

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Lone, Shahnaz Rahman; Sharma, Vijay Kumar

2012-04-01

In the fruit fly Drosophila melanogaster, social interactions especially among heterosexual couples have been shown to have significant impact on the circadian timing system. Olfaction plays a major role in such interactions; however, we do not know yet specifically which receptor(s) are involved. Further, the role of circadian clock neurons in the rhythmic regulation of such sociosexual interactions (SSIs) is not fully understood. Here, we report the results of our study in which we assayed the locomotor activity and sleep-wake behaviors of male-male (MM), female-female (FF), and male-female (MF) couples from several wild-type and mutant strains of Drosophila with an aim to identify specific olfactory receptor(s) and circadian clock neurons involved in the rhythmic regulation of SSI. The results indicate that Or47b receptor neurons are necessary for SSI, as ablation or silencing of these neurons has a severe impact on SSI. Further, the neuropeptide pigment dispersing factor (PDF) and PDF-positive ventral lateral (LN(v)) clock neurons appear to be dispensable for the regulation of SSI; however, dorsal neurons may be involved.

Phenotypic Plasticity through Transcriptional Regulation of the Evolutionary Hotspot Gene tan in Drosophila melanogaster.

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Jean-Michel Gibert

2016-08-01

Full Text Available Phenotypic plasticity is the ability of a given genotype to produce different phenotypes in response to distinct environmental conditions. Phenotypic plasticity can be adaptive. Furthermore, it is thought to facilitate evolution. Although phenotypic plasticity is a widespread phenomenon, its molecular mechanisms are only beginning to be unravelled. Environmental conditions can affect gene expression through modification of chromatin structure, mainly via histone modifications, nucleosome remodelling or DNA methylation, suggesting that phenotypic plasticity might partly be due to chromatin plasticity. As a model of phenotypic plasticity, we study abdominal pigmentation of Drosophila melanogaster females, which is temperature sensitive. Abdominal pigmentation is indeed darker in females grown at 18°C than at 29°C. This phenomenon is thought to be adaptive as the dark pigmentation produced at lower temperature increases body temperature. We show here that temperature modulates the expression of tan (t, a pigmentation gene involved in melanin production. t is expressed 7 times more at 18°C than at 29°C in female abdominal epidermis. Genetic experiments show that modulation of t expression by temperature is essential for female abdominal pigmentation plasticity. Temperature modulates the activity of an enhancer of t without modifying compaction of its chromatin or level of the active histone mark H3K27ac. By contrast, the active mark H3K4me3 on the t promoter is strongly modulated by temperature. The H3K4 methyl-transferase involved in this process is likely Trithorax, as we show that it regulates t expression and the H3K4me3 level on the t promoter and also participates in female pigmentation and its plasticity. Interestingly, t was previously shown to be involved in inter-individual variation of female abdominal pigmentation in Drosophila melanogaster, and in abdominal pigmentation divergence between Drosophila species. Sensitivity of t

Longitudinal stability of the diurnal rhythm of intraocular pressure in subjects with healthy eyes, ocular hypertension and pigment dispersion syndrome.

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Huchzermeyer, Cord; Reulbach, Udo; Horn, Folkert; Lämmer, Robert; Mardin, Christian Y; Jünemann, Anselm G M

2014-10-15

The diurnal fluctuation of intraocular pressure may be relevant in glaucoma. The aim of this study was to find out whether the timing of diurnal fluctuation is stable over the years. Long-term IOP data from the Erlangen Glaucoma Registry, consisting of several annual extended diurnal IOP profiles for each patient, was retrospectively analyzed. Normal subjects, patients with ocular hypertension and with pigment dispersion syndrome were included because these subjects had not been treated with antiglaucomatous medications at the time of data acquisition. A cosine curve was fitted to the IOP data and the stability of individual rhythms over the years was tested using the Rayleigh test. To compare the peak times among groups, means were calculated only from subjects with a significant Rayleigh test. Of the fifty-two eligible subjects, a total of 364 extended diurnal IOP profiles measured in a sitting position had been collected over a period of 114 ± 39 months. The Rayleigh test indicated intraindividual stability of phase timing only in 19 subjects (36%). In subjects with pigment dispersions syndrome, peak IOP occurred on average two hours and seven minutes later during the day compared with subjects without this condition (p = 0.05). Fitting of cosine curves to the clinical IOP profiles was generally feasible, although careful interpretation is warranted due to lack of measurements in supine position and between midnight and 7 am. The interesting observation of a phase lag in eyes with pigment dispersion syndrome warrants confirmation and exploration in future prospective studies. The analysis of the IOP data showed no stable individual rhythm in the long term in a majority of patients.

Molecular Genetics of Pigment Dispersion Syndrome and Pigmentary Glaucoma: New Insights into Mechanisms

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Adrian A. Lahola-Chomiak

2018-01-01

Full Text Available We explore the ideas and advances surrounding the genetic basis of pigment dispersion syndrome (PDS and pigmentary glaucoma (PG. As PG is the leading cause of nontraumatic blindness in young adults and current tailored interventions have proven ineffective, a better understanding of the underlying causes of PDS, PG, and their relationship is essential. Despite PDS being a subclinical disease, a large proportion of patients progress to PG with associated vision loss. Decades of research have supported a genetic component both for PDS and conversion to PG. We review the body of evidence supporting a genetic basis in humans and animal models and reevaluate classical mechanisms of PDS/PG considering this new evidence.

Molecular Genetics of Pigment Dispersion Syndrome and Pigmentary Glaucoma: New Insights into Mechanisms.

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Lahola-Chomiak, Adrian A; Walter, Michael A

2018-01-01

We explore the ideas and advances surrounding the genetic basis of pigment dispersion syndrome (PDS) and pigmentary glaucoma (PG). As PG is the leading cause of nontraumatic blindness in young adults and current tailored interventions have proven ineffective, a better understanding of the underlying causes of PDS, PG, and their relationship is essential. Despite PDS being a subclinical disease, a large proportion of patients progress to PG with associated vision loss. Decades of research have supported a genetic component both for PDS and conversion to PG. We review the body of evidence supporting a genetic basis in humans and animal models and reevaluate classical mechanisms of PDS/PG considering this new evidence.

Pigment dispersion glaucoma induced by the chafing effect of intraocular lens haptics in Asian eyes.

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Hong, Ying; Sun, Yan-Xiu; Qi, Hong; Zhou, Ji-Chao; Hao, Yan-Sheng

2013-03-01

To study the possible mechanism and treatment for pigment dispersion glaucoma (PDG) caused by single-piece acrylic (SPA) intraocular lens (IOL) ciliary sulcus fixation in Asian eyes. Patients referred for PDG caused by SPA IOL ciliary sulcus fixation to our hospital from April 2005 to June 2011 were included. The patients' general information, IOL type, interval between initial surgery and PDG occurrence, examination findings, antiglaucoma medicine regimen and surgical interventions were recorded. In total, six eyes from five Chinese patients were included in this study. The intraocular pressure (IOP) increased 19-30 days after cataract surgery and was not satisfactorily controlled with antiglaucoma medication. Dense pigmentation was deposited on the IOLs and on the anterior chamber angle. IOL haptic chafing was noted on the rear iris surface. IOL repositioning in the capsular bag was performed in three eyes and was combined with trabeculectomy in two eyes with progressive glaucoma. An IOL exchange with three-piece IOL ciliary sulcus fixation was performed in the other three eyes. Scanning electron microscopy of the explanted IOLs demonstrated a rough edge on the IOL haptics. SPA IOLs were not suitable for ciliary sulcus fixation. The chafing effect of the IOL haptics on the posterior iris pigment epithelium could induce PDG in Asian eyes. IOLs should be positioned in the capsular bag or a three-piece IOL should be used instead.

75 FR 977 - Carbazole Violet Pigment 23 From India: Preliminary Results of Countervailing Duty Administrative...

Science.gov (United States)

2010-01-07

... the form of presscake and dry color. Pigment dispersions in any form (e.g., pigments dispersed in... DEPARTMENT OF COMMERCE International Trade Administration [C-533-839] Carbazole Violet Pigment 23... countervailing duty order on carbazole violet pigment 23 (CVP-23) from India for the period January 1, 2007...

Lipid phosphate phosphatase activity regulates dispersal and bilateral sorting of embryonic germ cells in Drosophila

Science.gov (United States)

Renault, Andrew D.; Kunwar, Prabhat S.; Lehmann, Ruth

2010-01-01

In Drosophila, germ cell survival and directionality of migration are controlled by two lipid phosphate phosphatases (LPP), wunen (wun) and wunen-2 (wun2). wun wun2 double mutant analysis reveals that the two genes, hereafter collectively called wunens, act redundantly in primordial germ cells. We find that wunens mediate germ cell-germ cell repulsion and that this repulsion is necessary for germ cell dispersal and proper transepithelial migration at the onset of migration and for the equal sorting of the germ cells between the two embryonic gonads during their migration. We propose that this dispersal function optimizes adult fecundity by assuring maximal germ cell occupancy of both gonads. Furthermore, we find that the requirement for wunens in germ cell survival can be eliminated by blocking germ cell migration. We suggest that this essential function of Wunen is needed to maintain cell integrity in actively migrating germ cells. PMID:20431117

Corrosion inhibition by lithium zinc phosphate pigment

International Nuclear Information System (INIS)

Alibakhshi, E.; Ghasemi, E.; Mahdavian, M.

2013-01-01

Highlights: •Synthesis of lithium zinc phosphate (LZP) by chemical co-precipitation method. •Corrosion inhibition activity of pigments compare with zinc phosphate (ZP). •LZP showed superior corrosion inhibition effect in EIS measurements. •Evaluation of adhesion strength and dispersion stability. -- Abstract: Lithium zinc phosphate (LZP) has been synthesized through a co-precipitation process and characterized by XRD and IR spectroscopy. The inhibitive performances of this pigment for corrosion of mild steel have been discussed in comparison with the zinc phosphate (ZP) in the pigment extract solution by means of EIS and in the epoxy coating by means of salt spray. The EIS and salt spray results revealed the superior corrosion inhibitive effect of LZP compared to ZP. Moreover, adhesion strength and dispersion stability of the pigmented epoxy coating showed the advantage of LZP compared to ZP

What's in a Gene? Pseudoexfoliation Syndrome and Pigment Dispersion Syndrome in the Same Patient.

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Pokrovskaya, Olya; O'Brien, Colm

2016-01-01

Pseudoexfoliation syndrome (PXS) and pigment dispersion syndrome (PDS) are two of the commonest disorders to produce secondary open-angle glaucoma through trabecular meshwork blockage. Each is a defined clinical entity, and while genetics likely play a significant role in the pathogenesis of both, the specific genes involved appear to be distinct. There is surprisingly little published in the literature regarding the coexistence of PDS and PXS in the same patient. We present the intriguing case of a patient who developed PDS in one eye and PXS in the other. This unusual case acts as a platform for an interesting discussion of the genomics of PXS and PDS.

What's in a Gene Pseudoexfoliation Syndrome and Pigment Dispersion Syndrome in the Same Patient

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Olya Pokrovskaya

2016-01-01

Full Text Available Pseudoexfoliation syndrome (PXS and pigment dispersion syndrome (PDS are two of the commonest disorders to produce secondary open-angle glaucoma through trabecular meshwork blockage. Each is a defined clinical entity, and while genetics likely play a significant role in the pathogenesis of both, the specific genes involved appear to be distinct. There is surprisingly little published in the literature regarding the coexistence of PDS and PXS in the same patient. We present the intriguing case of a patient who developed PDS in one eye and PXS in the other. This unusual case acts as a platform for an interesting discussion of the genomics of PXS and PDS.

Modification of cadmium pigments for colouring of polyolefins

International Nuclear Information System (INIS)

Kalinskaya, T.V.; Livshits, I.M.

1976-01-01

Modification conditions are studied of cadmium pigments, obtained by different methods, aliphatic acids(C 5 , C 8 and C 17 ). It is found, that cadmium pigments can adsorb acids with the number of atoms of carbon not less than 8. Stearic acid adsorption on lemon cadmium pigment taken as an example has shown the efficiency of pigment modification influence on its dispersancy in non-polar medium. Modification of yellow cadmium pigments of stearic acid makes possible to obtain pigment output forms ensuring a good particle distribution during polyolefine colouring

75 FR 38076 - Carbazole Violet Pigment 23 from India: Final Results of Antidumping Duty Administrative Review

Science.gov (United States)

2010-07-01

... the form of presscake and dry color. Pigment dispersions in any form (e.g., pigment dispersed in... DEPARTMENT OF COMMERCE International Trade Administration [A-533-838] Carbazole Violet Pigment 23... carbazole violet pigment 23 (CVP 23) from India. The review covers exports of this merchandise to the United...

A Severe Case of Pigmentary Glaucoma in a Child With a Family History of Pigment Dispersion Syndrome.

Science.gov (United States)

Aragno, Vittoria; Zeboulon, Pierre; Baudouin, Christophe; Labbé, Antoine

2016-08-01

To report a case of severe pigmentary glaucoma (PG) in a 13-year-old boy of a family affected by pigment dispersion syndrome (PDS). A 13-year-old child was referred to our hospital for severe bilateral glaucoma. A complete ophthalmologic evaluation including refraction, intraocular pressure, central corneal thickness, slit-lamp biomicroscopy, gonioscopy, fundus examination, and ultrasound biomicroscopy was performed. Family members were also examined and a family pedigree was obtained. Ophthalmologic examination revealed a severe bilateral PG with Krukenberg spindle and a widely open heavily pigmented iridocorneal angle. Ultrasound biomicroscopy showed a deep anterior chamber with pronounced iris concavity in both eyes. Within his family, his 15-year-old sister and 7-year-old brother were both affected by PDS diagnosed on gonioscopy findings. We report for the first time a severe case of pediatric PG with a family history of PDS. This case demonstrates that accurate screening is necessary in cases of familial PDS and PG, even in the pediatric population.

Drosophila DH31 Neuropeptide and PDF Receptor Regulate Night-Onset Temperature Preference.

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Goda, Tadahiro; Tang, Xin; Umezaki, Yujiro; Chu, Michelle L; Hamada, Fumika N

2016-11-16

Body temperature exhibits rhythmic fluctuations over a 24 h period (Refinetti and Menaker, 1992) and decreases during the night, which is associated with sleep initiation (Gilbert et al., 2004; Kräuchi, 2007a,b). However, the underlying mechanism of this temperature decrease is largely unknown. We have previously shown that Drosophila exhibit a daily temperature preference rhythm (TPR), in which their preferred temperatures increase during the daytime and then decrease at the transition from day to night (night-onset) (Kaneko et al., 2012). Because Drosophila are small ectotherms, their body temperature is very close to that of the ambient temperature (Stevenson, 1985), suggesting that their TPR generates their body temperature rhythm. Here, we demonstrate that the neuropeptide diuretic hormone 31 (DH31) and pigment-dispersing factor receptor (PDFR) contribute to regulate the preferred temperature decrease at night-onset. We show that PDFR and tethered-DH31 expression in dorsal neurons 2 (DN2s) restore the preferred temperature decrease at night-onset, suggesting that DH31 acts on PDFR in DN2s. Notably, we previously showed that the molecular clock in DN2s is important for TPR. Although PDF (another ligand of PDFR) is a critical factor for locomotor activity rhythms, Pdf mutants exhibit normal preferred temperature decreases at night-onset. This suggests that DH31-PDFR signaling specifically regulates a preferred temperature decrease at night-onset. Thus, we propose that night-onset TPR and locomotor activity rhythms are differentially controlled not only by clock neurons but also by neuropeptide signaling in the brain. Body temperature rhythm (BTR) is fundamental for the maintenance of functions essential for homeostasis, such as generating metabolic energy and sleep. One major unsolved question is how body temperature decreases dramatically during the night. Previously, we demonstrated that a BTR-like mechanism, referred to as temperature preference rhythm (TPR

75 FR 10759 - Carbazole Violet Pigment 23 from India: Initiation of Antidumping Duty Changed-Circumstances Review

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2010-03-09

... dispersions in any form (e.g., pigment dispersed in oleoresins, flammable solvents, water) are not included... DEPARTMENT OF COMMERCE International Trade Administration [A-533-838] Carbazole Violet Pigment 23... changed-circumstances review of the antidumping duty order on carbazole violet pigment 23 from India with...

Nomadic enhancers: tissue-specific cis-regulatory elements of yellow have divergent genomic positions among Drosophila species.

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Gizem Kalay

2010-11-01

Full Text Available cis-regulatory DNA sequences known as enhancers control gene expression in space and time. They are central to metazoan development and are often responsible for changes in gene regulation that contribute to phenotypic evolution. Here, we examine the sequence, function, and genomic location of enhancers controlling tissue- and cell-type specific expression of the yellow gene in six Drosophila species. yellow is required for the production of dark pigment, and its expression has evolved largely in concert with divergent pigment patterns. Using Drosophila melanogaster as a transgenic host, we examined the expression of reporter genes in which either 5' intergenic or intronic sequences of yellow from each species controlled the expression of Green Fluorescent Protein. Surprisingly, we found that sequences controlling expression in the wing veins, as well as sequences controlling expression in epidermal cells of the abdomen, thorax, and wing, were located in different genomic regions in different species. By contrast, sequences controlling expression in bristle-associated cells were located in the intron of all species. Differences in the precise pattern of spatial expression within the developing epidermis of D. melanogaster transformants usually correlated with adult pigmentation in the species from which the cis-regulatory sequences were derived, which is consistent with cis-regulatory evolution affecting yellow expression playing a central role in Drosophila pigmentation divergence. Sequence comparisons among species favored a model in which sequential nucleotide substitutions were responsible for the observed changes in cis-regulatory architecture. Taken together, these data demonstrate frequent changes in yellow cis-regulatory architecture among Drosophila species. Similar analyses of other genes, combining in vivo functional tests of enhancer activity with in silico comparative genomics, are needed to determine whether the pattern of

Identification of Atg2 and ArfGAP1 as Candidate Genetic Modifiers of the Eye Pigmentation Phenotype of Adaptor Protein-3 (AP-3) Mutants in Drosophila melanogaster.

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Rodriguez-Fernandez, Imilce A; Dell'Angelica, Esteban C

2015-01-01

The Adaptor Protein (AP)-3 complex is an evolutionary conserved, molecular sorting device that mediates the intracellular trafficking of proteins to lysosomes and related organelles. Genetic defects in AP-3 subunits lead to impaired biogenesis of lysosome-related organelles (LROs) such as mammalian melanosomes and insect eye pigment granules. In this work, we have performed a forward screening for genetic modifiers of AP-3 function in the fruit fly, Drosophila melanogaster. Specifically, we have tested collections of large multi-gene deletions--which together covered most of the autosomal chromosomes-to identify chromosomal regions that, when deleted in single copy, enhanced or ameliorated the eye pigmentation phenotype of two independent AP-3 subunit mutants. Fine-mapping led us to define two non-overlapping, relatively small critical regions within fly chromosome 3. The first critical region included the Atg2 gene, which encodes a conserved protein involved in autophagy. Loss of one functional copy of Atg2 ameliorated the pigmentation defects of mutants in AP-3 subunits as well as in two other genes previously implicated in LRO biogenesis, namely Blos1 and lightoid, and even increased the eye pigment content of wild-type flies. The second critical region included the ArfGAP1 gene, which encodes a conserved GTPase-activating protein with specificity towards GTPases of the Arf family. Loss of a single functional copy of the ArfGAP1 gene ameliorated the pigmentation phenotype of AP-3 mutants but did not to modify the eye pigmentation of wild-type flies or mutants in Blos1 or lightoid. Strikingly, loss of the second functional copy of the gene did not modify the phenotype of AP-3 mutants any further but elicited early lethality in males and abnormal eye morphology when combined with mutations in Blos1 and lightoid, respectively. These results provide genetic evidence for new functional links connecting the machinery for biogenesis of LROs with molecules implicated in

Identification of Atg2 and ArfGAP1 as Candidate Genetic Modifiers of the Eye Pigmentation Phenotype of Adaptor Protein-3 (AP-3 Mutants in Drosophila melanogaster.

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Imilce A Rodriguez-Fernandez

Full Text Available The Adaptor Protein (AP-3 complex is an evolutionary conserved, molecular sorting device that mediates the intracellular trafficking of proteins to lysosomes and related organelles. Genetic defects in AP-3 subunits lead to impaired biogenesis of lysosome-related organelles (LROs such as mammalian melanosomes and insect eye pigment granules. In this work, we have performed a forward screening for genetic modifiers of AP-3 function in the fruit fly, Drosophila melanogaster. Specifically, we have tested collections of large multi-gene deletions--which together covered most of the autosomal chromosomes-to identify chromosomal regions that, when deleted in single copy, enhanced or ameliorated the eye pigmentation phenotype of two independent AP-3 subunit mutants. Fine-mapping led us to define two non-overlapping, relatively small critical regions within fly chromosome 3. The first critical region included the Atg2 gene, which encodes a conserved protein involved in autophagy. Loss of one functional copy of Atg2 ameliorated the pigmentation defects of mutants in AP-3 subunits as well as in two other genes previously implicated in LRO biogenesis, namely Blos1 and lightoid, and even increased the eye pigment content of wild-type flies. The second critical region included the ArfGAP1 gene, which encodes a conserved GTPase-activating protein with specificity towards GTPases of the Arf family. Loss of a single functional copy of the ArfGAP1 gene ameliorated the pigmentation phenotype of AP-3 mutants but did not to modify the eye pigmentation of wild-type flies or mutants in Blos1 or lightoid. Strikingly, loss of the second functional copy of the gene did not modify the phenotype of AP-3 mutants any further but elicited early lethality in males and abnormal eye morphology when combined with mutations in Blos1 and lightoid, respectively. These results provide genetic evidence for new functional links connecting the machinery for biogenesis of LROs with

Biometric analysis of pigment dispersion syndrome using anterior segment optical coherence tomography.

Science.gov (United States)

Aptel, Florent; Beccat, Sylvain; Fortoul, Vincent; Denis, Philippe

2011-08-01

To compare anterior chamber volume (ACV), iris volume, and iridolenticular contact (ILC) area before and after laser peripheral iridotomy (LPI) in eyes with pigment dispersion syndrome (PDS) using anterior segment optical coherence tomography (AS OCT) and image processing software. Cross-sectional study. Eighteen eyes of 18 patients with PDS; 30 eyes of 30 controls matched for age, gender, and refraction. Anterior segment OCT imaging was performed in all eyes before LPI and 1, 4, and 12 weeks after LPI. At each visit, 12 cross-sectional images of the AS were taken: 4 in bright conditions with accommodation (accommodation), 4 in bright conditions without accommodation (physiological miosis), and 4 under dark conditions (physiologic mydriasis). Biometric parameters were estimated using AS OCT radial sections and customized image-processing software. Anterior chamber volume, iris volume-to-length ratio, ILC area, AS OCT anterior chamber depth, and A-scan ultrasonography axial length. Before LPI, PDS eyes had a significantly greater ACV and ILC area than control eyes (PPigment dispersion syndrome eyes do not have an iris that is abnormally large, relative to the AS size, but have a weakly resistant iris that is stretched and pushed against the lens when there is a pressure difference across the iris. The author(s) have no proprietary or commercial interest in any materials discussed in this article. Copyright © 2011 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Pigment granule translocation in red ovarian chromatophores from the palaemonid shrimp Macrobrachium olfersi (Weigmann, 1836): functional roles for the cytoskeleton and its molecular motors.

Science.gov (United States)

Milograna, Sarah Ribeiro; Ribeiro, Márcia Regina; Baqui, Munira Muhammad Abdel; McNamara, John Campbell

2014-12-01

The binding of red pigment concentrating hormone (RPCH) to membrane receptors in crustacean chromatophores triggers Ca²⁺/cGMP signaling cascades that activate cytoskeletal motors, driving pigment granule translocation. We investigate the distributions of microfilaments and microtubules and their associated molecular motors, myosin and dynein, by confocal and transmission electron microscopy, evaluating a functional role for the cytoskeleton in pigment translocation using inhibitors of polymer turnover and motor activity in vitro. Microtubules occupy the chromatophore cell extensions whether the pigment granules are aggregated or dispersed. The inhibition of microtubule turnover by taxol induces pigment aggregation and inhibits re-dispersion. Phalloidin-FITC actin labeling, together with tannic acid fixation and ultrastructural analysis, reveals that microfilaments form networks associated with the pigment granules. Actin polymerization induced by jasplaquinolide strongly inhibits RPCH-induced aggregation, causes spontaneous pigment dispersion, and inhibits pigment re-dispersion. Inhibition of actin polymerization by latrunculin-A completely impedes pigment aggregation and re-dispersion. Confocal immunocytochemistry shows that non-muscle myosin II (NMMII) co-localizes mainly with pigment granules while blebbistatin inhibition of NMMII strongly reduces the RPCH response, also inducing spontaneous pigment dispersion. Myosin II and dynein also co-localize with the pigment granules. Inhibition of dynein ATPase by erythro-9-(2-hydroxy-3-nonyl) adenine induces aggregation, inhibits RPCH-triggered aggregation, and inhibits re-dispersion. Granule aggregation and dispersion depend mainly on microfilament integrity although microtubules may be involved. Both cytoskeletal polymers are functional only when subunit turnover is active. Myosin and dynein may be the molecular motors that drive pigment aggregation. These mechanisms of granule translocation in crustacean

[Long-term efficacy of laser peripheral iridotomy in preventing progression in eyes with pigment dispersion syndrome].

Science.gov (United States)

Qing, Guoping; Zhang, Shaodan; Wang, Huaizhou; Wang, Tao; Wang, Shuhua; Chen, Hong; Wang, Hua; Wang, Ningli

2014-07-01

To evaluate the long-term efficacy of laser peripheral iridotomy (LPI) in preventing deterioration in eyes with pigment dispersion syndrome (PDS). A cohort study. Nineteen patients with PDS were treated with LPI and followed up periodically in Beijing Tongren Eye Center from May 2006 to April 2007. One eye of each patient was chosen randomly for the study. Main investigating items included iris configuration, intraocular pressure (IOP), anterior chamber pigmentation, and visual field analysis. The average follow-up period was (6.5 ± 0.3) years. A paired sample t test was used to determine whether there is a significant difference between average values of pre- and post-LPI IOP and mean deviation of Humphrey visual field analysis in these PDS eyes. The average age of the 19 patients were (35.8 ± 7.1) years on admission. The initial IOP of the 19 eyes was (24.7 ± 2.2) mmHg (1 mmHg = 0.133 kPa) before LPI. The mean deviation (MD) of Humphrey visual field analysis (VFA) were (-1.82 ± 1.26) dB (-4.34--0.28 dB) . All 19 eyes had concave iris and heavy trabecular pigmentation. The iris became flat in all PDS eyes after the laser treatment. At the last follow-up visit, the average IOP was 14.8 ± 2.0 (12-20) mmHg, which was statistically lower than that of baseline (t = 11.49, P pigmentation reduced obviously in 16 eyes. No deterioration or new visual field defect was detected in any of the PDS eyes. MD of the last VFA was -1.79 ± 1.21 (-4.39--0.21 dB) . There was no statistical difference between MD of the last VFA and baseline (t = -0.26, P = 0.798). The long-term follow-up results showed that LPI prevents progression effectively in eyes with PDS.

75 FR 29719 - Carbazole Violet Pigment 23 From India: Continuation of Countervailing Duty Order

Science.gov (United States)

2010-05-27

..., paste, wet cake) and finished pigment in the form of presscake and dry color. Pigment dispersions in any... DEPARTMENT OF COMMERCE International Trade Administration [C-533-839] Carbazole Violet Pigment 23... Pigment 23 From India, 69 FR 77995 (December 29, 2004). On November 2, 2009, the Department initiated and...

Practice for dispersing pigments and other materials into water-based suspensions with a high intensity mixer

CERN Document Server

American Society for Testing and Materials. Philadelphia

2002-01-01

1.1 In preparing ceramic glazes and slurries for use, it is often necessary to add pigments to develop a desired fired color, to incorporate viscosity control agents for developing, or providing to develop the desired thickness of the glaze on the ware, to add materials which stabilize the suspension, control bacterial growth, and develop the desired hardness of the glaze on the ware to allow moving and handling before firing. While it is convenient to add these materials to the glaze or slurry in the dry form, it is often possible to use slurries where these materials are dispersed in a slurry and the slurry then added to the liquid glaze. Regardless of the state of the additions (dry or slurry), the dispersion can be done efficiently and effectively by the use of a high intensity mixer (sometimes referred to as a dissolver) and the procedure used is described here. 1.2 The values stated in SI units are to be regarded as the standard. This standard does not purport to address all of the safety concerns, if...

Evolution of pigment-dispersing factor neuropeptides in Panarthropoda: Insights from Onychophora (velvet worms) and Tardigrada (water bears).

Science.gov (United States)

Mayer, Georg; Hering, Lars; Stosch, Juliane M; Stevenson, Paul A; Dircksen, Heinrich

2015-09-01

Pigment-dispersing factor (PDF) denotes a conserved family of homologous neuropeptides present in several invertebrate groups, including mollusks, nematodes, insects, and crustaceans (referred to here as pigment-dispersing hormone [PDH]). With regard to their encoding genes (pdf, pdh), insects possess only one, nematodes two, and decapod crustaceans up to three, but their phylogenetic relationship is unknown. To shed light on the origin and diversification of pdf/pdh homologs in Panarthropoda (Onychophora + Tardigrada + Arthropoda) and other molting animals (Ecdysozoa), we analyzed the transcriptomes of five distantly related onychophorans and a representative tardigrade and searched for putative pdf homologs in publically available genomes of other protostomes. This revealed only one pdf homolog in several mollusk and annelid species; two in Onychophora, Priapulida, and Nematoda; and three in Tardigrada. Phylogenetic analyses suggest that the last common ancestor of Panarthropoda possessed two pdf homologs, one of which was lost in the arthropod or arthropod/tardigrade lineage, followed by subsequent duplications of the remaining homolog in some taxa. Immunolocalization of PDF-like peptides in six onychophoran species, by using a broadly reactive antibody that recognizes PDF/PDH peptides in numerous species, revealed an elaborate system of neurons and fibers in their central and peripheral nervous systems. Large varicose projections in the heart suggest that the PDF neuropeptides functioned as both circulating hormones and locally released transmitters in the last common ancestor of Onychophora and Arthropoda. The lack of PDF-like-immunoreactive somata associated with the onychophoran optic ganglion conforms to the hypothesis that onychophoran eyes are homologous to the arthropod median ocelli. © 2015 Wiley Periodicals, Inc.

75 FR 62765 - Carbazole Violet Pigment 23 From India: Final Results of Antidumping Duty Changed-Circumstances...

Science.gov (United States)

2010-10-13

... finished pigment in the form of presscake and dry color. Pigment dispersions in any form (e.g., pigment... DEPARTMENT OF COMMERCE International Trade Administration [A-533-838] Carbazole Violet Pigment 23... Act), that Meghmani Pigments is the successor-in-interest to Alpanil Industries. DATES: Effective Date...

Evaluating the Autonomy of the Drosophila Circadian Clock in Dissociated Neuronal Culture.

Science.gov (United States)

Sabado, Virginie; Vienne, Ludovic; Nagoshi, Emi

2017-01-01

Circadian behavioral rhythms offer an excellent model to study intricate interactions between the molecular and neuronal mechanisms of behavior. In mammals, pacemaker neurons in the suprachiasmatic nucleus (SCN) generate rhythms cell-autonomously, which are synchronized by the network interactions within the circadian circuit to drive behavioral rhythms. However, whether this principle is universal to circadian systems in animals remains unanswered. Here, we examined the autonomy of the Drosophila circadian clock by monitoring transcriptional and post-transcriptional rhythms of individual clock neurons in dispersed culture with time-lapse microscopy. Expression patterns of the transcriptional reporter show that CLOCK/CYCLE (CLK/CYC)-mediated transcription is constantly active in dissociated clock neurons. In contrast, the expression profile of the post-transcriptional reporter indicates that PERIOD (PER) protein levels fluctuate and ~10% of cells display rhythms in PER levels with periods in the circadian range. Nevertheless, PER and TIM are enriched in the cytoplasm and no periodic PER nuclear accumulation was observed. These results suggest that repression of CLK/CYC-mediated transcription by nuclear PER is impaired, and thus the negative feedback loop of the molecular clock is incomplete in isolated clock neurons. We further demonstrate that, by pharmacological assays using the non-amidated form of neuropeptide pigment-dispersing factor (PDF), which could be specifically secreted from larval LNvs and adult s-LNvs, downstream events of the PDF signaling are partly impaired in dissociated larval clock neurons. Although non-amidated PDF is likely to be less active than the amidated one, these results point out the possibility that alteration in PDF downstream signaling may play a role in dampening of molecular rhythms in isolated clock neurons. Taken together, our results suggest that Drosophila clocks are weak oscillators that need to be in the intact circadian

Evaluating the Autonomy of the Drosophila Circadian Clock in Dissociated Neuronal Culture

Directory of Open Access Journals (Sweden)

Virginie Sabado

2017-10-01

Full Text Available Circadian behavioral rhythms offer an excellent model to study intricate interactions between the molecular and neuronal mechanisms of behavior. In mammals, pacemaker neurons in the suprachiasmatic nucleus (SCN generate rhythms cell-autonomously, which are synchronized by the network interactions within the circadian circuit to drive behavioral rhythms. However, whether this principle is universal to circadian systems in animals remains unanswered. Here, we examined the autonomy of the Drosophila circadian clock by monitoring transcriptional and post-transcriptional rhythms of individual clock neurons in dispersed culture with time-lapse microscopy. Expression patterns of the transcriptional reporter show that CLOCK/CYCLE (CLK/CYC-mediated transcription is constantly active in dissociated clock neurons. In contrast, the expression profile of the post-transcriptional reporter indicates that PERIOD (PER protein levels fluctuate and ~10% of cells display rhythms in PER levels with periods in the circadian range. Nevertheless, PER and TIM are enriched in the cytoplasm and no periodic PER nuclear accumulation was observed. These results suggest that repression of CLK/CYC-mediated transcription by nuclear PER is impaired, and thus the negative feedback loop of the molecular clock is incomplete in isolated clock neurons. We further demonstrate that, by pharmacological assays using the non-amidated form of neuropeptide pigment-dispersing factor (PDF, which could be specifically secreted from larval LNvs and adult s-LNvs, downstream events of the PDF signaling are partly impaired in dissociated larval clock neurons. Although non-amidated PDF is likely to be less active than the amidated one, these results point out the possibility that alteration in PDF downstream signaling may play a role in dampening of molecular rhythms in isolated clock neurons. Taken together, our results suggest that Drosophila clocks are weak oscillators that need to be in the

On Dispersion in Visual Photoreceptors

NARCIS (Netherlands)

Stavenga, D.G.; Barneveld, H.H. van

1975-01-01

An idealized visual pigment absorbance spectrum is used together with a Kramers-Kronig dispersion relation to calculate the contribution of the visual pigment to the refractive index of the fly photoreceptor. It appears that an absorption coefficient of 0.010 µm-1 results in a refractive index

NON-AQUEOUS PIGMENTED INKJET INKS

NARCIS (Netherlands)

DEROOVER, GEERT; Bernaerts, Katrien; HOOGMARTENS, IVAN

2010-01-01

A non-aqueous inkjet ink includes a benzimidazolone pigment and a polymeric dispersant according to Formula (I): wherein, T represents hydrogen or a polymerization terminating group; Z represents the residue of polyethyleneimine having a number-average molecular weight of at least 100; A represents

Non-aqueous pigmented inkjet inks

NARCIS (Netherlands)

HOOGMARTENS, IVAN; Bernaerts, Katrien; DEROOVER, GEERT

2008-01-01

A non-aqueous inkjet ink comprising C.I. Pigment Yellow 150 and a polymeric dispersant according to Formula (I): wherein, T represents hydrogen or a polymerization terminating group; Z represents the residue of polyethyleneimine having a number-average molecular weight of at least 100; A represents

THE PIGMENT IMPACT ON RHEOLOGICAL PROPERTIES OF ANTICORROSION PROTECTION COVERS OF MANUFACTURED RAILWAY TRANSPORT CONSTRUCTIONS

Directory of Open Access Journals (Sweden)

A. N. Plugin

2010-03-01

Full Text Available In the article the influence of the electro-surface potential value on change of the suspension viscosity values of pigments was investigated. It was done for pigments different in chemical nature – titanium oxide and ferric oxide. It was demonstrated that at equal dispersed phase concentrations the higher viscosity value was shown by systems with pigment TiO2 and the lower one – with Fe2O3. This fact correlates well with the absolute values of electrosurface potentials of the pigments studied. The active centers of the particles produce structuring effect on the dispersed medium molecules thus increasing the system viscosity.

76 FR 55003 - Carbazole Violet Pigment 23 From the People's Republic of China: Preliminary Intent To Rescind...

Science.gov (United States)

2011-09-06

... finished pigment in the form of presscake and dry color. Pigment dispersions in any form (e.g., pigments... DEPARTMENT OF COMMERCE International Trade Administration [A-570-892] Carbazole Violet Pigment 23... antidumping duty order on carbazole violet pigment 23 (CVP 23) from the People's Republic of China (PRC). This...

77 FR 1463 - Carbazole Violet Pigment 23 From the People's Republic of China: Final Rescission of Antidumping...

Science.gov (United States)

2012-01-10

... finished pigment in the form of presscake and dry color. Pigment dispersions in any form (e.g., pigments... DEPARTMENT OF COMMERCE International Trade Administration [A-570-892] Carbazole Violet Pigment 23... administrative review of the antidumping duty order on carbazole violet pigment 23 (CVP-23) from the People's...

75 FR 33243 - Carbazole Violet Pigment 23 From India: Final Results of Countervailing Duty Administrative Review

Science.gov (United States)

2010-06-11

... powder, paste, wet cake) and finished pigment in the form of presscake and dry color. Pigment dispersions... DEPARTMENT OF COMMERCE International Trade Administration [C-533-839] Carbazole Violet Pigment 23... countervailing duty order on carbazole violet pigment 23 from India for the period January 1, 2007, through...

Recurrent uveitis and pigment dispersion in an eye with in-the-bag acrylic foldable intraocular lens.

Science.gov (United States)

Thakur, Monica; Bhatia, Prashant; Chandrasekhar, Garudadri; Senthil, Sirisha

2016-02-26

Phacoemulsification with in-the-bag intraocular lens (IOL) implantation is the standard procedure for cataract surgery. Pigment dispersion and uveitis can result when an IOL is placed in the sulcus. We report a case of a 64-year-old woman, with pigmentary glaucoma, who developed recurrent uveitis following uneventful cataract surgery and an in-the-bag hydrophobic acrylic IOL implant. Recurrent uveitis did not subside despite use of topical steroids over 3 months. Dilated examination revealed capsulophimosis with anterior dislocation of the IOL haptic. The mechanical trauma to the iris due to the displaced haptic was implicated as the cause of recurrent uveitis, which completely resolved after capsular excision and IOL repositioning. This case illustrates a rare cause of recurrent uveitis due to IOL haptic dislocation following severe capsulophimosis. 2016 BMJ Publishing Group Ltd.

Pigment and terracotta analyses of Hellenistic figurines in Crete

International Nuclear Information System (INIS)

Maravelaki-Kalaitzaki, P.; Kallithrakas-Kontos, N.

2003-01-01

The results of the analyses performed on blue, black, brown, orange, white and purple pigments decorating Hellenistic figurines, excavated in a rock-cut tomb in the archaeological zone of Chania, Crete, Greece, are presented. Different spectroscopic techniques, such as Fourier transform infrared spectroscopy and energy dispersive X-ray fluorescence identified the compounds present in the chromatic layers. X-ray diffraction analysis gave complementary information and further support to the spectral assignments. Optical microscopy revealed the nature and sequence of the pigmented layer on the terracotta. Several precious pigments, such as Egyptian blue for the bluish areas, Tyrian purple for the purple ones, and the rare huntite for the white-pigmented areas were identified among the studied pigmented areas. The pigment analysis provides information on the technical aspects related to terracotta manufacture and preservation, and promotes historical indications on cultural and commercial changes among the Mediterranean civilisations

75 FR 13257 - Carbazole Violet Pigment 23 from India: Final Results of the Expedited Five-year (Sunset) Review...

Science.gov (United States)

2010-03-19

...) and finished pigment in the form of presscake and dry color. Pigment dispersions in any form (e.g... DEPARTMENT OF COMMERCE International Trade Administration [C-533-839] Carbazole Violet Pigment 23... countervailing duty (CVD) order on Carbazole Violet Pigment 23 (CVP-23) [[Page 13258

Fish pigmentation and the melanocortin system.

Science.gov (United States)

Cal, Laura; Suarez-Bregua, Paula; Cerdá-Reverter, José Miguel; Braasch, Ingo; Rotllant, Josep

2017-09-01

The melanocortin system is a complex neuroendocrine signaling mechanism involved in numerous physiological processes in vertebrates, including pigmentation, steroidogenesis and metabolic control. This review focuses at one of its most fascinating function in fish, its regulatory role in the control of pigmentation, in which the melanocortin 1 receptor (Mc1r), its agonist α-melanocyte stimulating hormone (α-Msh), and the endogenous antagonist agouti signaling protein (Asip1) are the main players. Functional control of Mc1r, which is highly expressed in fish skin and whose activation stimulates melanin production and melanosome dispersion in fish melanophores, is considered a key mechanism for vertebrate pigment phenotypes. The α-Msh peptide, the most documented Mc1r agonist involved in pigmentation, is produced in the pituitary gland, activating melanin synthesis by binding to Mc1r in fish melanophores. Finally, Asip1 is the putative factor for establishing the evolutionarily conserved dorso-ventral pigment pattern found across vertebrates. However, we are just starting to understand how other melanocortin system components are acting in this complex regulatory network. Copyright © 2017 Elsevier Inc. All rights reserved.

Autoreceptor Control of Peptide/Neurotransmitter Corelease from PDF Neurons Determines Allocation of Circadian Activity in Drosophila

Directory of Open Access Journals (Sweden)

Charles Choi

2012-08-01

Full Text Available Drosophila melanogaster flies concentrate behavioral activity around dawn and dusk. This organization of daily activity is controlled by central circadian clock neurons, including the lateral-ventral pacemaker neurons (LNvs that secrete the neuropeptide PDF (pigment dispersing factor. Previous studies have demonstrated the requirement for PDF signaling to PDF receptor (PDFR-expressing dorsal clock neurons in organizing circadian activity. Although LNvs also express functional PDFR, the role of these autoreceptors has remained enigmatic. Here, we show that (1 PDFR activation in LNvs shifts the balance of circadian activity from evening to morning, similar to behavioral responses to summer-like environmental conditions, and (2 this shift is mediated by stimulation of the Gα,s-cAMP pathway and a consequent change in PDF/neurotransmitter corelease from the LNvs. These results suggest another mechanism for environmental control of the allocation of circadian activity and provide new general insight into the role of neuropeptide autoreceptors in behavioral control circuits.

Ultrasound biomicroscopy and iris pigment dispersion: a case--control study.

Science.gov (United States)

Mora, P; Sangermani, C; Ghirardini, S; Carta, A; Ungaro, N; Gandolfi, Sa

2010-04-01

The study involved eyes affected by pigment dispersion syndrome (PDS) or pigmentary glaucoma (PG) investigated by ultrasound biomicroscopy (UBM). Different irido-corneal parameters were assessed and compared with those from healthy controls. The aim was to investigate the capacity of the UBM in differentiating the cases and, potentially, in confirming the pathogenic mechanisms. Patients with a first diagnosis of PDS or PG were included. A cohort of healthy volunteers matched for sex, age and refractive errors was recruited. All underwent UBM examination: the following parameters were assessed in relaxed and stimulated accommodative state in one eye: iris-lens contact (ILC), irido-corneal angle (ICA) and iris concavity (IC). A receiver operating characteristic (ROC) analysis assessed the ability of UBM to discriminate between subjects with and without PDS/PG. There were 24 eyes in the case group: four diagnosed as PG and the remaining 20 as PDS. There were 25 eyes in the control group. The two groups were statistically superimposable except for baseline intraocular pressure, which was higher in the case group (p=0.0001). All UBM parameters were statistically different between the two groups. ICA in near vision was the best-performing parameter, reaching a sensitivity (=specificity) of 0.875 with a cut-off at 53.0 degrees . The second most sensitive parameter was IC, still in near vision. All UBM parameters examined were statistically different between the two groups. ROC analysis showed ICA and IC in near vision to be the most discriminatory parameters. This evidence confirms the importance of iris movements in inducing the particular features of PDS/PG.

Novel environment friendly corrosion inhibitor pigments based on naturally occurring clay minerals

Energy Technology Data Exchange (ETDEWEB)

Bohm, S.; McMurray, H.N.; Worsley, D.A. [University of Wales, Swansea (United Kingdom). Dept. of Materials Engineering; Powell, S.M. [University of Wales, Swansea (United Kingdom). Engineering Doktorate Centre

2001-12-01

Novel, ceramic, corrosion inhibitor pigments consisting of cerium (III) and calcium (II) cation exchanged bentonites have been shown to provide effective cut-edge corrosion resistance in organic coated galvanised steel. The bentonite pigments were prepared from a naturally occurring (Wyoming) bentonite with a cation-exchange-capacity of 0.7 milli-equivalents per gram. Cation exchange was carried out by repeated washing with aqueous solutions of cerium (III) chloride and calcium (II) chloride to produce bentonites containing 31500 ppm exchangeable cerium (III) and 13500 ppm exchangeable calcium (II) respectively. The resulting bentonite pigments were dispersed in a polyester-resin based primer paint system to give a pigment volume concentration of 19%. For comparison, two similar primer systems were prepared containing a commercial calcium (II) exchanged silica pigment Shieldex: 60 000 ppm calcium (II) and a strontium chromate dispersion, both with a 19% pigment volume concentration. All three primer systems were applied (5 {mu}m) to the zinc surface of galvanised 0.7 mm gauge sheet steel and overcoated with an architectural polyester topcoat (18 {mu}m). The performance of the inhibitor pigments was compared by measuring the rate of corrosion-driven organic coating delamination from the cut edge of samples during 1000 h of salt-spray testing. The calcium (II) bentonite pigment exhibited an anti-delamination performance similar to that of strontium chromate but superior to that of Shieldex. However, the cerium (III) bentonite pigment was superior in performance to both strontium chromate and Shieldex. Thus, the bentonite pigments represent promising, environmentally friendly, ion-exchange corrosion inhibitors which exhibit good anti-delamination performance by comparison with current commercial systems. (orig.)

Fine-structural changes in the midgut of old Drosophila melanogaster

Science.gov (United States)

Anton-Erxleben, F.; Miquel, J.; Philpott, D. E.

1983-01-01

Senescent fine-structural changes in the midgut of Drosophila melanogaster are investigated. A large number of midgut mitochondria in old flies exhibit nodular cristae and a tubular system located perpendicular to the normal cristae orientation. Anterior intestinal cells show a senescent accumulation of age pigment, either with a surrounding two-unit membrane or without any membrane. The predominant localization of enlarged mitochondria and pigment in the luminal gut region may be related to the polarized metabolism of the intestinal cells. Findings concur with previous observations of dense-body accumulations and support the theory that mitochondria are involved in the aging of fixed post-mitotic cells. Demonstrated by statistical analyses is that mitochondrial size increase is related to mitochondrial variation increase.

La iridotomía periférica con Nd YAG láser en el síndrome de dispersión pigmentaria/glaucoma pigmentario Nd YAG laser peripheral iridotomy in the pigment dispersion syndrome/pigmentary glaucoma

Directory of Open Access Journals (Sweden)

Francisco García González

2002-06-01

Full Text Available En 13 ojos con diagnóstico de síndrome de dispersión pigmentaria y 5 con glaucoma pigmentario, inicialmente se evaluaron la presión intraocular, los signos de dispersión pigmentaria, la relación excavación-papila y las alteraciones del campo visual; se realizó iridotomía periférica Nd YAG láser en los ojos con este síndrome y trabeculectomía a los que presentaban glaucoma pigmentario. Se chequearon cada 4 meses hasta 24 meses. Once ojos con iris cóncavo mostraron aplanamiento del iris y 2 con iris convexos no variaron con la iridotomía láser; en los 18 ojos disminuyeron evidentemente los signos de dispersión pigmentaria y la presión intraocular permaneció estable, la cual mejoró en los tratados con la trabeculectomía. En el síndrome de dispersión pigmentaria es muy frecuente la configuración cóncava del iris; la iridotomía lo aplana y evita el roce iridozonular, disminuyendo la dispersión y deposición de pigmento que prevendría el aumento de la presión intraocular y el glaucoma pigmentario.The intraocular pressure, the signs of pigment dispersion, the excavation-papilla relation and the alterations of the visual field were initially evaluated in 13 eyes with diagnosis of pigment dispersion syndrome and 5 with pigmentary glaucoma. Nd YAG laser perypheral iridotomy was performed in patients with this syndrome, whereas those who presented pigmentary glaucoma underwent trabeculectomy. They were checked every 4 months up to 24 months. 11 eyes with concave iris showed flattening of the iris and 2 with convex iris did not vary with laser iridotomy. An evident reduction of the signs of pigment dispersion was observed in the 18 eyes. The intraocular pressure remained stable and it improved in those treated with trabeculectomy. In the pigment dispersion syndrome it is very frequent the concave configuration of the iris; the iridotomy flattens it and avoids the iridozonular friction, reducing the dispersion and deposition of

Autoreceptor Modulation of Peptide/Neurotransmitter Co-release from PDF Neurons Determines Allocation of Circadian Activity in Drosophila

Science.gov (United States)

Choi, Charles; Cao, Guan; Tanenhaus, Anne K.; McCarthy, Ellena v.; Jung, Misun; Schleyer, William; Shang, Yuhua; Rosbash, Michael; Yin, Jerry C.P.; Nitabach, Michael N.

2012-01-01

Drosophila melanogaster flies concentrate behavioral activity around dawn and dusk. This organization of daily activity is controlled by central circadian clock neurons, including the lateral ventral pacemaker neurons (LNvs) that secrete the neuropeptide PDF (Pigment Dispersing Factor). Previous studies have demonstrated the requirement for PDF signaling to PDF receptor (PDFR)-expressing dorsal clock neurons in organizing circadian activity. While LNvs also express functional PDFR, the role of these autoreceptors has remained enigmatic. Here we show that (1) PDFR activation in LNvs shifts the balance of circadian activity from evening to morning, similar to behavioral responses to summer-like environmental conditions and (2) this shift is mediated by stimulation of the Ga,s-cAMP pathway and a consequent change in PDF/neurotransmitter co-release from the LNvs. These results suggest a novel mechanism for environmental control of the allocation of circadian activity and provide new general insight into the role of neuropeptide autoreceptors in behavioral control circuits. PMID:22938867

The Effect of Pigment Volume Concentration on Film Formation and the Mechanical Properties of Coatings Based on Water-Dispersion Paint and Varnish Materials

Science.gov (United States)

Kasyanenko, I. M.; Kramarenko, V. Yu.

2018-01-01

The effect of pigment volume concentration (PVC) on the film formation process and properties of coatings based on the water dispersion of an Acronal 290D styrene-acrylate copolymer and a pigment/filler system used for paint materials in construction was investigated. An analysis of the results obtained is performed within the framework of the concept of the critical PVC. It is shown that the initiation and development of internal stresses occurs the faster, the higher the PVC, but the position of the maximum or the inflection point of the internal stress-drying time curve complies with a universal value of the solid volume content in the compositions. It is found that the internal stresses and Young's modulus of coatings are characterized by an extreme concentration relation that, for the reduced elastic modulus, can be described by a system of equations based on the Halpin-Tsai equation.

Gingival pigmentation beneath a metallic crown

International Nuclear Information System (INIS)

Sakai, T.; Hirayasu, R.; Sakai, H.; Hashimoto, N.

1988-01-01

Light and electron microscopic studies and energy dispersive X-ray analysis disclosed that the essential cause of gingival discoloration following the placement of a metallic crown, was marked deposition of melanin pigment. Deposition of melanin pigment was observed in epithelial cells, on basement membranes, and in fibroblasts, macrophages and among intercellular ground substance of the proprial layer. Brown or dark brown colored granules were observed in the deep portion of the proprial layer. Some metallic elements as silver and sulfur were detected. It was presumed that these materials were dental metals accidentally implanted in gingival tissues during the therapeutic procedure. The deposition of melanin pigment closely corresponded with mucosal tissue where these materials were present in the deep portion of the proprial layer. These findings suggested that these materials influenced the physiological metabolism of melanin and induced its pathological deposition in the proprial tissue. (author)

High Throughput Measurement of Locomotor Sensitization to Volatilized Cocaine in Drosophila melanogaster.

Science.gov (United States)

Filošević, Ana; Al-Samarai, Sabina; Andretić Waldowski, Rozi

2018-01-01

Drosophila melanogaster can be used to identify genes with novel functional roles in neuronal plasticity induced by repeated consumption of addictive drugs. Behavioral sensitization is a relatively simple behavioral output of plastic changes that occur in the brain after repeated exposures to drugs of abuse. The development of screening procedures for genes that control behavioral sensitization has stalled due to a lack of high-throughput behavioral tests that can be used in genetically tractable organism, such as Drosophila . We have developed a new behavioral test, FlyBong, which combines delivery of volatilized cocaine (vCOC) to individually housed flies with objective quantification of their locomotor activity. There are two main advantages of FlyBong: it is high-throughput and it allows for comparisons of locomotor activity of individual flies before and after single or multiple exposures. At the population level, exposure to vCOC leads to transient and concentration-dependent increase in locomotor activity, representing sensitivity to an acute dose. A second exposure leads to further increase in locomotion, representing locomotor sensitization. We validate FlyBong by showing that locomotor sensitization at either the population or individual level is absent in the mutants for circadian genes period (per) , Clock (Clk) , and cycle (cyc) . The locomotor sensitization that is present in timeless (tim) and pigment dispersing factor (pdf) mutant flies is in large part not cocaine specific, but derived from increased sensitivity to warm air. Circadian genes are not only integral part of the neural mechanism that is required for development of locomotor sensitization, but in addition, they modulate the intensity of locomotor sensitization as a function of the time of day. Motor-activating effects of cocaine are sexually dimorphic and require a functional dopaminergic transporter. FlyBong is a new and improved method for inducing and measuring locomotor sensitization

High Throughput Measurement of Locomotor Sensitization to Volatilized Cocaine in Drosophila melanogaster

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Ana Filošević

2018-02-01

Full Text Available Drosophila melanogaster can be used to identify genes with novel functional roles in neuronal plasticity induced by repeated consumption of addictive drugs. Behavioral sensitization is a relatively simple behavioral output of plastic changes that occur in the brain after repeated exposures to drugs of abuse. The development of screening procedures for genes that control behavioral sensitization has stalled due to a lack of high-throughput behavioral tests that can be used in genetically tractable organism, such as Drosophila. We have developed a new behavioral test, FlyBong, which combines delivery of volatilized cocaine (vCOC to individually housed flies with objective quantification of their locomotor activity. There are two main advantages of FlyBong: it is high-throughput and it allows for comparisons of locomotor activity of individual flies before and after single or multiple exposures. At the population level, exposure to vCOC leads to transient and concentration-dependent increase in locomotor activity, representing sensitivity to an acute dose. A second exposure leads to further increase in locomotion, representing locomotor sensitization. We validate FlyBong by showing that locomotor sensitization at either the population or individual level is absent in the mutants for circadian genes period (per, Clock (Clk, and cycle (cyc. The locomotor sensitization that is present in timeless (tim and pigment dispersing factor (pdf mutant flies is in large part not cocaine specific, but derived from increased sensitivity to warm air. Circadian genes are not only integral part of the neural mechanism that is required for development of locomotor sensitization, but in addition, they modulate the intensity of locomotor sensitization as a function of the time of day. Motor-activating effects of cocaine are sexually dimorphic and require a functional dopaminergic transporter. FlyBong is a new and improved method for inducing and measuring locomotor

A homeostatic sleep-stabilizing pathway in Drosophila composed of the sex peptide receptor and its ligand, the myoinhibitory peptide.

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Yangkyun Oh

2014-10-01

Full Text Available Sleep, a reversible quiescent state found in both invertebrate and vertebrate animals, disconnects animals from their environment and is highly regulated for coordination with wakeful activities, such as reproduction. The fruit fly, Drosophila melanogaster, has proven to be a valuable model for studying the regulation of sleep by circadian clock and homeostatic mechanisms. Here, we demonstrate that the sex peptide receptor (SPR of Drosophila, known for its role in female reproduction, is also important in stabilizing sleep in both males and females. Mutants lacking either the SPR or its central ligand, myoinhibitory peptide (MIP, fall asleep normally, but have difficulty in maintaining a sleep-like state. Our analyses have mapped the SPR sleep function to pigment dispersing factor (pdf neurons, an arousal center in the insect brain. MIP downregulates intracellular cAMP levels in pdf neurons through the SPR. MIP is released centrally before and during night-time sleep, when the sleep drive is elevated. Sleep deprivation during the night facilitates MIP secretion from specific brain neurons innervating pdf neurons. Moreover, flies lacking either SPR or MIP cannot recover sleep after the night-time sleep deprivation. These results delineate a central neuropeptide circuit that stabilizes the sleep state by feeding a slow-acting inhibitory input into the arousal system and plays an important role in sleep homeostasis.

Matrix metalloproteinase 2 is required for ovulation and corpus luteum formation in Drosophila.

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Lylah D Deady

2015-02-01

Full Text Available Ovulation is critical for successful reproduction and correlates with ovarian cancer risk, yet genetic studies of ovulation have been limited. It has long been thought that the mechanism controlling ovulation is highly divergent due to speciation and fast evolution. Using genetic tools available in Drosophila, we now report that ovulation in Drosophila strongly resembles mammalian ovulation at both the cellular and molecular levels. Just one of up to 32 mature follicles per ovary pair loses posterior follicle cells ("trimming" and protrudes into the oviduct, showing that a selection process prefigures ovulation. Follicle cells that remain after egg release form a "corpus luteum (CL" at the end of the ovariole, develop yellowish pigmentation, and express genes encoding steroid hormone biosynthetic enzymes that are required for full fertility. Finally, matrix metalloproteinase 2 (Mmp2, a type of protease thought to facilitate mammalian ovulation, is expressed in mature follicle and CL cells. Mmp2 activity is genetically required for trimming, ovulation and CL formation. Our studies provide new insights into the regulation of Drosophila ovulation and establish Drosophila as a model for genetically investigating ovulation in diverse organisms, including mammals.

Molecular genetics of rhodopsin and phototrans duction in the visual system of Drosophila

International Nuclear Information System (INIS)

Zuker, C.; Cowman, A.; Montell, C.; Rubin, G.

1987-01-01

The authors have isolated the genes encoding four Drosophila visual pigments. Each of these opsins is expressed in a set of functionally and anatomically distinct photoreceptor cells of the eye. One is expressed in the six outer photoreceptor cells (R1-R6), the second in the central R8 photoreceptor cell, and the other two in the UV sensitive R7 photoreceptor cells. They have determined the structure and nucleotide sequence of each of these genes. They have used P element-mediated gene transfer to introduce the cloned structural gene for the R1-R6 opsin in the Drosophila germline and restored the ninaE mutant phenotype to wild-type. In an attempt to study the contribution of the various opsins to the specific functional properties of the different photoreceptor cell types, they have genetically engineered Drosophila lines that express R8 opsin in the R1-R6 photoreceptor cells. In collaboration with Drs. Ozaki and Pak at Purdue University, they have used oligonucleotide site-directed mutagenesis to mutate selected amino acids and regions of the rhodopsin molecule and reintroduced the mutated genes into Drosophila to analyze structure-function relationships in the rhodopsin molecule

Internal pigment cells respond to external UV radiation in frogs.

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Franco-Belussi, Lilian; Nilsson Sköld, Helen; de Oliveira, Classius

2016-05-01

Fish and amphibians have pigment cells that generate colorful skins important for signaling, camouflage, thermoregulation and protection against ultraviolet radiation (UVR). However, many animals also have pigment cells inside their bodies, on their internal organs and membranes. In contrast to external pigmentation, internal pigmentation is remarkably little studied and its function is not well known. Here, we tested genotoxic effects of UVR and its effects on internal pigmentation in a neotropical frog, Physalaemus nattereri We found increases in body darkness and internal melanin pigmentation in testes and heart surfaces and in the mesenterium and lumbar region after just a few hours of UVR exposure. The melanin dispersion in melanomacrophages in the liver and melanocytes in testes increased after UV exposure. In addition, the amount of melanin inside melanomacrophages cells also increased. Although mast cells were quickly activated by UVR, only longer UVR exposure resulted in genotoxic effects inside frogs, by increasing the frequency of micronuclei in red blood cells. This is the first study to describe systemic responses of external UVR on internal melanin pigmentation, melanomacrophages and melanocytes in frogs and thus provides a functional explanation to the presence of internal pigmentation. © 2016. Published by The Company of Biologists Ltd.

Autoreceptor control of peptide/neurotransmitter corelease from PDF neurons determines allocation of circadian activity in drosophila.

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Choi, Charles; Cao, Guan; Tanenhaus, Anne K; McCarthy, Ellena V; Jung, Misun; Schleyer, William; Shang, Yuhua; Rosbash, Michael; Yin, Jerry C P; Nitabach, Michael N

2012-08-30

Drosophila melanogaster flies concentrate behavioral activity around dawn and dusk. This organization of daily activity is controlled by central circadian clock neurons, including the lateral-ventral pacemaker neurons (LN(v)s) that secrete the neuropeptide PDF (pigment dispersing factor). Previous studies have demonstrated the requirement for PDF signaling to PDF receptor (PDFR)-expressing dorsal clock neurons in organizing circadian activity. Although LN(v)s also express functional PDFR, the role of these autoreceptors has remained enigmatic. Here, we show that (1) PDFR activation in LN(v)s shifts the balance of circadian activity from evening to morning, similar to behavioral responses to summer-like environmental conditions, and (2) this shift is mediated by stimulation of the Gα,s-cAMP pathway and a consequent change in PDF/neurotransmitter corelease from the LN(v)s. These results suggest another mechanism for environmental control of the allocation of circadian activity and provide new general insight into the role of neuropeptide autoreceptors in behavioral control circuits. Copyright © 2012 The Authors. Published by Elsevier Inc. All rights reserved.

New insights into melanosome transport in vertebrate pigment cells.

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Aspengren, Sara; Hedberg, Daniel; Sköld, Helen Nilsson; Wallin, Margareta

2009-01-01

Pigment cells of lower vertebrates provide an excellent model to study organelle transport as they specialize in the translocation of pigment granules in response to defined chemical cues. This review will focus on the well-studied melanophore/melanocyte systems in fish, amphibians, and mammals. We will describe the roles of melanin, melanophores, and melanocytes in animals, current views on how the three motor proteins dynein, kinesin, and myosin-V are involved in melanosome transport along microtubules and actin filaments, and how signal transduction pathways regulate the activities of the motors to achieve aggregation and dispersion of melanosomes. We will also describe how melanosomes are transferred to surrounding skin cells in amphibians and mammals. Comparative studies have revealed that the ability of physiological color change is lost during evolution while the importance of morphological color change, mainly via transfer of pigment to surrounding skin cells, increases. In humans, pigment mainly has a role in protection against ultraviolet radiation, but also perhaps in the immune system.

Distribution of corazonin and pigment-dispersing factor in the cephalic ganglia of termites.

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Závodská, Radka; Wen, Chih-Jen; Hrdý, Ivan; Sauman, Ivo; Lee, How-Jing; Sehnal, Frantisek

2008-07-01

Distribution of neurones detectable with antisera to the corazonin (Crz) and the pigment-dispersing factor (PDF) was mapped in the workers or pseudergates of 10 species representing six out of seven termite families. All species contained two triads of Crz-immunoreactive (Crz-ir) neurones in the protocerebrum. Their fibres were linked to the opposite hemisphere, formed a network in the fronto-lateral protocerebrum, and projected to the corpora cardiaca (CC); in most species the fibres also supplied the deuto- and tritocerebrum and the frontal ganglion. Some species possessed additional Crz-ir perikarya in the protocerebrum and the suboesophageal ganglion (SOG). The PDF-ir somata were primarily located in the optic lobe (OL) and SOG. OL harboured a group (3 groups in Coptotermes) of 2-6 PDF-ir cells with processes extending to the medulla, connecting to the contralateral OL, forming 1-2 networks in the protocerebrum, and in most species running also to CC. Such a PDF-ir system associated with the OL was missing in Reticulitermes. Except for Mastotermes, the termites contained 1-2 PDF-ir cell pairs in the SOG and two species had additional perikarya in the protocerebrum. The results are consistent with the view of a monophyletic termite origin and demonstrate how the Crz-ir and PDF-ir systems diversified in the course of termite phylogeny.

Analytical Investigation Of Pigments, Ground Layer And Media Of Cartonnage Fragments From Greek Roman Period

Science.gov (United States)

Afifi, Hala. A. M.

Some cartonnage fragments from Hawara, Fayoum Excavation were examined to identify pigments, media and grounds. It belonged to the Greek-Roman period. They were studied by X-ray diffraction (XRD), Energy dispersive X ray analysis (EDS) equipped with Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). These techniques were used to identify the composition and morphology of grounds, nature of pigments and media used in cartonnage fragments. The coarse ground layer was composed of calcite and traces of quartz. The fine ground layer used under the pigments directly was composed of calcite only. Carbon black was used as black pigment while lead oxide as red pigment, showing the influence of Roman and Greek pigments on Egyptian art in these later periods. Blue colorant was identified as cuprorivaite and yellow pigment was goethite. Animal glue was used in the four pigments as medium colored.

Smart textile framework: Photochromic and fluorescent cellulosic fabric printed by strontium aluminate pigment.

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Khattab, Tawfik A; Rehan, Mohamed; Hamouda, Tamer

2018-09-01

Smart clothing can be defined as textiles that respond to a certain stimulus accompanied by a change in their properties. A specific class herein is the photochromic and fluorescent textiles that change color with light. A photochromic and fluorescent cotton fabric based on pigment printing is obtained. Such fabric is prepared by aqueous-based pigment-binder printing formulation containing inorganic pigment phosphor characterized by good photo- and thermal stability. It exhibits optimal excitation wavelength (365 nm) results in color and fluorescence change of the fabric surface. To prepare the transparent pigment-binder composite film, the phosphor pigment must be well-dispersed via physical immobilization without their aggregation. The pigment-binder paste is applied successfully onto cotton fabric using screen printing technique followed by thermal fixation. After screen-printing, a homogenous photochromic film is assembled on a cotton substrate surface, which represents substantial greenish-yellow color development as indicated by CIE Lab color space measurements under ultraviolet light, even at a pigment concentration of 0.08 wt% of the printing paste. The photochromic cotton fabric exhibit three excitation peaks at 272, 325 and 365 nm and three emission peaks at 418, 495 and 520 nm. The fluorescent optical microscope, scanning electron microscope, elemental mapping, energy dispersive X-ray spectroscopy, fluorescence emission and UV/Vis absorption spectroscopic data of the printed cotton fabric are described. The printed fabric showed a reversible and rapid photochromic response during ultra-violet excitation without fatigue. The fastness properties including washing, crocking, perspiration, sublimation/heat, and light are described. Copyright © 2018 Elsevier Ltd. All rights reserved.

TEM studies of the crystal growth of indanthrone pigments

International Nuclear Information System (INIS)

McHendry, P.

1998-01-01

The aim of this work was to study the crystal growth of indanthrone during the pigmentation process. The colouring properties of a pigment are dependant on the chemical and crystallographic structure of the pigment. However, other factors are known to affect these properties including particle size, particle size distribution and level of dispersion in the chosen application medium. The parameters which affect the growth of the pigment particles were investigated with the emphasis placed on the mechanism by which growth took place. The final form of the crystals after growth was also investigated in some detail. Various electron microscopy techniques were employed in the investigations in this thesis. High and low magnification imaging and diffraction were studied on the CTEM (conventional transmission electron microscope) whilst PEELS (parallel electron energy loss spectroscopy) and DPC (differential phase contrast) studies took place on the VG HB5 STEM (scanning transmission electron microscope). In addition to these studies, x-ray diffraction and surface area analysis techniques were employed. The low magnification CTEM work gave good information on the size, shape and size distribution of the pigment particles and enabled detailed analysis of the level of growth attained under varied reaction conditions. (author)

Corrosion resistance of flaky aluminum pigment coated with cerium oxides/hydroxides in chloride and acidic electrolytes

Science.gov (United States)

Niroumandrad, S.; Rostami, M.; Ramezanzadeh, B.

2015-12-01

The objective of this study was to enhance the corrosion resistance of lamellar aluminum pigment through surface treatment by cerium oxides/hydroxides. The surface composition of the pigments was studied by energy-dispersive spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS). The corrosion resistance of the pigment was evaluated by conventional hydrogen evolution measurements in acidic solution and electrochemical impedance spectroscopy (EIS) in 3.5% NaCl solution. Results showed that the Ce-rich coating composed of Ce2O3 and CeO2 was precipitated on the pigment surface after immersion in the cerium solution. The corrosion resistance of pigment was significantly enhanced after modification with cerium layer.

[Synthesis and characterization of chromium doped Y3Al5O12 compound pigment].

Science.gov (United States)

Yue, Shi-Juan; Su, Xiao; Jiang, Han-Jie; Liu, Shao-Xuan; Hong, You-Li; Zhang, Kai; Huang, Wan-Xias; Xiong, Zu-Jiang; Zhao, Ying; Liu, Cui-Ge; Wei, Yong-Ju; Meng, Tao; Xu, Yi-Zhuang; Wu, Jin-Guang

2012-09-01

The authors synthesized a new kind of green pigment via co-precipitation method by doping Y3Al5O12 with Cr+. The size of the pigment particles is around 200 nm as observed under scanning electron microscope. XRD results demonstrate that the pigment crystalline form of the pigment is yttrium alluminium garnet. UV-Vis spectra were used to investigate the coordination states and transition behavior of the doping ions. In addition, the colour feature was measured by CIE L* a* b* chroma value. The pigment was blended with polypropylene and then polypropylene fiber was produced using the polypropelene-pigment composite via molten spinning process. The distribution of the pigment particles in the polypropylene fibers was characterized by Xray computed tomography (CT) technique on the Beijing synchrotron radiation facility. The result states that the composite oxide pigment particles are homogeneously dispersed in the polypropylene fibers. The pigments are stable, non-toxic to the environment, and may be applied in non-aqueous dyeing to reduce waste water emitted by textile dyeing and printing industry.

Distributions of elements in the human retinal pigment epithelium

International Nuclear Information System (INIS)

Ulshafer, R.J.; Allen, C.B.; Rubin, M.L.

1990-01-01

Distributions of elements above the atomic number of sodium were mapped in the retinal pigment epithelia of eight human eyes. X-ray energy spectra and maps were collected from cryofixed, freeze-dried, and epoxy-embedded tissues using energy-dispersive x-ray microanalysis. All eyes had high concentrations of phosphorus in the nuclei of retinal pigment epithelial cells. Melanosomes were rich in sulfur, zinc, calcium, and iron. Lipofuscin and cytoplasm contained only phosphorus and sulfur in detectable amounts. Drusen, when present, contained phosphorus and calcium. Six eyes had a prominent aluminum peak recorded from melanosomes, nuclei, and Bruch's membrane. In one pair of 90-year-old eyes, small, electron-dense deposits surrounded many melanosomes and contained mercury and selenium. Retinal pigment epithelial melanosomes may bind and accumulate metals and other potentially toxic ions over time, preventing them from reaching the neural retina

Antioxidative role of ocular melanin pigment in the model of lens induced uveitis.

Science.gov (United States)

Bilgihan, A; Bilgihan, M K; Akata, R F; Aricioğlu, A; Hasanreisoğlu, B

1995-12-01

Ocular melanin pigment has antioxidant effect against excess of dispersed light. To investigate whether it has a similar effect in ocular inflammations, we used albino and pigmented guinea pigs and measured retinal glutathione peroxidase activities and lipid peroxide levels (expressed as thiobarbituric acid reactive substances) in a model of lens induced uveitis. Although the increase in the levels of the retinal lipid peroxides were higher in the albino group (204%, p < 0.05), the decrease in the activities of glutathione peroxidase were higher in pigmented guinea pigs (26%, p < 0.005). The results of the study suggest that pigmentless animals are more sensitive to the ocular inflammations, and ocular melanin pigment may act as an endojen antioxidant in lens induced uveitis.

Single crystal X-ray structure of the artists’ pigment zinc yellow

DEFF Research Database (Denmark)

Simonsen, Kim Pilkjær; Christiansen, Marie Bitsch; Vinum, Morten Gotthold

2017-01-01

electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS), attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), and powder X-ray diffraction (PXRD), showed that the synthesised products and the industrial pigment were identical. Single-crystal X-ray crystallography......The artists’ pigment zinc yellow is in general described as a complex potassium zinc chromate with the empirical formula 4ZnCrO4·K2O·3H2O. Even though the pigment has been in use since the second half of the 19th century also in large-scale industrial applications, the exact structure had hitherto...... been unknown. In this work, zinc yellow was synthesised by precipitation from an aqueous solution of zinc nitrate and potassium chromate under both neutral and basic conditions, and the products were compared with the pigment used in industrial paints. Analyses by Raman microscopy (MRS), scanning...

The molecular mechanisms of OPA1-mediated optic atrophy in Drosophila model and prospects for antioxidant treatment.

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Will Yarosh

2008-01-01

Full Text Available Mutations in optic atrophy 1 (OPA1, a nuclear gene encoding a mitochondrial protein, is the most common cause for autosomal dominant optic atrophy (DOA. The condition is characterized by gradual loss of vision, color vision defects, and temporal optic pallor. To understand the molecular mechanism by which OPA1 mutations cause optic atrophy and to facilitate the development of an effective therapeutic agent for optic atrophies, we analyzed phenotypes in the developing and adult Drosophila eyes produced by mutant dOpa1 (CG8479, a Drosophila ortholog of human OPA1. Heterozygous mutation of dOpa1 by a P-element or transposon insertions causes no discernable eye phenotype, whereas the homozygous mutation results in embryonic lethality. Using powerful Drosophila genetic techniques, we created eye-specific somatic clones. The somatic homozygous mutation of dOpa1 in the eyes caused rough (mispatterning and glossy (decreased lens and pigment deposition eye phenotypes in adult flies; this phenotype was reversible by precise excision of the inserted P-element. Furthermore, we show the rough eye phenotype is caused by the loss of hexagonal lattice cells in developing eyes, suggesting an increase in lattice cell apoptosis. In adult flies, the dOpa1 mutation caused an increase in reactive oxygen species (ROS production as well as mitochondrial fragmentation associated with loss and damage of the cone and pigment cells. We show that superoxide dismutase 1 (SOD1, Vitamin E, and genetically overexpressed human SOD1 (hSOD1 is able to reverse the glossy eye phenotype of dOPA1 mutant large clones, further suggesting that ROS play an important role in cone and pigment cell death. Our results show dOpa1 mutations cause cell loss by two distinct pathogenic pathways. This study provides novel insights into the pathogenesis of optic atrophy and demonstrates the promise of antioxidants as therapeutic agents for this condition.

Zinc deficiency leads to lipofuscin accumulation in the retinal pigment epithelium of pigmented rats.

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Sylvie Julien

Full Text Available BACKGROUND: Age-related macular degeneration (AMD is associated with lipofuscin accumulation whereas the content of melanosomes decreases. Melanosomes are the main storage of zinc in the pigmented tissues. Since the elderly population, as the most affected group for AMD, is prone to zinc deficit, we investigated the chemical and ultrastructural effects of zinc deficiency in pigmented rat eyes after a six-month zinc penury diet. METHODOLOGY/PRINCIPAL FINDINGS: Adult Long Evans (LE rats were investigated. The control animals were fed with a normal alimentation whereas the zinc-deficiency rats (ZD-LE were fed with a zinc deficient diet for six months. Quantitative Energy Dispersive X-ray (EDX microanalysis yielded the zinc mole fractions of melanosomes in the retinal pigment epithelium (RPE. The lateral resolution of the analysis was 100 nm. The zinc mole fractions of melanosomes were significantly smaller in the RPE of ZD-LE rats as compared to the LE control rats. Light, fluorescence and electron microscopy, as well as immunohistochemistry were performed. The numbers of lipofuscin granules in the RPE and of infiltrated cells (Ø>3 µm found in the choroid were quantified. The number of lipofuscin granules significantly increased in ZD-LE as compared to control rats. Infiltrated cells bigger than 3 µm were only detected in the choroid of ZD-LE animals. Moreover, the thickness of the Bruch's membrane of ZD-LE rats varied between 0.4-3 µm and thin, rangy ED1 positive macrophages were found attached at these sites of Bruch's membrane or even inside it. CONCLUSIONS/SIGNIFICANCE: In pigmented rats, zinc deficiency yielded an accumulation of lipofuscin in the RPE and of large pigmented macrophages in the choroids as well as the appearance of thin, rangy macrophages at Bruch's membrane. Moreover, we showed that a zinc diet reduced the zinc mole fraction of melanosomes in the RPE and modulated the thickness of the Bruch's membrane.

A molecular investigation of adsorption onto mineral pigments

Science.gov (United States)

Ninness, Brian J.

of the modified pigments are dominated by the presence of TiO2. The modified kaolin pigments display increased dispersion stability as compared to the parent kaolin. The electrokinetic behavior of the modified kaolin is shown to be identical to that of pure TiO2 pigments.

Synthesis and Application of Carbon–Iron Oxide Microspheres’ Black Pigments in Electrophoretic Displays

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Meng Xianwei

2010-01-01

Full Text Available Abstract Carbon–iron oxide microspheres’ black pigments (CIOMBs had been prepared via ultrasonic spray pyrolysis of aqueous solutions containing ferrous chloride and glucose. Due to the presence of carbon, CIOMBs not only exhibited remarkably acid resistance, but also could be well dispersed in both polar solvents and nonpolar solvent. Finally, dispersions of hollow CIOMBs in tetrachloroethylene had successfully been applied in electrophoretic displays.

Corrosion resistance of flaky aluminum pigment coated with cerium oxides/hydroxides in chloride and acidic electrolytes

International Nuclear Information System (INIS)

Niroumandrad, S.; Rostami, M.; Ramezanzadeh, B.

2015-01-01

Graphical abstract: - Highlights: • Flaky aluminum pigments were modified with cerium nitrate salt. • pH value of 3.0 was chosen as the optimized pH for the cerium solution. • Corrosion resistance of the pigment significantly increased after modification. • Alkaline pre-treatment prior to modification affected the cerium layer performance. - Abstract: The objective of this study was to enhance the corrosion resistance of lamellar aluminum pigment through surface treatment by cerium oxides/hydroxides. The surface composition of the pigments was studied by energy-dispersive spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS). The corrosion resistance of the pigment was evaluated by conventional hydrogen evolution measurements in acidic solution and electrochemical impedance spectroscopy (EIS) in 3.5% NaCl solution. Results showed that the Ce-rich coating composed of Ce 2 O 3 and CeO 2 was precipitated on the pigment surface after immersion in the cerium solution. The corrosion resistance of pigment was significantly enhanced after modification with cerium layer.

Corrosion resistance of flaky aluminum pigment coated with cerium oxides/hydroxides in chloride and acidic electrolytes

Energy Technology Data Exchange (ETDEWEB)

Niroumandrad, S. [Institute for Color Science and Technology (ICST), PO 16765-654, Tehran (Iran, Islamic Republic of); Rostami, M. [Department of Nanomaterials and Nanocoatings, Institute for Color Science and Technology (ICST), PO 16765-654, Tehran (Iran, Islamic Republic of); Ramezanzadeh, B., E-mail: ramezanzadeh-bh@icrc.ac.ir [Department of Surface Coatings and Corrosion, Institute for Color Science and Technology (ICST), PO 16765-654, Tehran (Iran, Islamic Republic of)

2015-12-01

Graphical abstract: - Highlights: • Flaky aluminum pigments were modified with cerium nitrate salt. • pH value of 3.0 was chosen as the optimized pH for the cerium solution. • Corrosion resistance of the pigment significantly increased after modification. • Alkaline pre-treatment prior to modification affected the cerium layer performance. - Abstract: The objective of this study was to enhance the corrosion resistance of lamellar aluminum pigment through surface treatment by cerium oxides/hydroxides. The surface composition of the pigments was studied by energy-dispersive spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS). The corrosion resistance of the pigment was evaluated by conventional hydrogen evolution measurements in acidic solution and electrochemical impedance spectroscopy (EIS) in 3.5% NaCl solution. Results showed that the Ce-rich coating composed of Ce{sub 2}O{sub 3} and CeO{sub 2} was precipitated on the pigment surface after immersion in the cerium solution. The corrosion resistance of pigment was significantly enhanced after modification with cerium layer.

Fast determination of seven synthetic pigments from wine and soft drinks using magnetic dispersive solid-phase extraction followed by liquid chromatography-tandem mass spectrometry.

Science.gov (United States)

Chen, Xiao-Hong; Zhao, Yong-Gang; Shen, Hao-Yu; Zhou, Li-Xin; Pan, Sheng-Dong; Jin, Mi-Cong

2014-06-13

A novel, simple and sensitive method based on the use of magnetic dispersive solid-phase extraction (M-dSPE) procedure combined with ultra-fast liquid chromatography-tandem quadrupole mass spectrometry (UFLC-MS/MS) was developed to determine seven synthetic pigments (tartrazine, amaranth, carmine, sunset yellow, allura red, brilliant blue and erythrosine) in wines and soft drinks. An amino-functionalized low degrees of cross-linking magnetic polymer (NH2-LDC-MP) was synthesized via suspension polymerization, and characterized by transmission electron microscopy (TEM). The NH2-LDC-MP was used as the M-dSPE sorbent to remove the matrix from the solution, and the main factors affecting the extraction were investigated in detail. The obtained results demonstrated the higher extraction capacity of NH2-LDC-MP with recoveries between 84.0 and 116.2%. The limits of quantification (LOQs) for the seven synthetic pigments were between 1.51 and 5.0μg/L in wines and soft drinks. The developed M-dSPE UFLC-MS/MS method had been successfully applied to the real wines and soft drinks for food-safety risk monitoring in Zhejiang Province, China. The results showed that sunset yellow was in three out of thirty soft drink samples (2.95-42.6μg/L), and erythrosine in one out of fifteen dry red wine samples (3.22μg/L), respectively. It was confirmed that the NH2-LDC-MP was a kind of highly effective M-dSPE materials for the pigments analyses. Copyright © 2014 Elsevier B.V. All rights reserved.

Multianalytical characterization of a blue pigment used in art-crafts from Central Mexico

International Nuclear Information System (INIS)

Solis, C.; Mondragon, M.A.; Isaac-Olive, K.; Gleason, R.; Pina, C.; Sanchez del Rio, M.; Rocha, M.; Lopez-Aguilar, F.

2008-01-01

We report a preliminary characterization of a blue pigment because its color has been associated to objects found from Aztec and Precolumbian times. The pigment was examined before and after its purification by a variety of techniques: Particle Induced X-ray emission (PIXE), electron paramagnetic resonance (EPR), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy coupled to energy dispersion spectroscopy (SEM-EDS). The relationship of the chemical composition, the spectroscopic signals and the color are discussed

Multianalytical characterization of a blue pigment used in art-crafts from Central Mexico

Energy Technology Data Exchange (ETDEWEB)

Solis, C. [Instituto de Fisica, Departamento de Fisica Experimental, Universidad Nacional Autonoma de Mexico (UNAM), 04510 Mexico, DF (Mexico)], E-mail: corina@fisica.unam.mx; Mondragon, M.A. [Centro de Fisica Aplicada y Tecnologia Avanzada, UNAM, Boulevard Juriquilla 3001, Juriquilla, Queretaro 76230 (Mexico); Isaac-Olive, K.; Gleason, R. [Instituto de Fisica, Departamento de Fisica Experimental, Universidad Nacional Autonoma de Mexico (UNAM), 04510 Mexico, DF (Mexico); Pina, C. [Facultad de Quimica, UNAM, 04510 Mexico, DF (Mexico); Sanchez del Rio, M. [European Synchrotron Radiation Facility, BP 220, 38043 Grenoble-Cedex 9 (France); Rocha, M. [Instituto Politecnico Nacional, Escuela de Ingenieria, Mexico, DF (Mexico); Lopez-Aguilar, F. [Division de Posgrado, Escuela Nacional de Antropologia e Historia, Mexico, DF (Mexico)

2008-04-15

We report a preliminary characterization of a blue pigment because its color has been associated to objects found from Aztec and Precolumbian times. The pigment was examined before and after its purification by a variety of techniques: Particle Induced X-ray emission (PIXE), electron paramagnetic resonance (EPR), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy coupled to energy dispersion spectroscopy (SEM-EDS). The relationship of the chemical composition, the spectroscopic signals and the color are discussed.

Annular pigment band on the posterior capsule following blunt ocular trauma: a case report

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Harrison Rosalind J

2005-06-01

Full Text Available Abstract Background To report an unusual case of annular pigment band on the posterior capsule following blunt ocular trauma. Case presentation We describe an annular pigment band on the posterior capsule following blunt ocular trauma in a 28-year old male patient. Repeat examinations revealed no evidence of other signs of blunt ocular trauma or pigment dispersion syndrome in either eye. Conclusion The annular pigment band in this case corresponds to the adherence of the hyaloideocapsulare ligament to the posterior capsule and reconfirms its rare visualization in the living eye. This finding may be an isolated sign of blunt ocular trauma and a compromised integrity of the vitreolenticular interface should be strongly suspected. We recommend careful documentation in context of future cataract surgery in these eyes.

Electrochemical assessing corrosion inhibiting effects of zinc aluminum polyphosphate (ZAPP) as a modified zinc phosphate pigment

International Nuclear Information System (INIS)

Naderi, R.; Attar, M.M.

2008-01-01

Undesirable anti-corrosion performance of zinc phosphate pigment, the classical chromate replacement, has led researchers to take modification into account. Polyphosphate-based anti-corrosion pigments as a result of modification of zinc orthophosphate have been found to function much more efficiently. This study aimed to evaluate performance of steel samples immersed in 3.5% NaCl aqueous solution-containing zinc aluminum polyphosphate (ZAPP) pigment extract compared to those involving conventional zinc phosphate (ZP) pigment extract and also no pigment (blank) using electrochemical tests such as electrochemical impedance spectroscopy (EIS) and linear polarization (LP) as well as surface analysis. Impedance spectra and polarization curves revealed two different trends, showing the superiority of ZAPP pigment. Based on the results of scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX), presence of a precipitated layer on the surface was confirmed when steel sample was immersed into the solution-containing ZAPP

Common sequence variants in the LOXL1 gene in pigment dispersion syndrome and pigmentary glaucoma.

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Giardina, Emiliano; Oddone, Francesco; Lepre, Tiziana; Centofanti, Marco; Peconi, Cristina; Tanga, Lucia; Quaranta, Luciano; Frezzotti, Paolo; Novelli, Giuseppe; Manni, Gianluca

2014-04-16

Single nucleotide polymorphisms (SNPs) within the LOXL1 gene are associated with pseudoesfoliation syndrome and pseudoesfoliation glaucoma. The aim of our study is to investigate a potential involvement of LOXL1 gene in the pathogenesis of pigment dispersion syndrome (PDS) and pigmentary glaucoma (PG). A cohort of Caucasian origin of 84 unrelated and clinically well-characterised patients with PDS/PG and 200 control subjects were included in the study. Genomic DNA from whole blood was extracted and the coding and regulatory regions of LOXL1 gene were risequenced in both patients and controls to identify unknown sequence variations. Genotype and haplotype analysis were performed with UNPHASED software. The expression levels of LOXL1 were determined on c-DNA from peripheral blood lymphocytes by quantitative real-time RT-PCR. A significant allele association was detected for SNP rs2304722 within the fifth intron of LOXL1 (Odds ratio (OR = 2.43, p-value = 3,05e-2). Haplotype analysis revealed the existence of risk and protective haplotypes associated with PG-PDS (OR = 3.35; p-value = 1.00e-5 and OR = 3.35; p-value = 1.00e-4, respectively). Expression analysis suggests that associated haplotypes can regulate the expression level LOXL1. Haplotypes of LOXL1 are associated with PG-PDS independently from rs1048661, leading to a differential expression of the transcript.

Use of Fillers, Pigments and Additives in Fouling-Release Coatings: a Literature Review

DEFF Research Database (Denmark)

Tamaev, Nail; Kiil, Søren; Noguer, Albert Camós

elastomers. As an additional option, pretreatment operations for silica can be considered as they ensure necessary hydrophilic/phobic properties alongside with easy dispersion in the PDMS matrix and lower moisture content. However, in this case, impaired reinforcement is observed [2]. One of the challenges......, pigments also influence mechanical (tensile strength, abrasion resistance, elastic modulus, tear energy) and adhesion properties in condensation-cured PDMS-based coatings [2]. In addition to this, pigments can enhance biofouling resistance. For instance, titanium dioxide possesses a capability of switching...

Thermal insulation coating based on water-based polymer dispersion

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Panchenko Iuliia

2018-01-01

Full Text Available For Russia, due to its long winter period, improvement of thermal insulation properties of envelope structures by applying thermal insulation paint and varnish coating to its inner surface is considered perspective. Thermal insulation properties of such coatings are provided by adding aluminosilicate microspheres and aluminum pigment to their composition. This study was focused on defining the effect of hollow aluminosilicate microspheres and aluminum pigment on the paint thermal insulation coating based on water-based polymer dispersion and on its optimum filling ratio. The optimum filling ratio was determined using the method of critical pigment volume concentration (CPVC. The optimum filling ratio was found equal to 55%.

Smart options for simultaneous functionalization and pigment coloration of cellulosic/wool blends.

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Ibrahim, N A; Khalil, H M; El-Zairy, E M R; Abdalla, W A

2013-07-01

The present innovative research work deals with the individual use of chitosan (2.5 g/kg), Aloe vera (10 g/kg), triclosan (10 g/kg), TiO2-nanoparticles (TiO2-NP's, 10 g/kg), silicon micro-emulsion (20 g/kg) or a water/oil-repellent agent (40 g/kg) for modifying the pigment print paste to produce functionalized cotton/wool and viscose/wool pigment prints in one step process. The imparted functional properties such as antibacterial, antibacterial/UV-protection, soft-handle or water/oil-repellency together with the change in the printing properties were evaluated. Some of the obtained pigment prints were characterized by scanning electron microscope (SEM), and energy dispersive X-rays (EDX) to confirm deposition of certain functional additives on printed fabrics. The wide-range of imparted functional properties together with the depth of the obtained pigment prints were maintained over 80% even after 15 consecutive laundering cycles. The extent of retention in functional and pigment printing properties is influenced by the type of functional additive as well as the kind of substrate. Copyright © 2013 Elsevier Ltd. All rights reserved.

Genetic and Virulent Difference Between Pigmented and Non-pigmented Staphylococcus aureus

OpenAIRE

Jing Zhang; Yujuan Suo; Daofeng Zhang; Fangning Jin; Hang Zhao; Chunlei Shi

2018-01-01

Staphyloxanthin (STX), a golden carotenoid pigment produced by Staphylococcus aureus, is suggested to act as an important virulence factor due to its antioxidant properties. Restraining biosynthesis of STX was considered as an indicator of virulence decline in pigmented S. aureus isolates. However, it is not clear whether natural non-pigmented S. aureus isolates have less virulence than pigmented ones. In this study, it is aimed to compare the pigmented and non-pigmented S. aureus isolates to...

An investigation of multispectral imaging for the mapping of pigments in paintings

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Zhao, Yonghui; Berns, Roy S.; Taplin, Lawrence A.; Coddington, James

2008-02-01

Compared with colorimetric imaging, multispectral imaging has the advantage of retrieving spectral reflectance factor of each pixel of a painting. Using this spectral information, pigment mapping is concerned with decomposing the spectrum into its constituent pigments and their relative contributions. The output of pigment mapping is a series of spatial concentration maps of the pigments comprising the painting. This approach was used to study Vincent van Gogh's The Starry Night. The artist's palette was approximated using ten oil pigments, selected from a large database of pigments used in oil paintings and a priori analytical research on one of his self portraits, executed during the same time period. The pigment mapping was based on single-constant Kubelka-Munk theory. It was found that the region of blue sky where the stars were located contained, predominantly, ultramarine blue while the swirling sky and region surrounding the moon contained, predominantly, cobalt blue. Emerald green, used in light bluish-green brushstrokes surrounding the moon, was not used to create the dark green in the cypresses. A measurement of lead white from Georges Seurat's La Grande Jatte was used as the white when mapping The Starry Night. The absorption and scattering properties of this white were replaced with a modern dispersion of lead white in linseed oil and used to simulate the painting's appearance before the natural darkening and yellowing of lead white oil paint. Pigment mapping based on spectral imaging was found to be a viable and practical approach for analyzing pigment composition, providing new insight into an artist's working method, the possibility for aiding in restorative inpainting, and lighting design.

Comparison of Ganglion Cell and Retinal Nerve Fiber Layer Thickness in Pigment Dispersion Syndrome, Pigmentary Glaucoma, and Healthy Subjects with Spectral-domain OCT.

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Arifoglu, Hasan Basri; Simavli, Huseyin; Midillioglu, Inci; Berk Ergun, Sule; Simsek, Saban

2017-01-01

To evaluate the ganglion cell complex (GCC) and retinal nerve fiber layer (RNFL) thickness in pigment dispersion syndrome (PDS) and pigmentary glaucoma (PG) with RTVue spectral domain optical coherence tomography (SD-OCT). A total of 102 subjects were enrolled: 29 with PDS, 18 with PG, and 55 normal subjects. Full ophthalmic examination including visual field analysis was performed. SD-OCT was used to analyze GCC superior, GCC inferior, and average RNFL thickness. To compare the discrimination capabilities, the areas under the receiver operating characteristic curves were assessed. Superior GCC, inferior GCC, and RNFL thickness values of patients with PG were statistically signicantly lower than those of patients with PDS (p  0.05). The SD-OCT-derived GCC and RNFL thickness parameters can be useful to discriminate PG from both PDS and normal subjects.

Genetic and Virulent Difference Between Pigmented and Non-pigmented Staphylococcus aureus.

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Zhang, Jing; Suo, Yujuan; Zhang, Daofeng; Jin, Fangning; Zhao, Hang; Shi, Chunlei

2018-01-01

Staphyloxanthin (STX), a golden carotenoid pigment produced by Staphylococcus aureus , is suggested to act as an important virulence factor due to its antioxidant properties. Restraining biosynthesis of STX was considered as an indicator of virulence decline in pigmented S. aureus isolates. However, it is not clear whether natural non-pigmented S. aureus isolates have less virulence than pigmented ones. In this study, it is aimed to compare the pigmented and non-pigmented S. aureus isolates to clarify the genetic and virulent differences between the two groups. Here, 132 S. aureus isolates were divided into two phenotype groups depending on the absorbance (OD 450 ) of the extracted carotenoids. Then, all isolates were subjected to spa typing and multilocus sequence typing (MLST), and then the detection of presence of 30 virulence factors and the gene integrity of crtN and crtM . Furthermore, 24 typical S. aureus isolates and 4 S. argenteus strains were selected for the murine infection assay of in vivo virulence, in which the histological observation and enumeration of CFUs were carried out. These isolates were distributed in 26 sequence types (STs) and 49 spa types. The pigmented isolates were scattered in 25 STs, while the non-pigmented isolates were more centralized, which mainly belonged to ST20 (59%) and ST25 (13%). Among the 54 non-pigmented isolates, about 20% carried intact crtN and crtM genes. The in vivo assay suggested that comparing with pigmented S. aureus , non-pigmented S. aureus and S. argenteus strains did not show a reduced virulence in murine sepsis models. Therefore, it suggested that there were no significant genetic and virulent differences between pigmented and non-pigmented S. aureus .

[Pigment dispersion syndrome and pigmentary glaucoma. Morphometric analysis of the anterior chamber segment with SL-OCT].

Science.gov (United States)

Birner, B; Tourtas, T; Wessel, J M; Jünemann, A G; Mardin, C Y; Kruse, F E; Laemmer, R

2014-01-01

The purpose of this study was to analyze if anterior chamber parameters are risk factors for the development of pigment dispersion syndrome (PDS) and/or for the conversion to pigmentary glaucoma (PG). This study included a total of 63 eyes from 35 patients with PDS and PG and 65 eyes from 49 unaffected volunteers as the control group. The following parameters were measured by slit lamp optical coherence tomography (SL-OCT): anterior chamber volume (ACV) and depth (ACD), angle opening distance (AOD) and the trabecular iris space area (TISA) at 500 µm and 750 μm from the scleral spur. Comparisons between the following groups were performed: between the PDS/PG and the control group, between PDS and PG and between male and female patients. The results of ACV, ACD, AOD and TISA were significantly higher in PDS/PG patients when compared to the control group. There were no significant differences between PDS and PG. The gender-specific comparison also showed no significant differences. Significantly higher anterior chamber parameters are a possible risk factor for development of PDS; however, a higher risk of conversion to PG does not seem to correlate with increased anterior chamber parameters. The parameters of the anterior chamber are apparently not associated with the male predominance of PDS and PG.

Genetic and Virulent Difference Between Pigmented and Non-pigmented Staphylococcus aureus

Directory of Open Access Journals (Sweden)

Jing Zhang

2018-04-01

Full Text Available Staphyloxanthin (STX, a golden carotenoid pigment produced by Staphylococcus aureus, is suggested to act as an important virulence factor due to its antioxidant properties. Restraining biosynthesis of STX was considered as an indicator of virulence decline in pigmented S. aureus isolates. However, it is not clear whether natural non-pigmented S. aureus isolates have less virulence than pigmented ones. In this study, it is aimed to compare the pigmented and non-pigmented S. aureus isolates to clarify the genetic and virulent differences between the two groups. Here, 132 S. aureus isolates were divided into two phenotype groups depending on the absorbance (OD450 of the extracted carotenoids. Then, all isolates were subjected to spa typing and multilocus sequence typing (MLST, and then the detection of presence of 30 virulence factors and the gene integrity of crtN and crtM. Furthermore, 24 typical S. aureus isolates and 4 S. argenteus strains were selected for the murine infection assay of in vivo virulence, in which the histological observation and enumeration of CFUs were carried out. These isolates were distributed in 26 sequence types (STs and 49 spa types. The pigmented isolates were scattered in 25 STs, while the non-pigmented isolates were more centralized, which mainly belonged to ST20 (59% and ST25 (13%. Among the 54 non-pigmented isolates, about 20% carried intact crtN and crtM genes. The in vivo assay suggested that comparing with pigmented S. aureus, non-pigmented S. aureus and S. argenteus strains did not show a reduced virulence in murine sepsis models. Therefore, it suggested that there were no significant genetic and virulent differences between pigmented and non-pigmented S. aureus.

Liquid crystalline phases in suspensions of pigments in non-polar solvents

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Klein, Susanne; Richardson, Robert M.; Eremin, Alexey

We will discuss colloid suspensions of pigments and compare their electro-optic properties with those of traditional dyed low molecular weight liquid crystal systems. There are several potential advantages of colloidal suspensions over low molecular weight liquid crystal systems: a very high contrast because of the high orientational order parameter of suspensions of rod shaped nano-particles, the excellent light fastness of pigments as compared to dyes and high colour saturations resulting from the high loading of the colour stuff. Although a weak `single-particle' electro-optic response can be observed in dilute suspensions, the response is very much enhanced when the concentration of the particles is sufficient to lead to a nematic phase. Excellent stability of suspensions is beneficial for experimental observation and reproducibility, but it is a fundamental necessity for display applications. We therefore discuss a method to achieve long term stability of dispersed pigments and the reasons for its success. Small angle X-ray scattering was used to determine the orientational order parameter of the suspensions as a function of concentration and the dynamic response to an applied electric field. Optical properties were investigated for a wide range of pigment concentrations. Electro-optical phenomena, such as field-induced birefringence and switching, were characterised. In addition, mixtures of pigment suspensions with small amounts of ferrofluids show promise as future magneto-optical materials.

Pigments analysis and gold layer thickness evaluation of polychromy on wood objects by PXRF

International Nuclear Information System (INIS)

Blonski, M.S.; Appoloni, C.R.

2014-01-01

The X-ray fluorescence technique by energy dispersion (EDXRF), being a multi elemental and non-destructive technique, has been widely used in the analysis of artworks and archeometry. An X-ray fluorescence portable equipment from the Laboratory of Applied Nuclear Physics of the State University of Londrina (LFNA/UEL) was used for the measurement of pigments in golden parts of a Gilding Preparation Standard Plaque and also pigments measurement on the Wood Adornment of the High Altar Column of the Side Pulpit of the Immaculate Conception Church Parish Sao Paulo-SP. The portable X-ray fluorescence PXRF-LFNA-02 consists of an X-ray tube with Ag anode, a Si-PIN detector (FWHM=221 eV for Mn line at 5.9 keV), a chain of electronics nuclear standard of X-ray spectrometer, a multichannel 8 K, a notebook and a mechanical system designed for the positioning of detector and X-ray tube, which allows movements with two degrees of freedom from the system of excitation–detection. The excitation–detection time of each measurement was 100 and 500 s, respectively. The presence of elements Ti, Cr, Fe, Cu, Zn and Au was found in the golden area of the Altar Column ornament. On the other hand, analysis of the ratios for the intensities of K α /K β lines measured in the areas made it possible to explore the possibility of measuring the stratigraphies of the layers of pigments and to estimate the thickness of the same. - Highlights: • The X-ray fluorescence technique by energy dispersion (EDXRF) and an X-ray fluorescence portable equipment are used for measurement of pigments. • Analysis of the ratios for the intensities of K α /K β lines measured in the areas made it possible to explore the possibility of measuring the stratigraphies of the layers of pigments and to estimate the thickness of the same. • The result of pigment analysis performed on these objects indicates that they are of the twentieth century

Experimental and theoretical studies of perceptible color fading of decorative paints consisting of mixed pigments

International Nuclear Information System (INIS)

Auger, Jean-Claude; McLoughlin, Daragh

2017-01-01

We study the color fading of paints films composed of mixtures of white rutile titanium dioxide and yellow arylide pigments dispersed in two polymer binders at different volume concentrations. The samples were exposed to ultraviolet radiations in an accelerated weathering tester during three weeks. The measured patterns in color variations appeared to be independent of the chemistry of the binders. We then developed a theoretical framework, based on the Radiative transfer Equation of light and the One Particle T-Matrix formalism to simulate the color fading process. The loss of color is correlated to the progressive decrease of the original colored pigment volume-filling fraction as the destructive UV radiations penetrate deeper into the films. The calculated patterns of color variations of paints film composed by mixtures of white pigments with yellow Cadmium Sulfate (CdS) and red Cerium Sulfide (Ce_2S_3) pigments showed the same trend as that seen experimentally. - Highlights: • Theoretical framework to simulate color-fading process of paints. • Good comparison between simulation and experimental data. • Color Fading depends on total amount of perceptible pigments.

Drosophila Clock Is Required in Brain Pacemaker Neurons to Prevent Premature Locomotor Aging Independently of Its Circadian Function.

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Alexandra Vaccaro

2017-01-01

Full Text Available Circadian clocks control many self-sustained rhythms in physiology and behavior with approximately 24-hour periodicity. In many organisms, oxidative stress and aging negatively impact the circadian system and sleep. Conversely, loss of the clock decreases resistance to oxidative stress, and may reduce lifespan and speed up brain aging and neurodegeneration. Here we examined the effects of clock disruptions on locomotor aging and longevity in Drosophila. We found that lifespan was similarly reduced in three arrhythmic mutants (ClkAR, cyc0 and tim0 and in wild-type flies under constant light, which stops the clock. In contrast, ClkAR mutants showed significantly faster age-related locomotor deficits (as monitored by startle-induced climbing than cyc0 and tim0, or than control flies under constant light. Reactive oxygen species accumulated more with age in ClkAR mutant brains, but this did not appear to contribute to the accelerated locomotor decline of the mutant. Clk, but not Cyc, inactivation by RNA interference in the pigment-dispersing factor (PDF-expressing central pacemaker neurons led to similar loss of climbing performance as ClkAR. Conversely, restoring Clk function in these cells was sufficient to rescue the ClkAR locomotor phenotype, independently of behavioral rhythmicity. Accelerated locomotor decline of the ClkAR mutant required expression of the PDF receptor and correlated to an apparent loss of dopaminergic neurons in the posterior protocerebral lateral 1 (PPL1 clusters. This neuronal loss was rescued when the ClkAR mutation was placed in an apoptosis-deficient background. Impairing dopamine synthesis in a single pair of PPL1 neurons that innervate the mushroom bodies accelerated locomotor decline in otherwise wild-type flies. Our results therefore reveal a novel circadian-independent requirement for Clk in brain circadian neurons to maintain a subset of dopaminergic cells and avoid premature locomotor aging in Drosophila.

mc1r Pathway regulation of zebrafish melanosome dispersion

DEFF Research Database (Denmark)

Richardson, Jennifer; Lundegaard, Pia Rengtved; Reynolds, Natalie L

2008-01-01

Zebrafish rapidly alter their pigmentation in response to environmental changes. For black melanocytes, this change is due to aggregation or dispersion of melanin in the cell. Dispersion and aggregation are controlled by intracellular cyclic adenosine monophosphate (cAMP) levels, which increase...... in mammals, and melanosome dispersal in cold-blood vertebrates, the pathway components are highly conserved. However, it has only been assumed that mc1r mediates melanosome dispersal in fish. Here, using morpholino oligonucleotides designed to knockdown mc1r expression, we find that mc1r morphants are unable...... to disperse melanosomes when grown in dark conditions. We also use chemical modifiers of the cAMP pathway, and find an unexpected response to the specific phosphodiesterase 4 (PDE4) inhibitor, rolipram, in melanosome dispersal. When treated with the drug, melanosomes fail to fully disperse in dark conditions...

Skin Pigmentation Disorders

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Pigmentation means coloring. Skin pigmentation disorders affect the color of your skin. Your skin gets its color from a pigment called melanin. Special cells in the skin make melanin. When these cells become damaged or ...

Phylogenetic patterns of geographical and ecological diversification in the subgenus Drosophila.

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Ramiro Morales-Hojas

Full Text Available Colonisation of new geographic regions and/or of new ecological resources can result in rapid species diversification into the new ecological niches available. Members of the subgenus Drosophila are distributed across the globe and show a large diversity of ecological niches. Furthermore, taxonomic classification of Drosophila includes the rank radiation, which refers to closely related species groups. Nevertheless, it has never been tested if these taxonomic radiations correspond to evolutionary radiations. Here we present a study of the patterns of diversification of Drosophila to test for increased diversification rates in relation to the geographic and ecological diversification processes. For this, we have estimated and dated a phylogeny of 218 species belonging to the major species groups of the subgenus. The obtained phylogenies are largely consistent with previous studies and indicate that the major groups appeared during the Oligocene/Miocene transition or early Miocene, characterized by a trend of climate warming with brief periods of glaciation. Ancestral reconstruction of geographic ranges and ecological resource use suggest at least two dispersals to the Neotropics from the ancestral Asiatic tropical disribution, and several transitions to specialized ecological resource use (mycophagous and cactophilic. Colonisation of new geographic regions and/or of new ecological resources can result in rapid species diversification into the new ecological niches available. However, diversification analyses show no significant support for adaptive radiations as a result of geographic dispersal or ecological resource shift. Also, cactophily has not resulted in an increase in the diversification rate of the repleta and related groups. It is thus concluded that the taxonomic radiations do not correspond to adaptive radiations.

Phylogenetic patterns of geographical and ecological diversification in the subgenus Drosophila.

Science.gov (United States)

Morales-Hojas, Ramiro; Vieira, Jorge

2012-01-01

Colonisation of new geographic regions and/or of new ecological resources can result in rapid species diversification into the new ecological niches available. Members of the subgenus Drosophila are distributed across the globe and show a large diversity of ecological niches. Furthermore, taxonomic classification of Drosophila includes the rank radiation, which refers to closely related species groups. Nevertheless, it has never been tested if these taxonomic radiations correspond to evolutionary radiations. Here we present a study of the patterns of diversification of Drosophila to test for increased diversification rates in relation to the geographic and ecological diversification processes. For this, we have estimated and dated a phylogeny of 218 species belonging to the major species groups of the subgenus. The obtained phylogenies are largely consistent with previous studies and indicate that the major groups appeared during the Oligocene/Miocene transition or early Miocene, characterized by a trend of climate warming with brief periods of glaciation. Ancestral reconstruction of geographic ranges and ecological resource use suggest at least two dispersals to the Neotropics from the ancestral Asiatic tropical disribution, and several transitions to specialized ecological resource use (mycophagous and cactophilic). Colonisation of new geographic regions and/or of new ecological resources can result in rapid species diversification into the new ecological niches available. However, diversification analyses show no significant support for adaptive radiations as a result of geographic dispersal or ecological resource shift. Also, cactophily has not resulted in an increase in the diversification rate of the repleta and related groups. It is thus concluded that the taxonomic radiations do not correspond to adaptive radiations.

Raman analysis of cobalt blue pigment in blue and white porcelain: A reassessment

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Jiang, Xiaochenyang; Ma, Yanying; Chen, Yue; Li, Yuanqiu; Ma, Qinglin; Zhang, Zhaoxia; Wang, Changsui; Yang, Yimin

2018-02-01

Cobalt blue is a famous pigment in human history. In the past decade it is widely reported that the cobalt aluminate has been detected in ancient ceramics as blue colorant in glaze, yet the acquired Raman spectra are incredibly different from that of synthesised references, necessitating a reassessment of such contradictory scenario with more accurate analytic strategies. In this study, micro-Raman spectroscopy (MRS) and scanning electron microscopy (SEM) in association with energy dispersive spectrometry (EDS) were performed on under-glaze cobalt pigments from one submerged blue and white porcelain shard dated from Wanli reign (1573-1620 CE) of Ming dynasty (1365-1644 CE) excavated at Nan'ao I shipwreck off the southern coast of China. The micro-structural inspection reveals that the pigment particles have characteristics of small account, tiny size, heterogeneously distribution, and more importantly, been completely enwrapped by well-developed anorthite crystals in the glaze, indicating that the signals recorded in previous publications are probably not from cobalt pigments themselves but from outside thickset anorthite shell. The further spectromicroscopic analyses confirm this presumption when the accurate spectra of cobalt aluminate pigment and surrounding anorthite were obtained separately with precise optical positioning. Accordingly, we reassess and clarify the previous Raman studies dedicated to cobalt blue pigment in ancient ceramics, e.g. cobalt blue in celadon glaze, and in turn demonstrate the superiority and necessity of coupling spectroscopic analysis with corresponding structure observation, especially in the characterization of pigments from complicated physico-chemical environment like antiquities. Thus, this study promotes a better understanding of Raman spectroscopy study of cobalt blue pigments in art and archaeology field.

Single crystal X-ray structure of the artists' pigment zinc yellow

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Simonsen, Kim Pilkjær; Christiansen, Marie Bitsch; Vinum, Morten Gotthold; Sanyova, Jana; Bendix, Jesper

2017-08-01

The artists' pigment zinc yellow is in general described as a complex potassium zinc chromate with the empirical formula 4ZnCrO4·K2O·3H2O. Even though the pigment has been in use since the second half of the 19th century also in large-scale industrial applications, the exact structure had hitherto been unknown. In this work, zinc yellow was synthesised by precipitation from an aqueous solution of zinc nitrate and potassium chromate under both neutral and basic conditions, and the products were compared with the pigment used in industrial paints. Analyses by Raman microscopy (MRS), scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS), attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), and powder X-ray diffraction (PXRD), showed that the synthesised products and the industrial pigment were identical. Single-crystal X-ray crystallography determined the structure of zinc yellow as KZn2(CrO4)2(H2O)(OH) or as KZn2(CrO4)2(H3O2) emphasizing the μ-H3O2- moiety. Notably, the zinc yellow is isostructural to the recently structurally characterized cadmium analog and both belong to the natrochalcite structure type.

Rhythmic Behavior Is Controlled by the SRm160 Splicing Factor in Drosophila melanogaster.

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Beckwith, Esteban J; Hernando, Carlos E; Polcowñuk, Sofía; Bertolin, Agustina P; Mancini, Estefania; Ceriani, M Fernanda; Yanovsky, Marcelo J

2017-10-01

Circadian clocks organize the metabolism, physiology, and behavior of organisms throughout the day-night cycle by controlling daily rhythms in gene expression at the transcriptional and post-transcriptional levels. While many transcription factors underlying circadian oscillations are known, the splicing factors that modulate these rhythms remain largely unexplored. A genome-wide assessment of the alterations of gene expression in a null mutant of the alternative splicing regulator SR-related matrix protein of 160 kDa (SRm160) revealed the extent to which alternative splicing impacts on behavior-related genes. We show that SRm160 affects gene expression in pacemaker neurons of the Drosophila brain to ensure proper oscillations of the molecular clock. A reduced level of SRm160 in adult pacemaker neurons impairs circadian rhythms in locomotor behavior, and this phenotype is caused, at least in part, by a marked reduction in period ( per ) levels. Moreover, rhythmic accumulation of the neuropeptide PIGMENT DISPERSING FACTOR in the dorsal projections of these neurons is abolished after SRm160 depletion. The lack of rhythmicity in SRm160-downregulated flies is reversed by a fully spliced per construct, but not by an extra copy of the endogenous locus, showing that SRm160 positively regulates per levels in a splicing-dependent manner. Our findings highlight the significant effect of alternative splicing on the nervous system and particularly on brain function in an in vivo model. Copyright © 2017 by the Genetics Society of America.

Ion microprobe analysis of metallic pigments

International Nuclear Information System (INIS)

Pelicon, P.; Simcic, J.; Budnar, M.; Klanjsek-Gunde, M.; Kunavaer, M.

2001-01-01

Full text: Metallic paints consist of metallic flakes dispersed m a resinous binder, i.e. a light-element polymer matrix. The spatial distribution and orientation of metallic flakes inside the matrix determines the covering efficiency of the paint, glossiness, and its angular-dependent properties such as lightness flop or color flop (two-tone). Such coatings are extensively used for a functional (i.e. security) as well as decorative purpose. The ion microbeam analysis of two types of silver paint with imbedded metallic flake has been performed to test the ability of the ion microbeam spectroscopic methods on this type of samples. The average sizes of the aluminium flakes were 23 (size distribution 10-37) and 49 (size distribution 34-75) micrometers, respectively. The proton beam with the size of 2x2 micrometers at Ljubljana ion microprobe has been used to scan the surface of the pigments. PIXE mapping of Al Kα map shows lateral distribution of the aluminum flakes, whereas the RBS slicing method reveals tomographic image of the flakes in uppermost 5 micrometers of the pigment layer. The flake distribution in the larger layer depths has been accessed by RBS analysis in a point mode. (author)

Determination of pigments in colour layers on walls of some selected historical buildings using optical and scanning electron microscopy

International Nuclear Information System (INIS)

Skapin, A. Sever; Ropret, P.; Bukovec, P.

2007-01-01

For successful restoration of painted walls and painted coloured finishing coats it is necessary to determine the composition of the original colour layers. Identification of the pigments used in The Cistercian Abbey of Sticna and The Manor of Novo Celje was carried out using optical and scanning electron microscopy. Selected samples of wall paintings were inspected by the combined application of an optical microscope and a low-vacuum Scanning Electron Microscope to determine their colour and structural features and to identify the position of individual pigment grains. Energy dispersive spectroscopy was used to determine the elemental distribution on selected surfaces and elemental composition of individual pigments. It was found that the most abundantly used pigments were iron oxide red, cinnabar, green earth, umber, calcium carbonate white, ultramarine, yellow ochre and carbon black. These identifications have allowed us to compare the use of various pigments in buildings from different historical periods

Quantifying the refractive index dispersion of a pigmented biological tissue using Jamin-Lebedeff interference microscopy

NARCIS (Netherlands)

Stavenga, Doekele G.; Leertouwer, Hein L.; Wilts, Bodo D.

Jamin-Lebedeff polarizing interference microscopy is a classical method for determining the refractive index and thickness of transparent tissues. Here, we extend the application of this method to pigmented, absorbing biological tissues, based on a theoretical derivation using Jones calculus. This

Characterisation of the rare cadmium chromate pigment in a 19th century tube colour by Raman, FTIR, X-ray and EPR

DEFF Research Database (Denmark)

Christiansen, Marie Bitsch; Sørensen, Mikkel Agerbæk; Sanyova, Jana

2017-01-01

. However, in one of the tube colours labelled “Jaune de Cadmium Citron” (cadmium lemon yellow) an extremely rare cadmium chromate pigment was found. The pigment was analysed and characterised by Raman microscopy (MRS), scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS), attenuated...... chromate, and the resulting yellow crystals proved identical to the pigment found in the tube colour “Jaune de Cadmium Citron”. The structure determined by single-crystal X-ray diffraction identified the pigment as 2CdCrO4·KOH·H2O or more accurately as KCd2(CrO4)2(H3O2) illustrating the μ-H3O2– species...

Glass promotes the differentiation of neuronal and non-neuronal cell types in the Drosophila eye

Science.gov (United States)

Morrison, Carolyn A.; Chen, Hao; Cook, Tiffany; Brown, Stuart

2018-01-01

Transcriptional regulators can specify different cell types from a pool of equivalent progenitors by activating distinct developmental programs. The Glass transcription factor is expressed in all progenitors in the developing Drosophila eye, and is maintained in both neuronal and non-neuronal cell types. Glass is required for neuronal progenitors to differentiate as photoreceptors, but its role in non-neuronal cone and pigment cells is unknown. To determine whether Glass activity is limited to neuronal lineages, we compared the effects of misexpressing it in neuroblasts of the larval brain and in epithelial cells of the wing disc. Glass activated overlapping but distinct sets of genes in these neuronal and non-neuronal contexts, including markers of photoreceptors, cone cells and pigment cells. Coexpression of other transcription factors such as Pax2, Eyes absent, Lozenge and Escargot enabled Glass to induce additional genes characteristic of the non-neuronal cell types. Cell type-specific glass mutations generated in cone or pigment cells using somatic CRISPR revealed autonomous developmental defects, and expressing Glass specifically in these cells partially rescued glass mutant phenotypes. These results indicate that Glass is a determinant of organ identity that acts in both neuronal and non-neuronal cells to promote their differentiation into functional components of the eye. PMID:29324767

The analysis of pigments on rock surfaces

International Nuclear Information System (INIS)

Fankhauser, B.; O'Connor, S.; Pittelkow, Y.

1997-01-01

A limestone slab of roof fall coated with a red pigment was recovered from a Rockshelter in the Napier Ranges of the Kimberley region, Western Australia. Next to the roof fall fragment in the same stratigraphic layer was a piece of ochre. Three questions were presented: (1) is the red substance an ochre? (2) is the piece of ochre identical to the red substance on the roof fall? and (3) are the layers of pigment on the top and bottom of the limestone slab the same? In addition, as an extension from these questions, a general method was developed for the in situ analysis of ochre pigments on substrates to determine likely compositions and ochre sources. The analysis of the red pigment presented an analytical problem because the substance was intimately associated with the rock slab and therefore the analysis had to be done in situ. Not only was the red layer thin, but on a micro level it was uneven. Energy dispersive x-ray analysis (EDXA) penetrated the red layer, simultaneously analysing this layer and the rock substrate to different degrees depending upon the thickness of the red layer. Determining if the substance was actually ochre involved a comparison of elemental analyses between the background (slab) and background with red coating. Coatings of other ochres with known elemental concentrations on the same limestone background gave a comparison of the effect of simultaneously analysing a thin layer and background with different compositions. Three graphical methods useful for insitu analysis are demeonstrated. The find dates (around 40,000 BP) add to a growing body of data in support of the widespread use of ochre accompanying the earliest documented use of widely separated and environmentally diverse regions of Australia by Aboriginal people

The analysis of pigments on rock surfaces

Energy Technology Data Exchange (ETDEWEB)

Fankhauser, B.; O`Connor, S. [Australian National Univ., Canberra, ACT (Australia). Division of Archaeology and Natural History; Pittelkow, Y. [Australian National Univ., Canberra, ACT (Australia). Coombs Computing Unit

1997-12-31

A limestone slab of roof fall coated with a red pigment was recovered from a Rockshelter in the Napier Ranges of the Kimberley region, Western Australia. Next to the roof fall fragment in the same stratigraphic layer was a piece of ochre. Three questions were presented: (1) is the red substance an ochre? (2) is the piece of ochre identical to the red substance on the roof fall? and (3) are the layers of pigment on the top and bottom of the limestone slab the same? In addition, as an extension from these questions, a general method was developed for the in situ analysis of ochre pigments on substrates to determine likely compositions and ochre sources. The analysis of the red pigment presented an analytical problem because the substance was intimately associated with the rock slab and therefore the analysis had to be done in situ. Not only was the red layer thin, but on a micro level it was uneven. Energy dispersive x-ray analysis (EDXA) penetrated the red layer, simultaneously analysing this layer and the rock substrate to different degrees depending upon the thickness of the red layer. Determining if the substance was actually ochre involved a comparison of elemental analyses between the background (slab) and background with red coating. Coatings of other ochres with known elemental concentrations on the same limestone background gave a comparison of the effect of simultaneously analysing a thin layer and background with different compositions. Three graphical methods useful for insitu analysis are demeonstrated. The find dates (around 40,000 BP) add to a growing body of data in support of the widespread use of ochre accompanying the earliest documented use of widely separated and environmentally diverse regions of Australia by Aboriginal people.

Synthesis and structure of a pink pigment in the system Zr02-TiO2-SnO2-Cr2O3

International Nuclear Information System (INIS)

Zygadlo, M.

1979-01-01

The mechanism has been discussed of the formation of this pigment in the ceramic glazes and the results are communicated of the experiment to synthetize this pigment and to test it by the thermographic, X-ray and electron-microsonde methods. It has been found that the pink pigment is the result of dispersion of Cr 2 O 3 upon the grain areas of Zr0 2 , TiO 2 and SnO 2 : it is not a solid solution of Cr 2 O 3 in these oxides as has been earlier suggested. (author)

Behavioral Teratogenesis in Drosophila melanogaster.

Science.gov (United States)

Mishra, Monalisa; Barik, Bedanta Kumar

2018-01-01

Developmental biology is a fascinating branch of science which helps us to understand the mechanism of development, thus the findings are used in various therapeutic approach. Drosophila melanogaster served as a model to find the key molecules that initiate and regulate the mechanism of development. Various genes, transcription factors, and signaling pathways helping in development are identified in Drosophila. Many toxic compounds, which can affect the development, are also recognized using Drosophila model. These compounds, which can affect the development, are named as a teratogen. Many teratogens identified using Drosophila may also act as a teratogen for a human being since 75% of conservation exist between the disease genes present in Drosophila and human. There are certain teratogens, which do not cause developmental defect if exposed during pregnancy, however; behavioral defect appears in later part of development. Such compounds are named as a behavioral teratogen. Thus, it is worthy to identify the potential behavioral teratogen using Drosophila model. Drosophila behavior is well studied in various developmental stages. This chapter describes various methods which can be employed to test behavioral teratogenesis in Drosophila.

Action of the chlorophyllin before genetic damage induced by gamma radiation in germinal cells of Drosophila; Accion de la clorofilina ante el dano genetico inducido por radiacion gamma en celulas germinales de Drosophila

Energy Technology Data Exchange (ETDEWEB)

Moreno B, R

2004-07-01

The chlorophyllin (CHLN) is a porphyrin of nutritious grade and soluble in water, derived of the chlorophyll. It has been reported that this pigment is a good anti mutagen since it reduces the damage to the DNA caused by physical or chemical agents of direct or indirect action. Their anti carcinogenic action has also been demonstrated when it is administered itself during the induced post-initiation phase by aflatoxins and heterocyclic amines. However in the last decade it has been reported that it also has promoter activity against the genetic damage induced by diverse agents like the alkyl ants of direct and indirect action, the gamma radiation and some heterocyclic amines. This effect has been observed in testing systems like Salmonella, Drosophila, rainbow trout and rodents. In the mouse spermatogonia it has been reported that it reduces the damage to the DNA but with the test of lethal dominant in Drosophila increment the damage induced by gamma radiation. The present study consisted on evaluating the effect of the CHLN in the line germinal masculine of Drosophila by means of the lethal recessive test bound to the sex (LRLS) with the stump Muller 5 and a litters system. Its were pretreated wild males with CHLN and 24 h later were irradiated with 0, 10, 20 and 40 Gy of gamma radiation immediately later were crossed with virgin females of the stump Basc and at 72 h the male was transferred to a cultivation media with three new virgin females, this process repeated three times until completing 3 litters. The F1 it was crossed among itself and in the F2 it was analysed the presence or absence of lethals. The results indicated that the CHLN per se incremented the basal frequency of damage due to the pigment can act as an agent that is inserted to the ADN causing pre mutagenic leisure. Nevertheless with the groups treated with the different doses of gamma radiation the CHLN does not present any protector action, neither promoter except in the litter I of the group

EDXRF Analysis of pigments of the Joaquin Sorolla Artistic Paintings

International Nuclear Information System (INIS)

Ferrero, Jose L.; Roldan Clodoaldo, David; Mario Alvarez, Juanes

1999-01-01

The study of the pictorial work of Joaquin Sorolla has not been carried out from the point of view of the scientific analysis. Analytical techniques give us objective information about materials and process used in artistic works of art. In this sense, the Archaeometry Unit of the Institute of Material Science of the Valencia University (ICMUV), has carried out the first analysis of pigments of the paintings of Sorolla by Energy Dispersive X-Ray Fluorescence(EDXRF)

The Fly Sensitizing Pigment Enhances UV Spectral Sensitivity While Preventing Polarization-Induced Artifacts

Directory of Open Access Journals (Sweden)

Marko Ilić

2018-02-01

Full Text Available Microvillar photoreceptors are intrinsically capable of detecting the orientation of e-vector of linearly polarized light. They provide most invertebrates with an additional sensory channel to detect important features of their visual environment. However, polarization sensitivity (PS of photoreceptors may lead to the detection of polarization-induced false colors and intensity contrasts. Most insect photoreceptors are thus adapted to have minimal PS. Flies have twisted rhabdomeres with microvilli rotated along the length of the ommatidia to reduce PS. The additional UV-absorbing sensitizing pigment on their opsin minimizes PS in the ultraviolet. We recorded voltage from Drosophila photoreceptors R1–6 to measure the spectral dependence of PS and found that PS in the UV is invariably negligible but can be substantial above 400 nm. Using modeling, we demonstrate that in R1–6 without the sensitizing pigment, PS in the UV (PSUV would exceed PS in the visible part of the spectrum (PSVIS by a factor PSUV/PSVIS = 1.2–1.8, as lower absorption of Rh1 rhodopsin reduces self-screening. We use polarimetric imaging of objects relevant to fly polarization vision to show that their degree of polarization outdoors is highest in the short-wavelength part of the spectrum. Thus, under natural illumination, the sensitizing pigment in R1–6 renders even those cells with high PS in the visible part unsuitable for proper polarization vision. We assume that fly ventral polarization vision can be mediated by R7 alone, with R1–6 serving as an unpolarized reference channel.

The cuticular nature of corneal lenses in Drosophila melanogaster.

Science.gov (United States)

Stahl, Aaron L; Charlton-Perkins, Mark; Buschbeck, Elke K; Cook, Tiffany A

2017-07-01

The dioptric visual system relies on precisely focusing lenses that project light onto a neural retina. While the proteins that constitute the lenses of many vertebrates are relatively well characterized, less is known about the proteins that constitute invertebrate lenses, especially the lens facets in insect compound eyes. To address this question, we used mass spectrophotometry to define the major proteins that comprise the corneal lenses from the adult Drosophila melanogaster compound eye. This led to the identification of four cuticular proteins: two previously identified lens proteins, drosocrystallin and retinin, and two newly identified proteins, Cpr66D and Cpr72Ec. To determine which ommatidial cells contribute each of these proteins to the lens, we conducted in situ hybridization at 50% pupal development, a key age for lens secretion. Our results confirm previous reports that drosocrystallin and retinin are expressed in the two primary corneagenous cells-cone cells and primary pigment cells. Cpr72Ec and Cpr66D, on the other hand, are more highly expressed in higher order interommatidial pigment cells. These data suggest that the complementary expression of cuticular proteins give rise to the center vs periphery of the corneal lens facet, possibly facilitating a refractive gradient that is known to reduce spherical aberration. Moreover, these studies provide a framework for future studies aimed at understanding the cuticular basis of corneal lens function in holometabolous insect eyes.

Ecological-friendly pigments from fungi.

Science.gov (United States)

Durán, Nelson; Teixeira, Maria F S; De Conti, Roseli; Esposito, Elisa

2002-01-01

The dyestuff industry is suffering from the increases in costs of feedstock and energy for dye synthesis, and they are under increasing pressure to minimize the damage to the environment. The industries are continuously looking for cheaper, more environmentally friendly routes to existing dyes. The aim of this minireview is to discuss the most important advances in the fungal pigment area and its interest in biotechnological applications. Characteristic pigments are produced by a wide variety of fungi and the chemical composition of natural dyes are described. These pigments exhibit several biological activities besides cytotoxicity. The synthetic pigments authorized by the EC and in USA and the natural pigments available in the world market are discussed. The obstacle to the exploitation of new natural pigments sources is the food legislation, requesting costly toxicological research, manufacturing costs, and acceptance by consumers. The dislike for novel ingredients is likely to be the biggest impediment for expansion of the pigment list in the near future. If the necessary toxicological testing and the comparison with accepted pigments are made, the fungal pigments, could be acceptable by the current consumer. The potentiality of pigment production in Brazil is possible due to tremendous Amazonian region biodiversity.

EDXRF as an analytical tool in art. Case studies from pigment identification and treatment assessment

International Nuclear Information System (INIS)

Kallithrakas-Kontos, N.; Maravelaki-Kalaitzaki, P.

2004-01-01

Energy dispersive X-ray fluorescence (EDXRF) was employed for the identification of pigments decorating Hellenistic figurines, and the assessment of the efficiency of a treatment with barium hydroxide applied to stone. Elements present in the colored areas of the figurines, as well as the treated stone was identified by EDXRF. These data together with complementary information obtained by Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction analysis (XRD) led to the identification of several precious pigments. As far as the treatment efficiency is concerned, EDXRF analysis revealed that barium is unevenly distributed on the treated surface and reaches a maximum depth of 2.5 mm. (author)

Quantitative analysis of pigment dispersion taking into account the full agglomerate size distribution

DEFF Research Database (Denmark)

Kiil, Søren

were in good quantitative agreement with experimental data. The only adjustable parameter used was an apparent rate constant for the linear agglomerate erosion rate. Model simulations, at selected values of time, for the full agglomerate particle size distribution were in good qualitative agreement...... distribution was simulated. Data from previous experimental investigations with organic pigments were used for model validation.When the linear rate of agglomerate surface erosion was taken to be proportional to the external agglomerate surface area, simulations of the volume-moment mean diameter over time...

Preparation of spherical fine particulate pigments within water-in-oil emulsions and their properties. (II). ; Formation mechanism and characteristic of spherical fine particulate pigment of tartrazine. W/O emulsion wo mochiita kyujo biryushi ganryo no chosei to seishitsu(dai 2 ho). ; Kiiro 4 go kyujo biryushi ganryo no seisei kiko to tokusei

Energy Technology Data Exchange (ETDEWEB)

Imai, T.; Iwano, K.; Hotta, H.; Takano, S.; Tsutsumi, H. (Kao Corporation, Tokyo (Japan))

1991-12-20

The previous report explained that an excellent spherical particulate pigment with a grain size of 0.5 mm or less can be obtained by preparing multinuclear aluminum lakes from acidic dyes and multinuclear aluminum salt using water droplets in a W/O emulsion as reaction fields. This paper describes preparing pigments varying the charging concentrations of the pigments in a W/O emulsion and the droplet particle size to discuss the mechanism of forming the pigments. As a result, it was found that the particle sizes in the produced pigments have a clear correlation with the charging concentrations of the pigments and the droplet particle sizes in the W/O emulsion. A pigment produced in the W/O emulsion forms only in its own droplets, and reflects its particle sizes. Films dispersed with pigments having different particle sizes were prepared to discuss their tinting abilities, whereas it was clarified that the smaller the particle size, the higher the tinting ability and the higher saturation in colored paint films. 6 refs., 9 figs., 3 tabs.

Micro-analytical evidence of origin and degradation of copper pigments found in Bohemian Gothic murals.

Science.gov (United States)

Svarcová, Silvie; Hradil, David; Hradilová, Janka; Kocí, Eva; Bezdicka, Petr

2009-12-01

Correct identification of pigments and all accompanying phases found in colour layers of historical paintings are relevant for searching their origin and pigment preparation pathways and for specification of their further degradation processes. We successfully applied the analytical route combining non-destructive in situ X-ray fluorescence analyses with subsequent laboratory investigation of micro-samples by optical microscopy, scanning electron microscopy/energy-dispersive spectroscopy and X-ray powder micro-diffraction (micro-XRD) to obtain efficiently all the data relevant for mineralogical interpretations of the copper pigments origin. Cu salts (carbonates, chlorides, sulphates, etc.) used as pigments exist in a range of polymorphs with similar or identical composition. The efficiency of the micro-XRD for direct identification of such crystal phases present in micro-samples of colour layers was demonstrated in the presented paper. A new, until now unpublished, type of copper pigment--cumengeite, Pb(21)Cu(20)Cl(42)(OH)(40)--used as a blue pigment on a sacral wall painting in the Czech Republic was found by means of micro-XRD. Furthermore, azurite, malachite, paratacamite, atacamite and posnjakite were identified in fragments of colour layers of selected Gothic wall paintings. We found Cu-Zn arsenates indicating the natural origin of azurite and malachite; artificial malachite was distinguishable according to its typical spherulitic crystals. The corrosion of blue azurite to green basic Cu chloride was clearly evidenced on some places exposed to the action of salts and moisture-in a good agreement with the results of laboratory experiments, which also show that oxalic acid accelerates the corrosion of Cu pigments.

Modeling Human Cancers in Drosophila.

Science.gov (United States)

Sonoshita, M; Cagan, R L

2017-01-01

Cancer is a complex disease that affects multiple organs. Whole-body animal models provide important insights into oncology that can lead to clinical impact. Here, we review novel concepts that Drosophila studies have established for cancer biology, drug discovery, and patient therapy. Genetic studies using Drosophila have explored the roles of oncogenes and tumor-suppressor genes that when dysregulated promote cancer formation, making Drosophila a useful model to study multiple aspects of transformation. Not limited to mechanism analyses, Drosophila has recently been showing its value in facilitating drug development. Flies offer rapid, efficient platforms by which novel classes of drugs can be identified as candidate anticancer leads. Further, we discuss the use of Drosophila as a platform to develop therapies for individual patients by modeling the tumor's genetic complexity. Drosophila provides both a classical and a novel tool to identify new therapeutics, complementing other more traditional cancer tools. © 2017 Elsevier Inc. All rights reserved.

UV-B affects the immune system and promotes nuclear abnormalities in pigmented and non-pigmented bullfrog tadpoles.

Science.gov (United States)

Franco-Belussi, Lilian; Fanali, Lara Zácari; De Oliveira, Classius

2018-03-01

Ultra-Violet (UV) radiation is a stressor of the immune system and causes DNA damage. Leukocytes can change in response to environmental changes in anurans, making them an important biomarker of stressful situations. The initial barrier against UV in ectothermic animals is melanin-containing cells in skin and in their internal organs. Here, we tested the effects of UV exposure on immune cells and DNA integrity in pigmented and non-pigmented tadpoles of Lithobates catesbeianus. We used an inflammation model with lipopolysaccharide (LPS) of Escherichia coli to test synergic effects of UV and LPS. We tested the following hypotheses: 1) DNA damage caused by UV will be more pronounced in non-pigmented than in pigmented animals; 2) LPS increases leukocytes in both pigmented and non-pigmented animals by systemic inflammation; 3) The combined LPS and UV exposure will decrease the number of leukocytes. We found that the frequency of immune cells differed between pigmented and non-pigmented tadpoles. UV exposure increased mast cells and DNA damage in erythrocytes in both pigmented and non-pigmented tadpoles, while leukocytes decreased after UV exposure. Non-pigmented tadpoles experienced DNA damage and a lower lymphocyte count earlier than pigmented tadpoles. UV altered immune cells likely as a consequence of local and systemic inflammation. These alterations were less severe in pigmented than in non-pigmented animals. UV and LPS increased internal melanin in pigmented tadpoles, which were correlated with DNA damage and leukocytes. Here, we described for the first time the effects of UV and LPS in immune cells of pigmented and non-pigmented tadpoles. In addition, we demonstrated that internal melanin in tadpoles help in these defenses, since leukocyte responses were faster in non-pigmented animals, supporting the hypothesis that melanin is involved in the initial innate immune response. Copyright © 2018 Elsevier B.V. All rights reserved.

Semi-automated quantitative Drosophila wings measurements.

Science.gov (United States)

Loh, Sheng Yang Michael; Ogawa, Yoshitaka; Kawana, Sara; Tamura, Koichiro; Lee, Hwee Kuan

2017-06-28

Drosophila melanogaster is an important organism used in many fields of biological research such as genetics and developmental biology. Drosophila wings have been widely used to study the genetics of development, morphometrics and evolution. Therefore there is much interest in quantifying wing structures of Drosophila. Advancement in technology has increased the ease in which images of Drosophila can be acquired. However such studies have been limited by the slow and tedious process of acquiring phenotypic data. We have developed a system that automatically detects and measures key points and vein segments on a Drosophila wing. Key points are detected by performing image transformations and template matching on Drosophila wing images while vein segments are detected using an Active Contour algorithm. The accuracy of our key point detection was compared against key point annotations of users. We also performed key point detection using different training data sets of Drosophila wing images. We compared our software with an existing automated image analysis system for Drosophila wings and showed that our system performs better than the state of the art. Vein segments were manually measured and compared against the measurements obtained from our system. Our system was able to detect specific key points and vein segments from Drosophila wing images with high accuracy.

Action of the chlorophyllin before genetic damage induced by gamma radiation in germinal cells of Drosophila

International Nuclear Information System (INIS)

Moreno B, R.

2004-01-01

The chlorophyllin (CHLN) is a porphyrin of nutritious grade and soluble in water, derived of the chlorophyll. It has been reported that this pigment is a good anti mutagen since it reduces the damage to the DNA caused by physical or chemical agents of direct or indirect action. Their anti carcinogenic action has also been demonstrated when it is administered itself during the induced post-initiation phase by aflatoxins and heterocyclic amines. However in the last decade it has been reported that it also has promoter activity against the genetic damage induced by diverse agents like the alkyl ants of direct and indirect action, the gamma radiation and some heterocyclic amines. This effect has been observed in testing systems like Salmonella, Drosophila, rainbow trout and rodents. In the mouse spermatogonia it has been reported that it reduces the damage to the DNA but with the test of lethal dominant in Drosophila increment the damage induced by gamma radiation. The present study consisted on evaluating the effect of the CHLN in the line germinal masculine of Drosophila by means of the lethal recessive test bound to the sex (LRLS) with the stump Muller 5 and a litters system. Its were pretreated wild males with CHLN and 24 h later were irradiated with 0, 10, 20 and 40 Gy of gamma radiation immediately later were crossed with virgin females of the stump Basc and at 72 h the male was transferred to a cultivation media with three new virgin females, this process repeated three times until completing 3 litters. The F1 it was crossed among itself and in the F2 it was analysed the presence or absence of lethals. The results indicated that the CHLN per se incremented the basal frequency of damage due to the pigment can act as an agent that is inserted to the ADN causing pre mutagenic leisure. Nevertheless with the groups treated with the different doses of gamma radiation the CHLN does not present any protector action, neither promoter except in the litter I of the group

Unusual development of light-reflecting pigment cells in intact and regenerating tail in the periodic albino mutant of Xenopus laevis.

Science.gov (United States)

Fukuzawa, Toshihiko

2010-10-01

Unusual light-reflecting pigment cells, "white pigment cells", specifically appear in the periodic albino mutant (a(p) /a(p)) of Xenopus laevis and localize in the same place where melanophores normally differentiate in the wild-type. The mechanism responsible for the development of unusual pigment cells is unclear. In this study, white pigment cells in the periodic albino were compared with melanophores in the wild-type, using a cell culture system and a tail-regenerating system. Observations of both intact and cultured cells demonstrate that white pigment cells are unique in (1) showing characteristics of melanophore precursors at various stages of development, (2) accumulating reflecting platelets characteristic of iridophores, and (3) exhibiting pigment dispersion in response to α-melanocyte stimulating hormone (α-MSH) in the same way that melanophores do. When a tadpole tail is amputated, a functionally competent new tail is regenerated. White pigment cells appear in the mutant regenerating tail, whereas melanophores differentiate in the wild-type regenerating tail. White pigment cells in the mutant regenerating tail are essentially similar to melanophores in the wild-type regenerating tail with respect to their localization, number, and response to α-MSH. In addition to white pigment cells, iridophores which are never present in the intact tadpole tail appear specifically in the somites near the amputation level in the mutant regenerating tail. Iridophores are distinct from white pigment cells in size, shape, blue light-induced fluorescence, and response to α-MSH. These findings strongly suggest that white pigment cells in the mutant arise from melanophore precursors and accumulate reflecting platelets characteristic of iridophores.

Enhanced production of natural yellow pigments from Monascus purpureus by liquid culture: The relationship between fermentation conditions and mycelial morphology.

Science.gov (United States)

Lv, Jun; Zhang, Bo-Bo; Liu, Xiao-Dong; Zhang, Chan; Chen, Lei; Xu, Gan-Rong; Cheung, Peter Chi Keung

2017-10-01

Natural yellow pigments produced by submerged fermentation of Monascus purpureus have potential economic value and application in the food industry. In the present study, the relationships among fermentation conditions (in terms of pH and shaking/agitation speed), mycelial morphology and the production of Monascus yellow pigments were investigated in both shake-flask and scale-up bioreactor experiments. In the shake-flask fermentation, the highest yield of the Monascus yellow pigments was obtained at pH 5.0 and a shaking speed of 180 rpm. Microscopic images revealed that these results were associated with the formation of freely dispersed small mycelial pellets with shorter, thicker and multi-branched hyphae. Further investigation indicated that the hyphal diameter was highly correlated with the biosynthesis of the Monascus yellow pigments. In a scaled-up fermentation experiment, the yield of yellow pigments (401 U) was obtained in a 200-L bioreactor, which is the highest yield to the best of our knowledge. The present findings can advance our knowledge on the conditions used for enhancing the production of Monascus yellow pigments in submerged fermentation and facilitate large-scale production of these natural pigments. Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Physicochemical characterization of pigments and supports in mural paints: Mayapan, Yucatan case

International Nuclear Information System (INIS)

Silva V, Y.; Peraza L, C.A.; Bautista M, J.P.; Arenas A, J.

2006-01-01

The present work is focused in the study of pigments and supports located in mural paintings belonging to the archaeological site of Mayapan. The raw materials utilized by the pre hispanic are revealed by means of the use of different techniques of characterization such as Scanning and Transmission Electron Microscopy (SEM and TEM, respectively), Energy Dispersive X-Ray Spectroscopy (EDS), X-Ray Diffraction and Fourier Transform Infrared Spectroscopy (FTIR). The pigments analyzed cover the following colors: yellow, blue, white, orange, black, red, olive and aqua green. In general, the elements O, Ca and C were the main elements present, as well as quantities of Si and Fe were very significant in all the cases. The manufacture techniques for the production of pigments and supports coincided with all those reported in literature for the Maya culture; however, influence from the Central Altiplane could be appreciated. The results obtained by XRD show the phases of calcite (CaCO 3 ) and dolomite ferroan (Ca(Mg,Fe)(CO 3 ) 2 ) in all the support. The analyses by FTIR indicated the presence of some agglutinating, but it has not been identified yet. (Author)

Ancient balancing selection at tan underlies female colour dimorphism in Drosophila erecta.

Science.gov (United States)

Yassin, Amir; Bastide, Héloïse; Chung, Henry; Veuille, Michel; David, Jean R; Pool, John E

2016-01-18

Dimorphic traits are ubiquitous in nature, but the evolutionary factors leading to dimorphism are largely unclear. We investigate a potential case of sexual mimicry in Drosophila erecta, in which females show contrasting resemblance to males. We map the genetic basis of this sex-limited colour dimorphism to a region containing the gene tan. We find a striking signal of ancient balancing selection at the 'male-specific enhancer' of tan, with exceptionally high sequence divergence between light and dark alleles, suggesting that this dimorphism has been adaptively maintained for millions of years. Using transgenic reporter assays, we confirm that these enhancer alleles encode expression differences that are predicted to generate this pigmentation dimorphism. These results are compatible with the theoretical prediction that divergent phenotypes maintained by selection can evolve simple genetic architectures.

Analysis of metallic pigments by ion microbeam

International Nuclear Information System (INIS)

Pelicon, P.; Klanjsek-Gunde, M.; Kunaver, M.; Simcic, J.; Budnar, M.

2002-01-01

Metallic paints consist of metallic flakes dispersed in a resinous binder, i.e. a light-element polymer matrix. The spatial distribution and orientation of metallic flakes inside the matrix determines the covering efficiency of the paint, glossiness, and its angular-dependent properties such as lightness flop or color flop (two-tone). Such coatings are extensively used for a functional (i.e. security) as well as decorative purpose. The ion microbeam analysis of two types of silver paint with imbedded metallic flakes has been performed to determine the spatial distribution of the aluminum flakes in paint layer. The average sizes of the aluminum flakes were 23 μm (size distribution 10-37) and 49 μm (size distribution 34-75), respectively. The proton beam with the size of 2x2 μm 2 at Ljubljana ion microprobe has been used to scan the surface of the pigments. PIXE mapping of Al Kα map shows lateral distribution of the aluminum flakes, whereas the RBS slicing method reveals tomograms of the flakes in uppermost 7 μm of the pigment layer. The series of point analysis aligned over the single flake reveal the flake angle in respect to the polymer matrix surface. The angular sensitivity is well below 1 angular degree

Photosynthetic Pigments in Diatoms.

Science.gov (United States)

Kuczynska, Paulina; Jemiola-Rzeminska, Malgorzata; Strzalka, Kazimierz

2015-09-16

Photosynthetic pigments are bioactive compounds of great importance for the food, cosmetic, and pharmaceutical industries. They are not only responsible for capturing solar energy to carry out photosynthesis, but also play a role in photoprotective processes and display antioxidant activity, all of which contribute to effective biomass and oxygen production. Diatoms are organisms of a distinct pigment composition, substantially different from that present in plants. Apart from light-harvesting pigments such as chlorophyll a, chlorophyll c, and fucoxanthin, there is a group of photoprotective carotenoids which includes β-carotene and the xanthophylls, diatoxanthin, diadinoxanthin, violaxanthin, antheraxanthin, and zeaxanthin, which are engaged in the xanthophyll cycle. Additionally, some intermediate products of biosynthetic pathways have been identified in diatoms as well as unusual pigments, e.g., marennine. Marine algae have become widely recognized as a source of unique bioactive compounds for potential industrial, pharmaceutical, and medical applications. In this review, we summarize current knowledge on diatom photosynthetic pigments complemented by some new insights regarding their physico-chemical properties, biological role, and biosynthetic pathways, as well as the regulation of pigment level in the cell, methods of purification, and significance in industries.

Photosynthetic Pigments in Diatoms

Directory of Open Access Journals (Sweden)

Paulina Kuczynska

2015-09-01

Full Text Available Photosynthetic pigments are bioactive compounds of great importance for the food, cosmetic, and pharmaceutical industries. They are not only responsible for capturing solar energy to carry out photosynthesis, but also play a role in photoprotective processes and display antioxidant activity, all of which contribute to effective biomass and oxygen production. Diatoms are organisms of a distinct pigment composition, substantially different from that present in plants. Apart from light-harvesting pigments such as chlorophyll a, chlorophyll c, and fucoxanthin, there is a group of photoprotective carotenoids which includes β-carotene and the xanthophylls, diatoxanthin, diadinoxanthin, violaxanthin, antheraxanthin, and zeaxanthin, which are engaged in the xanthophyll cycle. Additionally, some intermediate products of biosynthetic pathways have been identified in diatoms as well as unusual pigments, e.g., marennine. Marine algae have become widely recognized as a source of unique bioactive compounds for potential industrial, pharmaceutical, and medical applications. In this review, we summarize current knowledge on diatom photosynthetic pigments complemented by some new insights regarding their physico-chemical properties, biological role, and biosynthetic pathways, as well as the regulation of pigment level in the cell, methods of purification, and significance in industries.

The Drosophila melanogaster host model

Science.gov (United States)

Igboin, Christina O.; Griffen, Ann L.; Leys, Eugene J.

2012-01-01

The deleterious and sometimes fatal outcomes of bacterial infectious diseases are the net result of the interactions between the pathogen and the host, and the genetically tractable fruit fly, Drosophila melanogaster, has emerged as a valuable tool for modeling the pathogen–host interactions of a wide variety of bacteria. These studies have revealed that there is a remarkable conservation of bacterial pathogenesis and host defence mechanisms between higher host organisms and Drosophila. This review presents an in-depth discussion of the Drosophila immune response, the Drosophila killing model, and the use of the model to examine bacterial–host interactions. The recent introduction of the Drosophila model into the oral microbiology field is discussed, specifically the use of the model to examine Porphyromonas gingivalis–host interactions, and finally the potential uses of this powerful model system to further elucidate oral bacterial-host interactions are addressed. PMID:22368770

The Drosophila melanogaster host model

Directory of Open Access Journals (Sweden)

Christina O. Igboin

2012-02-01

Full Text Available The deleterious and sometimes fatal outcomes of bacterial infectious diseases are the net result of the interactions between the pathogen and the host, and the genetically tractable fruit fly, Drosophila melanogaster, has emerged as a valuable tool for modeling the pathogen–host interactions of a wide variety of bacteria. These studies have revealed that there is a remarkable conservation of bacterial pathogenesis and host defence mechanisms between higher host organisms and Drosophila. This review presents an in-depth discussion of the Drosophila immune response, the Drosophila killing model, and the use of the model to examine bacterial–host interactions. The recent introduction of the Drosophila model into the oral microbiology field is discussed, specifically the use of the model to examine Porphyromonas gingivalis–host interactions, and finally the potential uses of this powerful model system to further elucidate oral bacterial-host interactions are addressed.

The Drosophila melanogaster host model.

Science.gov (United States)

Igboin, Christina O; Griffen, Ann L; Leys, Eugene J

2012-01-01

The deleterious and sometimes fatal outcomes of bacterial infectious diseases are the net result of the interactions between the pathogen and the host, and the genetically tractable fruit fly, Drosophila melanogaster, has emerged as a valuable tool for modeling the pathogen-host interactions of a wide variety of bacteria. These studies have revealed that there is a remarkable conservation of bacterial pathogenesis and host defence mechanisms between higher host organisms and Drosophila. This review presents an in-depth discussion of the Drosophila immune response, the Drosophila killing model, and the use of the model to examine bacterial-host interactions. The recent introduction of the Drosophila model into the oral microbiology field is discussed, specifically the use of the model to examine Porphyromonas gingivalis-host interactions, and finally the potential uses of this powerful model system to further elucidate oral bacterial-host interactions are addressed.

Characterization of pigments applied on archaeological material from Chincha's Culture by x-rays fluorescence and transmission electronic microscopy

International Nuclear Information System (INIS)

Lopez M, Alcides; Olivera, Paula

2007-01-01

The elementary characterization of some pigments applied in the decoration of recipients used by our ancestors of the Chincha Culture by Energy dispersive X-ray fluorescence (EDXRF)method was allowed. Additionally, the morphological and crystalline characterization by Transmission Electronic Microscopy (TEM) method has been possible. The results have allowed identifying the presence of mercury sulphur (HgS) (cinnabar) in the red pigment on the 'mate'; the black and white pigments are constituted by materials of organic aspect; in the case the dark brown one they are constituted by organic matter and ferric oxide. This work also demonstrates that a portable EDXRF spectrometer is the most suitable for the study of pieces of our cultural patrimony, mainly of those that are difficult to transport from an archaeological place or museum to an analytic laboratory by reason of its dimensions and conservation conditions. (author)

Natural pigments and sacred art

Science.gov (United States)

Kelekian, Lena, ,, Lady

2010-05-01

Since the dawn of mankind, cavemen has expressed himself through art. The earliest known cave paintings date to some 32,000 years ago and used 4 colours derived from the earth. These pigments were iron oxides and known as ochres, blacks and whites. All pigments known by the Egyptians, the Greeks, the Romans and Renaissance man were natural and it was not until the 18th century that synthetic pigments were made and widely used. Until that time all art, be it sacred or secular used only natural pigments, of which the preparation of many have been lost or rarely used because of their tedious preparation. As a geologist, a mineralogist and an artist specializing in iconography, I have been able to rediscover 89 natural pigments extracted from minerals. I use these pigments to paint my icons in the traditional Byzantine manner and also to restore old icons, bringing back their glamour and conserving them for years to come. The use of the natural pigments in its proper way also helps to preserve the traditional skills of the iconographer. In the ancient past, pigments were extremely precious. Many took an exceedingly long journey to reach the artists, and came from remote countries. Research into these pigments is the work of history, geography and anthropology. It is an interesting journey in itself to discover that the blue aquamarines came from Afghanistan, the reds from Spain, the greens Africa, and so on. In this contribution I will be describing the origins, preparation and use of some natural pigments, together with their history and provenance. Additionally, I will show how the natural pigments are used in the creation of an icon. Being a geologist iconographer, for me, is a sacrement that transforms that which is earthly, material and natural into a thing of beauty that is sacred. As bread and wine in the Eucharist, water during baptism and oil in Holy Union transmit sanctification to the beholder, natural pigments do the same when one considers an icon. The

Molecular cloning, functional expression, and gene silencing of two Drosophila receptors for the Drosophila neuropeptide pyrokinin-2

DEFF Research Database (Denmark)

Rosenkilde, Carina; Cazzamali, Giuseppe; Williamson, Michael

2003-01-01

The database of the Drosophila Genome Project contains the sequences of two genes, CG8784 and CG8795, predicted to code for two structurally related G protein-coupled receptors. We have cloned these genes and expressed their coding parts in Chinese hamster ovary cells. We found that both receptors...... can be activated by low concentrations of the Drosophila neuropeptide pyrokinin-2 (CG8784, EC(50) for pyrokinin-2, 1x10(-9)M; CG8795, EC(50) for pyrokinin-2, 5 x 10(-10)M). The precise role of Drosophila pyrokinin-2 (SVPFKPRLamide) in Drosophila is unknown, but in other insects, pyrokinins have...... embryos and first instar larvae. In addition to the two Drosophila receptors, we also identified two probable pyrokinin receptors in the genomic database from the malaria mosquito Anopheles gambiae. The two Drosophila pyrokinin receptors are, to our knowledge, the first invertebrate pyrokinin receptors...

Phototrophic pigment production with microalgae

NARCIS (Netherlands)

Mulders, K.J.M.

2014-01-01

Abstract

Microalgal pigments are regarded as natural alternatives for food colorants. To facilitate optimization of microalgae-based pigment production, this thesis aimed to obtain key insights in the pigment metabolism of phototrophic microalgae, with the main focus on secondary

A novel method for quantifying the amount of trabecular meshwork pigment in glaucomatous and nonglaucomatous eyes.

Science.gov (United States)

Kinori, Michael; Hostovsky, Avner; Skaat, Alon; Schwartsman, Jonathan; Melamed, Shlomo

2014-01-01

To assess the use of a computerized program for evaluating the amount of trabecular meshwork (TM) pigmentation in normal (control), primary open-angle glaucoma (POAG), and pseudoexfoliation glaucoma/pigmentary dispersion glaucoma (PXFG/PDG) patients. All included patients were from the Goldschleger Eye Institute glaucoma clinic. After signing an informed consent, each patient's anterior chamber angle was photographed using a single photo-slit under the same conditions. Only one eye per patient was photographed. The superior TM and the inferior TM were documented. Then, the degree of "blackness" (representing melanin pigment) was assessed using the ImageJ program. Of the 43 eyes photographed, 8 were excluded because of low-quality images. Of the remaining 35 patients, 14 were normal, 10 had POAG, and 11 had PXFG/PDG. The amount of pigment was the same in the control and the POAG patients whether the inferior TM (P=0.24), superior TM (P=0.58), or the sum inferior TM+superior TM (P=0.85) was measured. The pigment level was significantly higher in the PXFG/PDG group than in the control group (inferior TM, Ppigment levels was found to be statistically insignificant in all the groups (normal, P=0.86; POAG, P=0.10; PXFG/PDG, P=0.22). The use of ImageJ software might play a role in the quantification of pigment evaluation of the TM.

Genomic ancestry, self-reported "color" and quantitative measures of skin pigmentation in Brazilian admixed siblings.

Directory of Open Access Journals (Sweden)

Tailce K M Leite

Full Text Available A current concern in genetic epidemiology studies in admixed populations is that population stratification can lead to spurious results. The Brazilian census classifies individuals according to self-reported "color", but several studies have demonstrated that stratifying according to "color" is not a useful strategy to control for population structure, due to the dissociation between self-reported "color" and genomic ancestry. We report the results of a study in a group of Brazilian siblings in which we measured skin pigmentation using a reflectometer, and estimated genomic ancestry using 21 Ancestry Informative Markers (AIMs. Self-reported "color", according to the Brazilian census, was also available for each participant. This made it possible to evaluate the relationship between self-reported "color" and skin pigmentation, self-reported "color" and genomic ancestry, and skin pigmentation and genomic ancestry. We observed that, although there were significant differences between the three "color" groups in genomic ancestry and skin pigmentation, there was considerable dispersion within each group and substantial overlap between groups. We also saw that there was no good agreement between the "color" categories reported by each member of the sibling pair: 30 out of 86 sibling pairs reported different "color", and in some cases, the sibling reporting the darker "color" category had lighter skin pigmentation. Socioeconomic status was significantly associated with self-reported "color" and genomic ancestry in this sample. This and other studies show that subjective classifications based on self-reported "color", such as the one that is used in the Brazilian census, are inadequate to describe the population structure present in recently admixed populations. Finally, we observed that one of the AIMs included in the panel (rs1426654, which is located in the known pigmentation gene SLC24A5, was strongly associated with skin pigmentation in this sample.

Genomic ancestry, self-reported "color" and quantitative measures of skin pigmentation in Brazilian admixed siblings.

Science.gov (United States)

Leite, Tailce K M; Fonseca, Rômulo M C; de França, Nanci M; Parra, Esteban J; Pereira, Rinaldo W

2011-01-01

A current concern in genetic epidemiology studies in admixed populations is that population stratification can lead to spurious results. The Brazilian census classifies individuals according to self-reported "color", but several studies have demonstrated that stratifying according to "color" is not a useful strategy to control for population structure, due to the dissociation between self-reported "color" and genomic ancestry. We report the results of a study in a group of Brazilian siblings in which we measured skin pigmentation using a reflectometer, and estimated genomic ancestry using 21 Ancestry Informative Markers (AIMs). Self-reported "color", according to the Brazilian census, was also available for each participant. This made it possible to evaluate the relationship between self-reported "color" and skin pigmentation, self-reported "color" and genomic ancestry, and skin pigmentation and genomic ancestry. We observed that, although there were significant differences between the three "color" groups in genomic ancestry and skin pigmentation, there was considerable dispersion within each group and substantial overlap between groups. We also saw that there was no good agreement between the "color" categories reported by each member of the sibling pair: 30 out of 86 sibling pairs reported different "color", and in some cases, the sibling reporting the darker "color" category had lighter skin pigmentation. Socioeconomic status was significantly associated with self-reported "color" and genomic ancestry in this sample. This and other studies show that subjective classifications based on self-reported "color", such as the one that is used in the Brazilian census, are inadequate to describe the population structure present in recently admixed populations. Finally, we observed that one of the AIMs included in the panel (rs1426654), which is located in the known pigmentation gene SLC24A5, was strongly associated with skin pigmentation in this sample.

Diversity and functional properties of bistable pigments.

Science.gov (United States)

Tsukamoto, Hisao; Terakita, Akihisa

2010-11-01

Rhodopsin and related opsin-based pigments, which are photosensitive membrane proteins, have been extensively studied using a wide variety of techniques, with rhodopsin being the most understood G protein-coupled receptor (GPCR). Animals use various opsin-based pigments for vision and a wide variety of non-visual functions. Many functionally varied pigments are roughly divided into two kinds, based on their photoreaction: bistable and monostable pigments. Bistable pigments are thermally stable before and after photo-activation, but monostable pigments are stable only before activation. Here, we review the diversity of bistable pigments and their molecular characteristics. We also discuss the mechanisms underlying different molecular characteristics of bistable and monostable pigments. In addition, the potential of bistable pigments as a GPCR model is proposed.

Organization and evolution of Drosophila terminin: similarities and differences between Drosophila and human telomeres

Directory of Open Access Journals (Sweden)

Grazia Daniela Raffa

2013-05-01

Full Text Available Drosophila lacks telomerase and fly telomeres are elongated by occasional transposition of three specialized retroelements. Drosophila telomeres do not terminate with GC-rich repeats and are assembled independently of the sequence of chromosome ends. Recent work has shown that Drosophila telomeres are capped by the terminin complex, which includes the fast-evolving proteins HOAP, HipHop, Moi and Ver. These proteins are not conserves outside Drosophilidae and localize and function exclusively at telomeres, protecting them from fusion events. Other proteins required to prevent end-to-end fusion in flies include HP1, Eff/UbcD1, ATM, the components of the Mre11-Rad50-Nbs (MRN complex, and the Woc transcription factor. These proteins do not share the terminin properties; they are evolutionarily conserved non-fast-evolving proteins that do not accumulate only telomeres and do not serve telomere-specific functions. We propose that following telomerase loss, Drosophila rapidly evolved terminin to bind chromosome ends in a sequence-independent manner. This hypothesis suggests that terminin is the functional analog of the shelterin complex that protects human telomeres. The non-terminin proteins are instead likely to correspond to ancestral telomere-associated proteins that did not evolve as rapidly as terminin because of the functional constraints imposed by their involvement in diverse cellular processes. Thus, it appears that the main difference between Drosophila and human telomeres is in the protective complexes that specifically associate with the DNA termini. We believe that Drosophila telomeres offer excellent opportunities for investigations on human telomere biology. The identification of additional Drosophila genes encoding non-terminin proteins involved in telomere protection might lead to the discovery of novel components of human telomeres.

Hermann Muller and Mutations in Drosophila

Science.gov (United States)

dropdown arrow Site Map A-Z Index Menu Synopsis Hermann Muller and Mutations in Drosophila Resources with University of Texas. In Austin his experiments on fruit flies (Drosophila) first showed that exposure to September to spend a year at the only Drosophila laboratory in Europe which was doing parallel work

Skin pigmentation kinetics after UVB exposure

DEFF Research Database (Denmark)

Ravnbak, M.H.; Philipsen, P.A.; Wiegell, S.R.

2008-01-01

There have been few previous studies of the kinetics of pigmentation following ultraviolet B (UVB) exposure, and these have included only fair-skinned persons. The current study investigated pigmentation increase to steady state and fading in 12 Scandinavians and 12 Indians/Pakistanis. Over...... a period of 3 weeks the subjects were UV-irradiated 6 times on the right side of the back and 12 times on the left side using a Solar Simulator and narrowband UVB with equal sub-Minimal Melanogenesis Doses (individually predetermined). Pigmentation was measured from skin remittance at 555 urn and 660 nm...... (allowing correction for erythema). The absolute pigmentation increase was independent of pre-exposure pigmentation, therefore the percentage pigmentation increase was higher in fair-skinned volunteers. The UV dose to minimal pigmentation was higher in darker-skinned persons for single and multiple UV...

A definitive analytical spectroscopic study of Indian yellow, an ancient pigment used for dating purposes.

Science.gov (United States)

de Faria, Dalva L A; Edwards, Howell G M; Careaga, Valeria; Walt, Nicholas; Maier, Marta S

2017-02-01

The Raman spectrum of tartrazine has been mistakenly reported as being that of Indian yellow in the literature, which has serious consequences for the identification of this pigment in art works regarding their authentication. Unlike tartrazine, Indian yellow (a natural mixture of the magnesium and calcium salts of euxanthic acid) exhibits in its Raman spectrum a strong fluorescent background when visible excitation is used, however, excitation in the near infrared (1064nm) permitted the observation of the Raman bands from the raw pigment with the main features placed at 1346, 1368, 1425, 1441 and 1626cm -1 . Indian yellow identification was assured by 1 H and 13 C Nuclear Magnetic Resonance characterization and the complete assignment of the proton and carbon resonances was accomplished using heteronuclear single quantum correlation (HSQC), heteronuclear multiple bond correlation (HMBC), nuclear overhauser effect spectroscopy (NOESY) and 1 H- 1 H correlation spectroscopy (COSY). Scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) and X-ray fluorescence (XRF) analyzes were also conducted on a genuine sample of this historical pigment. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Identification of four Drosophila allatostatins as the cognate ligands for the Drosophila orphan receptor DAR-2

DEFF Research Database (Denmark)

Lenz, C; Williamson, M; Hansen, G N

2001-01-01

The allatostatins are generally inhibitory insect neuropeptides. The Drosophila orphan receptor DAR-2 is a G-protein-coupled receptor, having 47% amino acid residue identity with another Drosophila receptor, DAR-1 (which is also called dros. GPCR, or DGR) that was previously shown...... to be the receptor for an intrinsic Drosophila A-type (cockroach-type) allatostatin. Here, we have permanently expressed DAR-2 in CHO cells and found that it is the cognate receptor for four Drosophila A-type allatostatins, the drostatins-A1 to -A4. Of all the drostatins, drostatin-A4 (Thr...... weakly in the brain. The Drosophila larval gut also contains about 20-30 endocrine cells, expressing the gene for the drostatins-A1 to -A4. We suggest, therefore, that DAR-2 mediates an allatostatin (drostatin)-induced inhibition of gut motility. This is the first report on the permanent and functional...

Production of Monascus-like pigments

DEFF Research Database (Denmark)

2012-01-01

the cultivation medium with an inoculum of Penicillium to form a cultivation composition; d) cultivating the inoculated cultivation composition of (c); e) separating the one or more produced pigment compositions. The method of the invention may be used for producing Monascus-like pigment compositions for use......The present invention relates to a method for producing one or more Monascus-like pigment composition from Penicillium species comprising: a) providing a cultivation medium comprising a high concentration of C-and N-sources and a high C/N molar ratio, b) adjusting pH to about 5 to 8, c) inoculating...... as colouring agents in food items or non food items. The inventions further relates to Monascus-like pigment composition obtainable by a method of the inventions as well as use of the pigments....

Eumelanin and pheomelanin are predominant pigments in bumblebee (Apidae: Bombus pubescence

Directory of Open Access Journals (Sweden)

Carlo Polidori

2017-05-01

Full Text Available Background Bumblebees (Hymenoptera: Apidae: Bombus are well known for their important inter- and intra-specific variation in hair (or pubescence color patterns, but the chemical nature of the pigments associated with these patterns is not fully understood. For example, though melanization is believed to provide darker colors, it still unknown which types of melanin are responsible for each color, and no conclusive data are available for the lighter colors, including white. Methods By using dispersive Raman spectroscopy analysis on 12 species/subspecies of bumblebees from seven subgenera, we tested the hypothesis that eumelanin and pheomelanin, the two main melanin types occurring in animals, are largely responsible for bumblebee pubescence coloration. Results Eumelanin and pheomelanin occur in bumblebee pubescence. Black pigmentation is due to prevalent eumelanin, with visible signals of additional pheomelanin, while the yellow, orange, red and brown hairs clearly include pheomelanin. On the other hand, white hairs reward very weak Raman signals, suggesting that they are depigmented. Additional non-melanic pigments in yellow hair cannot be excluded but need other techniques to be detected. Raman spectra were more similar across similarly colored hairs, with no apparent effect of phylogeny and both melanin types appeared to be already used at the beginning of bumblebee radiation. Discussion We suggest that the two main melanin forms, at variable amounts and/or vibrational states, are sufficient in giving almost the whole color range of bumblebee pubescence, allowing these insects to use a single precursor instead of synthesizing a variety of chemically different pigments. This would agree with commonly seen color interchanges between body segments across Bombus species.

Microarray Analysis of Iris Gene Expression in Mice with Mutations Influencing Pigmentation

Science.gov (United States)

Trantow, Colleen M.; Cuffy, Tryphena L.; Fingert, John H.; Kuehn, Markus H.

2011-01-01

Purpose. Several ocular diseases involve the iris, notably including oculocutaneous albinism, pigment dispersion syndrome, and exfoliation syndrome. To screen for candidate genes that may contribute to the pathogenesis of these diseases, genome-wide iris gene expression patterns were comparatively analyzed from mouse models of these conditions. Methods. Iris samples from albino mice with a Tyr mutation, pigment dispersion–prone mice with Tyrp1 and Gpnmb mutations, and mice resembling exfoliation syndrome with a Lyst mutation were compared with samples from wild-type mice. All mice were strain (C57BL/6J), age (60 days old), and sex (female) matched. Microarrays were used to compare transcriptional profiles, and differentially expressed transcripts were described by functional annotation clustering using DAVID Bioinformatics Resources. Quantitative real-time PCR was performed to validate a subset of identified changes. Results. Compared with wild-type C57BL/6J mice, each disease context exhibited a large number of statistically significant changes in gene expression, including 685 transcripts differentially expressed in albino irides, 403 in pigment dispersion–prone irides, and 460 in exfoliative-like irides. Conclusions. Functional annotation clusterings were particularly striking among the overrepresented genes, with albino and pigment dispersion–prone irides both exhibiting overall evidence of crystallin-mediated stress responses. Exfoliative-like irides from mice with a Lyst mutation showed overall evidence of involvement of genes that influence immune system processes, lytic vacuoles, and lysosomes. These findings have several biologically relevant implications, particularly with respect to secondary forms of glaucoma, and represent a useful resource as a hypothesis-generating dataset. PMID:20739468

Pigment dispersion syndrome and pigmentary glaucoma after secondary sulcus transscleral fixation of single-piece foldable posterior chamber intraocular lenses in Chinese aphakic patients.

Science.gov (United States)

Tong, Nianting; Liu, Fuling; Zhang, Ting; Wang, Liangyu; Zhou, Zhanyu; Gong, Huimin; Yuan, Fuxiang

2017-05-01

To describe secondary pigment dispersion syndrome (PDS) and pigmentary glaucoma after secondary sulcus transscleral fixation of 1-piece hydrophobic acrylic foldable posterior chamber intraocular lenses (PC IOLs) in aphakic patients in a Chinese population. Department of Ophthalmology, Qingdao Municipal Hospital, Qingdao, China. Retrospective case series. This chart review included eyes that had secondary sulcus transscleral fixation of a 1-piece hydrophobic acrylic foldable PC IOL (Tecnis ZCB00) between March 2011 and March 2014. The patients' demographic data, clinical data, postoperative complications, intervals between initial surgery and the onset of PDS, pigmentary glaucoma occurrences, and findings on slitlamp biomicroscopy, gonioscopy, and ultrasound biomicroscopy (UBM) were recorded. The study comprised 23 consecutive eyes of 21 patients. Seventeen eyes of 16 patients were diagnosed with PDS, and 7 eyes of 6 patients were diagnosed with pigmentary glaucoma. The slitlamp examination and UBM showed that the location between the IOL optic and the posterior surface of the iris was very close. Slitlamp examination of the anterior chamber angle using a gonioscope showed dense pigment deposition on the IOL surfaces. A reverse pupillary block was found in 10 eyes of 9 patients. Other postoperative complications included intraocular hemorrhage, pupillary capture of the IOL optic, IOL tilt, IOL decentration, IOL dislocation, and suture erosion. The 1-piece hydrophobic acrylic foldable PC IOL was not suitable for sulcus transscleral fixation because of a high incidence of PDS and pigmentary glaucoma after surgery in a Chinese population. Copyright © 2017 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

Genomic Ancestry, Self-Reported “Color” and Quantitative Measures of Skin Pigmentation in Brazilian Admixed Siblings

Science.gov (United States)

Leite, Tailce K. M.; Fonseca, Rômulo M. C.; de França, Nanci M.; Parra, Esteban J.; Pereira, Rinaldo W.

2011-01-01

A current concern in genetic epidemiology studies in admixed populations is that population stratification can lead to spurious results. The Brazilian census classifies individuals according to self-reported “color”, but several studies have demonstrated that stratifying according to “color” is not a useful strategy to control for population structure, due to the dissociation between self-reported “color” and genomic ancestry. We report the results of a study in a group of Brazilian siblings in which we measured skin pigmentation using a reflectometer, and estimated genomic ancestry using 21 Ancestry Informative Markers (AIMs). Self-reported “color”, according to the Brazilian census, was also available for each participant. This made it possible to evaluate the relationship between self-reported “color” and skin pigmentation, self-reported “color” and genomic ancestry, and skin pigmentation and genomic ancestry. We observed that, although there were significant differences between the three “color” groups in genomic ancestry and skin pigmentation, there was considerable dispersion within each group and substantial overlap between groups. We also saw that there was no good agreement between the “color” categories reported by each member of the sibling pair: 30 out of 86 sibling pairs reported different “color”, and in some cases, the sibling reporting the darker “color” category had lighter skin pigmentation. Socioeconomic status was significantly associated with self-reported “color” and genomic ancestry in this sample. This and other studies show that subjective classifications based on self-reported “color”, such as the one that is used in the Brazilian census, are inadequate to describe the population structure present in recently admixed populations. Finally, we observed that one of the AIMs included in the panel (rs1426654), which is located in the known pigmentation gene SLC24A5, was strongly associated with

Pigment production from a mangrove Penicillium

African Journals Online (AJOL)

SAM

2014-06-25

Jun 25, 2014 ... Key words: Penicillium, 2-(4-acetyl phenyl) acetic acid, bio elements, salts, soluble pigment. .... Table 1. Characteristics of the pigment fractions after solvent extraction. ..... naphthoquinone pigment by Fusarium verticillioides.

Metabolomic Studies in Drosophila.

Science.gov (United States)

Cox, James E; Thummel, Carl S; Tennessen, Jason M

2017-07-01

Metabolomic analysis provides a powerful new tool for studies of Drosophila physiology. This approach allows investigators to detect thousands of chemical compounds in a single sample, representing the combined contributions of gene expression, enzyme activity, and environmental context. Metabolomics has been used for a wide range of studies in Drosophila , often providing new insights into gene function and metabolic state that could not be obtained using any other approach. In this review, we survey the uses of metabolomic analysis since its entry into the field. We also cover the major methods used for metabolomic studies in Drosophila and highlight new directions for future research. Copyright © 2017 by the Genetics Society of America.

Hairless pigmented guinea pigs: a new model for the study of mammalian pigmentation.

Science.gov (United States)

Bolognia, J L; Murray, M S; Pawelek, J M

1990-09-01

A stock of hairless pigmented guinea pigs was developed to facilitate studies of mammalian pigmentation. This stock combines the convenience of a hairless animal with a pigmentary system that is similar to human skin. In both human and guinea pig skin, active melanocytes are located in the basal layer of the interfollicular epidermis. Hairless albino guinea pigs on an outbred Hartley background (CrI:IAF/HA(hr/hr)BR; designated hr/hr) were mated with red-haired guinea pigs (designated Hr/Hr). Red-haired heterozygotes from the F1 generation (Hr/hr) were then mated with each other or with hairless albino guinea pigs. The F2 generation included hairless pigmented guinea pigs that retained their interfollicular epidermal melanocytes and whose skin was red-brown in color. Following UV irradiation, there was an increase in cutaneous pigmentation as well as an increase in the number of active epidermal melanocytes. An additional strain of black hairless guinea pigs was developed using black Hr/Hr animals and a similar breeding scheme. These two strains should serve as useful models for studies of the mammalian pigment system.

Biological effects of radon in Drosophila; Efectos biologicos del radon en Drosophila

Energy Technology Data Exchange (ETDEWEB)

Pimentel P, A E; Tavera D, L; Cruces M, M P; Arceo M, C; Rosa D, M.E. de la

1992-04-15

The main objective of this investigation, is to study the biological effects of the Radon-222 at low dose in 'Drosophila melanogaster'. It is necessary to mention that these effects will analyze from the genetic point of view for: 1) To evaluate in which form the Radon-222 to low dose it influences in some genetic components of the adaptation in Drosophila, such as: fecundity, viability egg-adult and sex proportion. 2) To evaluate which is the genetic effect that induces the Radon to low dose by means of the SMART technique in Drosophila melanogaster, and this way to try of to identify which is the possible mechanism that causes the genetic damage to somatic level. The carried out investigation was divided in three stages: 1. Tests to the vacuum resistance. 2. Test of somatic mutation, and 3. Determination of the presence of radon daughters on the adult of Drosophila. It is necessary to point out that all the experiments were made by triplicate and in each one of them was placed detectors in preset places. Those obtained results are presented inside the 4 charts included in the present work. (Author)

Biological effects of radon in Drosophila; Efectos biologicos del radon en Drosophila

Energy Technology Data Exchange (ETDEWEB)

Pimentel P, A.E.; Tavera D, L.; Cruces M, M.P.; Arceo M, C.; Rosa D, M.E. de la

1992-04-15

The main objective of this investigation, is to study the biological effects of the Radon-222 at low dose in 'Drosophila melanogaster'. It is necessary to mention that these effects will analyze from the genetic point of view for: 1) To evaluate in which form the Radon-222 to low dose it influences in some genetic components of the adaptation in Drosophila, such as: fecundity, viability egg-adult and sex proportion. 2) To evaluate which is the genetic effect that induces the Radon to low dose by means of the SMART technique in Drosophila melanogaster, and this way to try of to identify which is the possible mechanism that causes the genetic damage to somatic level. The carried out investigation was divided in three stages: 1. Tests to the vacuum resistance. 2. Test of somatic mutation, and 3. Determination of the presence of radon daughters on the adult of Drosophila. It is necessary to point out that all the experiments were made by triplicate and in each one of them was placed detectors in preset places. Those obtained results are presented inside the 4 charts included in the present work. (Author)

Evaluation of Off-season Potential Breeding Sources for Spotted Wing Drosophila (Drosophila suzukii Matsumura) in Michigan.

Science.gov (United States)

Bal, Harit K; Adams, Christopher; Grieshop, Matthew

2017-12-05

It has been suggested that fruit wastes including dropped and unharvested fruits, and fruit byproducts (i.e., pomace) found in fruit plantings and cideries or wine-making facilities could serve as potential off-season breeding sites for spotted wing Drosophila (Drosophila suzukii Matsumura (Diptera: Drosophilidae)). This idea, however, has yet to be widely tested. The goal of our study was to determine the potential of dropped fruit and fruit wastes as Fall spotted wing Drosophila breeding resources in Michigan, USA. Fruit waste samples were collected from 15 farms across the lower peninsula of Michigan and were evaluated for spotted wing Drosophila and other drosophilid emergence and used in host suitability bioassays. All of the dropped apples, pears, grapes, and raspberries and 40% of apple and 100% of grape fruit pomace evaluated were found to contain spotted wing Drosophila with the highest numbers collected from dropped grapes and pears. Greater spotted wing Drosophila recovery was found in fruit wastes at sites attached with cideries and wine-making facilities and with multiple cultivated fruit crops than sites with no cideries and only one crop. Females oviposited in raspberry, pear, apple, grape, apple pomace and grape pomace samples with the highest rates of reproduction in raspberries. Our results demonstrate that fruit wastes including dropped berry, pomme and stone fruits, as well as fruit compost may be important late season reproductive resources for spotted wing Drosophila. © The Author(s) 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Sensitizing pigment in the fly

International Nuclear Information System (INIS)

Vogt, K.; Kirschfeld, K.

1983-01-01

The sensitizing pigment hypothesis for the high UV sensitivity in fly photoreceptors (R1-6) is further substantiated by measurements of the polarisation sensitivity in the UV. The quantum yield of the energy transfer from sensitizing pigment to rhodopsin was estimated by electrophysiological measurements of the UV sensitivity and the rhabdomeric absorptance (at 490 nm) in individual receptor cells. The transfer efficiency is >=0.75 in receptors with an absorptance in the rhabdomeres of 0.55-0.95. This result suggests that the sensitizing pigment is bound in some way to the rhodopsin. A ratio of two molecules of sensitizing pigment per one rhodopsin is proposed. (orig.)

Raman Spectroscopy of Microbial Pigments

Science.gov (United States)

Edwards, Howell G. M.; Oren, Aharon

2014-01-01

Raman spectroscopy is a rapid nondestructive technique providing spectroscopic and structural information on both organic and inorganic molecular compounds. Extensive applications for the method in the characterization of pigments have been found. Due to the high sensitivity of Raman spectroscopy for the detection of chlorophylls, carotenoids, scytonemin, and a range of other pigments found in the microbial world, it is an excellent technique to monitor the presence of such pigments, both in pure cultures and in environmental samples. Miniaturized portable handheld instruments are available; these instruments can be used to detect pigments in microbiological samples of different types and origins under field conditions. PMID:24682303

A role for the deep orange and carnation eye color genes in lysosomal delivery in Drosophila.

Science.gov (United States)

Sevrioukov, E A; He, J P; Moghrabi, N; Sunio, A; Krämer, H

1999-10-01

Deep orange and carnation are two of the classic eye color genes in Drosophila. Here, we demonstrate that Deep orange is part of a protein complex that localizes to endosomal compartments. A second component of this complex is Carnation, a homolog of Sec1p-like regulators of membrane fusion. Because complete loss of deep orange function is lethal, the role of this complex in intracellular trafficking was analyzed in deep orange mutant clones. Retinal cells devoid of deep orange function completely lacked pigmentation and exhibited exaggerated multivesicular structures. Furthermore, a defect in endocytic trafficking was visualized in developing photoreceptor cells. These results provide direct evidence that eye color mutations of the granule group also disrupt vesicular trafficking to lysosomes.

Use of Drosophila to study DNA repair

International Nuclear Information System (INIS)

Boyd, J.B.; Harris, P.V.; Sakaguchi, K.

1988-01-01

This paper discusses Drosophila, the premier metazoan organism for analyzing many fundamental features of eukaryotic gene regulation. The authors present adaptations of several approaches for studying DNA repair to an analysis of repair-defective mutants in Drosophila. A current understanding of Drosophila DNA repair is described

Effect of pigment concentration on fastness and color values of thermal and UV curable pigment printing

Science.gov (United States)

Baysal, Gulcin; Kalav, Berdan; Karagüzel Kayaoğlu, Burçak

2017-10-01

In the current study, it is aimed to determine the effect of pigment concentration on fastness and colour values of thermal and ultraviolet (UV) curable pigment printing on synthetic leather. For this purpose, thermal curable solvent-based and UV curable water-based formulations were prepared with different pigment concentrations (3, 5 and 7%) separately and applied by screen printing technique using a screen printing machine. Samples printed with solvent-based formulations were thermally cured and samples printed with water-based formulations were cured using a UV curing machine equipped with gallium and mercury (Ga/Hg) lamps at room temperature. The crock fastness values of samples printed with solvent-based formulations showed that increase in pigment concentration was not effective on both dry and wet crock fastness values. On the other hand, in samples printed with UV curable water-based formulations, dry crock fastness was improved and evaluated as very good for all pigment concentrations. However, increasing the pigment concentration affected the wet crock fastness values adversely and lower values were observed. As the energy level increased for each irradiation source, the fastness values were improved. In comparison with samples printed with solvent-based formulations, samples printed with UV curable water-based formulations yielded higher K/S values at all pigment concentrations. The results suggested that, higher K/S values can be obtained in samples printed with UV curable water-based formulations at a lower pigment concentration compared to samples printed with solvent-based formulations.

Detecting novel low-abundant transcripts in Drosophila

DEFF Research Database (Denmark)

Lee, Sanggyu; Bao, Jingyue; Zhou, Guolin

2005-01-01

Increasing evidence suggests that low-abundant transcripts may play fundamental roles in biological processes. In an attempt to estimate the prevalence of low-abundant transcripts in eukaryotic genomes, we performed a transcriptome analysis in Drosophila using the SAGE technique. We collected 244......,313 SAGE tags from transcripts expressed in Drosophila embryonic, larval, pupae, adult, and testicular tissue. From these SAGE tags, we identified 40,823 unique SAGE tags. Our analysis showed that 55% of the 40,823 unique SAGE tags are novel without matches in currently known Drosophila transcripts...... in the Drosophila genome. Our study reveals the presence of a significant number of novel low-abundant transcripts in Drosophila, and highlights the need to isolate these novel low-abundant transcripts for further biological studies. Udgivelsesdato: 2005-Jun...

Hearing regulates Drosophila aggression.

Science.gov (United States)

Versteven, Marijke; Vanden Broeck, Lies; Geurten, Bart; Zwarts, Liesbeth; Decraecker, Lisse; Beelen, Melissa; Göpfert, Martin C; Heinrich, Ralf; Callaerts, Patrick

2017-02-21

Aggression is a universal social behavior important for the acquisition of food, mates, territory, and social status. Aggression in Drosophila is context-dependent and can thus be expected to involve inputs from multiple sensory modalities. Here, we use mechanical disruption and genetic approaches in Drosophila melanogaster to identify hearing as an important sensory modality in the context of intermale aggressive behavior. We demonstrate that neuronal silencing and targeted knockdown of hearing genes in the fly's auditory organ elicit abnormal aggression. Further, we show that exposure to courtship or aggression song has opposite effects on aggression. Our data define the importance of hearing in the control of Drosophila intermale aggression and open perspectives to decipher how hearing and other sensory modalities are integrated at the neural circuit level.

The visual pigment cyanide effect.

Science.gov (United States)

Crescitelli, F; Karvaly, B

1989-12-01

The visual pigment of the Tokay gecko (Gekko gekko) with its in situ absorption maximum at 521 nm has its spectral position at 500 to 505 nm when chloride-deficient digitonin is used for the extraction. In this case the addition of chloride or bromide to the extract restores the maximum to 521 nm. This property, characteristic of gecko pigments in general, does not occur with any of the rhodopsins that have been tested. Simple salts of cyanide, a pseudohalogenoid with an ionic radius close to those of chloride and bromide and/or its hydrolysis product attacks both this gecko pigment and rhodopsins in the dark. This is seen as a slow thermal loss of photopigment if (sodium) cyanide is present at concentrations above 40 mM for the gecko pigment and 150 mM for the rhodopsins of the midshipman (Porichthys notatus) and of the frog (Rana pipiens). In all cases the loss of the photopigment is accompanied by the appearance of a spectral product with maximum absorption at about 340 nm. Cyanide addition has no effect on the photosensitivity of the native pigments and neither does it alter, as do chloride, bromide and other anions, the spectral absorbance curve. The spectral product at 340 nm also appears when the visual pigments are photolyzed in the presence of cyanide salts below the threshold concentrations given above. Incubation of digitonin-solubilized all-trans-retinal with (sodium) cyanide leads to a reaction product with absorption spectrum similar to that obtained with visual pigments under comparable conditions.(ABSTRACT TRUNCATED AT 250 WORDS)

Synthesis of pigments of Fe2O3·SiO2 system, with Ca, Mg, or Co oxide additions

Directory of Open Access Journals (Sweden)

Tsvetan Dimitrov

2017-03-01

Full Text Available The present research work is based on the comparative evaluation of the Ca, Mg, and Co dopant impact on the properties of new ceramic pigments from the system Fe2O3·SiO2 obtained via classical ceramic technology. This approach enabled determination of the optimal temperature for the synthesis and the most appropriate mineralizer. The obtained specimens were submitted to systematical analysis, including X-ray Diffraction (XRD spectroscopy, Electron Paramagnetic Resonance (EPR analysis and Mössbauer spectroscopy for crystalline phase determination. The color characteristics are quantified by spectrophotometric measurements. The pigments particle size has been determined by Scanning Electron Microscopy (SEM, combined by Energy Dispersion X-ray spectroscopy (EDX. The obtained results enabled to determine the correlation between the calcination temperature and the phase compositions of the obtained pigments. In addition, some interesting magnetic properties were detected for the Co-doped composition.

Synthesis of pigments of Fe2O3·SiO2 system, with Ca, Mg, or Co oxide additions

Energy Technology Data Exchange (ETDEWEB)

Dimitrov, T.; Kozhukharov, S.; Velinov, N.

2017-07-01

The present research work is based on the comparative evaluation of the Ca, Mg, and Co dopant impact on the properties of new ceramic pigments from the system Fe2O3·SiO2 obtained via classical ceramic technology. This approach enabled determination of the optimal temperature for the synthesis and the most appropriate mineralizer. The obtained specimens were submitted to systematical analysis, including X-ray Diffraction (XRD) spectroscopy, Electron Paramagnetic Resonance (EPR) analysis and Mössbauer spectroscopy for crystalline phase determination. The color characteristics are quantified by spectrophotometric measurements. The pigments particle size has been determined by Scanning Electron Microscopy (SEM), combined by Energy Dispersion X-ray spectroscopy (EDX). The obtained results enabled to determine the correlation between the calcination temperature and the phase compositions of the obtained pigments. In addition, some interesting magnetic properties were detected for the Co-doped composition. (Author)

High efficiency non-viral transfection of retinal and iris pigment epithelial cells with pigment epithelium-derived factor.

Science.gov (United States)

Thumann, G; Stöcker, M; Maltusch, C; Salz, A K; Barth, S; Walter, P; Johnen, S

2010-02-01

Transplantation of pigment epithelial cells in patients with age-related macular degeneration and Parkinson's disease has the potential to improve functional rehabilitation. Genetic modification of cells before transplantation may allow the delivery of neuroprotective factors to achieve functional improvement. As transplantation of cells modified using viral vectors is complicated by the possible dissemination of viral particles and severe immune reactions, we have explored non-viral methods to insert genetic material in pigment epithelial cells. Using lipofection or nucleofection ARPE-19 cells, freshly isolated and primary retinal and iris pigment epithelial (IPE) cells were transfected with plasmids encoding green fluorescent protein (GFP) and with three plasmids encoding recombinant pigment epithelium-derived factor (PEDF) and GFP. Transfection efficiency was evaluated by fluorescence microscopy and stability of protein expression by immunoblotting. Pigment epithelial cells were successfully transfected with plasmid encoding GFP. Expression of GFP in ARPE-19 was transient, but was observed for up to 1 year in IPE cells. Analysis of pigment epithelial cells transfected with PEDF plasmids revealed that PEDF fusion proteins were successfully expressed and functionally active. In conclusion, efficient transfer of genetic information in pigment epithelial cells can be achieved using non-viral transfection protocols.

Social Experience Is Sufficient to Modulate Sleep Need of Drosophila without Increasing Wakefulness.

Science.gov (United States)

Lone, Shahnaz Rahman; Potdar, Sheetal; Srivastava, Manishi; Sharma, Vijay Kumar

2016-01-01

Organisms quickly learn about their surroundings and display synaptic plasticity which is thought to be critical for their survival. For example, fruit flies Drosophila melanogaster exposed to highly enriched social environment are found to show increased synaptic connections and a corresponding increase in sleep. Here we asked if social environment comprising a pair of same-sex individuals could enhance sleep in the participating individuals. To study this, we maintained individuals of D. melanogaster in same-sex pairs for a period of 1 to 4 days, and after separation, monitored sleep of the previously socialized and solitary individuals under similar conditions. Males maintained in pairs for 3 or more days were found to sleep significantly more during daytime and showed a tendency to fall asleep sooner as compared to solitary controls (both measures together are henceforth referred to as "sleep-enhancement"). This sleep phenotype is not strain-specific as it is observed in males from three different "wild type" strains of D. melanogaster. Previous studies on social interaction mediated sleep-enhancement presumed 'waking experience' during the interaction to be the primary underlying cause; however, we found sleep-enhancement to occur without any significant increase in wakefulness. Furthermore, while sleep-enhancement due to group-wise social interaction requires Pigment Dispersing Factor (PDF) positive neurons; PDF positive and CRYPTOCHROME (CRY) positive circadian clock neurons and the core circadian clock genes are not required for sleep-enhancement to occur when males interact in pairs. Pair-wise social interaction mediated sleep-enhancement requires dopamine and olfactory signaling, while visual and gustatory signaling systems seem to be dispensable. These results suggest that socialization alone (without any change in wakefulness) is sufficient to cause sleep-enhancement in fruit fly D. melanogaster males, and that its neuronal control is context-specific.

Social Experience Is Sufficient to Modulate Sleep Need of Drosophila without Increasing Wakefulness.

Directory of Open Access Journals (Sweden)

Shahnaz Rahman Lone

Full Text Available Organisms quickly learn about their surroundings and display synaptic plasticity which is thought to be critical for their survival. For example, fruit flies Drosophila melanogaster exposed to highly enriched social environment are found to show increased synaptic connections and a corresponding increase in sleep. Here we asked if social environment comprising a pair of same-sex individuals could enhance sleep in the participating individuals. To study this, we maintained individuals of D. melanogaster in same-sex pairs for a period of 1 to 4 days, and after separation, monitored sleep of the previously socialized and solitary individuals under similar conditions. Males maintained in pairs for 3 or more days were found to sleep significantly more during daytime and showed a tendency to fall asleep sooner as compared to solitary controls (both measures together are henceforth referred to as "sleep-enhancement". This sleep phenotype is not strain-specific as it is observed in males from three different "wild type" strains of D. melanogaster. Previous studies on social interaction mediated sleep-enhancement presumed 'waking experience' during the interaction to be the primary underlying cause; however, we found sleep-enhancement to occur without any significant increase in wakefulness. Furthermore, while sleep-enhancement due to group-wise social interaction requires Pigment Dispersing Factor (PDF positive neurons; PDF positive and CRYPTOCHROME (CRY positive circadian clock neurons and the core circadian clock genes are not required for sleep-enhancement to occur when males interact in pairs. Pair-wise social interaction mediated sleep-enhancement requires dopamine and olfactory signaling, while visual and gustatory signaling systems seem to be dispensable. These results suggest that socialization alone (without any change in wakefulness is sufficient to cause sleep-enhancement in fruit fly D. melanogaster males, and that its neuronal control is

Effect of non-nutritive sugars to decrease the survivorship of spotted wing drosophila, Drosophila suzukii

Science.gov (United States)

In this study, we investigated the effects of non-nutritive sugars and sugar alcohols on the survivorship of spotted wing drosophila, Drosophila suzukii, and found erythritol and erythrose as potentially toxic to the fly. In a dose-dependent study, erythritol and erythrose significantly reduced fly ...

Iron-containing pigment from an archaeological rupestrian painting of the Planalto Tradition in Minas Gerais, Brazil

Energy Technology Data Exchange (ETDEWEB)

Floresta, D. L., E-mail: denise.floresta@ifmg.edu.br [Instituto Federal Minas Gerais campus Santa Luzia (Brazil); Fagundes, M.; Fabris, J. D. [Universidade Federal dos Vales do Jequitinhonha e Mucuri (Brazil); Ardisson, J. D. [Centro de Desenvolvimento da Tecnologia Nuclear (Brazil)

2015-06-15

Archaeological rupestrian arts of the Planalto Tradition are of relatively widespread occurrence all over the land area of the state of Minas Gerais (MG), Brazil. They are typically composed by monochromic zoomorphic figures, especially of cervids, mainly in red or orange color. A fragment of a rock wall containing an archaeological painting was collected at the Itanguá site, in the municipality of Senador Modestino Gonçalves (geographical coordinates, 17° 56′ 51″ S 43° 13′ 22″ W), MG. The rock piece was covered with an archaeological painting with pigments of two different hues of red. The X-ray fluorescence (XRF) analysis revealed only a slight difference in Fe and P content for the two different color zones. The pigment materials on this small fragment of rock were analyzed by X-ray diffraction on the conventional incidence mode (XRD) and on grazing incidence X-ray mode (GIXRD), scanning electron microscopy with energy dispersive x-ray detector (SEM/EDS) and conversion electron Mössbauer spectroscopy (CEMS) at room temperature. Results indicated the occurrence of mainly hematite but also of diopside in the pigment. CEMS at RT reveal the presence of hematite and (super)paramagnetic ferric components. In order to confirm these results a small amount of powder from the painting pigments was also analyzed by transmission Mössbauer spectroscopy at 20 K.

Iron-containing pigment from an archaeological rupestrian painting of the Planalto Tradition in Minas Gerais, Brazil

Science.gov (United States)

Floresta, D. L.; Fagundes, M.; Fabris, J. D.; Ardisson, J. D.

2015-06-01

Archaeological rupestrian arts of the Planalto Tradition are of relatively widespread occurrence all over the land area of the state of Minas Gerais (MG), Brazil. They are typically composed by monochromic zoomorphic figures, especially of cervids, mainly in red or orange color. A fragment of a rock wall containing an archaeological painting was collected at the Itanguá site, in the municipality of Senador Modestino Gonçalves (geographical coordinates, 17° 56' 51″ S 43° 13' 22″ W), MG. The rock piece was covered with an archaeological painting with pigments of two different hues of red. The X-ray fluorescence (XRF) analysis revealed only a slight difference in Fe and P content for the two different color zones. The pigment materials on this small fragment of rock were analyzed by X-ray diffraction on the conventional incidence mode (XRD) and on grazing incidence X-ray mode (GIXRD), scanning electron microscopy with energy dispersive x-ray detector (SEM/EDS) and conversion electron Mössbauer spectroscopy (CEMS) at room temperature. Results indicated the occurrence of mainly hematite but also of diopside in the pigment. CEMS at RT reveal the presence of hematite and (super)paramagnetic ferric components. In order to confirm these results a small amount of powder from the painting pigments was also analyzed by transmission Mössbauer spectroscopy at 20 K.

Iron-containing pigment from an archaeological rupestrian painting of the Planalto Tradition in Minas Gerais, Brazil

International Nuclear Information System (INIS)

Floresta, D. L.; Fagundes, M.; Fabris, J. D.; Ardisson, J. D.

2015-01-01

Archaeological rupestrian arts of the Planalto Tradition are of relatively widespread occurrence all over the land area of the state of Minas Gerais (MG), Brazil. They are typically composed by monochromic zoomorphic figures, especially of cervids, mainly in red or orange color. A fragment of a rock wall containing an archaeological painting was collected at the Itanguá site, in the municipality of Senador Modestino Gonçalves (geographical coordinates, 17° 56′ 51″ S 43° 13′ 22″ W), MG. The rock piece was covered with an archaeological painting with pigments of two different hues of red. The X-ray fluorescence (XRF) analysis revealed only a slight difference in Fe and P content for the two different color zones. The pigment materials on this small fragment of rock were analyzed by X-ray diffraction on the conventional incidence mode (XRD) and on grazing incidence X-ray mode (GIXRD), scanning electron microscopy with energy dispersive x-ray detector (SEM/EDS) and conversion electron Mössbauer spectroscopy (CEMS) at room temperature. Results indicated the occurrence of mainly hematite but also of diopside in the pigment. CEMS at RT reveal the presence of hematite and (super)paramagnetic ferric components. In order to confirm these results a small amount of powder from the painting pigments was also analyzed by transmission Mössbauer spectroscopy at 20 K

First experience with energy dispersive X-ray analysis (EDXA) in lung fibrosis

International Nuclear Information System (INIS)

Liebetrau, G.; Wiesner, B.; Strausz, J.; Zglinicki, T. von

1987-01-01

Biopsies from 68 patients suffering from interstitial lung disease were examined with regard to minerals using energy dispersive X-ray analysis. In 31 patients a higher portion of minerals or elements were found as pigments. The interpretation of these findings is difficult. If there is a occupational exposure and a reaction of the lung parenchyma the findings could be of clinical value. (author)

State of art in research of ceramic pigments

International Nuclear Information System (INIS)

Sulcova, P.; Trojan, M.

2004-01-01

The research of our laboratory is focused on investigation of special inorganic pigments, mainly on ceramic pigments. many pigments used just now are questionable from the hygienic point of view. The fact that the most of the pigments contain problematic elements opens necessity of substitution of pigments containing toxic metals (chromium). Yellow ceramic pigments commonly used such as Pb 2 Sb 2 O 7 , PbCrO 4 and CdS are now being expelled from the market because of their toxicity. For this reason the main attention has been directed to the synthesis of new inorganic compounds mainly with yellow, orange and red colour hues, which can be used as pigments for colouring of glaze, plastics or building materials. In harmony with this postulate the pigments based on CeO 2 represent new special inorganic pigments with high-temperature stability have been synthesized. The commercial significance is in thermal, chemical and light stability, combined with their low toxicity. (author)

True bursal pigmented villonodular synovitis

International Nuclear Information System (INIS)

Abdelwahab, Ibrahim Fikry; Kenan, Samuel; Steiner, German C.; Abdul-Quader, Mohammed

2002-01-01

We describe two cases of pigmented villonodular synovitis affecting true bursae. This study was also designed to discuss the term ''pigmented villonodular bursitis'', not confined to true synovial bursae, sometimes creating misunderstanding. (orig.)

Synthesis of new environment-friendly yellow pigments

International Nuclear Information System (INIS)

Furukawa, Shinya; Masui, Toshiyuki; Imanaka, Nobuhito

2006-01-01

New inorganic pigments based on amorphous cerium tungstate, Ce 1-x M x W 2 O 8 (M = Zr or Ti, 0 ≤ x ≤ 0.6), were synthesized and their color properties were characterized from the viewpoint of possible ecological inorganic pigments. The Ce 1-x M x W 2 O 8 materials absorb the visible and the ultraviolet light under 500 nm efficiently, which is originated in the O 2p -Ce 4f and the O 2p -W 5d double charge transfer transitions, and, as a result, the pigments can show a brilliant yellow color. The optical absorption edge wavelength of these pigments depends on the Zr or Ti content, and the effective yellow hue was observed at x = 0.2 for both pigments. The color properties of the present pigments suggest that they have a potential to be applied as a satisfactory pigment for paints. Furthermore, these pigments can be prepared by a simple co-precipitation method. They are inert and safe and do not produce side effects in the human body because they are composed of non-toxic and safe elements

Multilocus analysis of introgression between two sympatric sister species of Drosophila: Drosophila yakuba and D. santomea.

Science.gov (United States)

Llopart, Ana; Lachaise, Daniel; Coyne, Jerry A

2005-09-01

Drosophila yakuba is widely distributed in sub-Saharan Africa, while D. santomea is endemic to the volcanic island of São Tomé in the Atlantic Ocean, 280 km west of Gabon. On São Tomé, D. yakuba is found mainly in open lowland forests, and D. santomea is restricted to the wet misty forests at higher elevations. At intermediate elevations, the species form a hybrid zone where hybrids occur at a frequency of approximately 1%. To determine the extent of gene flow between these species we studied polymorphism and divergence patterns in 29 regions distributed throughout the genome, including mtDNA and three genes on the Y chromosome. This multilocus approach, together with the comparison to the two allopatric species D. mauritiana and D. sechellia, allowed us to distinguish between forces that should affect all genes and forces that should act on some genes (e.g., introgression). Our results show that D. yakuba mtDNA has replaced that of D. santomea and that there is also significant introgression for two nuclear genes, yellow and salr. The majority of genes, however, has remained distinct. These two species therefore do not form a "hybrid swarm" in which much of the genome shows substantial introgression while disruptive selection maintains distinctness for only a few traits (e.g., pigmentation and male genitalia).

Swapping one red pigment for another.

Science.gov (United States)

Davies, Kevin M

2015-01-01

Betalains are bright red and yellow pigments, which are produced in only one order of plants, the Caryophyllales, and replace the more familiar anthocyanin pigments. The evolutionary origin of betalain production is a mystery, but a new study has identified the first regulator of betalain production and discovered a previously unknown link between the two pigment pathways.

First record of spotted wing drosophila Drosophila suzukii (Diptera: Drosophilidae in Montenegro

Directory of Open Access Journals (Sweden)

Snježana Hrnčić

2015-01-01

Full Text Available The spotted wing drosophila Drosophila suzukii Matsumura (Diptera: Drosophilidae is an invasive pest originating from Southeast Asia. It was detected for the first time in Europe in 2008 (Spain and Italy and subsequently in other European countries. It is a highly polyphagous pest that infests healthy, ripening fruit and presents a serious threat to fruit production, particularly of soft skinned fruit. In the first half of October 2013, a new fruit fly species was unexpectedly detected in Tephri traps baited with the three-component female-biased attractant BioLure that is regularly used for monitoring the Mediterranean fruit fly Ceratitis capitata Wiedem. (Diptera: Tephritidae in Montenegro. Brief visual inspection identified the new species as the spotted wing drosophila D. suzukii. The pest was first recorded in several localities on the Montenegrin seacoast around Boka Kotor Bay. After the finding, all Drosophila specimens were collected from traps for further laboratory observation. A quick follow-up monitoring of other Tephri traps was carried out within the next few days on the rest of the seacoast (localities from Tivat to Ulcinj. Additionally, Tephri traps were set up around Lake Skadar and in the city of Podgorica, as well as on fresh fruit markets in Podgorica. The results of this preliminary study showed that D. suzukii was present in all surveyed locations and adults were captured until late December. Both sexes were found in traps with BioLure. Our data show that D. suzukii is present in southern parts of Montenegro and there is a serious threat of its further spreading, particularly towards northern parts of the country where the main raspberry and blueberry production is placed. The results also show that Tephri traps baited with BioLure can be used for detection and monitoring of spotted wing drosophila.

The penetration depth and lateral distribution of pigment related to the pigment grain size and the calendering of paper

International Nuclear Information System (INIS)

Buelow, K.; Kristiansson, P.; Schueler, B.; Tullander, E.; Oestling, S.; Elfman, M.; Malmqvist, K.; Pallon, J.; Shariff, A.

2002-01-01

The interaction of ink and newspaper has been investigated and the specific question of penetration of ink into the paper has been addressed with a nuclear microprobe using particle induced X-ray emission. The penetration depth of the newsprint is a critical factor in terms of increasing the quality of newsprint and minimising the amount of ink used. The objective of the experiment was to relate the penetration depth of pigment with the calendering of the paper. The dependence of the penetration depth on the pigment grain size was also studied. To study the penetration depth of pigment in paper, cyan ink with Cu as a tracer of the coloured pigment was used. For the study of the penetration depth dependence of pigment size, specially grounded Japanese ink with well-defined pigment grain size was used. This was compared to Swedish ink with pigment grains with normal size-distribution. The results show that the calendering of the paper considerably affects the penetration depth of ink

Metabolome analysis of Drosophila melanogaster during embryogenesis.

Science.gov (United States)

An, Phan Nguyen Thuy; Yamaguchi, Masamitsu; Bamba, Takeshi; Fukusaki, Eiichiro

2014-01-01

The Drosophila melanogaster embryo has been widely utilized as a model for genetics and developmental biology due to its small size, short generation time, and large brood size. Information on embryonic metabolism during developmental progression is important for further understanding the mechanisms of Drosophila embryogenesis. Therefore, the aim of this study is to assess the changes in embryos' metabolome that occur at different stages of the Drosophila embryonic development. Time course samples of Drosophila embryos were subjected to GC/MS-based metabolome analysis for profiling of low molecular weight hydrophilic metabolites, including sugars, amino acids, and organic acids. The results showed that the metabolic profiles of Drosophila embryo varied during the course of development and there was a strong correlation between the metabolome and different embryonic stages. Using the metabolome information, we were able to establish a prediction model for developmental stages of embryos starting from their high-resolution quantitative metabolite composition. Among the important metabolites revealed from our model, we suggest that different amino acids appear to play distinct roles in different developmental stages and an appropriate balance in trehalose-glucose ratio is crucial to supply the carbohydrate source for the development of Drosophila embryo.

Ozone Sensitivity and Catalase Activity in Pigmented and Non-Pigmented Strains of Serratia Marcescens.

Science.gov (United States)

de Ondarza, José

2017-01-01

Ozone exposure rapidly leads to bacterial death, making ozone an effective disinfectant in food industry and health care arena. However, microbial defenses may moderate this effect and play a role in the effective use of oxidizing agents for disinfection. Serratia marcescens is an opportunistic pathogen, expressing genes differentially during infection of a human host. A better understanding of regulatory systems that control expression of Serratia 's virulence genes and defenses is therefore valuable. Here, we investigated the role of pigmentation and catalase in Serratia marcescens on survival to ozone exposure. Pigmented and non-pigmented strains of Serratia marcescens were cultured to exponential or stationary phase and exposed to 5 ppm of gaseous ozone for 2.5 - 10 minutes. Survival was calculated via plate counts. Catalase activity was measured photometrically and tolerance to hydrogen peroxide was assayed by disk-diffusion. Exposure of S. marcescens to 5 ppm gaseous ozone kills > 90% of cells within 10 minutes in a time and concentration-dependent manner. Although pigmented Serratia (grown at 28°C) survived ozonation better than unpigmented Serratia (grown at 35°C), non-pigmented mutant strains of Serratia had similar ozone survival rates, catalase activity and H 2 O 2 tolerance as wild type strains. Rather, ozone survival and catalase activity were elevated in 6 hour cultures compared to 48 hour cultures. Our studies did not bear out a role for prodigiosin in ozone survival. Rather, induction of oxidative stress responses during exponential growth increased both catalase activity and ozone survival in both pigmented and unpigmented S. marcescens .

Production of Monascus-like pigments

DEFF Research Database (Denmark)

2012-01-01

The present invention relates to a method for producing one or more Monascus-like pigment composition from Penicillium species comprising: a) providing a cultivation medium comprising a high concentration of C-and N-sources and a high C/N molar ratio, b) adjusting pH to about 5 to 8, c) inoculati...... as colouring agents in food items or non food items. The inventions further relates to Monascus-like pigment composition obtainable by a method of the inventions as well as use of the pigments....

True bursal pigmented villonodular synovitis

Energy Technology Data Exchange (ETDEWEB)

Abdelwahab, Ibrahim Fikry [Department of Radiology, New York Methodist Hospital, Affiliated with New York Hospital-Cornell Medical Center, Brooklyn, NY (United States); Kenan, Samuel [Department of Orthopedics, New York University Medical Center, NY (United States); Steiner, German C. [Department of Pathology, Hospital for Joint Diseases/Orthopedic Institute, New York, NY (United States); Abdul-Quader, Mohammed [Department of Radiology, New York Presbyterian Hospital, Columbia University, New York, NY (United States)

2002-06-01

We describe two cases of pigmented villonodular synovitis affecting true bursae. This study was also designed to discuss the term ''pigmented villonodular bursitis'', not confined to true synovial bursae, sometimes creating misunderstanding. (orig.)

X-ray texture analysis of paper coating pigments and the correlation with chemical composition analysis

Science.gov (United States)

Roine, J.; Tenho, M.; Murtomaa, M.; Lehto, V.-P.; Kansanaho, R.

2007-10-01

The present research experiments the applicability of x-ray texture analysis in investigating the properties of paper coatings. The preferred orientations of kaolin, talc, ground calcium carbonate, and precipitated calcium carbonate particles used in four different paper coatings were determined qualitatively based on the measured crystal orientation data. The extent of the orientation, namely, the degree of the texture of each pigment, was characterized quantitatively using a single parameter. As a result, the effect of paper calendering is clearly seen as an increase on the degree of texture of the coating pigments. The effect of calendering on the preferred orientation of kaolin was also evident in an independent energy dispersive spectrometer analysis on micrometer scale and an electron spectroscopy for chemical analysis on nanometer scale. Thus, the present work proves x-ray texture analysis to be a potential research tool for characterizing the properties of paper coating layers.

Crystalline Organic Pigment-Based Field-Effect Transistors.

Science.gov (United States)

Zhang, Haichang; Deng, Ruonan; Wang, Jing; Li, Xiang; Chen, Yu-Ming; Liu, Kewei; Taubert, Clinton J; Cheng, Stephen Z D; Zhu, Yu

2017-07-05

Three conjugated pigment molecules with fused hydrogen bonds, 3,7-diphenylpyrrolo[2,3-f]indole-2,6(1H,5H)-dione (BDP), (E)-6,6'-dibromo-[3,3'-biindolinylidene]-2,2'-dione (IIDG), and 3,6-di(thiophen-2-yl)-2,5-dihydropyrrolo-[3,4-c]pyrrole-1,4-dione (TDPP), were studied in this work. The insoluble pigment molecules were functionalized with tert-butoxylcarbonyl (t-Boc) groups to form soluble pigment precursors (BDP-Boc, IIDG-Boc, and TDPP-Boc) with latent hydrogen bonding. The single crystals of soluble pigment precursors were obtained. Upon simple thermal annealing, the t-Boc groups were removed and the soluble pigment precursor molecules with latent hydrogen bonding were converted into the original pigment molecules with fused hydrogen bonding. Structural analysis indicated that the highly crystalline soluble precursors were directly converted into highly crystalline insoluble pigments, which are usually only achievable by gas-phase routes like physical vapor transport. The distinct crystal structure after the thermal annealing treatment suggests that fused hydrogen bonding is pivotal for the rearrangement of molecules to form a new crystal in solid state, which leads to over 2 orders of magnitude enhancement in charge mobility in organic field-effect transistor (OFET) devices. This work demonstrated that crystalline OFET devices with insoluble pigment molecules can be fabricated by their soluble precursors. The results indicated that a variety of commercially available conjugated pigments could be potential active materials for high-performance OFETs.

Pigmented xerodermoid - Report of three cases

Directory of Open Access Journals (Sweden)

Das Jayanta Kumar

2005-01-01

Full Text Available Pigmented xerodermoid, a rare genodermatosis, presents with clinical features and pathology similar to xeroderma pigmentosum, but at a later age. DNA repair replication is normal, but there is total depression of DNA synthesis after exposure to UV radiation. Two siblings in their teens and a man in his thirties with features of pigmented xerodermoid, e.g. photophobia, freckle-like lesions, keratoses, dryness of skin, and hypo- and hyper-pigmentation, are described. Although classically the onset of pigmented xerodermoid is said to be delayed till third to fourth decade of life, it seems the disease may appear earlier in the tropics. Early diagnosis and management could be life-saving.

A single and rapid calcium wave at egg activation in Drosophila

Directory of Open Access Journals (Sweden)

Anna H. York-Andersen

2015-03-01

Full Text Available Activation is an essential process that accompanies fertilisation in all animals and heralds major cellular changes, most notably, resumption of the cell cycle. While activation involves wave-like oscillations in intracellular Ca2+ concentration in mammals, ascidians and polychaete worms and a single Ca2+ peak in fish and frogs, in insects, such as Drosophila, to date, it has not been shown what changes in intracellular Ca2+ levels occur. Here, we utilise ratiometric imaging of Ca2+ indicator dyes and genetically encoded Ca2+ indicator proteins to identify and characterise a single, rapid, transient wave of Ca2+ in the Drosophila egg at activation. Using genetic tools, physical manipulation and pharmacological treatments we demonstrate that the propagation of the Ca2+ wave requires an intact actin cytoskeleton and an increase in intracellular Ca2+ can be uncoupled from egg swelling, but not from progression of the cell cycle. We further show that mechanical pressure alone is not sufficient to initiate a Ca2+ wave. We also find that processing bodies, sites of mRNA decay and translational regulation, become dispersed following the Ca2+ transient. Based on this data we propose the following model for egg activation in Drosophila: exposure to lateral oviduct fluid initiates an increase in intracellular Ca2+ at the egg posterior via osmotic swelling, possibly through mechano-sensitive Ca2+ channels; a single Ca2+ wave then propagates in an actin dependent manner; this Ca2+ wave co-ordinates key developmental events including resumption of the cell cycle and initiation of translation of mRNAs such as bicoid.

New record for the invasive Spotted Wing Drosophila, Drosophila suzukii Matsumura (Diptera: Drosophilidae) in Anillaco, Argentina

Science.gov (United States)

The invasive Spotted Wing Drosophila (SWD), Drosophila suzukii Matsumura, is reported for the first time in La Rioja, Argentina. This represents a major range expansion for this species. The natural enemies of SWD, Leptopilina clavipes and Ganaspis hookeri were also collected with the SWD at the s...

The influence of sterol metabolism upon radiation-induced aneuploidy of Drosophila melanogaster in the yeast-drosophila system

International Nuclear Information System (INIS)

Savitsij, V.V.; Luchnikova, E.M.; Inge-Vechtomov, S.I.

1985-01-01

The influence of sterol metabolism upon induced Drosophila melanogaster mutagenesis in an ecology-genetic yeast-drosophila system has been studied. The sterol deficit in fly organism has been created for account of using as food substrate for fremales of biomass of saccharomyces cerevisiae living cells of 9-2-PZ12 train with nyssup(r1) locus mutation which blocks the ergosterol synthesis. It has been found that the Drosophila females content on mutant yeast increases the frequency of losses and non discrepancy of X-chromosomes induced by X-radiation (1000 R). Addition into yeast biomass of 0.1 % cholesterol solution in 10 %-ethanol reduces the oocytes resistance to X-radiation up to control level. Possible hormonal and membrane mechanisms of increasing radiation-induced aneuploidy of Drosophila and the role of sterol metabolism in organism resistance to damaging factors are discussed

Distribution of DNA replication proteins in Drosophila cells

Science.gov (United States)

Easwaran, Hariharan P; Leonhardt, Heinrich; Cardoso, M Cristina

2007-01-01

Background DNA replication in higher eukaryotic cells is organized in discrete subnuclear sites called replication foci (RF). During the S phase, most replication proteins assemble at the RF by interacting with PCNA via a PCNA binding domain (PBD). This has been shown to occur for many mammalian replication proteins, but it is not known whether this mechanism is conserved in evolution. Results Fluorescent fusions of mammalian replication proteins, Dnmt1, HsDNA Lig I and HsPCNA were analyzed for their ability to target to RF in Drosophila cells. Except for HsPCNA, none of the other proteins and their deletions showed any accumulation at RF in Drosophila cells. We hypothesized that in Drosophila cells there might be some other peptide sequence responsible for targeting proteins to RF. To test this, we identified the DmDNA Lig I and compared the protein sequence with HsDNA Lig I. The two orthologs shared the PBD suggesting a functionally conserved role for this domain in the Drosophila counterpart. A series of deletions of DmDNA Lig I were analyzed for their ability to accumulate at RF in Drosophila and mammalian cells. Surprisingly, no accumulation at RF was observed in Drosophila cells, while in mammalian cells DmDNA Lig I accumulated at RF via its PBD. Further, GFP fusions with the PBD domains from Dnmt1, HsDNA Lig I and DmDNA Lig I, were able to target to RF only in mammalian cells but not in Drosophila cells. Conclusion We show that S phase in Drosophila cells is characterized by formation of RF marked by PCNA like in mammalian cells. However, other than PCNA none of the replication proteins and their deletions tested here showed accumulation at RF in Drosophila cells while the same proteins and deletions are capable of accumulating at RF in mammalian cells. We hypothesize that unlike mammalian cells, in Drosophila cells, replication proteins do not form long-lasting interactions with the replication machinery, and rather perform their functions via very

Mechanism of silver nanoparticles action on insect pigmentation reveals intervention of copper homeostasis.

Directory of Open Access Journals (Sweden)

Najealicka Armstrong

Full Text Available Silver nanoparticles (AgNPs, like almost all nanoparticles, are potentially toxic beyond a certain concentration because the survival of the organism is compromised due to scores of pathophysiological abnormalities past that concentration. However, the mechanism of AgNP toxicity remains undetermined. Instead of applying a toxic dose, we attempted to monitor the effects of AgNPs at a nonlethal concentration on wild type Drosophila melanogaster by exposing them throughout their development. All adult flies raised in AgNP doped food showed that up to 50 mg/L concentration AgNP has no negative influence on median survival; however, these flies appeared uniformly lighter in body color due to the loss of melanin pigments in their cuticle. Additionally, fertility and vertical movement ability were compromised due to AgNP feeding. Determination of the amount of free ionic silver (Ag(+ led us to claim that the observed biological effects have resulted from the AgNPs and not from Ag(+. Biochemical analysis suggests that the activity of copper dependent enzymes, namely tyrosinase and Cu-Zn superoxide dismutase, are decreased significantly following the consumption of AgNPs, despite the constant level of copper present in the tissue. Consequently, we propose a mechanism whereby consumption of excess AgNPs in association with membrane bound copper transporter proteins cause sequestration of copper, thus creating a condition that resembles copper starvation. This model also explains the cuticular demelanization effect resulting from AgNP since tyrosinase activity is essential for melanin biosynthesis. Finally, we claim that Drosophila, an established genetic model system, can be well utilized for further understanding of the biological effects of nanoparticles.

The Drosophila melanogaster circadian pacemaker circuit

Indian Academy of Sciences (India)

2016-08-26

Aug 26, 2016 ... Keywords. circadian rhythm; neuronal network; ion channel; behaviour; neurotransmitter; electrophysiology; Drosophila. Abstract. As an experimental model system, the fruit fly Drosophila melanogaster has been seminal in shaping our understanding of the circadian clockwork. The wealth of genetic tools ...

The gecko visual pigments. The behavior of opsin.

Science.gov (United States)

Crescitelli, F

1979-05-01

The 521-pigment extracted out of the retina of the Tokay gecko has the typical stereospecificity of the vertebrate visual pigments. This is true for the pigment in the chloride-depleted, "blue-shifted" state as well as for the normal pigment with added chloride. While in the chloride-deficient state, pigment regeneration occurred with both 11-cis- and 9-cis-retinals and the regenerated photopigments were also in the blue-shifted, chloride-depleted state. As with the native pigment, these regenerated pigments were bathochromically shifted to their normal positions by the addition of chloride. Chloride-deficient opsin by itself also responded to chloride for the pigment regenerated with 11-cis-retinal from such chloride-treated opsin was in the normal 521-position. Regeneration was always rapid, reaching completion in less than 5 min, and was significantly faster than for cow rhodopsin regenerating under the same conditions. This rapid rate was found with or without chloride, with both 11-cis- and 9-cis-retinals and in the presence of the sulfhydryl poison, p-hydroxymercuribenzoate (PMB). Like the native chloride-deficient pigment, the regenerated chloride-depleted photopigments responded to PMB by a blue shift beyond the position of the chloride-deficient state. The addition of chloride to these "poisoned" regenerated pigments caused a bathochromic shift of such magnitude as to indicate a repair of both the PMB and chloride-deficient blue shift. In this discussion the possible implications of these results to phylogenetic considerations are considered as well as to some molecular properties of the 521-pigment.

Effects of the Distributions of Energy or Charge Transfer Rates on Spectral Hole Burning in Pigment-Protein Complexes at Low Temperatures

Energy Technology Data Exchange (ETDEWEB)

Herascu, N.; Ahmouda, S.; Picorel, R.; Seibert, M.; Jankowiak, R.; Zazubovich, V.

2011-12-22

Effects of the distributions of excitation energy transfer (EET) rates (homogeneous line widths) on the nonphotochemical (resonant) spectral hole burning (SHB) processes in photosynthetic chlorophyll-protein complexes (reaction center [RC] and CP43 antenna of Photosystem II from spinach) are considered. It is demonstrated that inclusion of such a distribution results in somewhat more dispersive hole burning kinetics. More importantly, however, inclusion of the EET rate distributions strongly affects the dependence of the hole width on the fractional hole depth. Different types of line width distributions have been explored, including those resulting from Foerster type EET between weakly interacting pigments as well as Gaussian ones, which may be a reasonable approximation for those resulting, for instance, from so-called extended Foerster models. For Gaussian line width distributions, it is possible to determine the parameters of both line width and tunneling parameter distributions from SHB data without a priori knowledge of any of them. Concerning more realistic asymmetric distributions, we demonstrate, using the simple example of CP43 antenna, that one can use SHB modeling to estimate electrostatic couplings between pigments and support or exclude assignment of certain pigment(s) to a particular state.

Use of Whole-Cell Bioassays for Screening Quorum Signaling, Quorum Interference, and Biofilm Dispersion.

Science.gov (United States)

Thornhill, Starla G; McLean, Robert J C

2018-01-01

In most bacteria, a global level of regulation, termed quorum sensing (QS), exists involving intercellular communication via the production and response to cell density-dependent signal molecules. QS has been associated with a number of important features in bacteria including virulence regulation and biofilm formation. Consequently, there is considerable interest in understanding, detecting, and inhibiting QS. N-acylated homoserine lactones (AHLs) are used as extracellular QS signals by a variety of Gram-negative bacteria. Chromobacterium violaceum, commonly found in soil and water, produces the characteristic purple pigment violacein, regulated by AHL-mediated QS. Based on this readily observed pigmentation phenotype, C. violaceum strains can be used to detect various aspects of AHL-mediated QS activity. In another commonly used bioassay organism, Agrobacterium tumefaciens, QS can be detected by the use of a reporter gene such as lacZ. Here, we describe several commonly used approaches incorporating C. violaceum and A. tumefaciens that can be used to detect AHL and QS inhibitors. Due to the inherent low susceptibility of biofilm bacteria to antimicrobial agents, biofilm dispersion, whereby bacteria reenter the planktonic community, is another increasingly important area of research. At least one signal, distinct from traditional QS, has been identified and there are a variety of other environmental factors that also trigger dispersion. We describe a microtiter-based experimental strategy whereby potential biofilm dispersion compounds can be screened.

Microscopic Analysis of Pigments Extracted from Spalting Fungi

Directory of Open Access Journals (Sweden)

Sarath M. Vega Gutierrez

2017-03-01

Full Text Available Pigments that are currently available in the market usually come from synthetic sources, or, if natural, often need mordants to bind to the target substrate. Recent research on the fungal pigment extracts from Scytalidium cuboideum, Scytalidium ganodermophthorum, Chlorociboria aeruginosa, and Chlorociboria aeruginascens have been shown to successfully dye materials, like wood, bamboo, and textiles, however, there is no information about their binding mechanisms. Due to this, a microscopic study was performed to provide information to future manufacturers interested in these pigments. The results of this study show that S. ganodermophthorum and C. aeruginosa form an amorphous layer on substrates, while S. cuboideum forms crystal-like structures. The attachment and morphology indicate that there might be different chemical and physical interactions between the extracted pigments and the materials. This possibility can explain the high resistance of the pigments to UV light and color fastness that makes them competitive against synthetic pigments. These properties make these pigments a viable option for an industry that demands natural pigments with the properties of the synthetic ones.

Phylogeny of the Genus Drosophila

Science.gov (United States)

O’Grady, Patrick M.; DeSalle, Rob

2018-01-01

Understanding phylogenetic relationships among taxa is key to designing and implementing comparative analyses. The genus Drosophila, which contains over 1600 species, is one of the most important model systems in the biological sciences. For over a century, one species in this group, Drosophila melanogaster, has been key to studies of animal development and genetics, genome organization and evolution, and human disease. As whole-genome sequencing becomes more cost-effective, there is increasing interest in other members of this morphologically, ecologically, and behaviorally diverse genus. Phylogenetic relationships within Drosophila are complicated, and the goal of this paper is to provide a review of the recent taxonomic changes and phylogenetic relationships in this genus to aid in further comparative studies. PMID:29716983

YAG laser peripheral iridotomy for the prevention of pigment dispersion glaucoma a prospective, randomized, controlled trial.

Science.gov (United States)

Scott, Andrew; Kotecha, Aachal; Bunce, Catey; Balidis, Miltos; Garway-Heath, David F; Miller, Michael H; Wormald, Richard

2011-03-01

To test the hypothesis that neodymium:yttrium-aluminum-garnet (Nd:YAG) laser peripheral iridotomy (LPI) significantly reduces the incidence of conversion from pigment dispersion syndrome (PDS) with ocular hypertension (OHT) to pigmentary glaucoma (PG). Prospective, randomized, controlled 3-year trial. One hundred sixteen eyes of 116 patients with PDS and OHT. Patients were assigned randomly either to Nd:YAG LPI or to a control group (no laser). The primary outcome measure was conversion to PG within 3 years, based on full-threshold visual field (VF) analysis using the Ocular Hypertension Treatment Study criteria. Secondary outcome measures were whether eyes required topical antiglaucoma medications during the study period and the time to conversion or medication. Fifty-seven patients were randomized to undergo laser treatment and 59 were randomized to no laser (controls). Age, gender, spherical equivalent refraction, and intraocular pressure at baseline were similar between groups. Outcome data were available for 105 (90%) of recruited subjects, 52 in the laser treatment group and 53 in the no laser treatment group. Patients were followed up for a median of 35.9 months (range, 10-36 months) in the laser arm and 35.9 months (range, 1-36 months) in the control arm. Eight eyes (15%) in the laser group and 3 eyes (6%) in the control group converted to glaucoma in the study period. The proportion of eyes started on medical treatment was similar in the 2 groups: 8 eyes (15%) in the laser group and 9 eyes (17%) in the control group. Survival analyses showed no evidence of any difference in time to VF progression or commencement of topical therapy between the 2 groups. Cataract extraction was performed on 1 patient in the laser group and in 1 patient in the control group during the study period (laser eye at 18 months; control eye at 34 months). This study suggests that there was no benefit of Nd:YAG LPI in preventing progression from PDS with OHT to PG within 3 years of

Gingival Pigmentation Affected by Smoking among Different Age Groups: A Quantitative Analysis of Gingival Pigmentation Using Clinical Oral Photographs.

Science.gov (United States)

Kato, Tomotaka; Mizutani, Shinsuke; Takiuchi, Hiroya; Sugiyama, Seiichi; Hanioka, Takashi; Naito, Toru

2017-08-04

The presence of any age-related differences in gingival pigmentation associated with smoking, particularly in a young population, remains to be fully investigated. The purpose of this study was to determine the age-related differences in smoking gingival pigmentation. Gingival pigmentation was analyzed using the gingival melanosis record (GMR) and Hedin's classification with frontal oral photographs taken at 16 dental offices in Japan. Participants were categorized into 10-year age groups, and their baseline photographs were compared. In addition, to evaluate the effect of smoking cessation on gingival pigmentation, subjects were divided into a former smoker group (stopped smoking) and current smoker group. A total of 259 patients 19 to 79 years of age were analyzed. People in their 30s showed the most widespread gingival pigmentation. In addition, subjects in their 20s showed a weak effect of smoking cessation on gingival pigmentation. These findings suggested that the gingival pigmentation induced by smoking was more remarkable in young people than in middle-aged people. This information may be useful for anti-smoking education, especially among young populations with a high affinity for smoking.

PRODUCTION OF MONASCUS-LIKE AZAPHILONE PIGMENT

DEFF Research Database (Denmark)

2009-01-01

The present invention relates to the field of biotechnological production of polyketide based colorants from filamentous fungi, in particular a method for preparing a biomass comprising a Monascus-like pigment composition from a nontoxigenic and non-pathogenic fungal source. The present invention...... further relates to use of the Monascus-like pigment composition as a colouring agent for food items and/or non-food items, and a cosmetic composition comprising the Monascus-like pigment composition....

Pigmented xerodermoid - Report of three cases

OpenAIRE

Das Jayanta Kumar; Gangopadhyay Asok Kumar

2005-01-01

Pigmented xerodermoid, a rare genodermatosis, presents with clinical features and pathology similar to xeroderma pigmentosum, but at a later age. DNA repair replication is normal, but there is total depression of DNA synthesis after exposure to UV radiation. Two siblings in their teens and a man in his thirties with features of pigmented xerodermoid, e.g. photophobia, freckle-like lesions, keratoses, dryness of skin, and hypo- and hyper-pigmentation, are described. Although classically the on...

Production of Monascus-like azaphilone Pigment

DEFF Research Database (Denmark)

2009-01-01

The present invention relates to the field of biotechnological production of polyketide based colorants from filamentous fungi, in particular a method for preparing a biomass comprising a Monascus-like pigment composition from a nontoxigenic and non-pathogenic fungal source. The present invention...... further relates to use of the Monascus-like pigment composition as a colouring agent for food items and/or non-food items, and a cosmetic composition comprising the Monascus-like pigment composition....

Photosynthetic Pigments in Diatoms

OpenAIRE

Kuczynska, Paulina; Jemiola-Rzeminska, Malgorzata; Strzalka, Kazimierz

2015-01-01

Photosynthetic pigments are bioactive compounds of great importance for the food, cosmetic, and pharmaceutical industries. They are not only responsible for capturing solar energy to carry out photosynthesis, but also play a role in photoprotective processes and display antioxidant activity, all of which contribute to effective biomass and oxygen production. Diatoms are organisms of a distinct pigment composition, substantially different from that present in plants. Apart from light-harvestin...

Radioresistance and radiosensitivity in Drosophila melanogaster

International Nuclear Information System (INIS)

Reguly, M.L.

1983-01-01

Studying the mechanisms controlling radioresistant in Drosophila the sensibility of four strains of Drosophila melanogaster to sex-linked recessive lethal mutations induced by 5kR Cobalt-60 gamma radiation and 0,006 M EMS or 0,25% of caffeine was determined. (M.A.C.) [pt

Characterization of Autophagic Responses in Drosophila melanogaster.

Science.gov (United States)

Xu, T; Kumar, S; Denton, D

2017-01-01

Drosophila is an excellent model system for studying autophagy during animal development due to the availability of genetic reagents and opportunity for in vivo cell biological analysis. The regulation and mechanism of autophagy are highly evolutionarily conserved and the role of autophagy has been characterized during various stages of Drosophila development as well as following starvation. Studies in Drosophila have revealed novel insights into the role of distinct components of the autophagy machinery. This chapter describes protocols for examining autophagy during Drosophila development. A crucial step in the induction of autophagy is the incorporation of Atg8a into the autophagosome. This can be measured as autophagic puncta using live fluorescent imaging, immunostaining, or immunoblot analysis of LC3/Atg8a processing. The level of autophagy can also be examined using other specific components of the autophagy pathway as markers detected by immunofluorescent imaging. Based on the distinct morphology of autophagy, it can also be examined by transmission electron microscopy. In addition, one of the advantages of using Drosophila as a model is the ability to undertake genetic analysis of individual components of the autophagy machinery. Current approaches that can be used to monitor autophagy, including the overall flux and individual steps in Drosophila melanogaster, will be discussed. © 2017 Elsevier Inc. All rights reserved.

Mutations in CTNNA1 cause butterfly-shaped pigment dystrophy and perturbed retinal pigment epithelium integrity

NARCIS (Netherlands)

Saksens, N.T.; Krebs, M.P.; Schoenmaker, F.E.; Hicks, W.; Yu, M.; Shi, L.; Rowe, L.; Collin, G.B.; Charette, J.R.; Letteboer, S.J.; Neveling, K.; Moorsel, T.W. van; Abu-Ltaif, S.; Baere, E. De; Walraedt, S.; Banfi, S.; Simonelli, F.; Cremers, F.P.; Boon, C.J.; Roepman, R.; Leroy, B.P.; Peachey, N.S.; Hoyng, C.B.; Nishina, P.M.; Hollander, A.I. den

2016-01-01

Butterfly-shaped pigment dystrophy is an eye disease characterized by lesions in the macula that can resemble the wings of a butterfly. Here we report the identification of heterozygous missense mutations in the CTNNA1 gene (encoding alpha-catenin 1) in three families with butterfly-shaped pigment

Seperation, identification and analysis of pigment (melanin ...

African Journals Online (AJOL)

Nine strains among 180 Streptomyces isolates produce a diffusible dark brown pigment on both peptone-yeast extract agar and synthetic tyrosine-agar. They also show the positive reaction to Ltyrosine or L-dopa substrates. The pigment has been referred to be as merely as dark brown watersoluble pigment, as melanoid or ...

Proton beam modification of lead white pigments

International Nuclear Information System (INIS)

Beck, L.; Gutiérrez, P.C.; Miserque, F.; Thomé, L.

2013-01-01

Pigments and paint materials are known to be sensitive to particle irradiation. Occasionally, the analysis of paintings by PIXE can induce a slight or dark stain depending on the experimental conditions (beam current, dose, particle energy). In order to understand this discoloration, we have irradiated various types of art white pigments – lead white (hydrocerussite and basic lead sulfate), gypsum, calcite, zinc oxide and titanium oxide – with an external 3 MeV proton micro-beam commonly used for PIXE experiments. We have observed various sensitivities depending on the pigment. No visible change occurs for calcite and titanium oxide, whereas lead white pigments are very sensitive. For the majority of the studied compounds, the discoloration is proportional to the beam current and charge. The damage induced by proton beam irradiation in lead white pigments was studied by micro-Raman and XPS spectroscopies. Structural modifications and dehydration were detected. Damage recovery was investigated by thermal treatment and UV-light irradiation. The discoloration disappeared after one week of UV illumination, showing that PIXE experiments could be safely undertaken for pigments and paintings

Intestinal stem cells in the adult Drosophila midgut

International Nuclear Information System (INIS)

Jiang, Huaqi; Edgar, Bruce A.

2011-01-01

Drosophila has long been an excellent model organism for studying stem cell biology. Notably, studies of Drosophila's germline stem cells have been instrumental in developing the stem cell niche concept. The recent discovery of somatic stem cells in adult Drosophila, particularly the intestinal stem cells (ISCs) of the midgut, has established Drosophila as an exciting model to study stem cell-mediated adult tissue homeostasis and regeneration. Here, we review the major signaling pathways that regulate the self-renewal, proliferation and differentiation of Drosophila ISCs, discussing how this regulation maintains midgut homeostasis and mediates regeneration of the intestinal epithelium after injury. -- Highlights: ► The homeostasis and regeneration of adult fly midguts are mediated by ISCs. ► Damaged enterocytes induce the proliferation of intestinal stem cells (ISC). ► EGFR and Jak/Stat signalings mediate compensatory ISC proliferation. ► Notch signaling regulates ISC self-renewal and differentiation.

Interorgan Communication Pathways in Physiology: Focus on Drosophila

OpenAIRE

Droujinine, Ilia A.; Perrimon, Norbert

2016-01-01

Studies in mammals and Drosophila have demonstrated the existence and significance of secreted factors involved in communication between distal organs. In this review, primarily focusing on Drosophila, we examine the known interorgan communication factors and their functions, physiological inducers, and integration in regulating physiology. Moreover, we describe how organ-sensing screens in Drosophila can systematically identify novel conserved interorgan communication factors. Finally, we di...

Candida glabrata tryptophan-based pigment production via the Ehrlich pathway.

Science.gov (United States)

Brunke, Sascha; Seider, Katja; Almeida, Ricardo Sergio; Heyken, Antje; Fleck, Christian Benjamin; Brock, Matthias; Barz, Dagmar; Rupp, Steffen; Hube, Bernhard

2010-04-01

Pigments contribute to the pathogenicity of many fungi, mainly by protecting fungal cells from host defence activities. Here, we have dissected the biosynthetic pathway of a tryptophan-derived pigment of the human pathogen Candida glabrata, identified key genes involved in pigment production and have begun to elucidate the possible biological function of the pigment. Using transcriptional analyses and a transposon insertion library, we have identified genes associated with pigment production. Targeted deletion mutants revealed that the pigment is a by-product of the Ehrlich pathway of tryptophan degradation: a mutant lacking a tryptophan-upregulated aromatic aminotransferase (Aro8) displayed significantly reduced pigmentation and a recombinantly expressed version of this protein was sufficient for pigment production in vitro. Pigment production is tightly regulated as the synthesis is affected by the presence of alternative nitrogen sources, carbon sources, cyclic AMP and oxygen. Growth of C. glabrata on pigment inducing medium leads to an increased resistance to hydrogen peroxide, an effect which was not observed with a mutant defective in pigmentation. Furthermore, pigmented yeast cells had a higher survival rate when exposed to human neutrophils and caused increased damage in a monolayer model of human epithelia, indicating a possible role of pigmentation during interactions with host cells.

Laser ablation-inductively coupled plasma mass spectrometry for the characterization of pigments in prehistoric rock art.

Science.gov (United States)

Resano, Martin; García-Ruiz, Esperanza; Alloza, Ramiro; Marzo, Maria P; Vandenabeele, Peter; Vanhaecke, Frank

2007-12-01

In this work, several red-colored paintings of post-Paleolithic schematic style found in 10 different shelters in the vicinity of the Vero River (Huesca) were sampled and subjected to analysis by means of scanning electron microscopy-energy-dispersive X-ray spectrometry (SEM-EDX), Raman spectroscopy, and laser ablation-inductively coupled plasma mass spectrometry (LA-ICPMS). The goal of this research was to obtain meaningful information on the samples composition, in order to establish differences or similarities among them. The combined use of these techniques proved beneficial, as Raman data permitted structural information on the compounds present (hematite was identified as the main pigment, whereas calcite and gypsum are the main components of the substrate layer, as well as of the accretions that covered the pigments) to be obtained, while the quantitative values obtained by SEM were suitable for the use of Ca as internal reference during LA-ICPMS analysis. However, it was this latter technique that provided the most relevant data for fingerprinting purposes. The potential of this technique for obtaining spatially resolved information allowed the multielement quantitative analysis of the pigment layer, in spite of the presence of superficial accretions. The sensitivity of the technique permitted the determination of more than 40 elements present in a wide concentration range (from microgram per gram to 10% level) with minimum sample consumption (approximately 900 ng for each sample, corresponding to five replicates). Finally, in order to establish significant differences, only those elements showing a high correlation with Fe (As, Co, Mo, Sb, Tl, and Zr, in this case) were selected, as it is expected that these were truly present in the original pigment, while others could have migrated into the pigment layer throughout time. By using this information, it seems feasible to discriminate between various paint pots, as demonstrated for the samples under

Effect of sterol metabolism in the yeast-Drosophila system on the frequency of radiation-induced aneuploidy in the Drosophila melanogaster oocytes

International Nuclear Information System (INIS)

Savitskii, V.V.; Luchnikova, E.M.; Inge-Vechtomov, S.G.

1986-01-01

The effect of sterol metabolism on induced mutagenesis of Drosophila melanogaster was studied in the ecogenetic system of yeast-Drosophila. Sterol deficiency was created in Drosophila by using the biomass of live cells of Saccharomyces cerevisiae strain 9-2-P712 till mutation in locus nys/sup r1/ blocking the synthesis of ergosterol as the food. It was found that rearing of Drosophila females on the mutant yeast increases the frequency of loss and nondisjunction of X chromosomes induced in mature oocytes by X rays (1000 R). Addition of 0.1% of cholesterol solution in 10% ethanol to the yeast biomass restores the resistance of oocyte to X irradiation to the control level. The possible hormonal effect on membrane leading to increased radiation-induced aneuploidy in Drosophila and the role of sterol metabolism in determining the resistance to various damaging factors are discussed

DNA damage in isolated rat hepatocytes exposed to C.I. pigment orange 5 and C.I. pigment yellow 12 by the alkaline comet assay

DEFF Research Database (Denmark)

Møller, P; Wallin, Håkan; Grunnet, N

1998-01-01

The induction of DNA damage by commonly used printing ink pigments, C.I. pigment orange 5 (C.I. 12075) and C.I. pigment yellow 12 (C.I. 21090), was investigated in freshly isolated rat hepatocytes with the comet assay. C.I. pigment yellow 12 is a 3,3'-dichlorobenzidine-based diarylide pigment...

Impact of Pigments on Self-Compacting Concrete

Directory of Open Access Journals (Sweden)

Ernestas Ivanauskas

2011-04-01

Full Text Available We describe an impact of using iron oxide pigment on self-compacting concrete (SCC properties. We have experimented with adding portions of iron oxide pigment from 3 % to 6 % into cement paste. A few alternative pigments (chromic oxide and iron oxide hydroxide were used for performing the same experiments. The impact of these pigments on a normal cement paste is described in this paper. We demonstrate that iron oxide pigment reduces the need for water in a normal cement paste. However, adding the pigment also reduces the compressive strength of concrete up to 20 %. The concrete specimens were tested in various time spans, i.e. 1 day to 28 days, by keeping them in 20 ± 2 ºC water – normal consolidation regimen. Some of the specimens were processed in steam chamber, at 60 ºC in order to make the process of the cement hydration faster, as well as to estimate an impact of active SiO2 proportion in ash on SCC properties. We show that using iron oxide pigment for SCC mixture increases the slump-flow property of concrete mix up to 5 %. Experiments with solidified concrete have demonstrated that iron oxide diminishes water absorption up to 6 % and decreases open concrete porosity that makes concrete resistant against freezing. Article in Lithuanian

Intestinal stem cells in the adult Drosophila midgut

Energy Technology Data Exchange (ETDEWEB)

Jiang, Huaqi, E-mail: Huaqi.Jiang@UTSouthwestern.edu [Department of Developmental Biology, UT Southwestern Medical Center, 6000 Harry Hines Blvd., Dallas, TX, 75235 (United States); Edgar, Bruce A., E-mail: b.edgar@dkfz.de [ZMBH-DKFZ Alliance, Im Neuenheimer Feld 282, D-69120 Heidelberg (Germany); Division of Basic Sciences, Fred Hutchinson Cancer Research Center, 1100 Fairview Ave. N., Seattle, WA 98109 (United States)

2011-11-15

Drosophila has long been an excellent model organism for studying stem cell biology. Notably, studies of Drosophila's germline stem cells have been instrumental in developing the stem cell niche concept. The recent discovery of somatic stem cells in adult Drosophila, particularly the intestinal stem cells (ISCs) of the midgut, has established Drosophila as an exciting model to study stem cell-mediated adult tissue homeostasis and regeneration. Here, we review the major signaling pathways that regulate the self-renewal, proliferation and differentiation of Drosophila ISCs, discussing how this regulation maintains midgut homeostasis and mediates regeneration of the intestinal epithelium after injury. -- Highlights: Black-Right-Pointing-Pointer The homeostasis and regeneration of adult fly midguts are mediated by ISCs. Black-Right-Pointing-Pointer Damaged enterocytes induce the proliferation of intestinal stem cells (ISC). Black-Right-Pointing-Pointer EGFR and Jak/Stat signalings mediate compensatory ISC proliferation. Black-Right-Pointing-Pointer Notch signaling regulates ISC self-renewal and differentiation.

Early Olfactory Processing in Drosophila: Mechanisms and Principles

OpenAIRE

Wilson, Rachel I.

2013-01-01

In the olfactory system of Drosophila melanogaster, it is relatively straightforward to make in vivo measurements of activity in neurons corresponding to targeted processing. This, together with the numerical simplicity of the Drosophila olfactory system, has produced rapid gains in our understanding of Drosophila olfaction. This review summarizes the neurophysiology of the first two layers of this system: the peripheral olfactory receptor neurons and their postsynaptic targets in the antenna...

The effect of polyhedral oligomeric silsesquioxane dispersant and low surface energy additives on spectrally selective paint coatings with self-cleaning properties

Energy Technology Data Exchange (ETDEWEB)

Jerman, Ivan; Kozelj, Matjaz; Orel, Boris [National Institute of Chemistry, Hajdrihova 19, SI-1000 Ljubljana (Slovenia)

2010-02-15

Thickness-Insensitive Spectrally Selective (TISS) paint coatings were made of fluoropolymer resin binder (Lumiflon (LF), Asahi Glass Co., Ltd., Japan) and their water- and oil-repellent properties were obtained (contact angle: {theta}{sub water}{proportional_to}150 , {theta}{sub n-hexadecane}{proportional_to}55 ) by the addition of Polyhedral Oligomeric Silsesquioxane (POSS) characterized by amino (AP), isooctyl (IO) and perfluoro (PF) groups (i.e. AP{sub 2}IO{sub 4}PF{sub 2}) attached on the silsesquioxane cube (-SiO{sub 3/2}){sub 8}. Paint dispersions were made by modifying of black spinel pigment with trisilanol isobutyl (IB{sub 7}T{sub 7}(OH){sub 3}) POSS dispersant and with a single-capped silane isobutyltrimethoxysilane (IBTMS). Infrared and {sup 29}Si NMR spectra measurements were used for the identification of the structural characteristic of the corresponding POSS compounds. Surface free energy values of the pure cross-linked (no pigment added) LF binder which was determined from the measured contact angles for water, diiodomethane and formamide revealed the {gamma}{sup tot} value of the LF unpigmented resin with added AP{sub 2}IO{sub 4}PF{sub 2} T{sub 8} POSS was about 16.4 mN/m, which led to the {theta}{sub water}{proportional_to}110 , indicating enhancement of the hydrophobicity of the pure LF resin binder ({theta}{sub water}{proportional_to}89 ). SEM micrographs, which were used for the assessment of the TISS paint coating surface morphology confirmed the beneficial dispersive effect of IB{sub 7} T{sub 7}(OH){sub 3} dispersant as compared to the IBTMS silane. The presence of large Aluminium flake pigment and finely ground black pigment led to the formation of TISS paint coating surface, which exhibited bi-hierarchical roughness, resulting in water sliding angles of less than 10 , indicating the possible self-cleaning effect ({theta}{sub water}>150 and {theta}{sub n-hexadecane}{proportional_to}55 ). The use of POSS dispersant and POSS low surface energy

Isolation of protease-free alcohol dehydrogenase (ADH) from Drosophila simulans and several homozygous and heterozygous Drosophila melanogaster variants

NARCIS (Netherlands)

Smilda, T; Lamme, DA; Collu, G; Jekel, PA; Reinders, P; Beintema, JJ

The enzyme alcohol dehydrogenase (ADH) from several naturally occurring ADH variants of Drosophila melanogaster and Drosophila simulans Lc,as isolated. Affinity chromatography with the ligand Cibacron Blue and elution with NAD(+) showed similar behavior for D. melanogaster ADH-FF, ADH-71k, and D.

Adaptive genic evolution in the Drosophila genomes

DEFF Research Database (Denmark)

Shapiro, Joshua A; Huang, Wei; Zhang, Chenhui

2007-01-01

and stable population. In this study, we sequenced 419 genes from 24 lines of Drosophila melanogaster and its close relatives. Together with data from Drosophila simulans, these data reveal the following. (i) Approximately 10% of the loci in regions of normal recombination are much less polymorphic at silent...... sites than expected, hinting at the action of selective sweeps. (ii) The level of polymorphism is negatively correlated with the rate of nonsynonymous divergence across loci. Thus, even under strict neutrality, the ratio of amino acid to silent nucleotide changes (A:S) between Drosophila species...

Introducing Pitt-Hopkins syndrome-associated mutations of TCF4 to Drosophila daughterless

Directory of Open Access Journals (Sweden)

Laura Tamberg

2015-12-01

Full Text Available Pitt-Hopkins syndrome (PTHS is caused by haploinsufficiency of Transcription factor 4 (TCF4, one of the three human class I basic helix-loop-helix transcription factors called E-proteins. Drosophila has a single E-protein, Daughterless (Da, homologous to all three mammalian counterparts. Here we show that human TCF4 can rescue Da deficiency during fruit fly nervous system development. Overexpression of Da or TCF4 specifically in adult flies significantly decreases their survival rates, indicating that these factors are crucial even after development has been completed. We generated da transgenic fruit fly strains with corresponding missense mutations R578H, R580W, R582P and A614V found in TCF4 of PTHS patients and studied the impact of these mutations in vivo. Overexpression of wild type Da as well as human TCF4 in progenitor tissues induced ectopic sensory bristles and the rough eye phenotype. By contrast, overexpression of DaR580W and DaR582P that disrupt DNA binding reduced the number of bristles and induced the rough eye phenotype with partial lack of pigmentation, indicating that these act dominant negatively. Compared to the wild type, DaR578H and DaA614V were less potent in induction of ectopic bristles and the rough eye phenotype, respectively, suggesting that these are hypomorphic. All studied PTHS-associated mutations that we introduced into Da led to similar effects in vivo as the same mutations in TCF4 in vitro. Consequently, our Drosophila models of PTHS are applicable for further studies aiming to unravel the molecular mechanisms of this disorder.

Microbial Production of Food Grade Pigments

Directory of Open Access Journals (Sweden)

Laurent Dufossé

2006-01-01

Full Text Available The controversial topic of synthetic dyes in food has been discussed for many years. The scrutiny and negative assessment of synthetic food dyes by the modern consumer have raised a strong interest in natural colouring alternatives. Nature is rich in colours (minerals, plants, microalgae, etc., and pigment-producing microorganisms (fungi, yeasts, bacteria are quite common. Among the molecules produced by microorganisms are carotenoids, melanins, flavins, quinones, and more specifically monascins, violacein or indigo. The success of any pigment produced by fermentation depends upon its acceptability on the market, regulatory approval, and the size of the capital investment required to bring the product to market. A few years ago, some expressed doubts about the successful commercialization of fermentation-derived food grade pigments because of the high capital investment requirements for fermentation facilities and the extensive and lengthy toxicity studies required by regulatory agencies. Public perception of biotechnology-derived products also had to be taken into account. Nowadays some fermentative food grade pigments are on the market: Monascus pigments, astaxanthin from Xanthophyllomyces dendrorhous, Arpink Red from Penicillium oxalicum, riboflavin from Ashbya gossypii, b-carotene from Blakeslea trispora. The successful marketing of pigments derived from algae or extracted from plants, both as a food colour and a nutritional supplement, reflects the presence and importance of niche markets in which consumers are willing to pay a premium for »all natural ingredients«.

Studies on pigments of the myxomycete Physarum nudum. II. Separation and optical properties of the pigments from plasmodia cultured in darkness

Directory of Open Access Journals (Sweden)

L. Raczkowski

2015-01-01

Full Text Available The paper presents the data on Separation and some optical properties of the pigments obtained from the plasmodium of the myxomycete Physarum nudum grown in the dark. Pigment Separation was performed by means of thin-layer chromatography with celulose MN 300 as adsorbent and with the solvent: tert.-butylalcohol, H2O, 3N NH4OH at the ratio 5:2:1 In these conditions the chromatograms revealed 12 coloured bands from which pigments were eluted and their absorption spectra as well as the spectra of fluorescence emission were determined. The isolated pigments differ from one another by their physical properties (different Rf values, localization of absorption maxima, and behaviour in acid solution. Nevertheless, certain analogies perceptible between particular pigments per-mitted to distinguish 3 families of the studied pigments demonstrating similar properties.

Identification of plant cells in black pigments of prehistoric Spanish Levantine rock art by means of a multi-analytical approach. A new method for social identity materialization using chaîne opératoire.

Science.gov (United States)

López-Montalvo, Esther; Roldán, Clodoaldo; Badal, Ernestina; Murcia-Mascarós, Sonia; Villaverde, Valentín

2017-01-01

We present a new multi-analytical approach to the characterization of black pigments in Spanish Levantine rock art. This new protocol seeks to identify the raw materials that were used, as well as reconstruct the different technical gestures and decision-making processes involved in the obtaining of these black pigments. For the first of these goals, the pictorial matter of the black figurative motifs documented at the Les Dogues rock art shelter (Ares del Maestre, Castellón, Spain) was characterized through the combination of physicochemical and archeobotanical analyses. During the first stage of our research protocol, in situ and non-destructive analyses were carried out by means of portable Energy Dispersive X-Ray Fluorescence spectrometry (EDXRF); during the second stage, samples were analyzed by Optical Microscopy (OM), Raman spectroscopy, and Scanning Electron Microscopy coupled with Energy Dispersive X-ray spectroscopy (SEM-EDX). Two major conclusions have been drawn from these analyses: first, charred plant matter has been identified as a main component of these prehistoric black pigments; and second, angiosperm and conifer charcoal was a primary raw material for pigment production, identified by means of the archaeobotanical study of plant cells. For the second goal, black charcoal pigments were replicated in the laboratory by using different raw materials and binders and by reproducing two main chaînes opératoires. The comparative study of the structure and preservation of plant tissues of both prehistoric and experimental pigments by means of SEM-EDX underlines both a complex preparation process and the use of likely pigment recipes, mixing raw material with fatty or oily binders. Finally, the formal and stylistic analysis of the motifs portrayed at Les Dogues allowed us to explore the relationship between identified stylistic phases and black charcoal pigment use, raising new archaeological questions concerning the acquisition of know-how and the

Structural insights into the neuroprotective-acting carbonyl reductase Sniffer of Drosophila melanogaster.

Science.gov (United States)

Sgraja, Tanja; Ulschmid, Julia; Becker, Katja; Schneuwly, Stephan; Klebe, Gerhard; Reuter, Klaus; Heine, Andreas

2004-10-01

In vivo studies with the fruit-fly Drosophila melanogaster have shown that the Sniffer protein prevents age-dependent and oxidative stress-induced neurodegenerative processes. Sniffer is a NADPH-dependent carbonyl reductase belonging to the enzyme family of short-chain dehydrogenases/reductases (SDRs). The crystal structure of the homodimeric Sniffer protein from Drosophila melanogaster in complex with NADP+ has been determined by multiple-wavelength anomalous dispersion and refined to a resolution of 1.75 A. The observed fold represents a typical dinucleotide-binding domain as detected for other SDRs. With respect to the cofactor-binding site and the region referred to as substrate-binding loop, the Sniffer protein shows a striking similarity to the porcine carbonyl reductase (PTCR). This loop, in both Sniffer and PTCR, is substantially shortened compared to other SDRs. In most enzymes of the SDR family this loop adopts a well-defined conformation only after substrate binding and remains disordered in the absence of any bound ligands or even if only the dinucleotide cofactor is bound. In the structure of the Sniffer protein, however, the conformation of this loop is well defined, although no substrate is present. Molecular modeling studies provide an idea of how binding of substrate molecules to Sniffer could possibly occur.

Non-destructive characterization of oriental porcelain glazes and blue underglaze pigments using μ-EDXRF, μ-Raman and VP-SEM

Energy Technology Data Exchange (ETDEWEB)

Coutinho, M.L. [Universidade Nova de Lisboa, REQUIMTE-CQFB, Faculdade de Ciencias e Tecnologia, Caparica (Portugal); Universidade Nova de Lisboa, Departamento de Conservacao e Restauro, Faculdade de Ciencias e Tecnologia, Caparica (Portugal); Muralha, V.S.F. [Universidade Nova de Lisboa, Research Unit VICARTE, Vidro e Ceramica para as Artes, Faculdade de Ciencias e Tecnologia, Caparica (Portugal); Mirao, J. [Universidade de Evora, Laboratorio HERCULES, Evora (Portugal); Veiga, J.P. [Universidade Nova de Lisboa, CENIMAT/I3N, Departamento de Ciencia dos Materiais, Faculdade de Ciencias e Tecnologia, Caparica (Portugal)

2014-03-15

The study of ancient materials with recognized cultural and economic value is a challenge to scientists and conservators, since it is usually necessary an approach through non-destructive techniques. Difficulties in establishing a correct analytical strategy are often significantly increased by the lack of knowledge on manufacture technologies and raw materials employed combined with the diversity of decay processes that may have acted during the lifetime of the cultural artefacts. A non-destructive characterization was performed on the glaze and underglaze pigments from a group of Chinese porcelain shards dated from the late Ming Dynasty (1368-1644) excavated at the Monastery of Santa Clara-a-Velha in Coimbra (Portugal). Chemical analysis was performed using micro-energy dispersive X-ray fluorescence spectrometry (μ-EDXRF). Mineralogical characterization was achieved by Raman microscopy (μ-Raman) and observation of small-surface crystallization dark spots with a metallic lustre in areas with high pigment concentration was done by variable pressure scanning electron microscopy (VP-SEM). Cobalt aluminate was identified as the blue underglaze pigment and a comparison of blue and dark blue pigments was performed by the ratio of Co, Mn, and Fe oxides, indicating a compositional difference between the two blue tonalities. Manganese oxide compounds were also identified as colouring agents in dark blue areas and surface migration of manganese compounds was verified. (orig.)

Non-destructive characterization of oriental porcelain glazes and blue underglaze pigments using μ-EDXRF, μ-Raman and VP-SEM

International Nuclear Information System (INIS)

Coutinho, M.L.; Muralha, V.S.F.; Mirao, J.; Veiga, J.P.

2014-01-01

The study of ancient materials with recognized cultural and economic value is a challenge to scientists and conservators, since it is usually necessary an approach through non-destructive techniques. Difficulties in establishing a correct analytical strategy are often significantly increased by the lack of knowledge on manufacture technologies and raw materials employed combined with the diversity of decay processes that may have acted during the lifetime of the cultural artefacts. A non-destructive characterization was performed on the glaze and underglaze pigments from a group of Chinese porcelain shards dated from the late Ming Dynasty (1368-1644) excavated at the Monastery of Santa Clara-a-Velha in Coimbra (Portugal). Chemical analysis was performed using micro-energy dispersive X-ray fluorescence spectrometry (μ-EDXRF). Mineralogical characterization was achieved by Raman microscopy (μ-Raman) and observation of small-surface crystallization dark spots with a metallic lustre in areas with high pigment concentration was done by variable pressure scanning electron microscopy (VP-SEM). Cobalt aluminate was identified as the blue underglaze pigment and a comparison of blue and dark blue pigments was performed by the ratio of Co, Mn, and Fe oxides, indicating a compositional difference between the two blue tonalities. Manganese oxide compounds were also identified as colouring agents in dark blue areas and surface migration of manganese compounds was verified. (orig.)

Non-destructive characterization of oriental porcelain glazes and blue underglaze pigments using μ-EDXRF, μ-Raman and VP-SEM

Science.gov (United States)

Coutinho, M. L.; Muralha, V. S. F.; Mirão, J.; Veiga, J. P.

2014-03-01

The study of ancient materials with recognized cultural and economic value is a challenge to scientists and conservators, since it is usually necessary an approach through non-destructive techniques. Difficulties in establishing a correct analytical strategy are often significantly increased by the lack of knowledge on manufacture technologies and raw materials employed combined with the diversity of decay processes that may have acted during the lifetime of the cultural artefacts. A non-destructive characterization was performed on the glaze and underglaze pigments from a group of Chinese porcelain shards dated from the late Ming Dynasty (1368-1644) excavated at the Monastery of Santa Clara- a- Velha in Coimbra (Portugal). Chemical analysis was performed using micro-energy dispersive X-ray fluorescence spectrometry (μ-EDXRF). Mineralogical characterization was achieved by Raman microscopy (μ-Raman) and observation of small-surface crystallization dark spots with a metallic lustre in areas with high pigment concentration was done by variable pressure scanning electron microscopy (VP-SEM). Cobalt aluminate was identified as the blue underglaze pigment and a comparison of blue and dark blue pigments was performed by the ratio of Co, Mn, and Fe oxides, indicating a compositional difference between the two blue tonalities. Manganese oxide compounds were also identified as colouring agents in dark blue areas and surface migration of manganese compounds was verified.

Light-induced vegetative anthocyanin pigmentation in Petunia

OpenAIRE

Albert, Nick W.; Lewis, David H.; Zhang, Huaibi; Irving, Louis J.; Jameson, Paula E.; Davies, Kevin M.

2009-01-01

The Lc petunia system, which displays enhanced, light-induced vegetative pigmentation, was used to investigate how high light affects anthocyanin biosynthesis, and to assess the effects of anthocyanin pigmentation upon photosynthesis. Lc petunia plants displayed intense purple anthocyanin pigmentation throughout the leaves and stems when grown under high-light conditions, yet remain acyanic when grown under shade conditions. The coloured phenotypes matched with an accumulation of anthocyanins...

40 CFR 798.5955 - Heritable translocation test in drosophila melanogaster.

Science.gov (United States)

2010-07-01

... drosophila melanogaster. 798.5955 Section 798.5955 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY....5955 Heritable translocation test in drosophila melanogaster. (a) Purpose. The heritable translocation test in Drosophila measures the induction of chromosomal translocations in germ cells of insects...

Single Nucleotide Polymorphism Markers for Genetic Mapping in Drosophila melanogaster

OpenAIRE

Hoskins, Roger A.; Phan, Alexander C.; Naeemuddin, Mohammed; Mapa, Felipa A.; Ruddy, David A.; Ryan, Jessica J.; Young, Lynn M.; Wells, Trent; Kopczynski, Casey; Ellis, Michael C.

2001-01-01

For nearly a century, genetic analysis in Drosophila melanogaster has been a powerful tool for analyzing gene function, yet Drosophila lacks the molecular genetic mapping tools that recently have revolutionized human, mouse, and plant genetics. Here, we describe the systematic characterization of a dense set of molecular markers in Drosophila by using a sequence tagged site-based physical map of the genome. We identify 474 biallelic markers in standard laboratory strains of Drosophila that sp...

Pigmented skin disorders: Evaluation and treatment

NARCIS (Netherlands)

Kroon, M.W.

2015-01-01

Pigmentary disorders are disturbances of human skin color. Minor changes in the cellular physiology of the skin can dramatically affect pigment production in positive or negative manner. In this these, associated diseases, therapeutical options and disease parameters for the pigmentation disorder

Positive selection of a duplicated UV-sensitive visual pigment coincides with wing pigment evolution in Heliconius butterflies

Science.gov (United States)

Briscoe, Adriana D.; Bybee, Seth M.; Bernard, Gary D.; Yuan, Furong; Sison-Mangus, Marilou P.; Reed, Robert D.; Warren, Andrew D.; Llorente-Bousquets, Jorge; Chiao, Chuan-Chin

2010-01-01

The butterfly Heliconius erato can see from the UV to the red part of the light spectrum with color vision proven from 440 to 640 nm. Its eye is known to contain three visual pigments, rhodopsins, produced by an 11-cis-3-hydroxyretinal chromophore together with long wavelength (LWRh), blue (BRh) and UV (UVRh1) opsins. We now find that H. erato has a second UV opsin mRNA (UVRh2)—a previously undescribed duplication of this gene among Lepidoptera. To investigate its evolutionary origin, we screened eye cDNAs from 14 butterfly species in the subfamily Heliconiinae and found both copies only among Heliconius. Phylogeny-based tests of selection indicate positive selection of UVRh2 following duplication, and some of the positively selected sites correspond to vertebrate visual pigment spectral tuning residues. Epi-microspectrophotometry reveals two UV-absorbing rhodopsins in the H. erato eye with λmax = 355 nm and 398 nm. Along with the additional UV opsin, Heliconius have also evolved 3-hydroxy-DL-kynurenine (3-OHK)-based yellow wing pigments not found in close relatives. Visual models of how butterflies perceive wing color variation indicate this has resulted in an expansion of the number of distinguishable yellow colors on Heliconius wings. Functional diversification of the UV-sensitive visual pigments may help explain why the yellow wing pigments of Heliconius are so colorful in the UV range compared to the yellow pigments of close relatives lacking the UV opsin duplicate. PMID:20133601

Medium-term changes in Drosophila subobscura chromosomal ...

Indian Academy of Sciences (India)

2015-06-02

Jun 2, 2015 ... Krimbas C. B. 1993 Drosophila subobscura: biology, genetics and inversion polymorphism. Verlag Dr, Kovac, Hamburg. Menozzi P. and Krimbas C. B. 1992 The inversion polymorphism of Drosophila subobscura revisited: synthetic maps of gene arrangements frequencies and their interpretation. J. Evol.

Gut-associated microbes of Drosophila melanogaster

Science.gov (United States)

Broderick, Nichole; Lemaitre, Bruno

2012-01-01

There is growing interest in using Drosophila melanogaster to elucidate mechanisms that underlie the complex relationships between a host and its microbiota. In addition to the many genetic resources and tools Drosophila provides, its associated microbiota is relatively simple (1–30 taxa), in contrast to the complex diversity associated with vertebrates (> 500 taxa). These attributes highlight the potential of this system to dissect the complex cellular and molecular interactions that occur between a host and its microbiota. In this review, we summarize what is known regarding the composition of gut-associated microbes of Drosophila and their impact on host physiology. We also discuss these interactions in the context of their natural history and ecology and describe some recent insights into mechanisms by which Drosophila and its gut microbiota interact. “Workers with Drosophila have been considered fortunate in that they deal with the first multicellular invertebrate to be cultured monoxenically (Delcourt and Guyenot, 1910); the first to be handled axenically on a semisynthetic diet (Guyenot, 1917); and the first to be grown on a defined diet (Schultz et al., 1946). This list of advantages is somewhat embarrassing, since it implies an interest in nutrition that, in reality, was only secondary. The very first studies were concerned with the reduction of variability in genetic experiments (Delcourt and Guyenot, 1910) and standardization of the nutritional environment.” -James Sang, 1959 Ann NY Acad 1 PMID:22572876

Interaction between Vaccinium bracteatum Thunb. leaf pigment and rice proteins.

Science.gov (United States)

Wang, Li; Xu, Yuan; Zhou, Sumei; Qian, Haifeng; Zhang, Hui; Qi, Xiguang; Fan, Meihua

2016-03-01

In this study, we investigated the interaction of Vaccinium bracteatum Thunb. leaf (VBTL) pigment and rice proteins. In the presence of rice protein, VBTL pigment antioxidant activity and free polyphenol content decreased by 67.19% and 68.11%, respectively, and L(∗) of the protein-pigment complex decreased significantly over time. L(∗) values of albumin, globulin and glutelin during 60-min pigment exposure decreased by 55.00, 57.14, and 54.30%, respectively, indicating that these proteins had bound to the pigment. A significant difference in protein surface hydrophobicity was observed between rice proteins and pigment-protein complexes, indicating that hydrophobic interaction is a major binding mechanism between VBTL pigment and rice proteins. A significant difference in secondary structures between proteins and protein-pigment complexes was also uncovered, indicating that hydrogen bonding may be another mode of interaction between VBTL pigment and rice proteins. Our results indicate that VBTL pigment can stain rice proteins with hydrophobic and hydrogen interactions. Copyright © 2015 Elsevier Ltd. All rights reserved.

Skin Pigmentation Kinetics after Exposure to Ultraviolet A

DEFF Research Database (Denmark)

Ravnbak, M.H.; Philipsen, P.A.; Wiegell, S.R.

2009-01-01

Multiple exposures to ultraviolet radiation (UVR) are the norm in nature and phototherapy. However, studies of the kinetics of pigmentation following UVA exposure have included only fair-skinned persons. The aim of this study was to investigate steady-state pigmentation and fading in 12 Scandinav......Multiple exposures to ultraviolet radiation (UVR) are the norm in nature and phototherapy. However, studies of the kinetics of pigmentation following UVA exposure have included only fair-skinned persons. The aim of this study was to investigate steady-state pigmentation and fading in 12...... Scandinavians and 12 Indians/Pakistanis after 6 and 12 exposures on the back using broadband UVA and UVA1 with equal sub-minimal melanogenic doses (individually predetermined). Pigmentation was measured by skin reflectance at 555 and 660 urn. The UV dose to minimal pigmentation was higher in dark......-skinned persons after a single broadband UVA exposure, but independent of pigmentation/skin type after single and multiple UVA1 exposures. To elicit minimal melanogenic doses after 6 and 12 exposures, every dose is lowered by a factor of 2 and 3, respectively, but the cumulative dose increases three- and four...

Pigment Production by the Edible Filamentous Fungus Neurospora Intermedia

Directory of Open Access Journals (Sweden)

Rebecca Gmoser

2018-02-01

Full Text Available The production of pigments by edible filamentous fungi is gaining attention as a result of the increased interest in natural sources with added functionality in the food, feed, cosmetic, pharmaceutical and textile industries. The filamentous fungus Neurospora intermedia, used for production of the Indonesian food “oncom”, is one potential source of pigments. The objective of the study was to evaluate the fungus’ pigment production. The joint effect from different factors (carbon and nitrogen source, ZnCl2, MgCl2 and MnCl2 on pigment production by N. intermedia is reported for the first time. The scale-up to 4.5 L bubble column bioreactors was also performed to investigate the effect of pH and aeration. Pigment production of the fungus was successfully manipulated by varying several factors. The results showed that the formation of pigments was strongly influenced by light, carbon, pH, the co-factor Zn2+ and first- to fourth-order interactions between factors. The highest pigmentation (1.19 ± 0.08 mg carotenoids/g dry weight biomass was achieved in a bubble column reactor. This study provides important insights into pigmentation of this biotechnologically important fungus and lays a foundation for future utilizations of N. intermedia for pigment production.

Preparation, characterization and application of some anti- corrosive molybdate pigments

International Nuclear Information System (INIS)

Abd El-Ghaffar, M.A.; El-Sawy, S.M.; Ahmed, N.M.

2005-01-01

Some molybdate pigments of single and mixed metal ions, namely, zinc, calcium and zinc-calcium molybdates were prepared, characterized and evaluated according to international standard methods. The evaluated pigments were incorporated in some paint formulations. The physicomechanical, chemical and corrosion protective properties of the paint films were measured; this was done in comparison with a commercial imported molybdate pigment. It was found that, the prepared pigments under investigation are fine white crystalline powders of suitable pigment properties. They can be successfully used as environmentally acceptable anti corrosive pigments. They can replace satisfactorily the similar commercial imported pigment and possess adequate or superior properties against corrosion

Micro energy dispersive X-ray fluorescence analysis of polychrome lead-glazed Portuguese faiences

International Nuclear Information System (INIS)

Guilherme, A.; Pessanha, S.; Carvalho, M.L.; Santos, J.M.F. dos; Coroado, J.

2010-01-01

Several glazed ceramic pieces, originally produced in Coimbra (Portugal), were submitted to elemental analysis, having as premise the pigment manufacture production recognition. Although having been produced in Coimbra, their location changed as time passed due to historical reasons. A recent exhibition in Coimbra brought together a great number of these pieces and in situ micro Energy Dispersive X-ray Fluorescence (μ-EDXRF) analyses were performed in order to achieve some chemical and physical data on the manufacture of faiences in Coimbra. A non-commercial μ-EDXRF equipment for in situ analysis was employed in this work, carrying some important improvements when compared to the conventional ones, namely, analyzing spot sizes of about 100 μm diameter. The combination of a capillary X-ray lens with a new generation of low power microfocus X-ray tube and a drift chamber detector enabled a portable unit for micro-XRF with a few tens of μm lateral resolution. The advantages in using a portable system emphasized with polycapillary optics enabled to distinguish proximal different pigmented areas, as well as the glaze itself. These first scientific results on the pigment analysis of the collection of faiences seem to point to a unique production center with own techniques and raw materials. This conclusion arose with identification of the blue pigments having in its constitution Mn, Fe Co and As and the yellows as a result of the combination between Pb and Sb. A statistical treatment was used to reveal groups of similarities on the pigments elemental profile.

Alternative Carrier Solvents for Pigments Extracted from Spalting Fungi

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Lauren Pittis

2018-05-01

Full Text Available The use of both naturally occurring and synthetic pigmented wood has been prevalent in woodcraft for centuries. Modern manifestations generally involve either woodworkers’ aniline dyes, or pigments derived from a special class of fungi known as spalting fungi. While fungal pigments are more renewable than anilines and pose less of an environmental risk, the carrier required for these pigments—dichloromethane (DCM—is both problematic for humans and tends to only deposit the pigments on the surface of wood instead of evenly within the material. Internal coloration of wood is key to adoption of a pigmenting system by woodworkers. To address this issue, five solvents that had moderate solubility with the pigments extracted from Chlorociboria aeruginosa and Scytalidium cuboideum were identified, in the hopes that a reduction in solubility would result in a greater amount of the pigment deposited inside the wood. Of the tested solvents, acetonitrile was found to produce the highest internal color in ash, Douglas-fir, madrone, mountain hemlock, Port-Orford cedar, Pacific silver fir, red alder and sugar maple. While these carrier solvents are not ideal for extracting the pigments from the fungi, acetonitrile in particular does appear to allow for more pigment to be deposited within wood. The use of acetonitrile over DCM offers new opportunities for possible industrial spalting applications, in which larger pieces of wood could be uniformly pigmented and sold to the end user in larger quantities than are currently available with spalted wood.

Surface modification and characterization for dispersion stability of inorganic nanometer-scaled particles in liquid media

International Nuclear Information System (INIS)

Kamiya, Hidehiro; Iijima, Motoyuki

2010-01-01

Inorganic nanoparticles are indispensable for science and technology as materials, pigments and cosmetics products. Improving the dispersion stability of nanoparticles in various liquids is essential for those applications. In this review, we discuss why it is difficult to control the stability of nanoparticles in liquids. We also overview the role of surface interaction between nanoparticles in their dispersion and characterization, e.g. by colloid probe atomic force microscopy (CP-AFM). Two types of surface modification concepts, post-synthesis and in situ modification, were investigated in many previous studies. Here, we focus on post-synthesis modification using adsorption of various kinds of polymer dispersants and surfactants on the particle surface, as well as surface chemical reactions of silane coupling agents. We discuss CP-AFM as a technique to analyze the surface interaction between nanoparticles and the effect of surface modification on the nanoparticle dispersion in liquids. (topical review)

Surface modification and characterization for dispersion stability of inorganic nanometer-scaled particles in liquid media

Directory of Open Access Journals (Sweden)

Hidehiro Kamiya and Motoyuki Iijima

2010-01-01

Full Text Available Inorganic nanoparticles are indispensable for science and technology as materials, pigments and cosmetics products. Improving the dispersion stability of nanoparticles in various liquids is essential for those applications. In this review, we discuss why it is difficult to control the stability of nanoparticles in liquids. We also overview the role of surface interaction between nanoparticles in their dispersion and characterization, e.g. by colloid probe atomic force microscopy (CP-AFM. Two types of surface modification concepts, post-synthesis and in situ modification, were investigated in many previous studies. Here, we focus on post-synthesis modification using adsorption of various kinds of polymer dispersants and surfactants on the particle surface, as well as surface chemical reactions of silane coupling agents. We discuss CP-AFM as a technique to analyze the surface interaction between nanoparticles and the effect of surface modification on the nanoparticle dispersion in liquids.

Light-induced vegetative anthocyanin pigmentation in Petunia

Science.gov (United States)

Albert, Nick W.; Lewis, David H.; Zhang, Huaibi; Irving, Louis J.; Jameson, Paula E.; Davies, Kevin M.

2009-01-01

The Lc petunia system, which displays enhanced, light-induced vegetative pigmentation, was used to investigate how high light affects anthocyanin biosynthesis, and to assess the effects of anthocyanin pigmentation upon photosynthesis. Lc petunia plants displayed intense purple anthocyanin pigmentation throughout the leaves and stems when grown under high-light conditions, yet remain acyanic when grown under shade conditions. The coloured phenotypes matched with an accumulation of anthocyanins and flavonols, as well as the activation of the early and late flavonoid biosynthetic genes required for flavonol and anthocyanin production. Pigmentation in Lc petunia only occurred under conditions which normally induce a modest amount of anthocyanin to accumulate in wild-type Mitchell petunia [Petunia axillaris×(Petunia axillaris×Petunia hybrida cv. ‘Rose of Heaven’)]. Anthocyanin pigmentation in Lc petunia leaves appears to screen underlying photosynthetic tissues, increasing light saturation and light compensation points, without reducing the maximal photosynthetic assimilation rate (Amax). In the Lc petunia system, where the bHLH factor Leaf colour is constitutively expressed, expression of the bHLH (Lc) and WD40 (An11) components of the anthocyanin regulatory system were not limited, suggesting that the high-light-induced anthocyanin pigmentation is regulated by endogenous MYB transcription factors. PMID:19380423

Non-conventional synthesis of ceramic pigments

International Nuclear Information System (INIS)

Dziubak, C.; Rutkowski, R.; Gebel, R.

2003-01-01

A short characterization of traditional methods of homogenization of components, used to produce ceramic pigments, was presented. Efficient and economic methods are searched to prepare raw material sets for ceramic pigments as alternative methods for the traditional way of wet mixing in ball mill or of dry mixing in the mixer of 'Z' type. The results of research of the use of sol-gel method to achieve these aims are presented. At the present stage of research, carried out on the yellow praseodymium and coral-pink iron-zirconium pigments show that traditional methods are better. (author)

[Spectral analysis of green pigments of painting and colored drawing in northern Chinese ancient architectures].

Science.gov (United States)

Wang, Li-Qin; Yan, Jing; Fan, Xiao-Lei; Ma, Tao

2010-02-01

It is important to identify pigments of painting and colored drawing in ancient architectures in order to restore and conserve them. The components of green pigments were detected with X-ray diffraction (XRD), X-ray fluorescence (XRF) and scanning electron microscopy-energy dispersive X-ray (SEM-EDX). Twenty-seven samples were collected from painting and colored drawing in northern Chinese ancient architectures in Beijing, Shanxi province and Gansu province. The experiment results showed that emerald green [CuCH3COO]2 x Cu(AsO2)2], a complex of copper aceto-arsenite pigment, had been used as the colored component in fifteen samples, whereas organic materials synthesized in the rest. However, in all samples there were no malachite and atacamite, green pigments commonly used in ancient time a long time ago. These two pigments have been found in Qin Shihuang's Terracotta Army and the wall paintings at Mogao Grettoes, Dunhuang, and some other famous wall paintings and color pottery figurines. However, emerald green was used many years later. It was reported that emerald green was synthesized by Germany in 1814 and had been widely used in China as watercolor on pith paper works and on scroll paintings since the 1850s. Because painting and colored drawing in ancient architectures stands outside, under sunlight and rain, it must be repaired and repainted in less than fifty years. Therefore, it is not surprising that emerald green was used in them. In recent years, artificial organic materials are increasingly used in painting and colored drawing in ancient architectures. From experiments it was also showed that in the same recolored painting and colored drawing, organic materials are usually in the later layers, but emerald green is in the earlier layers. This work supplies a lot of data for the purpose of selecting restoration materials and identifying painting and colored drawing in ancient architectures with a new method.

Biological effects of radon in Drosophila

International Nuclear Information System (INIS)

Pimentel P, A.E.; Tavera D, L.; Cruces M, M.P.; Arceo M, C.; Rosa D, M.E. de la

1992-04-01

The main objective of this investigation, is to study the biological effects of the Radon-222 at low dose in 'Drosophila melanogaster'. It is necessary to mention that these effects will analyze from the genetic point of view for: 1) To evaluate in which form the Radon-222 to low dose it influences in some genetic components of the adaptation in Drosophila, such as: fecundity, viability egg-adult and sex proportion. 2) To evaluate which is the genetic effect that induces the Radon to low dose by means of the SMART technique in Drosophila melanogaster, and this way to try of to identify which is the possible mechanism that causes the genetic damage to somatic level. The carried out investigation was divided in three stages: 1. Tests to the vacuum resistance. 2. Test of somatic mutation, and 3. Determination of the presence of radon daughters on the adult of Drosophila. It is necessary to point out that all the experiments were made by triplicate and in each one of them was placed detectors in preset places. Those obtained results are presented inside the 4 charts included in the present work. (Author)

Drosophila melanogaster as a model organism to study nanotoxicity.

Science.gov (United States)

Ong, Cynthia; Yung, Lin-Yue Lanry; Cai, Yu; Bay, Boon-Huat; Baeg, Gyeong-Hun

2015-05-01

Drosophila melanogaster has been used as an in vivo model organism for the study of genetics and development since 100 years ago. Recently, the fruit fly Drosophila was also developed as an in vivo model organism for toxicology studies, in particular, the field of nanotoxicity. The incorporation of nanomaterials into consumer and biomedical products is a cause for concern as nanomaterials are often associated with toxicity in many in vitro studies. In vivo animal studies of the toxicity of nanomaterials with rodents and other mammals are, however, limited due to high operational cost and ethical objections. Hence, Drosophila, a genetically tractable organism with distinct developmental stages and short life cycle, serves as an ideal organism to study nanomaterial-mediated toxicity. This review discusses the basic biology of Drosophila, the toxicity of nanomaterials, as well as how the Drosophila model can be used to study the toxicity of various types of nanomaterials.

Platelet-Rich Plasma Increases Pigmentation.

Science.gov (United States)

Uysal, Cagri A; Ertas, Nilgun Markal

2017-11-01

Platelet-rich plasma (PRP) is an autologous solution of plasma containing 4 to 7 times the baseline concentration of human platelets. Platelet-rich plasma has been widely popular in facial rejuvenation to attenuate wrinkles and has been practically used. The authors have been encountering various patients of increased hiperpigmentation following PRP applications that were performed to attenuate the postinflammatory hiperpigmentation especially after laser treatment. The authors have been using PRP for facial rejuvenation in selected patients and in 1 patient the authors have encountered increased pigmentation over the pigmented skin lesions that were present before the application. The authors recommend that the PRP might increase pigmentation especially in the face region and precautions might be taken before and after the application. Platelet-rich plasma should not be used for the treatment of post inflammatory hiperpigmentation.

Hyperspectral remote sensing of plant pigments.

Science.gov (United States)

Blackburn, George Alan

2007-01-01

The dynamics of pigment concentrations are diagnostic of a range of plant physiological properties and processes. This paper appraises the developing technologies and analytical methods for quantifying pigments non-destructively and repeatedly across a range of spatial scales using hyperspectral remote sensing. Progress in deriving predictive relationships between various characteristics and transforms of hyperspectral reflectance data are evaluated and the roles of leaf and canopy radiative transfer models are reviewed. Requirements are identified for more extensive intercomparisons of different approaches and for further work on the strategies for interpreting canopy scale data. The paper examines the prospects for extending research to the wider range of pigments in addition to chlorophyll, testing emerging methods of hyperspectral analysis and exploring the fusion of hyperspectral and LIDAR remote sensing. In spite of these opportunities for further development and the refinement of techniques, current evidence of an expanding range of applications in the ecophysiological, environmental, agricultural, and forestry sciences highlights the growing value of hyperspectral remote sensing of plant pigments.

Drosophila's contribution to stem cell research [version 2; referees: 2 approved

Directory of Open Access Journals (Sweden)

Gyanesh Singh

2016-08-01

Full Text Available The discovery of Drosophila stem cells with striking similarities to mammalian stem cells has brought new hope for stem cell research. Recent developments in Drosophila stem cell research is bringing wider opportunities for contemporary stem cell biologists. In this regard, Drosophila germ cells are becoming a popular model of stem cell research. In several cases, genes that controlled Drosophila stem cells were later discovered to have functional homologs in mammalian stem cells. Like mammals, Drosophila germline stem cells (GSCs are controlled by both intrinsic as well as external signals. Inside the Drosophila testes, germline and somatic stem cells form a cluster of cells (the hub. Hub cells depend on JAK-STAT signaling, and, in absence of this signal, they do not self-renew. In Drosophila, significant changes occur within the stem cell niche that contributes to a decline in stem cell number over time. In case of aging Drosophila, somatic niche cells show reduced DE-cadherin and unpaired (Upd proteins. Unpaired proteins are known to directly decrease stem cell number within the niches, and, overexpression of upd within niche cells restored GSCs in older males also . Stem cells in the midgut of Drosophila are also very promising. Reduced Notch signaling was found to increase the number of midgut progenitor cells. On the other hand, activation of the Notch pathway decreased proliferation of these cells. Further research in this area should lead to the discovery of additional factors that regulate stem and progenitor cells in Drosophila.

[Primary pigmented breast adenocarcinoma in a male patient].

Science.gov (United States)

Dauendorffer, J-N; Pages, C; Abd Alsamad, I; Bagot, M; Fraitag, S

2013-01-01

Pigmented mammary tumours are rare. Herein, we report the third case of primary pigmented breast adenocarcinoma in a male patient with clinical mimicking of nodular melanoma of the nipple. A male patient presented with a pigmented nodule of the right nipple. Histological examination of the lesion showed dermal and subcutaneous adenocarcinomatous proliferation. The perilesional stroma contained melanin both inside and outside macrophages, leading us to conclude on primary pigmented breast adenocarcinoma clinically mimicking nodular melanoma of the nipple. Local production of melanin by neoplastic cells in the mammary carcinoma was postulated as the cause of hyperpigmentation of the tumour. Other possible causes are transfer of melanin from overlying melanocytes of the pigmented areolar epidermis to the underlying neoplastic cells, or melanin synthesis by intratumoral melanocytes migrating from the epidermis (which strikes us as the most convincing interpretation for the reported case). Breast adenocarcinoma is a rare tumour in men and may present clinically as a pigmented lesion of the nipple, resulting in the problem of differential diagnosis with primary or metastasised nodular melanoma. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

Micro-pigmentation: implications for patients and professionals.

Science.gov (United States)

Collingridge, Kim; Calcluth, Julie

In the UK, reconstructive breast surgery is routinely offered to patients undergoing surgery for breast cancer. The results can be excellent, but without a nipple-areola complex the patient can feel incomplete. In response to patient need, an innovative nurse-led micro-pigmentation service has been developed in the authors' NHS trust, which provides women (and men) an opportunity to complete their reconstruction process. With the use of coloured pigments, micro-pigmentation creates a permanent image of a nipple-areola complex, which improves the aesthetic appearance of the surgically-created breast. As with the development of any new nurse-led innovation, the micro-pigmentation service has professional and client implications. Breast cancer can be devastating and may induce many psychological concerns, not least about body image and sexuality. This article addresses these issues, along with professional matters, such as autonomous practice, role expansion and the blurring of clinical boundaries. These factors are considered in relation to the nursing management of the micro-pigmentation service, where patient autonomy is encouraged to promote acceptance of self-image and closure on the breast cancer experience.

Rapid and highly accurate detection of Drosophila suzukii, spotted wing Drosophila (Diptera: Drosophilidae) by loop-mediated isothermal amplification assays

Science.gov (United States)

Drosophila suzukii, the spotted wing drosophila (SWD), is currently a major pest that causes severe economic losses to thin-skinned, small fruit growers in North America and Europe. The monitoring and early detection of SWD in the field is of the utmost importance for its proper management. Althou...

Viruses and Antiviral Immunity in Drosophila

Science.gov (United States)

Xu, Jie; Cherry, Sara

2013-01-01

Viral pathogens present many challenges to organisms, driving the evolution of a myriad of antiviral strategies to combat infections. A wide variety of viruses infect invertebrates, including both natural pathogens that are insect-restricted, and viruses that are transmitted to vertebrates. Studies using the powerful tools available in the model organism Drosophila have expanded our understanding of antiviral defenses against diverse viruses. In this review, we will cover three major areas. First, we will describe the tools used to study viruses in Drosophila. Second, we will survey the major viruses that have been studied in Drosophila. And lastly, we will discuss the well-characterized mechanisms that are active against these diverse pathogens, focusing on non-RNAi mediated antiviral mechanisms. Antiviral RNAi is discussed in another paper in this issue. PMID:23680639

Receptor Tyrosine Kinases in Drosophila Development

Science.gov (United States)

Sopko, Richelle; Perrimon, Norbert

2013-01-01

Tyrosine phosphorylation plays a significant role in a wide range of cellular processes. The Drosophila genome encodes more than 20 receptor tyrosine kinases and extensive studies in the past 20 years have illustrated their diverse roles and complex signaling mechanisms. Although some receptor tyrosine kinases have highly specific functions, others strikingly are used in rather ubiquitous manners. Receptor tyrosine kinases regulate a broad expanse of processes, ranging from cell survival and proliferation to differentiation and patterning. Remarkably, different receptor tyrosine kinases share many of the same effectors and their hierarchical organization is retained in disparate biological contexts. In this comprehensive review, we summarize what is known regarding each receptor tyrosine kinase during Drosophila development. Astonishingly, very little is known for approximately half of all Drosophila receptor tyrosine kinases. PMID:23732470

Pigment Production from Immobilized Monascus sp. Utilizing Polymeric Resin Adsorption

OpenAIRE

Evans, Patrick J.; Wang, Henry Y.

1984-01-01

Pigment production by the fungus Monascus sp. was studied to determine why Monascus sp. provides more pigment in solid culture than in submerged culture. Adding a sterilized nonionic polymeric adsorbent resin directly to the growing submerged culture did not enhance the pigment production, thus indicating that pigment extraction is probably not a factor. Monascus cells immobilized in hydrogel were studied and exhibited decreased pigment production as a result of immobilization. This result is...

Effect of Hawthorn on Drosophila Melanogaster Antioxidant-Related ...

African Journals Online (AJOL)

Results: The results indicate that hawthorn extract prolonged the life span of Drosophila, with 50 % survival time of 0.8 ... Drosophila's aging gene is highly similar to humans [4,5]. ..... reduces lipid peroxidation in senescence-accelerated mice .

Analysis of basidiomycete pigments in situ by Raman spectroscopy.

Science.gov (United States)

Tauber, James P; Matthäus, Christian; Lenz, Claudius; Hoffmeister, Dirk; Popp, Jürgen

2018-02-07

Basidiomycetes, that is, mushroom-type fungi, are known to produce pigments in response to environmental impacts. As antioxidants with a high level of unsaturation, these compounds can neutralize highly oxidative species. In the event of close contact with other microbes, the enzymatically controlled pigment production is triggered and pigment secretion is generated at the interaction zone. The identification and analysis of these pigments is important to understand the defense mechanism of fungi, which is essential to counteract an uncontrolled spread of harmful species. Usually, a detailed analysis of the pigments is time consuming as it depends on laborious sample preparation and isolation procedures. Furthermore, the applied protocols often influence the chemical integrity of the compound of interest. A possibility to noninvasively investigate the pigmentation is Raman microspectroscopy. The methodology has the potential to analyze the chemical composition of the sample spatially resolved at the interaction zone. After the acquisition of a representative spectroscopic library, the pigment production by basidiomycetes was monitored for during response to different fungi and bacteria. The presented results describe a very efficient noninvasive way of pigment analysis which can be applied with minimal sample preparation. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Synthesis of chromium containing pigments from chromium galvanic sludges

International Nuclear Information System (INIS)

Andreola, F.; Barbieri, L.; Bondioli, F.; Cannio, M.; Ferrari, A.M.; Lancellotti, I.

2008-01-01

In this work the screening results of the scientific activity conducted on laboratory scale to valorise chromium(III) contained in the galvanic sludge as chromium precursor for ceramic pigments are reported. The valorisation of this waste as a secondary raw material (SRM) is obtained by achievement of thermal and chemical stable crystal structures able to color ceramic material. Two different pigments pink CaCr 0.04 Sn 0.97 SiO 5 and green Ca 3 Cr 2 (SiO 4 ) 3 were synthesized by solid-state reactions using dried Cr sludge as chromium oxide precursor. The obtained pigments were characterized by X-ray diffraction and SEM analysis. Furthermore the color developed in a suitable ceramic glaze was investigated in comparison with the color developed by the pigments prepared from pure Cr 2 O 3 . The characterization carried out corroborates the thermal and chemical stability of the synthesized pigments and, especially for the Cr-Sn pink pigment, the powders develop an intense color that is very similar to the color developed by the pigments obtained starting from pure Cr 2 O 3

Chemical characterisation of zircon-cadmium sulfoselenide ceramic pigments

International Nuclear Information System (INIS)

Gazulla Barreda, M. F.; Rodrigo Edo, M.; Blasco Roca, E.; Orduna Cordero, M.

2013-01-01

The present paper addresses the development of a methodology that allows the complete chemical characterisation of zircon cadmium sulfoselenide ceramic pigments including minor and major elements. To develop the methodology, five zircon-cadmium sulfoselenide pigments with different hues were selected, studying the different measurement process steps, from sample preparation to the optimisation of the measurement of the different components of the pigments by spectroscopic techniques (WD-XRF and elemental analysis by combustion and IR detection). The chemical characterisation method developed was validated with synthetic standards prepared from the mixture of certified reference materials and pure oxides because no certified referenced materials of this type of pigments were commercially available. The developed method can be used for a complete chemical characterization of zircon-cadmium sulfoselenide ceramic pigments with a very low uncertainty for all the elements analysed. (Author)

The Assessment of Natural Pigmentation in Archaeological Wool

DEFF Research Database (Denmark)

Scharff, Annemette Bruselius

2018-01-01

Naturally coloured wool contains pigment grains that mainly occur as ellipsoidal organelles (eumelanin) or spher¬ical grains (pheomelanin). Eumelanin is the most commonly occurring pigment, but naturally coloured wool fi¬bres contain both eumelanin and pheomelanin. In black and brown wool....... This can especially be the case if the pigments are degraded. When analysing the textiles from Lønne Hede (a Danish Iron Age inhumation grave), it was difficult to gain exact information about the natural pigmentation in some of the samples. To investigate this further, four samples of red-brown yarns from...... patterned fragments were selected for analyses. Earlier dyestuff analyses of the red-brown yarns gave no results, and it was therefore necessary to test the yarns for natural pigmentation. Three different methods were used for the analy¬ses. Transmitted light microscopy of whole mounts of the fibres...

Neurotized congenital melanocytic nevus resembling a pigmented neurofibroma

Directory of Open Access Journals (Sweden)

Nidhi Singh

2015-01-01

Full Text Available Neurotized congenital melanocytic nevus and pigmented neurofibroma (PNF are close mimics and pose a clinicopathological challenge. We present a case of pigmented hypertrichotic plaque over lumbosacral region and discuss the differential diagnosis and its clinical, histopathological and immunohistochemistry features which may aid in differentiation. We highlight the difficulties faced in differentiating neurotized congenital melanocytic nevus from pigmented neurofibroma.

Differences in wing melanization and pigmentation pattern in Drosophila buzzatii (Diptera: Drosophilidae under chemical stress

Directory of Open Access Journals (Sweden)

Nicolás MONGIARDINO KOCH

2012-01-01

Full Text Available Recientemente, hemos avanzado en nuestra comprensión de las bases genéticas y los mecanismos subyacentes al proceso de melanización durante el desarrollo, lo que permite el estudio de los procesos evolutivos que gobiernan la variabilidad de pigmentación presente en la naturaleza. Sin embargo, los factores ambientales que contribuyen a dicha variabilidad han recibido poca atención, aún cuando pueden conllevar profundas consecuencias a nivel ecológico. En este trabajo, presentamos un método para analizar los patrones de melanización alar de drosofílidos, de forma cualitativa y cuantitativa. Ponemos a prueba esta metodología comparando las alas de Drosophila buzzatii Patterson & Wheeler, criadas en medio control y con el agregado de alcaloides. Los alcaloides fueron extraídos del huésped secundario de estas moscas, Echinopsis terscheckii (Parm. ex Pfeiff. Friedrich & Rowley, los cuales, se sabe, presentan efectos negativos en el desarrollo de D. buzzatii. Las moscas criadas en un medio enriquecido con alcaloides mostraron una mayor melanización alar, junto con diferencias en la distribución espacial del pigmento. Planteamos modificaciones a nivel metabólico y de expresión génica para explicar los cambios que las condiciones de estrés inducen sobre el carácter. Proponemos la utilización de este procedimiento para el estudio de la dependencia ambiental de la melanización.

The gecko visual pigment: the anion hypsochromic effect.

Science.gov (United States)

Crescitelli, F; Karvaly, B

1991-01-01

The 521-pigment in the retina of the Tokay gecko (Gekko gekko) readily responds to particular physical and chemical changes in its environment. When solubilized in chloride deficient state the addition of Class I anions (Cl-, Br-) induces a bathochromic shift of the absorption spectrum. Class II anions (NO3-, IO3-, N3-, OCN-, SCN-, SeCN-, N(CN)2-), which exhibit ambidental properties, cause an hypsochromic shift. Class III anions (F-, I-, NO2-, CN-, AsO3-, SO2(4-), S2O2(3-) have no spectral effect on the 521-pigment. Cations appear to have no influence on the pigment absorption and Class I anions prevent or reverse the hypsochromic shift caused by Class II anions. It is suggested that the spectral displacements reflect specific changes in the opsin conformation, which alter the immediate (dipolar) environment of the retinal chromophore. The protein conformation seems to promote excited-state processes most in the native 521-pigment state and least in the presence of Class II anions. This in turn suggests that the photosensitivity of the 521-pigment is controlled by the excited rather than by the ground-state properties of the pigment.

Antimicrobial activity of Micrococcus luteus Cartenoid pigment

Directory of Open Access Journals (Sweden)

Huda Z. Majeed

2017-11-01

Full Text Available Cartenoids are group of pigments, with enormous types different structurally and functionally, have colors range from red to yellow found in a wide variety of plants, fungi, algae and bacteria. The animals took from food because they cannot make it, on contrary, the plants and microbes produce them due to subjection to environment. The aim of the study is to isolate and characterize the cartenoid pigment from Micrococcus luteus. The pigment extraction was done by acetone, and then was characterized with UltraViolet-Visible spectroscopy (UV–Vis and Fourier Transform Infrared (FTIR spectroscopy. Then, it was tested for antibacterial activity against five different bacterial isolates and antifungal activity tests against six different fungal isolates by well diffusion method. The results found that, the extracted pigment having antibacterial activity and antifungal activity and having the ability to absorb UVA rays within the range of 300-500 nm. There was no significant difference in antimicrobial effect of pigment, even when the extraction and isolation were done by two culture mediums (Nutrient Broth and Luria Bertani Broth. There were considerable inhibition percentages of adhesion after subjection to Cartenoid pigment ranged between (5.71, 23.84 % for Klebsiella spp. and Pseudomonas aeruginosa respectively and all the 11 isolate changed from Biofilm producer to non-producer. The isolated compound can be used against different bacterial and fungal infections. So they had a great future in medicine, cosmetics and as a sun protecting agent.

Intraclutch variation in avian eggshell pigmentation: the anaemia hypothesis.

Science.gov (United States)

De Coster, Greet; De Neve, Liesbeth; Lens, Luc

2012-10-01

Many passerine species lay eggs that are speckled with dark protoporphyrin pigmentation. Because protoporphyrin is mainly derived from the blood, we here formulate and test a new hypothesis that links an increase in anaemia along the laying sequence to within-clutch variation in egg pigmentation. More intense pigmentation is expected if pigments accumulate during enhanced red blood cell production in response to anaemia. Reduced pigmentation is expected if pigments are derived from the degradation of red blood cells that circulate in smaller numbers due to blood loss. To test this hypothesis, we manipulated anaemia in great tit (Parus major) females by infesting the nests with hen fleas (Ceratophyllus gallinae) prior to egg laying. Polychromatophil (i.e., immature red blood cells) percentage, as a measure of blood cell production, was positively correlated with parasite load confirming that female great tits experienced stronger anaemia when infested with haematophagous parasites during egg laying. We found a positive relationship between spot darkness and laying order that weakened under high parasite load. This result suggests that anaemia in females due to blood-sucking parasites led to diminished protoporphyrin from disintegrated red blood cells and hence a decreased deposition of protoporphyrin. However, the overall increase in pigment darkness along the laying sequence suggests that pigments also accumulate by enhanced red blood cell production caused by anaemia due to egg production itself.

Novel nanoparticulate carrier system based on carnauba wax and decyl oleate for the dispersion of inorganic sunscreens in aqueous media.

Science.gov (United States)

Villalobos-Hernández, J R; Müller-Goymann, C C

2005-05-01

The purpose of this study was to characterize carrier systems for inorganic sunscreens based on a matrix composed of carnauba wax and decyl oleate. Ultraviolet radiation attenuators like barium sulfate, strontium carbonate and titanium dioxide were tested. The lipid matrices were used either as capsules or as accompanying vehicles for the pigments in aqueous dispersions. Manufacturing was performed using high pressure homogenization at 300bar and a temperature of 75 degrees C. To evaluate the effect of the pigments on the crystalline structure of the wax-oil mixture, X-ray diffraction and differential scanning calorimetry were used. Further parameters determined were particle size, polydispersity index, z-potential, viscosity and sun protection factor (SPF). Transmission electron microscopy was also applied for visualization of nanoparticles. The X-ray diffraction patterns and the melting points of the lipid mixtures remained unchanged after the pigments were added. The particle sizes of the encapsulated species ranged from 239 to 749.9nm showing polydispersity values between 0.100 and 0.425. Surface charge measurements comprising values up to -40.8mV denoted the presence of stable dispersions. The formulations could be described as ideal viscous presenting viscosities in a range of 1.40-20.5mPas. Significant increases in SPF up to about 50 were reported after the encapsulation of titanium dioxide. Freeze fracture micrographs confirmed the presence of encapsulated inorganic crystals.

Multiscale Pigment Analysis of Medieval Illuminated Manuscripts

Science.gov (United States)

Sestak, Erica; Manukyan, Khachatur; Wiescher, Michael; Gura, David

2017-09-01

Three medieval illuminated manuscripts (codd. Lat. b. 1; Lat. b. 2; Lat. e. 4), housed at the University of Notre Dame's Hesburgh Library, vary in style, pigments, scribes, and regions, despite all three being Psalters used in the Late Middle Ages. XRF and Raman spectroscopy, which provided the elemental and molecular composition of the pigments, respectively, were used to analyze the pigments' compositions in an attempt to narrow further the manuscripts' possible origins. This experimental investigation emphasizes the importance of understanding the history of the manuscript through their pigments. Codd. Lat. b. 1 and Lat. b. 2 are Latinate German Psalters from the fifteenth century likely used in Katharinenkloster in Nuremberg. While there are visible differences in style within each Psalter, the variations in some of the pigment compositions, such as the inconstant presence of zinc, suggest different admixtures. Cod. Lat. e. 4 is a Latinate English Psalter from the fourteenth century, and it was written by two scribes and illuminated by two distinct painters. It is currently being tested to determine whether there are any correlations between the scribes and painters. These physical analyses will clarify the origins and provenances of the manuscripts.

Patterns of mutation and selection at synonymous sites in Drosophila

DEFF Research Database (Denmark)

Singh, Nadia D; Bauer DuMont, Vanessa L; Hubisz, Melissa J

2007-01-01

, when applied to 18 coding sequences in 3 species of Drosophila, confirmed an earlier report that the Notch gene in Drosophila melanogaster was evolving under selection in favor of those codons defined as unpreferred in this species. This finding opened the possibility that synonymous sites may...... be subject to a variety of selective pressures beyond weak selection for increased frequencies of the codons currently defined as "preferred" in D. melanogaster. To further explore patterns of synonymous site evolution in Drosophila in a lineage-specific manner, we expanded the application of the maximum...... likelihood framework to 8,452 protein coding sequences with well-defined orthology in D. melanogaster, Drosophila sechellia, and Drosophila yakuba. Our analyses reveal intragenomic and interspecific variation in mutational patterns as well as in patterns and intensity of selection on synonymous sites. In D...

Differences in pigmentation between life cycle stages in Scrippsiella lachrymosa (dinophyceae).

Science.gov (United States)

Persson, Agneta; Smith, Barry C; Cyronak, Tyler; Cooper, Emily; DiTullio, Giacomo R

2016-02-01

Various life cycle stages of cyst-producing dinoflagellates often appear differently colored under the microscope; gametes appear paler while zygotes are darker in comparison to vegetative cells. To compare physiological and photochemical competency, the pigment composition of discrete life cycle stages was determined for the common resting cyst-producing dinoflagellate Scrippsiella lachrymosa. Vegetative cells had the highest cellular pigment content (25.2 ± 0.5 pg · cell(-1) ), whereas gamete pigment content was 22% lower. The pigment content of zygotes was 82% lower than vegetative cells, even though they appeared darker under the microscope. Zygotes of S. lachrymosa contained significantly higher cellular concentrations of β-carotene (0.65 ± 0.15 pg · cell(-1) ) than all other life stages. Photoprotective pigments and the de-epoxidation ratio of xanthophylls-cycle pigments in S. lachrymosa were significantly elevated in zygotes and cysts compared to other stages. This suggests a role for accessory pigments in combating intracellular oxidative stress during sexual reproduction or encystment. Resting cysts contained some pigments even though chloroplasts were not visible, suggesting that the brightly colored accumulation body contained photosynthetic pigments. The differences in pigmentation between life stages have implications for interpretation of pigment data from field samples when sampled during dinoflagellate blooms. © 2015 Phycological Society of America.

Evolution of genes and genomes on the Drosophila phylogeny

DEFF Research Database (Denmark)

Clark, Andrew G; Eisen, Michael B; Smith, Douglas R

2007-01-01

Comparative analysis of multiple genomes in a phylogenetic framework dramatically improves the precision and sensitivity of evolutionary inference, producing more robust results than single-genome analyses can provide. The genomes of 12 Drosophila species, ten of which are presented here for the ......Comparative analysis of multiple genomes in a phylogenetic framework dramatically improves the precision and sensitivity of evolutionary inference, producing more robust results than single-genome analyses can provide. The genomes of 12 Drosophila species, ten of which are presented here...... tools that have made Drosophila melanogaster a pre-eminent model for animal genetics, and will further catalyse fundamental research on mechanisms of development, cell biology, genetics, disease, neurobiology, behaviour, physiology and evolution. Despite remarkable similarities among these Drosophila...

Fe K-edge XANES of Maya blue pigment

Science.gov (United States)

Río, M. Sánchez del; Sodo, A.; Eeckhout, S. G.; Neisius, T.; Martinetto, P.; Dooryhée, E.; Reyes-Valerio, C.

2005-08-01

The utilization of techniques used in Materials Science for the characterization of artefacts of interest for cultural heritage is getting more and more attention nowadays. One of the products of the ancient Maya chemistry is the "Maya blue" pigment, made with natural indigo and palygorskite. This pigment is different from any other pigment used in other parts of the world. It is durable and acid-resistant, and still keeps many secrets to scientists even though it has been studied for more than 50 years. Although the pigment is basically made of palygorskite Si8(Mg2Al2)O20(OH)2(OH2)4.4H2O and an organic colourant (indigo: C16H10N2O2), a number of other compounds have been found in previous studies on archaeological samples, like other clays and minerals, iron nanoparticles, iron oxides, impurities of transition metals (Cr, Mn, Ti, V), etc. We measured at the ESRF ID26 beamline the Fe K-edge XANES spectra of the blue pigment in ancient samples. They are compared to XANES spectra of Maya blue samples synthesized under controlled conditions, and iron oxides usually employed as pigments (hematite and goethite). Our results show that the iron found in ancient Maya blue pigment is related to the Fe exchanged in the palygorskite clay. We did not find iron in metallic form or goethite in archaeological Maya blue.

Fe K-edge XANES of Maya blue pigment

International Nuclear Information System (INIS)

Rio, M. Sanchez del; Sodo, A.; Eeckhout, S.G.; Neisius, T.; Martinetto, P.; Dooryhee, E.; Reyes-Valerio, C.

2005-01-01

The utilization of techniques used in Materials Science for the characterization of artefacts of interest for cultural heritage is getting more and more attention nowadays. One of the products of the ancient Maya chemistry is the 'Maya blue' pigment, made with natural indigo and palygorskite. This pigment is different from any other pigment used in other parts of the world. It is durable and acid-resistant, and still keeps many secrets to scientists even though it has been studied for more than 50 years. Although the pigment is basically made of palygorskite Si 8 (Mg 2 Al 2 )O 20 (OH) 2 (OH 2 ) 4 .4H 2 O and an organic colourant (indigo: C 16 H 10 N 2 O 2 ), a number of other compounds have been found in previous studies on archaeological samples, like other clays and minerals, iron nanoparticles, iron oxides, impurities of transition metals (Cr, Mn, Ti, V), etc. We measured at the ESRF ID26 beamline the Fe K-edge XANES spectra of the blue pigment in ancient samples. They are compared to XANES spectra of Maya blue samples synthesized under controlled conditions, and iron oxides usually employed as pigments (hematite and goethite). Our results show that the iron found in ancient Maya blue pigment is related to the Fe exchanged in the palygorskite clay. We did not find iron in metallic form or goethite in archaeological Maya blue

Nematocytes: Discovery and characterization of a novel anculeate hemocyte in Drosophila falleni and Drosophila phalerata.

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Julianna Bozler

Full Text Available Immune challenges, such as parasitism, can be so pervasive and deleterious that they constitute an existential threat to a species' survival. In response to these ecological pressures, organisms have developed a wide array of novel behavioral, cellular, and molecular adaptations. Research into these immune defenses in model systems has resulted in a revolutionary understanding of evolution and functional biology. As the field has expanded beyond the limited number of model organisms our appreciation of evolutionary innovation and unique biology has widened as well. With this in mind, we have surveyed the hemolymph of several non-model species of Drosophila. Here we identify and describe a novel hemocyte, type-II nematocytes, found in larval stages of numerous Drosophila species. Examined in detail in Drosophila falleni and Drosophila phalerata, we find that these remarkable cells are distinct from previously described hemocytes due to their anucleate state (lacking a nucleus and unusual morphology. Type-II nematocytes are long, narrow cells with spindle-like projections extending from a cell body with high densities of mitochondria and microtubules, and exhibit the ability to synthesize proteins. These properties are unexpected for enucleated cells, and together with our additional characterization, we demonstrate that these type-II nematocytes represent a biological novelty. Surprisingly, despite the absence of a nucleus, we observe through live cell imaging that these cells remain motile with a highly dynamic cellular shape. Furthermore, these cells demonstrate the ability to form multicellular structures, which we suggest may be a component of the innate immune response to macro-parasites. In addition, live cell imaging points to a large nucleated hemocyte, type-I nematocyte, as the progenitor cell, leading to enucleation through a budding or asymmetrical division process rather than nuclear ejection: This study is the first to report such a

Pigments analysis and gold layer thickness evaluation of polychromy on wood objects by PXRF.

Science.gov (United States)

Blonski, M S; Appoloni, C R

2014-07-01

The X-ray fluorescence technique by energy dispersion (EDXRF), being a multi elemental and non-destructive technique, has been widely used in the analysis of artworks and archeometry. An X-ray fluorescence portable equipment from the Laboratory of Applied Nuclear Physics of the State University of Londrina (LFNA/UEL) was used for the measurement of pigments in golden parts of a Gilding Preparation Standard Plaque and also pigments measurement on the Wood Adornment of the High Altar Column of the Side Pulpit of the Immaculate Conception Church Parish Sao Paulo-SP. The portable X-ray fluorescence PXRF-LFNA-02 consists of an X-ray tube with Ag anode, a Si-PIN detector (FWHM=221 eV for Mn line at 5.9 keV), a chain of electronics nuclear standard of X-ray spectrometer, a multichannel 8K, a notebook and a mechanical system designed for the positioning of detector and X-ray tube, which allows movements with two degrees of freedom from the system of excitation-detection. The excitation-detection time of each measurement was 100 and 500 s, respectively. The presence of elements Ti, Cr, Fe, Cu, Zn and Au was found in the golden area of the Altar Column ornament. On the other hand, analysis of the ratios for the intensities of Kα/Kβ lines measured in the areas made it possible to explore the possibility of measuring the stratigraphies of the layers of pigments and to estimate the thickness of the same. Copyright © 2014 Elsevier Ltd. All rights reserved.

Quantification of Drosophila Grooming Behavior.

Science.gov (United States)

Barradale, Francesca; Sinha, Kairav; Lebestky, Tim

2017-07-19

Drosophila grooming behavior is a complex multi-step locomotor program that requires coordinated movement of both forelegs and hindlegs. Here we present a grooming assay protocol and novel chamber design that is cost-efficient and scalable for either small or large-scale studies of Drosophila grooming. Flies are dusted all over their body with Brilliant Yellow dye and given time to remove the dye from their bodies within the chamber. Flies are then deposited in a set volume of ethanol to solubilize the dye. The relative spectral absorbance of dye-ethanol samples for groomed versus ungroomed animals are measured and recorded. The protocol yields quantitative data of dye accumulation for individual flies, which can be easily averaged and compared across samples. This allows experimental designs to easily evaluate grooming ability for mutant animal studies or circuit manipulations. This efficient procedure is both versatile and scalable. We show work-flow of the protocol and comparative data between WT animals and mutant animals for the Drosophila type I Dopamine Receptor (DopR).

On Variations in the Level of PER in Glial Clocks of Drosophila Optic Lobe and Its Negative Regulation by PDF Signaling.

Science.gov (United States)

Górska-Andrzejak, Jolanta; Chwastek, Elżbieta M; Walkowicz, Lucyna; Witek, Kacper

2018-01-01

We show that the level of the core protein of the circadian clock Period (PER) expressed by glial peripheral oscillators depends on their location in the Drosophila optic lobe. It appears to be controlled by the ventral lateral neurons (LNvs) that release the circadian neurotransmitter Pigment Dispersing Factor (PDF). We demonstrate that glial cells of the distal medulla neuropil (dMnGl) that lie in the vicinity of the PDF-releasing terminals of the LNvs possess receptors for PDF (PDFRs) and express PER at significantly higher level than other types of glia. Surprisingly, the amplitude of PER molecular oscillations in dMnGl is increased twofold in PDF-free environment, that is in Pdf 0 mutants. The Pdf 0 mutants also reveal an increased level of glia-specific protein REPO in dMnGl. The photoreceptors of the compound eye (R-cells) of the PDF-null flies, on the other hand, exhibit de-synchrony of PER molecular oscillations, which manifests itself as increased variability of PER-specific immunofluorescence among the R-cells. Moreover, the daily pattern of expression of the presynaptic protein Bruchpilot (BRP) in the lamina terminals of the R-cells is changed in Pdf 0 mutant. Considering that PDFRs are also expressed by the marginal glia of the lamina that surround the R-cell terminals, the LNv pacemakers appear to be the likely modulators of molecular cycling in the peripheral clocks of both the glial cells and the photoreceptors of the compound eye. Consequently, some form of PDF-based coupling of the glial clocks and the photoreceptors of the eye with the central LNv pacemakers must be operational.

Interorgan Communication Pathways in Physiology: Focus on Drosophila.

Science.gov (United States)

Droujinine, Ilia A; Perrimon, Norbert

2016-11-23

Studies in mammals and Drosophila have demonstrated the existence and significance of secreted factors involved in communication between distal organs. In this review, primarily focusing on Drosophila, we examine the known interorgan communication factors and their functions, physiological inducers, and integration in regulating physiology. Moreover, we describe how organ-sensing screens in Drosophila can systematically identify novel conserved interorgan communication factors. Finally, we discuss how interorgan communication enabled and evolved as a result of specialization of organs. Together, we anticipate that future studies will establish a model for metazoan interorgan communication network (ICN) and how it is deregulated in disease.

Single Molecule Spectroscopy on Photosynthetic Pigment-Protein Complexes

CERN Document Server

Jelezko, F; Schuler, S; Thews, E; Tietz, C; Wechsler, A; Wrachtrup, J

2001-01-01

Single molecule spectroscopy was applied to unravel the energy transfer pathway in photosynthetic pigment-protein complexes. Detailed analysis of excitation and fluorescence emission spectra has been made for peripheral plant antenna LHC II and Photosystem I from cyanobacterium Synechococcus elongatus. Optical transitions of individual pigments were resolved under nonselective excitation of antenna chlorophylls. High-resolution fluorescence spectroscopy of individual plant antenna LHC II indicates that at low temperatures, the excitation energy is localized on the red-most Chl a pool absorbing at 680 nm. More than one pigment molecule is responsible for the fluorescence emission of the LHC II trimer. The spectral lines of single Chl a molecules absorbing at 675 nm are broadened because of the Foerster energy transfer towards the red-most pigments. Low-temperature spectroscopy on single PS I trimers indicates that two subgroups of pigments, which are present in the red antenna pool, differ by the strength of t...

Emerging greener extraction systems for fungal pigments isolation

OpenAIRE

Lebeau , Juliana; Venkatachalam , Mekala; Fouillaud , Mireille; Dufossé , Laurent; Caro , Yanis

2016-01-01

International audience; Filamentous fungi produce a mixture of various metabolites such as pigments, fatty acids, proteins and other cellular metabolites. Thus, extraction and isolation of the pigmented molecules of interest are necessary steps before proceeding to any further utilization of these metabolites for commercial applications. Pigments can be stored within the biomass, excreted in the fermentation broth or both, suggesting that extraction methods need to be developed accordingly to...

Neoplasia versus hyperplasia of the retinal pigment epithelium

DEFF Research Database (Denmark)

Heegaard, Steffen; Larsen, J.N.B.; Fledelius, Hans C.

2001-01-01

ophthalmology, retinal pigment epithelium, adenoma, tumor-like hyperplasia, histology, immunohistochemistry, tumor, neoplasm, ultrasonography......ophthalmology, retinal pigment epithelium, adenoma, tumor-like hyperplasia, histology, immunohistochemistry, tumor, neoplasm, ultrasonography...

Genomic and karyotypic variation in Drosophila parasitoids (Hymenoptera, Cynipoidea, Figitidae

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Vladimir Gokhman

2011-08-01

Full Text Available Drosophila melanogaster Meigen, 1830 has served as a model insect for over a century. Sequencing of the 11 additional Drosophila Fallen, 1823 species marks substantial progress in comparative genomics of this genus. By comparison, practically nothing is known about the genome size or genome sequences of parasitic wasps of Drosophila. Here, we present the first comparative analysis of genome size and karyotype structures of Drosophila parasitoids of the Leptopilina Förster, 1869 and Ganaspis Förster, 1869 species. The gametic genome size of Ganaspis xanthopoda (Ashmead, 1896 is larger than those of the three Leptopilina species studied. The genome sizes of all parasitic wasps studied here are also larger than those known for all Drosophila species. Surprisingly, genome sizes of these Drosophila parasitoids exceed the average value known for all previously studied Hymenoptera. The haploid chromosome number of both Leptopilina heterotoma (Thomson, 1862 and L. victoriae Nordlander, 1980 is ten. A chromosomal fusion appears to have produced a distinct karyotype for L. boulardi (Barbotin, Carton et Keiner-Pillault, 1979 (n = 9, whose genome size is smaller than that of wasps of the L. heterotoma clade. Like L. boulardi, the haploid chromosome number for G. xanthopoda is also nine. Our studies reveal a positive, but non linear, correlation between the genome size and total chromosome length in Drosophila parasitoids. These Drosophila parasitoids differ widely in their host range, and utilize different infection strategies to overcome host defense. Their comparative genomics, in relation to their exceptionally well-characterized hosts, will prove to be valuable for understanding the molecular basis of the host-parasite arms race and how such mechanisms shape the genetic structures of insect communities.

The bacterial communities of Drosophila suzukii collected from undamaged cherries

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James Angus Chandler

2014-07-01

Full Text Available Drosophila suzukii is an introduced pest insect that feeds on undamaged, attached fruit. This diet is distinct from the fallen, discomposing fruits utilized by most other species of Drosophila. Since the bacterial microbiota of Drosophila, and of many other animals, is affected by diet, we hypothesized that the bacteria associated with D. suzukii are distinct from that of other Drosophila. Using 16S rDNA PCR and Illumina sequencing, we characterized the bacterial communities of larval and adult D. suzukii collected from undamaged, attached cherries in California, USA. We find that the bacterial communities associated with these samples of D. suzukii contain a high frequency of Tatumella. Gluconobacter and Acetobacter, two taxa with known associations with Drosophila, were also found, although at lower frequency than Tatumella in four of the five samples examined. Sampling D. suzukii from different locations and/or while feeding on different fruits is needed to determine the generality of the results determined by these samples. Nevertheless this is, to our knowledge, the first study characterizing the bacterial communities of this ecologically unique and economically important species of Drosophila.

Maximum likelihood estimation of ancestral codon usage bias parameters in Drosophila

DEFF Research Database (Denmark)

Nielsen, Rasmus; Bauer DuMont, Vanessa L; Hubisz, Melissa J

2007-01-01

: the selection coefficient for optimal codon usage (S), allowing joint maximum likelihood estimation of S and the dN/dS ratio. We apply the method to previously published data from Drosophila melanogaster, Drosophila simulans, and Drosophila yakuba and show, in accordance with previous results, that the D...

Finnish wallpaper pigments in the 18th-19th century: Presence of KFe3(CrO4)2(OH)6 and odd pigment mixtures

Science.gov (United States)

Castro, Kepa; Knuutinen, Ulla; Vallejuelo, Silvia Fdez-Ortiz de; Irazola, Mireia; Madariaga, Juan Manuel

2013-04-01

Several Finish wallpapers from the 18th and 19th century were analysed by using Raman spectroscopy assisted with EDXRF instrumentation, in an attempt of determine the pigments used in their manufacture process as well as of trying to date some of the samples through pigment composition. All pigments present in samples were determined and surprisingly the unusual and strange iron (III) chromate yellow pigment was found. Besides, unusual mixtures were found to obtain fashionable colours, especially in blue and green areas, where more than one blue pigments were mixed with green and yellow pigments. Blue verditer, ultramarine blue, Prussian blue, chrome yellow, calcite, lead white, red and yellow iron oxide, gypsum and carbon black were identified. The presence of the risky and poisonous emerald green must be highlighted. The results were compared with those found in other wallpapers from Spain and France.

Resources for Functional Genomics Studies in Drosophila melanogaster

Science.gov (United States)

Mohr, Stephanie E.; Hu, Yanhui; Kim, Kevin; Housden, Benjamin E.; Perrimon, Norbert

2014-01-01

Drosophila melanogaster has become a system of choice for functional genomic studies. Many resources, including online databases and software tools, are now available to support design or identification of relevant fly stocks and reagents or analysis and mining of existing functional genomic, transcriptomic, proteomic, etc. datasets. These include large community collections of fly stocks and plasmid clones, “meta” information sites like FlyBase and FlyMine, and an increasing number of more specialized reagents, databases, and online tools. Here, we introduce key resources useful to plan large-scale functional genomics studies in Drosophila and to analyze, integrate, and mine the results of those studies in ways that facilitate identification of highest-confidence results and generation of new hypotheses. We also discuss ways in which existing resources can be used and might be improved and suggest a few areas of future development that would further support large- and small-scale studies in Drosophila and facilitate use of Drosophila information by the research community more generally. PMID:24653003

Functional Gustatory Role of Chemoreceptors in Drosophila Wings.

Science.gov (United States)

Raad, Hussein; Ferveur, Jean-François; Ledger, Neil; Capovilla, Maria; Robichon, Alain

2016-05-17

Neuroanatomical evidence argues for the presence of taste sensilla in Drosophila wings; however, the taste physiology of insect wings remains hypothetical, and a comprehensive link to mechanical functions, such as flight, wing flapping, and grooming, is lacking. Our data show that the sensilla of the Drosophila anterior wing margin respond to both sweet and bitter molecules through an increase in cytosolic Ca(2+) levels. Conversely, genetically modified flies presenting a wing-specific reduction in chemosensory cells show severe defects in both wing taste signaling and the exploratory guidance associated with chemodetection. In Drosophila, the chemodetection machinery includes mechanical grooming, which facilitates the contact between tastants and wing chemoreceptors, and the vibrations of flapping wings that nebulize volatile molecules as carboxylic acids. Together, these data demonstrate that the Drosophila wing chemosensory sensilla are a functional taste organ and that they may have a role in the exploration of ecological niches. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

Modelling Cooperative Tumorigenesis in Drosophila

Science.gov (United States)

2018-01-01

The development of human metastatic cancer is a multistep process, involving the acquisition of several genetic mutations, tumour heterogeneity, and interactions with the surrounding microenvironment. Due to the complexity of cancer development in mammals, simpler model organisms, such as the vinegar fly, Drosophila melanogaster, are being utilized to provide novel insights into the molecular mechanisms involved. In this review, we highlight recent advances in modelling tumorigenesis using the Drosophila model, focusing on the cooperation of oncogenes or tumour suppressors, and the interaction of mutant cells with the surrounding tissue in epithelial tumour initiation and progression. PMID:29693007

Modelling Cooperative Tumorigenesis in Drosophila

Directory of Open Access Journals (Sweden)

Helena E. Richardson

2018-01-01

Full Text Available The development of human metastatic cancer is a multistep process, involving the acquisition of several genetic mutations, tumour heterogeneity, and interactions with the surrounding microenvironment. Due to the complexity of cancer development in mammals, simpler model organisms, such as the vinegar fly, Drosophila melanogaster, are being utilized to provide novel insights into the molecular mechanisms involved. In this review, we highlight recent advances in modelling tumorigenesis using the Drosophila model, focusing on the cooperation of oncogenes or tumour suppressors, and the interaction of mutant cells with the surrounding tissue in epithelial tumour initiation and progression.

Fe K-edge XANES of Maya blue pigment

Energy Technology Data Exchange (ETDEWEB)

Rio, M. Sanchez del [ESRF, Experiments Division, B.P. 220, F-38043, Grenoble Cedex (France)]. E-mail: srio@esrf.fr; Sodo, A. [ESRF, Experiments Division, B.P. 220, F-38043, Grenoble Cedex (France); Eeckhout, S.G. [ESRF, Experiments Division, B.P. 220, F-38043, Grenoble Cedex (France); Neisius, T. [ESRF, Experiments Division, B.P. 220, F-38043, Grenoble Cedex (France); Martinetto, P. [Laboratoire de Cristallographie, CNRS, Grenoble B.P. 166, F-38042, Grenoble Cedex 09 (France); Dooryhee, E. [Laboratoire de Cristallographie, CNRS, Grenoble B.P. 166, F-38042, Grenoble Cedex 09 (France); Reyes-Valerio, C. [INAH, Mexico DF (Mexico)

2005-08-15

The utilization of techniques used in Materials Science for the characterization of artefacts of interest for cultural heritage is getting more and more attention nowadays. One of the products of the ancient Maya chemistry is the 'Maya blue' pigment, made with natural indigo and palygorskite. This pigment is different from any other pigment used in other parts of the world. It is durable and acid-resistant, and still keeps many secrets to scientists even though it has been studied for more than 50 years. Although the pigment is basically made of palygorskite Si{sub 8}(Mg{sub 2}Al{sub 2})O{sub 20}(OH){sub 2}(OH{sub 2}){sub 4}.4H{sub 2}O and an organic colourant (indigo: C{sub 16}H{sub 10}N{sub 2}O{sub 2}), a number of other compounds have been found in previous studies on archaeological samples, like other clays and minerals, iron nanoparticles, iron oxides, impurities of transition metals (Cr, Mn, Ti, V), etc. We measured at the ESRF ID26 beamline the Fe K-edge XANES spectra of the blue pigment in ancient samples. They are compared to XANES spectra of Maya blue samples synthesized under controlled conditions, and iron oxides usually employed as pigments (hematite and goethite). Our results show that the iron found in ancient Maya blue pigment is related to the Fe exchanged in the palygorskite clay. We did not find iron in metallic form or goethite in archaeological Maya blue.

Identificação por microscopia Raman de pigmentos da pintura a óleo "Retrato de Murilo Mendes" de Cândido Portinari Identification of pigments from Candido Portinari's oil painting "Portrait of Murilo Mendes" by Raman microscopy

Directory of Open Access Journals (Sweden)

Luiz Fernando Cappa de Oliveira

1998-04-01

Full Text Available In the present work "ex situ"Raman microscopy was employed in the identification of some of the pigments present in the painting "Portrait of Murilo Mendes" by Cândido Portinari. In the investigated samples it was possible to identify unambiguously two pigments: Prussian blue and lapis-lazuli (or its synthetic analogue, ultramarine blue - the former is observed together with organic substances, possibly used as dispersants, what suggests a further use of a mass for recover the painting.

Low-resolution structure of Drosophila translin

Science.gov (United States)

Kumar, Vinay; Gupta, Gagan D.

2012-01-01

Crystals of native Drosophila melanogaster translin diffracted to 7 Å resolution. Reductive methylation of the protein improved crystal quality. The native and methylated proteins showed similar profiles in size-exclusion chromatography analyses but the methylated protein displayed reduced DNA-binding activity. Crystals of the methylated protein diffracted to 4.2 Å resolution at BM14 of the ESRF synchrotron. Crystals with 49% solvent content belonged to monoclinic space group P21 with eight protomers in the asymmetric unit. Only 2% of low-resolution structures with similar low percentage solvent content were found in the PDB. The crystal structure, solved by molecular replacement method, refined to Rwork (Rfree) of 0.24 (0.29) with excellent stereochemistry. The crystal structure clearly shows that drosophila protein exists as an octamer, and not as a decamer as expected from gel-filtration elution profiles. The similar octameric quaternary fold in translin orthologs and in translin–TRAX complexes suggests an up-down dimer as the basic structural subunit of translin-like proteins. The drosophila oligomer displays asymmetric assembly and increased radius of gyration that accounts for the observed differences between the elution profiles of human and drosophila proteins on gel-filtration columns. This study demonstrates clearly that low-resolution X-ray structure can be useful in understanding complex biological oligomers. PMID:23650579

Nanoscale Coloristic Pigments: Upper Limits on Releases from Pigmented Plastic during Environmental Aging, In Food Contact, and by Leaching.

Science.gov (United States)

Neubauer, Nicole; Scifo, Lorette; Navratilova, Jana; Gondikas, Andreas; Mackevica, Aiga; Borschneck, Daniel; Chaurand, Perrine; Vidal, Vladimir; Rose, Jerome; von der Kammer, Frank; Wohlleben, Wendel

2017-10-17

The life cycle of nanoscale pigments in plastics may cause environmental or human exposure by various release scenarios. We investigated spontaneous and induced release with mechanical stress during/after simulated sunlight and rain degradation of polyethylene (PE) with organic and inorganic pigments. Additionally, primary leaching in food contact and secondary leaching from nanocomposite fragments with an increased surface into environmental media was examined. Standardized protocols/methods for release sampling, detection, and characterization of release rate and form were applied: Transformation of the bulk material was analyzed by Scanning Electron Microscopy (SEM), X-ray-tomography and Fourier-Transform Infrared spectroscopy (FTIR); releases were quantified by Inductively Coupled Plasma Mass Spectrometry (ICP-MS), single-particle-ICP-MS (sp-ICP-MS), Transmission Electron Microscopy (TEM), Analytical Ultracentrifugation (AUC), and UV/Vis spectroscopy. In all scenarios, the detectable particulate releases were attributed primarily to contaminations from handling and machining of the plastics, and were not identified with the pigments, although the contamination of 4 mg/kg (Fe) was dwarfed by the intentional content of 5800 mg/kg (Fe as Fe 2 O 3 pigment). We observed modulations (which were at least partially preventable by UV stabilizers) when comparing as-produced and aged nanocomposites, but no significant increase of releases. Release of pigments was negligible within the experimental error for all investigated scenarios, with upper limits of 10 mg/m 2 or 1600 particles/mL. This is the first holistic confirmation that pigment nanomaterials remain strongly contained in a plastic that has low diffusion and high persistence such as the polyolefin High Density Polyethylene (HDPE).

Pigment Production on L-Tryptophan Medium by Cryptococcus gattii and Cryptococcus neoformans

Science.gov (United States)

Chaskes, Stuart; Cammer, Michael; Nieves, Edward; Casadevall, Arturo

2014-01-01

In recent years strains previously grouped within Cryptococcus neoformans have been divided into two species C. neoformans and C. gattii, with Cryptococcus neoformans comprising serotypes A, D, and AD and C. gattii comprising serotypes B and C. Cryptococcus neoformans have also been subdivided into two varieties C. neoformans var. grubii, serotype A, and C. neoformans var. neoformans, serotype D. We analyzed the growth and pigment production characteristics of 139 strains of Cryptococcus spp. in L-tryptophan containing media. Nearly all strains of Cryptococcus, including each variety and serotype tested produced a pink water-soluble pigment (molecular weight of 535.2 Da) from L-tryptophan. Consequently, the partial separation of the species was based on whether the pink pigment was secreted into the medium (extracellular) or retained as an intracellular pigment. On L-tryptophan medium C. neoformans var. grubii and serotype AD produced a pink extracellular pigment. In contrast, for C. gattii, the pink pigment was localized intracellularly and masked by heavy production of brown pigments. Pigment production by C. neoformans var. neoformans was variable with some strains producing the pink extracellular pigment and others retained the pink pigment intracellularly. The pink intracellular pigment produced by strains of C. neoformans var. neoformans was masked by production of brown pigments. Cryptococcus laccase mutants failed to produce pigments from L-tryptophan. This is the first report that the enzyme laccase is involved in tryptophan metabolism. Prior to this report Cryptococcus laccase produced melanin or melanin like-pigments from heterocyclic compounds that contained ortho or para diphenols, diaminobenzenes and aminophenol compounds. The pigments produced from L-tryptophan were not melanin. PMID:24736553

Pigment production on L-tryptophan medium by Cryptococcus gattii and Cryptococcus neoformans.

Science.gov (United States)

Chaskes, Stuart; Cammer, Michael; Nieves, Edward; Casadevall, Arturo

2014-01-01

In recent years strains previously grouped within Cryptococcus neoformans have been divided into two species C. neoformans and C. gattii, with Cryptococcus neoformans comprising serotypes A, D, and AD and C. gattii comprising serotypes B and C. Cryptococcus neoformans have also been subdivided into two varieties C. neoformans var. grubii, serotype A, and C. neoformans var. neoformans, serotype D. We analyzed the growth and pigment production characteristics of 139 strains of Cryptococcus spp. in L-tryptophan containing media. Nearly all strains of Cryptococcus, including each variety and serotype tested produced a pink water-soluble pigment (molecular weight of 535.2 Da) from L-tryptophan. Consequently, the partial separation of the species was based on whether the pink pigment was secreted into the medium (extracellular) or retained as an intracellular pigment. On L-tryptophan medium C. neoformans var. grubii and serotype AD produced a pink extracellular pigment. In contrast, for C. gattii, the pink pigment was localized intracellularly and masked by heavy production of brown pigments. Pigment production by C. neoformans var. neoformans was variable with some strains producing the pink extracellular pigment and others retained the pink pigment intracellularly. The pink intracellular pigment produced by strains of C. neoformans var. neoformans was masked by production of brown pigments. Cryptococcus laccase mutants failed to produce pigments from L-tryptophan. This is the first report that the enzyme laccase is involved in tryptophan metabolism. Prior to this report Cryptococcus laccase produced melanin or melanin like-pigments from heterocyclic compounds that contained ortho or para diphenols, diaminobenzenes and aminophenol compounds. The pigments produced from L-tryptophan were not melanin.

Pigment production on L-tryptophan medium by Cryptococcus gattii and Cryptococcus neoformans.

Directory of Open Access Journals (Sweden)

Stuart Chaskes

Full Text Available In recent years strains previously grouped within Cryptococcus neoformans have been divided into two species C. neoformans and C. gattii, with Cryptococcus neoformans comprising serotypes A, D, and AD and C. gattii comprising serotypes B and C. Cryptococcus neoformans have also been subdivided into two varieties C. neoformans var. grubii, serotype A, and C. neoformans var. neoformans, serotype D. We analyzed the growth and pigment production characteristics of 139 strains of Cryptococcus spp. in L-tryptophan containing media. Nearly all strains of Cryptococcus, including each variety and serotype tested produced a pink water-soluble pigment (molecular weight of 535.2 Da from L-tryptophan. Consequently, the partial separation of the species was based on whether the pink pigment was secreted into the medium (extracellular or retained as an intracellular pigment. On L-tryptophan medium C. neoformans var. grubii and serotype AD produced a pink extracellular pigment. In contrast, for C. gattii, the pink pigment was localized intracellularly and masked by heavy production of brown pigments. Pigment production by C. neoformans var. neoformans was variable with some strains producing the pink extracellular pigment and others retained the pink pigment intracellularly. The pink intracellular pigment produced by strains of C. neoformans var. neoformans was masked by production of brown pigments. Cryptococcus laccase mutants failed to produce pigments from L-tryptophan. This is the first report that the enzyme laccase is involved in tryptophan metabolism. Prior to this report Cryptococcus laccase produced melanin or melanin like-pigments from heterocyclic compounds that contained ortho or para diphenols, diaminobenzenes and aminophenol compounds. The pigments produced from L-tryptophan were not melanin.

Pigments produced by the bacteria belonging to the genus Arthrobacter

OpenAIRE

Sutthiwong , Nuthathai; Caro , Yanis; Fouillaud , Mireille; Laurent , Philippe; Valla , A.; Dufossé , Laurent

2013-01-01

Poster communication, 7th International Congress of Pigments in Food – New technologies towards health, through colors, Novara, Italy, June 18-21, 2013.; International audience; Since several decades, pigments have been used as a taxonomic tool for the identification and classification of bacteria. Nowadays, pigment producing microorganisms have been also widely interested in scientific disciplines because of their biotechnological potential. With the growing interest in microbial pigments be...

Generation of genome-modified Drosophila cell lines using SwAP.

Science.gov (United States)

Franz, Alexandra; Brunner, Erich; Basler, Konrad

2017-10-02

The ease of generating genetically modified animals and cell lines has been markedly increased by the recent development of the versatile CRISPR/Cas9 tool. However, while the isolation of isogenic cell populations is usually straightforward for mammalian cell lines, the generation of clonal Drosophila cell lines has remained a longstanding challenge, hampered by the difficulty of getting Drosophila cells to grow at low densities. Here, we describe a highly efficient workflow to generate clonal Cas9-engineered Drosophila cell lines using a combination of cell pools, limiting dilution in conditioned medium and PCR with allele-specific primers, enabling the efficient selection of a clonal cell line with a suitable mutation profile. We validate the protocol by documenting the isolation, selection and verification of eight independently Cas9-edited armadillo mutant Drosophila cell lines. Our method provides a powerful and simple workflow that improves the utility of Drosophila cells for genetic studies with CRISPR/Cas9.

Pigment Production Analysis in Human Melanoma Cells.

Science.gov (United States)

Hopkin, Amelia Soto; Paterson, Elyse K; Ruiz, Rolando; Ganesan, Anand K

2016-05-25

The human epidermal melanocyte is a highly specialized pigmented cell that serves to protect the epidermis from ultraviolet (UV) damage through the production of melanin, or melanogenesis. Misregulation in melanogenesis leading to either hyper- or hypo-pigmentation is found in human diseases such as malasma and vitiligo. Current therapies for these diseases are largely unsuccessful and the need for new therapies is necessary. In order to identify genes and or compounds that can alter melanogenesis, methods are required that can detect changes in pigment production as well as expression of key melanogenesis transcription factors and enzymes. Here we describe methods to detect changes in melanogenesis in a human melanoma cell line, MNT-1, by (1) analyzing pigment production by measuring the absorbance of melanin present by spectrophotometry, (2) analyzing transcript expression of potent regulators of melanogenesis by qunatitative reverse-transcription (RT)PCR and (3) analyzing protein expression of potent regulators of melanogenesis by Western blot (WB).

Multi-analytical study of historical semiconductor pigments

International Nuclear Information System (INIS)

Caporosso, V.

2015-01-01

This work is focused on the study of semiconductor-based pigments, which substituted traditional pigments in the second half of the 19. century. Synthetic semiconductor pigments may be chemically unstable due to the presence of many impurities unintentionally introduced during manufacturing. The aim of this work is to provide an insight on the application of X-ray Fluorescence (XRF) for the analysis of these painting materials, including both Cd- and Zn-based pigments. Three different approaches have been followed: the semi-quantitative analysis of samples with similar elemental composition, the complementary use of XRF and Raman spectroscopy for the analysis of elemental and molecular composition and the synchrotron-based XRF and XANES for the detection of impurities. The synergetic combination of different techniques provides information useful for the definition of specific markers for future analysis of paint-samples with implications for the conservation and treatment of late 19. and early 20. century paintings.

Blue Pseudoazulene-Skeleton Pigments of Natural Origin

OpenAIRE

井上, 謙一郎; イノウエ, ケンイチロウ; KENICHIRO, INOUE

1993-01-01

Genipin, an iridoid constituent of Genipa americana, readily reacts with amino acids in the presence of oxygen to give a mixture of polymeric blue pigments whose structures are not determined. In the basic studies to elucidate the structure and formation mechnism of blue pigments, the reaction of genipin with methylamine in the absence of oxygen yielded 9 red compounds leading to blue pigments. In this article, the structures and spectroscopic properties of these red compounds were described....

Cancer in Drosophila

DEFF Research Database (Denmark)

Herranz, Héctor; Eichenlaub, Teresa; Cohen, Stephen M

2016-01-01

Cancer genomics has greatly increased our understanding of the complexity of the genetic and epigenetic changes found in human tumors. Understanding the functional relationships among these elements calls for the use of flexible genetic models. We discuss the use of Drosophila models to study...

The Drosophila homolog of the mammalian imprint regulator, CTCF, maintains the maternal genomic imprint in Drosophila melanogaster

Directory of Open Access Journals (Sweden)

Rasheva Vanya

2010-07-01

Full Text Available Abstract Background CTCF is a versatile zinc finger DNA-binding protein that functions as a highly conserved epigenetic transcriptional regulator. CTCF is known to act as a chromosomal insulator, bind promoter regions, and facilitate long-range chromatin interactions. In mammals, CTCF is active in the regulatory regions of some genes that exhibit genomic imprinting, acting as insulator on only one parental allele to facilitate parent-specific expression. In Drosophila, CTCF acts as a chromatin insulator and is thought to be actively involved in the global organization of the genome. Results To determine whether CTCF regulates imprinting in Drosophila, we generated CTCF mutant alleles and assayed gene expression from the imprinted Dp(1;fLJ9 mini-X chromosome in the presence of reduced CTCF expression. We observed disruption of the maternal imprint when CTCF levels were reduced, but no effect was observed on the paternal imprint. The effect was restricted to maintenance of the imprint and was specific for the Dp(1;fLJ9 mini-X chromosome. Conclusions CTCF in Drosophila functions in maintaining parent-specific expression from an imprinted domain as it does in mammals. We propose that Drosophila CTCF maintains an insulator boundary on the maternal X chromosome, shielding genes from the imprint-induced silencing that occurs on the paternally inherited X chromosome. See commentary: http://www.biomedcentral.com/1741-7007/8/104

Adsorption of Small Cationic Nanoparticles onto Large Anionic Particles from Aqueous Solution: A Model System for Understanding Pigment Dispersion and the Problem of Effective Particle Density.

Science.gov (United States)

North, S M; Jones, E R; Smith, G N; Mykhaylyk, O O; Annable, T; Armes, S P

2017-02-07

The present study focuses on the use of copolymer nanoparticles as a dispersant for a model pigment (silica). Reversible addition-fragmentation chain transfer (RAFT) alcoholic dispersion polymerization was used to synthesize sterically stabilized diblock copolymer nanoparticles. The steric stabilizer block was poly(2-(dimethylamino)ethyl methacrylate) (PDMA) and the core-forming block was poly(benzyl methacrylate) (PBzMA). The mean degrees of polymerization for the PDMA and PBzMA blocks were 71 and 100, respectively. Transmission electron microscopy (TEM) studies confirmed a near-monodisperse spherical morphology, while dynamic light scattering (DLS) studies indicated an intensity-average diameter of 30 nm. Small-angle X-ray scattering (SAXS) reported a volume-average diameter of 29 ± 0.5 nm and a mean aggregation number of 154. Aqueous electrophoresis measurements confirmed that these PDMA 71 -PBzMA 100 nanoparticles acquired cationic character when transferred from ethanol to water as a result of protonation of the weakly basic PDMA chains. Electrostatic adsorption of these nanoparticles from aqueous solution onto 470 nm silica particles led to either flocculation at submonolayer coverage or steric stabilization at or above monolayer coverage, as judged by DLS. This technique indicated that saturation coverage was achieved on addition of approximately 465 copolymer nanoparticles per silica particle, which corresponds to a fractional surface coverage of around 0.42. These adsorption data were corroborated using thermogravimetry, UV spectroscopy and X-ray photoelectron spectroscopy. TEM studies indicated that the cationic nanoparticles remained intact on the silica surface after electrostatic adsorption, while aqueous electrophoresis confirmed that surface charge reversal occurred below pH 7. The relatively thick layer of adsorbed nanoparticles led to a significant reduction in the effective particle density of the silica particles from 1.99 g cm -3 to

The dopaminergic system in the aging brain of Drosophila

Directory of Open Access Journals (Sweden)

Katherine E White

2010-12-01

Full Text Available Drosophila models of Parkinson’s disease are characterised by two principal phenotypes: the specific loss of dopaminergic neurons in the aging brain and defects in motor behavior. However, an age-related analysis of these baseline parameters in wildtype Drosophila is lacking. Here we analysed the dopaminergic system and motor behavior in aging Drosophila. Dopaminergic neurons in the adult brain can be grouped into bilateral symmetric clusters, each comprising a stereotypical number of cells. Analysis of TH>mCD8::GFP and cell type-specific MARCM clones revealed that dopaminergic neurons show cluster-specific, stereotypical projection patterns with terminal arborization in target regions that represent distinct functional areas of the adult brain. Target areas include the mushroom bodies, involved in memory formation and motivation, and the central complex, involved in the control of motor behavior, indicating that similar to the mammalian brain, dopaminergic neurons in the fly brain are involved in the regulation of specific behaviors. Behavioral analysis revealed that Drosophila show an age-related decline in startle-induced locomotion and negative geotaxis. Motion tracking however, revealed that walking activity and exploration behavior, but not centrophobism increase at late stages of life. Analysis of TH>Dcr2, mCD8::GFP revealed a specific effect of Dcr2 expression on walking activity but not on exploratory or centrophobic behavior, indicating that the siRNA pathway may modulate distinct dopaminergic behaviors in Drosophila. Moreover, dopaminergic neurons were maintained between early- and late life, as quantified by TH>mCD8::GFP and anti-TH labelling, indicating that adult onset, age-related degeneration of dopaminergic neurons does not occur in the aging brain of Drosophila. Taken together, our data establish baseline parameters in Drosophila for the study of Parkinson’s disease as well as other disorders affecting dopaminergic neurons

Research progress on Drosophila visual cognition in China

Institute of Scientific and Technical Information of China (English)

无

2010-01-01

Visual cognition,as one of the fundamental aspects of cognitive neuroscience,is generally associated with high-order brain functions in animals and human.Drosophila,as a model organism,shares certain features of visual cognition in common with mammals at the genetic,molecular,cellular,and even higher behavioral levels.From learning and memory to decision making,Drosophila covers a broad spectrum of higher cognitive behaviors beyond what we had expected.Armed with powerful tools of genetic manipulation in Drosophila,an increasing number of studies have been conducted in order to elucidate the neural circuit mechanisms underlying these cognitive behaviors from a genes-brain-behavior perspective.The goal of this review is to integrate the most important studies on visual cognition in Drosophila carried out in mainland China during the last decade into a body of knowledge encompassing both the basic neural operations and circuitry of higher brain function in Drosophila.Here,we consider a series of the higher cognitive behaviors beyond learning and memory,such as visual pattern recognition,feature and context generalization,different feature memory traces,salience-based decision,attention-like behavior,and cross-modal leaning and memory.We discuss the possible general gain-gating mechanism implementing by dopamine-mushroom body circuit in fly’s visual cognition.We hope that our brief review on this aspect will inspire further study on visual cognition in flies,or even beyond.

Research progress on Drosophila visual cognition in China.

Science.gov (United States)

Guo, AiKe; Zhang, Ke; Peng, YueQin; Xi, Wang

2010-03-01

Visual cognition, as one of the fundamental aspects of cognitive neuroscience, is generally associated with high-order brain functions in animals and human. Drosophila, as a model organism, shares certain features of visual cognition in common with mammals at the genetic, molecular, cellular, and even higher behavioral levels. From learning and memory to decision making, Drosophila covers a broad spectrum of higher cognitive behaviors beyond what we had expected. Armed with powerful tools of genetic manipulation in Drosophila, an increasing number of studies have been conducted in order to elucidate the neural circuit mechanisms underlying these cognitive behaviors from a genes-brain-behavior perspective. The goal of this review is to integrate the most important studies on visual cognition in Drosophila carried out in mainland China during the last decade into a body of knowledge encompassing both the basic neural operations and circuitry of higher brain function in Drosophila. Here, we consider a series of the higher cognitive behaviors beyond learning and memory, such as visual pattern recognition, feature and context generalization, different feature memory traces, salience-based decision, attention-like behavior, and cross-modal leaning and memory. We discuss the possible general gain-gating mechanism implementing by dopamine - mushroom body circuit in fly's visual cognition. We hope that our brief review on this aspect will inspire further study on visual cognition in flies, or even beyond.

Functional requirements driving the gene duplication in 12 Drosophila species.

Science.gov (United States)

Zhong, Yan; Jia, Yanxiao; Gao, Yang; Tian, Dacheng; Yang, Sihai; Zhang, Xiaohui

2013-08-15

Gene duplication supplies the raw materials for novel gene functions and many gene families arisen from duplication experience adaptive evolution. Most studies of young duplicates have focused on mammals, especially humans, whereas reports describing their genome-wide evolutionary patterns across the closely related Drosophila species are rare. The sequenced 12 Drosophila genomes provide the opportunity to address this issue. In our study, 3,647 young duplicate gene families were identified across the 12 Drosophila species and three types of expansions, species-specific, lineage-specific and complex expansions, were detected in these gene families. Our data showed that the species-specific young duplicate genes predominated (86.6%) over the other two types. Interestingly, many independent species-specific expansions in the same gene family have been observed in many species, even including 11 or 12 Drosophila species. Our data also showed that the functional bias observed in these young duplicate genes was mainly related to responses to environmental stimuli and biotic stresses. This study reveals the evolutionary patterns of young duplicates across 12 Drosophila species on a genomic scale. Our results suggest that convergent evolution acts on young duplicate genes after the species differentiation and adaptive evolution may play an important role in duplicate genes for adaption to ecological factors and environmental changes in Drosophila.

Optimization and design of pigments for heat-insulating coatings

Science.gov (United States)

Wang, Guang-Hai; Zhang, Yue

2010-12-01

This paper reports that heat insulating property of infrared reflective coatings is obtained through the use of pigments which diffuse near-infrared thermal radiation. Suitable structure and size distribution of pigments would attain maximum diffuse infrared radiation and reduce the pigment volume concentration required. The optimum structure and size range of pigments for reflective infrared coatings are studied by using Kubelka—Munk theory, Mie model and independent scattering approximation. Taking titania particle as the pigment embedded in an inorganic coating, the computational results show that core-shell particles present excellent scattering ability, more so than solid and hollow spherical particles. The optimum radius range of core-shell particles is around 0.3 ~ 1.6 μm. Furthermore, the influence of shell thickness on optical parameters of the coating is also obvious and the optimal thickness of shell is 100-300 nm.

Studies on the bio production of monascus red pigment

International Nuclear Information System (INIS)

Emam, D.A.

2007-01-01

there is an increasing interest on natural pigments to replace some currently used synthetic dyes, since the latter have been associated with toxic effects in foods. the red pigment of the fungus Monascus is widely used in all the world as food additives or pharmaceuticals. although pigment production by Monascus spp.in chemically defined media is well documented, very few information is available about the use of agro-industrial wastes. in this regard, the present study has been devoted to investigate the effect of different parameters on red pigment production by the local isolated strain of M. purpureu, in an attempt to maximize the production, and also to develop a potential fermentation process for the production of red pigment using potato processing wastewater (PPW,waters used to wash the potato slices prior to cooking in chips and crisp manufacture) as cheap production medium

Structure of Pigment Yellow 181 dimethylsulfoxide N-methyl-2-pyrrolidone (1:1:1) solvate from XRPD plus DFT-D

DEFF Research Database (Denmark)

van de Streek, Jacco

2015-01-01

With only a 2.6 Å resolution laboratory powder diffraction pattern of the phase of Pigment Yellow 181 (P.Y. 181) available, crystal-structure solution and Rietveld refinement proved challenging; especially when the crystal structure was shown to be a triclinic dimethylsulfoxide N-methyl-2...... of commercial interest, additional experiments were not economically feasible and additional dispersion-corrected density functional theory (DFT-D) calculations were employed to confirm the correctness of the crystal structure. After the correctness of the structure had been ascertained, the bond lengths...

Identification of the man-made barium copper silicate pigments among some ancient Chinese artifacts through spectroscopic analysis.

Science.gov (United States)

Li, Q H; Yang, J C; Li, L; Dong, J Q; Zhao, H X; Liu, S

2015-03-05

This article describes the complementary application of non-invasive micro-Raman spectroscopy and energy dispersive X-ray fluorescence spectrometry to the characterization of some ancient Chinese silicate artifacts. A total of 28 samples dated from fourth century BC to third century AD were analyzed. The results of chemical analysis showed that the vitreous PbO-BaO-SiO2 material was used to sinter these silicate artifacts. The barium copper silicate pigments including BaCuSi4O10, BaCuSi2O6 and BaCu2Si2O7 were widely identified from colorful areas of the samples by Raman spectroscopy. In addition, other crystalline phases such as Fe2O3, BaSi2O5, BaSO4, PbCO3 and quartz were also identified. The present study provides very valuable information to trace the technical evolution of man-made barium copper silicate pigments and their close relationship with the making of ancient PbO-BaO-SiO2 glaze and glass. Copyright © 2014 Elsevier B.V. All rights reserved.

A comparison of Frost expression among species and life stages of Drosophila.

Science.gov (United States)

Bing, X; Zhang, J; Sinclair, Brent J

2012-02-01

Frost (Fst) is a gene associated with cold exposure in Drosophila melanogaster. We used real-time PCR to assess whether cold exposure induces expression of Fst in 10 different life stages of D. melanogaster, and adults of seven other Drosophila species. We exposed groups of individuals to 0 °C (2 h), followed by 1 h recovery (22 °C). Frost was significantly upregulated in response to cold in eggs, third instar larvae, and 2- and 5-day-old male and female adults in D. melanogaster. Life stages in which cold did not upregulate Fst had high constitutive expression. Frost is located on the opposite strand of an intron of Diuretic hormone (DH), but cold exposure did not upregulate DH. Frost orthologues were identified in six other species within the Melanogaster group (Drosophila sechellia, Drosophila simulans, Drosophila yakuba, Drosophila erecta, Drosophila ananassae and Drosophila mauritiana). Frost orthologues were upregulated in response to cold exposure in both sexes in adults of all of these species. The predicted structure of a putative Frost consensus protein shows highly conserved tandem repeats of motifs involved in cell signalling (PEST and TRAF2), suggesting that Fst might encode an adaptor protein involved in acute stress or apoptosis signalling in vivo. © 2011 The Authors. Insect Molecular Biology © 2011 The Royal Entomological Society.

Drosophila melanogaster as a Versatile Model Organism in Food and Nutrition Research.

Science.gov (United States)

Staats, Stefanie; Lüersen, Kai; Wagner, Anika E; Rimbach, Gerald

2018-04-18

Drosophila melanogaster has been widely used in the biological sciences as a model organism. Drosophila has a relatively short life span of 60-80 days, which makes it attractive for life span studies. Moreover, approximately 60% of the fruit fly genes are orthologs to mammals. Thus, metabolic and signal transduction pathways are highly conserved. Maintenance and reproduction of Drosophila do not require sophisticated equipment and are rather cheap. Furthermore, there are fewer ethical issues involved in experimental Drosophila research compared with studies in laboratory rodents, such as rats and mice. Drosophila is increasingly recognized as a model organism in food and nutrition research. Drosophila is often fed complex solid diets based on yeast, corn, and agar. There are also so-called holidic diets available that are defined in terms of their amino acid, fatty acid, carbohydrate, vitamin, mineral, and trace element compositions. Feed intake, body composition, locomotor activity, intestinal barrier function, microbiota, cognition, fertility, aging, and life span can be systematically determined in Drosophila in response to dietary factors. Furthermore, diet-induced pathophysiological mechanisms including inflammation and stress responses may be evaluated in the fly under defined experimental conditions. Here, we critically evaluate Drosophila melanogaster as a versatile model organism in experimental food and nutrition research, review the corresponding data in the literature, and make suggestions for future directions of research.

The Drosophila gene CG9918 codes for a pyrokinin-1 receptor

DEFF Research Database (Denmark)

Cazzamali, Giuseppe; Torp, Malene; Hauser, Frank

2005-01-01

The database from the Drosophila Genome Project contains a gene, CG9918, annotated to code for a G protein-coupled receptor. We cloned the cDNA of this gene and functionally expressed it in Chinese hamster ovary cells. We tested a library of about 25 Drosophila and other insect neuropeptides......, and seven insect biogenic amines on the expressed receptor and found that it was activated by low concentrations of the Drosophila neuropeptide, pyrokinin-1 (TGPSASSGLWFGPRLamide; EC50, 5 x 10(-8) M). The receptor was also activated by other Drosophila neuropeptides, terminating with the sequence PRLamide...... (Hug-gamma, ecdysis-triggering-hormone-1, pyrokinin-2), but in these cases about six to eight times higher concentrations were needed. The receptor was not activated by Drosophila neuropeptides, containing a C-terminal PRIamide sequence (such as ecdysis-triggering-hormone-2), or PRVamide (such as capa...

Relative Pigment Composition and Remote Sensing Reflectance of Caribbean Shallow-Water Corals.

Directory of Open Access Journals (Sweden)

Juan L Torres-Pérez

Full Text Available Reef corals typically contain a number of pigments, mostly due to their symbiotic relationship with photosynthetic dinoflagellates. These pigments usually vary in presence and concentration and influence the spectral characteristics of corals. We studied the variations in pigment composition among seven Caribbean shallow-water Scleractinian corals by means of High Performance Liquid Chromatography (HPLC analysis to further resolve the discrimination of corals. We found a total of 27 different pigments among the coral species, including some alteration products of the main pigments. Additionally, pigments typically found in endolithic algae were also identified. A Principal Components Analysis and a Hierarchical Cluster Analysis showed the separation of coral species based on pigment composition. All the corals were collected under the same physical environmental conditions. This suggests that pigment in the coral's symbionts might be more genetically-determined than influenced by prevailing physical conditions of the reef. We further investigated the use of remote sensing reflectance (Rrs as a tool for estimating the total pigment concentration of reef corals. Depending on the coral species, the Rrs and the total symbiont pigment concentration per coral tissue area correlation showed 79.5-98.5% confidence levels demonstrating its use as a non-invasive robust technique to estimate pigment concentration in studies of coral reef biodiversity and health.

Relative Pigment Composition and Remote Sensing Reflectance of Caribbean Shallow-Water Corals.

Science.gov (United States)

Torres-Pérez, Juan L; Guild, Liane S; Armstrong, Roy A; Corredor, Jorge; Zuluaga-Montero, Anabella; Polanco, Ramón

2015-01-01

Reef corals typically contain a number of pigments, mostly due to their symbiotic relationship with photosynthetic dinoflagellates. These pigments usually vary in presence and concentration and influence the spectral characteristics of corals. We studied the variations in pigment composition among seven Caribbean shallow-water Scleractinian corals by means of High Performance Liquid Chromatography (HPLC) analysis to further resolve the discrimination of corals. We found a total of 27 different pigments among the coral species, including some alteration products of the main pigments. Additionally, pigments typically found in endolithic algae were also identified. A Principal Components Analysis and a Hierarchical Cluster Analysis showed the separation of coral species based on pigment composition. All the corals were collected under the same physical environmental conditions. This suggests that pigment in the coral's symbionts might be more genetically-determined than influenced by prevailing physical conditions of the reef. We further investigated the use of remote sensing reflectance (Rrs) as a tool for estimating the total pigment concentration of reef corals. Depending on the coral species, the Rrs and the total symbiont pigment concentration per coral tissue area correlation showed 79.5-98.5% confidence levels demonstrating its use as a non-invasive robust technique to estimate pigment concentration in studies of coral reef biodiversity and health.

The Drosophila Pericentrin-like-protein (PLP cooperates with Cnn to maintain the integrity of the outer PCM

Directory of Open Access Journals (Sweden)

Jennifer H. Richens

2015-08-01

Full Text Available Centrosomes comprise a pair of centrioles surrounded by a matrix of pericentriolar material (PCM. In vertebrate cells, Pericentrin plays an important part in mitotic PCM assembly, but the Drosophila Pericentrin-like protein (PLP appears to have a more minor role in mitotic fly cells. Here we investigate the function of PLP during the rapid mitotic cycles of the early Drosophila embryo. Unexpectedly, we find that PLP is specifically enriched in the outer-most regions of the PCM, where it largely co-localizes with the PCM scaffold protein Cnn. In the absence of PLP the outer PCM appears to be structurally weakened, and it rapidly disperses along the centrosomal microtubules (MTs. As a result, centrosomal MTs are subtly disorganized in embryos lacking PLP, although mitosis is largely unperturbed and these embryos develop and hatch at near-normal rates. Y2H analysis reveals that PLP can potentially form multiple interactions with itself and with the PCM recruiting proteins Asl, Spd-2 and Cnn. A deletion analysis suggests that PLP participates in a complex network of interactions that ultimately help to strengthen the PCM.

Production and chemical characterization of pigments in filamentous fungi.

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Souza, Patrícia Nirlane da Costa; Grigoletto, Tahuana Luiza Bim; de Moraes, Luiz Alberto Beraldo; Abreu, Lucas M; Guimarães, Luís Henrique Souza; Santos, Cledir; Galvão, Luciano Ribeiro; Cardoso, Patrícia Gomes

2016-01-01

Production of pigments by filamentous fungi is gaining interest owing to their use as food colourants, in cosmetics and textiles, and because of the important biological activities of these compounds. In this context, the objectives of this study were to select pigment-producing fungi, identify these fungi based on internal transcribed spacer sequences, evaluate the growth and pigment production of the selected strains on four different media, and characterize the major coloured metabolites in their extracts. Of the selected fungal strains, eight were identified as Aspergillus sydowii (CML2967), Aspergillus aureolatus (CML2964), Aspergillus keveii (CML2968), Penicillium flavigenum (CML2965), Penicillium chermesinum (CML2966), Epicoccum nigrum (CML2971), Lecanicillium aphanocladii (CML2970) and Fusarium sp. (CML2969). Fungal pigment production was influenced by medium composition. Complex media, such as potato dextrose and malt extract, favoured increased pigment production. The coloured compounds oosporein, orevactaene and dihydrotrichodimerol were identified in extracts of L. aphanocladii (CML2970), E. nigrum (CML2971), and P. flavigenum (CML2965), respectively. These results indicate that the selected fungal strains can serve as novel sources of pigments that have important industrial applications.

Analysis of ancient pigments by Raman microscopy

International Nuclear Information System (INIS)

Zuo Jian; Xu Cunyi

1999-01-01

Raman microscopy can be applied for the spatial resolution, and non-destructive in situ analysis of inorganic pigments in pottery, manuscripts and paintings. Compared with other techniques, it is the best single technique for this purpose. An overview is presented of the applications of Raman microscopy in the analysis of ancient pigments

Heterotrophic cultivation of microalgae for pigment production: A review.

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Hu, Jianjun; Nagarajan, Dillirani; Zhang, Quanguo; Chang, Jo-Shu; Lee, Duu-Jong

Pigments (mainly carotenoids) are important nutraceuticals known for their potent anti-oxidant activities and have been used extensively as high end health supplements. Microalgae are the most promising sources of natural carotenoids and are devoid of the toxic effects associated with synthetic derivatives. Compared to photoautotrophic cultivation, heterotrophic cultivation of microalgae in well-controlled bioreactors for pigments production has attracted much attention for commercial applications due to overcoming the difficulties associated with the supply of CO 2 and light, as well as avoiding the contamination problems and land requirements in open autotrophic culture systems. In this review, the heterotrophic metabolic potential of microalgae and their uses in pigment production are comprehensively described. Strategies to enhance pigment production under heterotrophic conditions are critically discussed and the challenges faced in heterotrophic pigment production with possible alternative solutions are presented. Copyright © 2017 Elsevier Inc. All rights reserved.

Study of radioadaptive response in Drosophila melanogaster at different oogenesis stages

International Nuclear Information System (INIS)

Glushkova, I.V.; Aksyutik, T.V.

2005-01-01

We study radioadaptive response in the Canton-S strain of Drosophila melanogaster at different oogenesis stages using the test of dominant lethal mutations (DLM). AR was not revealed at the stages of 14-7 and 7--1 oocytes in the studied Drosophila stock. It is likely to be associated with a genetic constitution of the Drosophila strain under study. (authors)

Production of Monascus pigments as extracellular crystals by cell suspension culture.

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Lu, Fengling; Liu, Lujie; Huang, Yaolin; Zhang, Xuehong; Wang, Zhilong

2018-01-01

It is generally accepted that Monascus pigments are predominantly cell-bound, including both intracellular and surface-bound pigments. This long-term misconception was corrected in the present work. Production of extracellular crystal pigments by submerged culture of Monascus sp. was confirmed by microscopic observation and collection of Monascus pigments from extracellular broth by direct membrane filtration. Following up the new fact, the bioactivity of mycelia as whole-cell biocatalyst for biosynthesis and biodegradation of Monascus pigments had been detailedly examined in both an aqueous solution and a nonionic surfactant micelle aqueous solution. Based on those experimental results, cell suspension culture in an aqueous medium was developed as a novel strategy for accumulation of high concentration of Monascus pigments. Thus, glucose feeding during submerged culture in the aqueous medium was carried out successfully and high orange Monascus pigments concentration of near 4 g/L was achieved.

Genome-wide comparative analysis of four Indian Drosophila species.

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Mohanty, Sujata; Khanna, Radhika

2017-12-01

Comparative analysis of multiple genomes of closely or distantly related Drosophila species undoubtedly creates excitement among evolutionary biologists in exploring the genomic changes with an ecology and evolutionary perspective. We present herewith the de novo assembled whole genome sequences of four Drosophila species, D. bipectinata, D. takahashii, D. biarmipes and D. nasuta of Indian origin using Next Generation Sequencing technology on an Illumina platform along with their detailed assembly statistics. The comparative genomics analysis, e.g. gene predictions and annotations, functional and orthogroup analysis of coding sequences and genome wide SNP distribution were performed. The whole genome of Zaprionus indianus of Indian origin published earlier by us and the genome sequences of previously sequenced 12 Drosophila species available in the NCBI database were included in the analysis. The present work is a part of our ongoing genomics project of Indian Drosophila species.

Drosophila increase exploration after visually detecting predators.

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Miguel de la Flor

Full Text Available Novel stimuli elicit behaviors that are collectively known as specific exploration. These behaviors allow the animal to become more familiar with the novel objects within its environment. Specific exploration is frequently suppressed by defensive reactions to predator cues. Herein, we examine if this suppression occurs in Drosophila melanogaster by measuring the response of these flies to wild harvested predators. The flies used in our experiments have been cultured and had not lived under predator threat for multiple decades. In a circular arena with centrally-caged predators, wild type Drosophila actively avoided the pantropical jumping spider, Plexippus paykulli, and the Texas unicorn mantis, Phyllovates chlorophaena, indicating an innate defensive reaction to these predators. Interestingly, wild type Drosophila males also avoided a centrally-caged mock spider, and the avoidance of the mock spider became exaggerated when it was made to move within the cage. Visually impaired Drosophila failed to detect and avoid the Plexippus paykulli and the moving mock spider, while the broadly anosmic orco2 mutants were fully capable of detecting and avoiding Plexippus paykulli, indicating that these flies principally relied upon vison to perceive the predator stimuli. During early exploration of the arena, exploratory activity increased in the presence of Plexippus paykulli and the moving mock spider. The elevated activity induced by Plexippus paykulli disappeared after the fly had finished exploring, suggesting the flies were capable of habituating the predator cues. Taken together, these results indicate that despite being isolated from predators for decades Drosophila will visually detect these predators, retain innate defensive behaviors, respond by increasing exploratory activity in the arena rather than suppressing activity, and may habituate to normal predator cues.

Optogenetic pacing in Drosophila melanogaster (Conference Presentation)

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Alex, Aneesh; Li, Airong; Men, Jing; Jerwick, Jason; Tanzi, Rudolph E.; Zhou, Chao

2016-03-01

A non-invasive, contact-less cardiac pacing technology can be a powerful tool in basic cardiac research and in clinics. Currently, electrical pacing is the gold standard for cardiac pacing. Although highly effective in controlling the cardiac function, the invasive nature, non-specificity to cardiac tissues and possible tissue damage limits its capabilities. Optical pacing of heart is a promising alternative, which is non-invasive and more specific, has high spatial and temporal precision, and avoids shortcomings in electrical stimulation. Optical coherence tomography has been proved to be an effective technique in non-invasive imaging in vivo with ultrahigh resolution and imaging speed. In the last several years, non-invasive specific optical pacing in animal hearts has been reported in quail, zebrafish, and rabbit models. However， Drosophila Melanogaster, which is a significant model with orthologs of 75% of human disease genes, has rarely been studied concerning their optical pacing in heart. Here, we combined optogenetic control of Drosophila heartbeat with optical coherence microscopy (OCM) technique for the first time. The light-gated cation channel, channelrhodopsin-2 (ChR2) was specifically expressed by transgene as a pacemaker in drosophila heart. By stimulating the pacemaker with 472 nm pulsed laser light at different frequencies, we achieved non-invasive and more specific optical control of the Drosophila heart rhythm, which demonstrates the wide potential of optical pacing for studying cardiac dynamics and development. Imaging capability of our customized OCM system was also involved to observe the pacing effect visually. No tissue damage was found after long exposure to laser pulses, which proved the safety of optogenetic control of Drosophila heart.

A third, ultraviolet-sensitive, visual pigment in the Tokay gecko (Gekko gekko).

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Loew, E R

1994-06-01

Numerous extraction and microspectrophotometric studies have shown that the nocturnal Tokay gecko (Gekko gekko), has two visual pigments: a "green" with lambda max at 521 nm and a "blue" at 467 nm. In addition, similar studies on other nocturnal gecko species have found only the same two classes of visual pigment. With the finding that some diurnal species of gecko have a third visual pigment class with lambda max peaking in the UV, doubts were raised concerning the presence of only two visual pigment classes in nocturnal forms. Therefore, a microspectrophotometric re-examination of the Tokay gecko was undertaken to look specifically for a UV visual pigment. A UV-absorbing pigment (364 nm lambda max) was found in approx. 20% of the thin outer segments of type C double rods, thought previously to contain only the 467 nm pigment. That this UV-absorbing pigment was truly a visual pigment was confirmed by its dichroism, behaviour following exposure to UV radiation and "nomogram" fit. It is suggested that this visual pigment had been seen in previous microspectrophotometric studies, but its similarity to known photoproducts peaking in the same spectral region resulted in a case of mistaken identity.

Separation of Chloroplast Pigments Using Reverse Phase Chromatography.

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Reese, R. Neil

1997-01-01

Presents a protocol that uses reverse phase chromatography for the separation of chloroplast pigments. Provides a simple and relatively safe procedure for use in teaching laboratories. Discusses pigment extraction, chromatography, results, and advantages of the process. (JRH)

Vibrational spectroscopic analyses of unique yellow feather pigments (spheniscins) in penguins.

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Thomas, Daniel B; McGoverin, Cushla M; McGraw, Kevin J; James, Helen F; Madden, Odile

2013-06-06

Many animals extract, synthesize and refine chemicals for colour display, where a range of compounds and structures can produce a diverse colour palette. Feather colours, for example, span the visible spectrum and mostly result from pigments in five chemical classes (carotenoids, melanins, porphyrins, psittacofulvins and metal oxides). However, the pigment that generates the yellow colour of penguin feathers appears to represent a sixth, poorly characterized class of feather pigments. This pigment class, here termed 'spheniscin', is displayed by half of the living penguin genera; the larger and richer colour displays of the pigment are highly attractive. Using Raman and mid-infrared spectroscopies, we analysed yellow feathers from two penguin species (king penguin, Aptenodytes patagonicus; macaroni penguin, Eudyptes chrysolophus) to further characterize spheniscin pigments. The Raman spectrum of spheniscin is distinct from spectra of other feather pigments and exhibits 17 distinctive spectral bands between 300 and 1700 cm(-1). Spectral bands from the yellow pigment are assigned to aromatically bound carbon atoms, and to skeletal modes in an aromatic, heterocyclic ring. It has been suggested that the penguin pigment is a pterin compound; Raman spectra from yellow penguin feathers are broadly consistent with previously reported pterin spectra, although we have not matched it to any known compound. Raman spectroscopy can provide a rapid and non-destructive method for surveying the distribution of different classes of feather pigments in the avian family tree, and for correlating the chemistry of spheniscin with compounds analysed elsewhere. We suggest that the sixth class of feather pigments may have evolved in a stem-lineage penguin and endowed modern penguins with a costly plumage trait that appears to be chemically unique among birds.

An Experimental Evolution Test of the Relationship between Melanism and Desiccation Survival in Insects.

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Subhash Rajpurohit

Full Text Available We used experimental evolution to test the 'melanism-desiccation' hypothesis, which proposes that dark cuticle in several Drosophila species is an adaptation for increased desiccation tolerance. We selected for dark and light body pigmentation in replicated populations of D. melanogaster and assayed several traits related to water balance. We also scored pigmentation and desiccation tolerance in populations selected for desiccation survival. Populations in both selection regimes showed large differences in the traits directly under selection. However, after over 40 generations of pigmentation selection, dark-selected populations were not more desiccation-tolerant than light-selected and control populations, nor did we find significant changes in mass or carbohydrate amounts that could affect desiccation resistance. Body pigmentation of desiccation-selected populations did not differ from control populations after over 140 generations of selection, although selected populations lost water less rapidly. Our results do not support an important role for melanization in Drosophila water balance.

Bar represses dPax2 and decapentaplegic to regulate cell fate and morphogenetic cell death in Drosophila eye.

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Jongkyun Kang

Full Text Available The coordinated regulation of cell fate and cell survival is crucial for normal pattern formation in developing organisms. In Drosophila compound eye development, crystalline arrays of hexagonal ommatidia are established by precise assembly of diverse cell types, including the photoreceptor cells, cone cells and interommatidial (IOM pigment cells. The molecular basis for controlling the number of cone and IOM pigment cells during ommatidial pattern formation is not well understood. Here we present evidence that BarH1 and BarH2 homeobox genes are essential for eye patterning by inhibiting excess cone cell differentiation and promoting programmed death of IOM cells. Specifically, we show that loss of Bar from the undifferentiated retinal precursor cells leads to ectopic expression of Prospero and dPax2, two transcription factors essential for cone cell specification, resulting in excess cone cell differentiation. We also show that loss of Bar causes ectopic expression of the TGFβ homolog Decapentaplegic (Dpp posterior to the morphogenetic furrow in the larval eye imaginal disc. The ectopic Dpp expression is not responsible for the formation of excess cone cells in Bar loss-of-function mutant eyes. Instead, it causes reduction in IOM cell death in the pupal stage by antagonizing the function of pro-apoptotic gene reaper. Taken together, this study suggests a novel regulatory mechanism in the control of developmental cell death in which the repression of Dpp by Bar in larval eye disc is essential for IOM cell death in pupal retina.

Apoptosis in Drosophila: which role for mitochondria?

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