Mutation analysis in a family with oculocutaneous albinism manifesting in the same generation of three branches

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Preising, Markus N.; Forster, Hedwig; Tan, H.; Lorenz, Birgit; de Jong, Paulus T. V. M.; Plomp, Astrid S.

2007-01-01

To elucidate the molecular basis of oculocutaneous albinism with variable expressivity in a family from The Netherlands in which no consanguinity was reported. Three affected family members were screened for mutations in tyrosinase (TYR) and the pink-eye-dilution gene (P) by using SSCP. The

Partial Oculocutaneous Albinism: Two Siblings with Features of both Hermansky Pudlak and Waardenburg's Syndrome.

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Ishaq, Mazhar; Niazi, Muhammad Khizar; Khan, Muhammad Saim; Nadeem, Yasser

2015-04-01

Albinism is an inherited abnormality of melanin synthesis with incidence of one per 20,000 births. Its clinical manifestations are related to the reduction or absence of pigmentation in the visual system and/or the skin and teguments. The clinical spectrum of Oculocutaneous Albinism (OCA) has four types ranging from OCA 1 - 4, of which OCA 1, A-1 is the most severe form. Partial cutaneous albinism which is a subtype of OCA is associated with systemic immunodeficiency disorders like Chediak Higashi (CHS), Griscelli (GS) and Hermansky-Pudlak (HPS) syndromes. A7 years boy was labeled initially as a case of Hermansky Pudlak syndrome at the age of 01 year. He as well as his 4 years old younger brother when examined in detail along with audiological investigations were diagnosed as a rare presentation of both Hermansky Pudlak and Waardenburg's syndrome.

Incidental finding of alpha-methylacyl-CoA racemase deficiency in a patient with oculocutaneous albinism type 4

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Verhagen, Judith M. A.; Huijmans, Jan G.; Williams, Monique; van Ruyven, Rutger L. J.; Bergen, Arthur A. B.; Wouters, Cokkie H.; Brooks, Alice S.

2012-01-01

Genome-wide studies may lead to the discovery of genetic variants of potential clinical importance beyond the aims of the study. We performed single nucleotide polymorphism array analysis in a boy with oculocutaneous albinism to identify copy-neutral regions of homozygosity harboring genes involved

A Japanese Family With Autosomal Dominant Oculocutaneous Albinism Type 4.

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Oki, Ryoko; Yamada, Kisaburo; Nakano, Satoko; Kimoto, Kenichi; Yamamoto, Ken; Kondo, Hiroyuki; Kubota, Toshiaki

2017-02-01

We report the clinical characteristics of a Japanese family with autosomal dominant oculocutaneous albinism and a SLC45A2 gene mutation. A total of 16 members of a Japanese family with general hypopigmentation and foveal hypoplasia underwent detailed clinical examinations. We evaluated the severity of foveal hypoplasia using spectral-domain optical coherence tomography (SD-OCT) and graded it according to the criteria of Thomas et al. DNA was extracted from 17 family members and used for genome-wide single nucleotide polymorphism genotyping and linkage analysis. Mutational search was performed for the SLC45A2 gene responsible for oculocutaneous albinism type 4 (OCA4). All 16 patients exhibited hypopigmentation of their hair and/or iris. They showed foveal hypoplasia, including 3 patients with grade 1 foveal hypoplasia, 7 with grade 2, and 6 with grade 3. No patient had grade 4 foveal hypoplasia. Optical coherence tomography showed macular ganglion cell complex thinning in the temporal area, and a slight reduction of visual field sensitivity in the centrotemporal area. A maximum multipoint parametric logarithm of the odds (LOD) score of approximately 2.00 to 3.56 was obtained on chromosome 5, spanning approximately 7.2 Mb between rs13187570 and rs395967 that included the SLC45A2 gene. All affected members showed a novel heterozygous variant, c.208T>C (p.Y70H), in the SLC45A2 gene, which supported a diagnosis of OCA4. The present study reports a very rare family with autosomal dominant OCA4 whose diagnosis was confirmed by a mutational analysis. Most family members exhibited mild general hypopigmentation and low-grade foveal hypoplasia.

Informed reasoning: repositioning of nitisinone to treat oculocutaneous albinism.

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Manga, Prashiela; Orlow, Seth J

2011-10-01

Oculocutaneous albinism (OCA) is a group of genetic disorders characterized by hypopigmentation of the skin, hair, and eyes. Affected individuals experience reduced visual acuity and substantially increased skin cancer risk. There are four major types of OCA (OCA1-OCA4) that result from disruption in production of melanin from tyrosine. Current treatment options for individuals with OCA are limited to attempts to correct visual problems and counseling to promote use of sun protective measures. However, Onojafe et al., reporting in this issue of the JCI, provide hope for a new treatment approach for OCA, as they demonstrate that treating mice that model OCA-1b with nitisinone, which is FDA approved for treating hereditary tyrosinemia type 1, elevates plasma tyrosine levels, and increases eye and hair pigmentation.

Oculocutaneous albinism in a patient with 17p13.2-pter duplication - a review on the molecular syndromology of 17p13 duplication.

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Kucharczyk, Marzena; Jezela-Stanek, Aleksandra; Gieruszczak-Bialek, Dorota; Kugaudo, Monika; Cieslikowska, Agata; Pelc, Magdalena; Krajewska-Walasek, Malgorzata

2015-06-01

Chromosomal duplications involving 17p13.3 have recently been defined as a new distinctive syndrome with several diagnosed patients. Some variation is known to occur in the breakpoints of the duplicated region and, consequently, in the phenotype as well. We report on a patient, the fifth to our knowledge, a 4-year-old girl with a pure de novo subtelomeric 17p13.2-pter duplication. She presents all of the facial features described so far for this duplication and in addition, a unilateral palmar transversal crease and oculocutaneous albinism which has not been reported previously. A detailed molecular description of the reported aberration and correlation with the observed phenotypical features based on a literature review. We discuss the possible molecular etiology of albinism in regard to the mode of inheritance. The new data provided here may be useful for further genotype correlations in syndromes with oculocutaneous albinism, especially of autosomal dominant inheritance.

Prenatal molecular diagnosis of oculocutaneous albinism (OCA) in a large cohort of Israeli families.

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Rosenmann, Ada; Bejarano-Achache, Idit; Eli, Dalia; Maftsir, Genia; Mizrahi-Meissonnier, Liliana; Blumenfeld, Anat

2009-10-01

To present our accumulated data on prenatal molecular diagnosis of oculocutaneous albinism (OCA) in a large cohort of Israeli albino families. Albinism consists of variable phenotypes, but only families with predicted severely handicapped albino offspring, who declared their wish to terminate a pregnancy of such a fetus, are eligible for prenatal testing. Prenatal testing is not offered otherwise. Following detailed genetic investigation and counseling, molecular prenatal testing was performed using the combination of mutation screening, direct sequencing, and haplotype analysis. A total of 55 prenatal tests were performed in 37 families; in 26 families the propositus was the child, and in 11, a parent or a close relative. In 32 families tyrosinase (TYR) mutations were diagnosed. In 5 families a P gene mutation was detected. Twelve albino fetuses were diagnosed. Following further genetic counseling, all couples elected to terminate the pregnancy. Three additional pregnancies were terminated for other reasons. Families with increased risk for an albino child with severe visual handicap, seek premarital and prenatal genetic counseling and testing, for the prevention of affected offspring. Our combined methods of molecular genetic testing enable a nationwide approach for prevention of albinism. The same paradigm can be applied to other populations affected with albinism.

The Role of Optical Coherence Tomography in an Atypical Case of Oculocutaneous Albinism: A Case Report

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Settimio Rossi

2012-03-01

Full Text Available Background: Oculocutaneous albinism is a group of autosomal recessive disorders featuring hypopigmentation of the hair, skin and eyes. Ocular signs associated with the disease are nystagmus, decreased visual acuity, hypopigmentation of the retina, foveal hypoplasia, translucency of the iris, macular transparency, photophobia and abnormal decussation of nerve fibers at the chiasm. Case Report: An 8-year-old Caucasian girl presented to our clinic ‘Referral Center for Hereditary Retinopathies’ of the Second University of Naples with a diagnosis of Stargardt disease and a progressive reduction in visual acuity in both eyes. She underwent a complete ophthalmic examination including standard electroretinography and optical coherence tomography (OCT. A molecular analysis was also performed. Best-corrected visual acuity was 20/30 in the right eye and 20/40 in the left eye. Biomicroscopy of the anterior segment revealed a transparent cornea, in situ and transparent lens and normally pigmented iris. A mild diffuse depigmentation and macular dystrophy were observed at fundus examination. Standard electroretinography showed normal scotopic and photopic responses. OCT revealed high reflectivity across the fovea without depression. The typical OCT pattern led us to direct the molecular analysis towards the genes involved in oculocutaneous albinism. The molecular analysis identified mutations in the TYR gene. Conclusion: In this case, the role of OCT was crucial in guiding the molecular analysis for the diagnosis of albinism. OCT is therefore instrumental in similar cases that do not present typical characteristics of a disease. The case also proves the relevance of molecular analysis to confirm clinical diagnoses in hereditary retinal diseases.

OCA2 splice site variant in German Spitz dogs with oculocutaneous albinism.

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Caduff, Madleina; Bauer, Anina; Jagannathan, Vidhya; Leeb, Tosso

2017-01-01

We investigated a German Spitz family where the mating of a black male to a white female had yielded three puppies with an unexpected light brown coat color, lightly pigmented lips and noses, and blue eyes. Combined linkage and homozygosity analysis based on a fully penetrant monogenic autosomal recessive mode of inheritance identified a critical interval of 15 Mb on chromosome 3. We obtained whole genome sequence data from one affected dog, three wolves, and 188 control dogs. Filtering for private variants revealed a single variant with predicted high impact in the critical interval in LOC100855460 (XM_005618224.1:c.377+2T>G LT844587.1:c.-45+2T>G). The variant perfectly co-segregated with the phenotype in the family. We genotyped 181 control dogs with normal pigmentation from diverse breeds including 22 unrelated German Spitz dogs, which were all homozygous wildtype. Comparative sequence analyses revealed that LOC100855460 actually represents the 5'-end of the canine OCA2 gene. The CanFam 3.1 reference genome assembly is incorrect and separates the first two exons from the remaining exons of the OCA2 gene. We amplified a canine OCA2 cDNA fragment by RT-PCR and determined the correct full-length mRNA sequence (LT844587.1). Variants in the OCA2 gene cause oculocutaneous albinism type 2 (OCA2) in humans, pink-eyed dilution in mice, and similar phenotypes in corn snakes, medaka and Mexican cave tetra fish. We therefore conclude that the observed oculocutaneous albinism in German Spitz is most likely caused by the identified variant in the 5'-splice site of the first intron of the canine OCA2 gene.

Albinism in Europe.

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Mártinez-García, Mónica; Montoliu, Lluís

2013-05-01

Albinism is a rare genetic condition associated with a variable hypopigmentation phenotype, which can affect the pigmentation of only the eyes or both the eyes and the skin/hair, resulting in ocular (OA) or oculocutaneous albinism (OCA), respectively. At least four forms of OCA and one of OA are known, associated with TYR (OCA1), OCA2 (OCA2), TYRP1 (OCA3), SLC45A2 (OCA4) and GPR143 (OA1) loci, respectively. Additionally, the rarest syndromic forms of albinism, affecting the normal function of other organs, can be grouped in Hermansky-Pudlak syndrome (HPS1-9) and the Chediak-Higashi syndrome (CHS1). In summary, a total of 15 genes are currently associated with various types of albinism. However, new genes have been recently described, associated with autosomal recessive oculocutaneous albinism with highly similar phenotypes but diverse molecular origin, indicating that there are likely to be more than 15 genes whose mutations will be associated with albinism. In this review, we will describe the different types of albinism and comment on its prevalence in European countries. Some preclinical attempts for innovative therapeutic approaches of different types of albinism will be also discussed. © 2013 Japanese Dermatological Association.

OCA2 splice site variant in German Spitz dogs with oculocutaneous albinism.

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Madleina Caduff

Full Text Available We investigated a German Spitz family where the mating of a black male to a white female had yielded three puppies with an unexpected light brown coat color, lightly pigmented lips and noses, and blue eyes. Combined linkage and homozygosity analysis based on a fully penetrant monogenic autosomal recessive mode of inheritance identified a critical interval of 15 Mb on chromosome 3. We obtained whole genome sequence data from one affected dog, three wolves, and 188 control dogs. Filtering for private variants revealed a single variant with predicted high impact in the critical interval in LOC100855460 (XM_005618224.1:c.377+2T>G LT844587.1:c.-45+2T>G. The variant perfectly co-segregated with the phenotype in the family. We genotyped 181 control dogs with normal pigmentation from diverse breeds including 22 unrelated German Spitz dogs, which were all homozygous wildtype. Comparative sequence analyses revealed that LOC100855460 actually represents the 5'-end of the canine OCA2 gene. The CanFam 3.1 reference genome assembly is incorrect and separates the first two exons from the remaining exons of the OCA2 gene. We amplified a canine OCA2 cDNA fragment by RT-PCR and determined the correct full-length mRNA sequence (LT844587.1. Variants in the OCA2 gene cause oculocutaneous albinism type 2 (OCA2 in humans, pink-eyed dilution in mice, and similar phenotypes in corn snakes, medaka and Mexican cave tetra fish. We therefore conclude that the observed oculocutaneous albinism in German Spitz is most likely caused by the identified variant in the 5'-splice site of the first intron of the canine OCA2 gene.

Oculocutaneous albinism and the oral manifestation in a 14-year-old boy - A case report and review of literature

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Deepak Sharma

2017-01-01

Full Text Available Albinism consists of a group of genetically inherited autosomal recessive conditions which are typically characterized by a congenital reduction or absence in melanin pigment biosynthesis which gives the natural color in the skin, iris of the eyes, and hair. A person with albinism may have one or many of the following symptoms: absence of color in the hair, skin, or iris of the eye, lighter than normal skin and hair, patchy, missing skin color, crossed eyes (strabismus, light sensitivity (photophobia, rapid eye movements (nystagmus, vision problems, or functional blindness, severe gingivitis, oral mucosal ulceration, and periodontal disease. A dentist can play a significant role in successfully treating albino patients if he/she has basic knowledge of the symptoms of albinism. We present a case report of a 14-year-old child suffering from oculocutaneous albinism who was reported to the Department of Periodontology, Himachal Pradesh Government Dental College and Hospital, Shimla, Himachal Pradesh, with a chief complaint of bleeding gums and oral malodor.

Albinism and Developmental Delay: The Need to Test for 15q11–q13 deletion

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Saadeh, Reem; Lisi, Emily C.; Batista, Denise A.S.; McIntosh, Iain; Hoover-Fong, Julie E.

2007-01-01

We report a 17-month-old African female with cutaneous and ophthalmologic features of oculocutaneous albinism type 2 as well as microcephaly, absent speech, tremulous movements. P gene mutations within the Angelman/Prader-Willi syndrome critical region at 15q11–q13 cause oculocutaneous albinism type 2. Co-morbid oculocutaneous albinism and Angelman syndrome were suspected and confirmed by cytogenetics. Phenotypic features of Angelman syndrome or Prader-Willi syndrome in a patient with albinism should prompt further investigation. PMID:17903679

Detection of two non-synonymous SNPs in SLC45A2 on BTA20 as candidate causal mutations for oculocutaneous albinism in Braunvieh cattle.

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Rothammer, Sophie; Kunz, Elisabeth; Seichter, Doris; Krebs, Stefan; Wassertheurer, Martina; Fries, Ruedi; Brem, Gottfried; Medugorac, Ivica

2017-10-05

Cases of albinism have been reported in several species including cattle. So far, research has identified many genes that are involved in this eye-catching phenotype. Thus, when two paternal Braunvieh half-sibs with oculocutaneous albinism were detected on a private farm, we were interested in knowing whether their phenotype was caused by an already known gene/mutation. Analysis of genotyping data (50K) of the two albino individuals, their mothers and five other relatives identified a 47.61-Mb candidate haplotype on Bos taurus chromosome BTA20. Subsequent comparisons of the sequence of this haplotype with sequence data from four Braunvieh sires and the Aurochs genome identified two possible candidate causal mutations at positions 39,829,806 bp (G/A; R45Q) and 39,864,148 bp (C/T; T444I) that were absent in 1682 animals from various bovine breeds included in the 1000 bull genomes project. Both polymorphisms represent coding variants in the SLC45A2 gene, for which the human equivalent harbors numerous variants associated with oculocutaneous albinism type 4. We demonstrate an association of R45Q and T444I with the albino phenotype by targeted genotyping. Although the candidate gene SLC45A2 is known to be involved in albinism in different species, to date in cattle only mutations in the TYR and MITF genes were reported to be associated with albinism or albinism-like phenotypes. Thus, our study extends the list of genes that are associated with bovine albinism. However, further research and more samples from related animals are needed to elucidate if only one of these two single nucleotide polymorphisms or the combination of both is the actual causal variant.

Oculocutaneous albinism type 1: link between mutations, tyrosinase conformational stability, and enzymatic activity.

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Dolinska, Monika B; Kus, Nicole J; Farney, S Katie; Wingfield, Paul T; Brooks, Brian P; Sergeev, Yuri V

2017-01-01

Oculocutaneous albinism type 1 (OCA1) is an autosomal recessive disorder caused by mutations in the tyrosinase gene. Two subtypes of OCA1 have been described: severe OCA1A with complete absence of tyrosinase activity and less severe OCA1B with residual tyrosinase activity. Here, we characterize the recombinant human tyrosinase intramelanosomal domain and mutant variants, which mimic genetic changes in both subtypes of OCA1 patients. Proteins were prepared using site-directed mutagenesis, expressed in insect larvae, purified by chromatography, and characterized by enzymatic activities, tryptophan fluorescence, and Gibbs free energy changes. The OCA1A mutants showed very low protein expression and protein yield and are enzymatically inactive. Mutants mimicking OCA1B were biochemically similar to the wild type, but exhibited lower specific activities and protein stabilities. The results are consistent with clinical data, which indicates that OCA1A mutations inactivate tyrosinase and result in severe phenotype, while OCA1B mutations partially inactivate tyrosinase and result in OCA1B albinism. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

Oculocutaneous albinism in sub-Saharan Africa: adverse sun-associated health effects and photoprotection.

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Wright, Caradee Y; Norval, Mary; Hertle, Richard W

2015-01-01

Oculocutaneous albinism (OCA) is a genetically inherited autosomal recessive condition. Individuals with OCA lack melanin and therefore are susceptible to the harmful effects of solar ultraviolet radiation, including extreme sun sensitivity, photophobia and skin cancer. OCA is a grave public health issue in sub-Saharan Africa with a prevalence as high as 1 in 1000 in some tribes. This article considers the characteristics and prevalence of OCA in sub-Saharan African countries. Sun-induced adverse health effects in the skin and eyes of OCA individuals are reviewed. Sun exposure behavior and the use of photoprotection for the skin and eyes are discussed to highlight the major challenges experienced by these at-risk individuals and how these might be best resolved. © 2014 The American Society of Photobiology.

Clinical, laboratory and molecular signs of immunodeficiency in patients with partial oculo-cutaneous albinism.

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Dotta, Laura; Parolini, Silvia; Prandini, Alberto; Tabellini, Giovanna; Antolini, Maddalena; Kingsmore, Stephen F; Badolato, Raffaele

2013-10-17

Hypopigmentation disorders that are associated with immunodeficiency feature both partial albinism of hair, skin and eyes together with leukocyte defects. These disorders include Chediak Higashi (CHS), Griscelli (GS), Hermansky-Pudlak (HPS) and MAPBP-interacting protein deficiency syndromes. These are heterogeneous autosomal recessive conditions in which the causal genes encode proteins with specific roles in the biogenesis, function and trafficking of secretory lysosomes. In certain specialized cells, these organelles serve as a storage compartment. Impaired secretion of specific effector proteins from that intracellular compartment affects biological activities. In particular, these intracellular granules are essential constituents of melanocytes, platelets, granulocytes, cytotoxic T lymphocytes (CTLs) and natural killer (NK) cells. Thus, abnormalities affect pigmentation, primary hemostasis, blood cell counts and lymphocyte cytotoxic activity against microbial pathogens. Among eight genetically distinct types of HPS, only type 2 is characterized by immunodeficiency. Recently, a new subtype, HPS9, was defined in patients presenting with immunodeficiency and oculocutaneous albinism, associated with mutations in the pallidin-encoding gene, PLDN.Hypopigmentation together with recurrent childhood bacterial or viral infections suggests syndromic albinism. T and NK cell cytotoxicity are generally impaired in patients with these disorders. Specific clinical and biochemical phenotypes can allow differential diagnoses among these disorders before molecular testing. Ocular symptoms, including nystagmus, that are usually evident at birth, are common in patients with HPS2 or CHS. Albinism with short stature is unique to MAPBP-interacting protein (MAPBPIP) deficiency, while hemophagocytic lymphohistiocytosis (HLH) mainly suggests a diagnosis of CHS or GS type 2 (GS2). Neurological disease is a long-term complication of CHS, but is uncommon in other syndromic albinism. Chronic

Phacoemulsification and intraocular lens implantation in patients with oculocutaneous albinism.

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Dávila, Pedro J; Ulloa-Padilla, Jan P; Izquierdo, Natalio J

2017-01-01

To evaluate the benefits of phacoemulsification and intraocular lens implantation in patients with oculocutaneous albinism (OCA). The charts of 195 patients with OCA who visited a local eye clinic were reviewed. All of these patients had genetic linkage analysis to establish OCA type. Frequencies and Paired t-test analysis were determined. Of the 195 patients, nine (4.6%) underwent clear cornea phacoemulsification with intraocular lens implantation. Seven of the nine patients with OCA had the Hermansky-Pudlak (HPS) type 1; two had OCA type 1. Pre-operative BCVA of all eyes ranged from 1.0 to 2.3 logMAR with a mean of 1.42 logMAR and a standard deviation of 0.41 logMAR. Post-operative BCVA of all eyes ranged from 1.0 to 1.30 logMAR with a mean of 1.04 logMAR and a standard deviation of 0.10 logMAR. BCVA improved after phacoemulsification surgery and intraocular lens implantation (p = 0.002). Pre-operative astigmatism of all eyes ranged from +0.50 to +5.75 with a mean of +2.25 and a standard deviation of +2.40. Post-operative astigmatism of all eyes ranged from +0.50 to +2.00 with a mean of +1.23 and a standard deviation of +0.42. Astigmatism improved after phacoemulsification surgery and intraocular lens implantation (p = 0.05). Nine patients with OCA who underwent phacoemulsification and intraocular lens implant experienced improved visual acuity and reduced astigmatism post-operatively. These results suggest cataract surgery may improve vision and refractive errors, and thus quality of life, in patients with albinism.

Comprehensive Analysis of Oculocutaneous Albinism among Non-Hispanic Caucasians Shows that OCA1 Is the Most Prevalent OCA Type

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Hutton, Saunie M.; Spritz, Richard A.

2008-01-01

Oculocutaneous albinism (OCA) is a genetically heterogeneous group of disorders characterized by absent or reduced pigmentation of the skin, hair, and eyes. In humans, four genes have been associated with “classical” OCA and another 12 genes with syndromic forms of OCA. To assess the prevalence of different forms of OCA and different gene mutations among non-Hispanic Caucasian patients, we performed DNA sequence analysis of the four genes associated with “classical” OCA (TYR, OCA2, TYRP1, SLC...

Mutations in the Human Orthologue of the Mouse underwhite Gene (uw) Underlie a New Form of Oculocutaneous Albinism, OCA4

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Newton, J. M.; Cohen-Barak, Orit; Hagiwara, Nobuko; Gardner, John M.; Davisson, Muriel T.; King, Richard A.; Brilliant, Murray H.

2001-01-01

Oculocutaneous albinism (OCA) affects ∼1/20,000 people worldwide. All forms of OCA exhibit generalized hypopigmentation. Reduced pigmentation during eye development results in misrouting of the optic nerves, nystagmus, alternating strabismus, and reduced visual acuity. Loss of pigmentation in the skin leads to an increased risk for skin cancer. Two common forms and one infrequent form of OCA have been described. OCA1 (MIM 203100) is associated with mutations of the TYR gene encoding tyrosinas...

DNA Variations in Oculocutaneous Albinism: An Updated Mutation List and Current Outstanding Issues in Molecular Diagnostics

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Simeonov, Dimitre R.; Wang, Xinjing; Wang, Chen; Sergeev, Yuri; Dolinska, Monika; Bower, Matthew; Fischer, Roxanne; Winer, David; Dubrovsky, Genia; Balog, Joan Z.; Huizing, Marjan; Hart, Rachel; Zein, Wadih M.; Gahl, William A.; Brooks, Brian P.; Adams, David R.

2014-01-01

Oculocutaneous albinism (OCA) is a rare genetic disorder of melanin synthesis that results in hypopigmented hair, skin, and eyes. There are four types of OCA, caused by mutations in TYR (OCA-1), OCA2 (OCA-2), TYRP1 (OCA-3), or SLC45A2 (OCA-4). Here we report 22 novel mutations; 14 from a cohort of 61 patients seen as part of the NIH OCA Natural History Study and 8 from a prior study at the University of Minnesota. We also include a comprehensive list of almost 600 previously reported OCA mutations, along with ethnicity information, carrier frequencies, and in silico pathogenicity predictions. In addition to discussing the clinical and molecular features of OCA, we address the cases of apparent missing heritability. In our cohort, 25% of patients did not have two mutations in a single OCA gene. We demonstrate the utility of multiple detection methods to reveal mutations missed by Sanger sequencing. Finally, we review the TYR p.R402Q temperature sensitive variant and confirm its association with cases of albinism with only one identifiable TYR mutation. PMID:23504663

Lack of adequate sun protection for children with oculocutaneous albinism in South Africa

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Lund, Patricia M; Taylor, Julie S

2008-01-01

Background Childhood is a high risk time for ultraviolet induced skin damage as this age group has more time and opportunity to be outdoors in the sun. Children in Africa with the inherited condition oculocutaneous albinism (OCA) are especially vulnerable due to their lack of protective melanin. They are highly susceptible to developing skin lesions that have both cosmetic and health complications, with a high risk of developing skin cancers. The study aimed to explore the adequacy of sun protection strategies of children with albinism in order to inform future provision. Methods Community based participatory research methods were employed to investigate sun protection strategies in 90 pupils with OCA (40 female and 50 male) boarding at a special school educating pupils with visual impairment in a rural area of northern South Africa. Hats worn and sunscreen preparations used were examined during semi-structured face to face interviews conducted in small peer groups. The resident nurse interpreted if necessary and provided additional information on monitoring and treatment of skin lesions. Results Participants with albinism in this study were exposed to high levels of ultraviolet radiation throughout the year and showed skin damage despite wearing protective head gear. All except one pupil possessed at least one hat, with a mean brim width of 5.4 cm. Gender differences in sun avoidance behaviour were documented, with females seeking shade during recreational periods and males playing soccer outside. Although 38% of pupils were using a sunscreen with a sun protection factor (SPF) rating, only 12% had government sponsored tubes of SPF15 cream. Government sponsored sunscreen preparations were only provided if actively sought, involving time consuming trips to regional hospitals, with inadequate availability and insufficient supply. Conclusion Children with albinism living away from home in rural areas appear to have inadequate sun protection strategies. Changes in

Lack of adequate sun protection for children with oculocutaneous albinism in South Africa

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Taylor Julie S

2008-06-01

Full Text Available Abstract Background Childhood is a high risk time for ultraviolet induced skin damage as this age group has more time and opportunity to be outdoors in the sun. Children in Africa with the inherited condition oculocutaneous albinism (OCA are especially vulnerable due to their lack of protective melanin. They are highly susceptible to developing skin lesions that have both cosmetic and health complications, with a high risk of developing skin cancers. The study aimed to explore the adequacy of sun protection strategies of children with albinism in order to inform future provision. Methods Community based participatory research methods were employed to investigate sun protection strategies in 90 pupils with OCA (40 female and 50 male boarding at a special school educating pupils with visual impairment in a rural area of northern South Africa. Hats worn and sunscreen preparations used were examined during semi-structured face to face interviews conducted in small peer groups. The resident nurse interpreted if necessary and provided additional information on monitoring and treatment of skin lesions. Results Participants with albinism in this study were exposed to high levels of ultraviolet radiation throughout the year and showed skin damage despite wearing protective head gear. All except one pupil possessed at least one hat, with a mean brim width of 5.4 cm. Gender differences in sun avoidance behaviour were documented, with females seeking shade during recreational periods and males playing soccer outside. Although 38% of pupils were using a sunscreen with a sun protection factor (SPF rating, only 12% had government sponsored tubes of SPF15 cream. Government sponsored sunscreen preparations were only provided if actively sought, involving time consuming trips to regional hospitals, with inadequate availability and insufficient supply. Conclusion Children with albinism living away from home in rural areas appear to have inadequate sun protection

Children with albinism in African regions: their rights to 'being' and 'doing'.

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Franklin, Anita; Lund, Patricia; Bradbury-Jones, Caroline; Taylor, Julie

2018-01-12

Albinism is an inherited condition with a relatively high prevalence in populations throughout sub-Saharan Africa. People with oculocutaneous albinism have little or no pigment in their hair, skin and eyes; thus they are visually impaired and extremely sensitive to the damaging effect of the sun on their skin. Aside from the health implications of oculocutaneous albinism, there are also significant sociocultural risks. The impacts of albinism are particularly serious in areas that associate albinism with legend and folklore, leading to stigmatisation and discrimination. In regions of Africa those with albinism may be assaulted and sometimes killed for their body parts for use in witchcraft-related rites or to make 'lucky' charms. There is a dearth of research on the psychosocial aspects of albinism and particularly on how albinism impacts on the everyday lives of people with albinism. There is a growing recognition and acceptance in Africa that people with albinism should be considered disabled. Thomas's social-relational model of disability proposes it is essential to understand both the socio-structural barriers and restrictions that exclude disabled people (barriers to doing); and the social processes and practices which can negatively affect their psycho-emotional wellbeing (barriers to being). In this article, we combine a social model of disability with discussion on human rights to address the lacuna surrounding the psychosocial and daily experiences of people with albinism. Through using this combined framework we conclude that the rights of people with albinism in some regions of Africa are not being enacted. Our debate highlights the need to develop a holistic concept of rights for children and young people with albinism which sees human rights as indivisible. We illuminate some of the specific ways in which the lives of children with albinism could be improved by addressing 'barriers to being' and 'barriers to doing', at the heart of which requires a

[Prenatal genetic diagnosis for two Chinese families affected with oculocutaneous albinism type Ⅱ].

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Hu, Hao; Wang, Hua; Jia, Zhengjun; Xie, Qiong

2014-08-01

To perform genotyping analysis and subsequent prenatal genetic diagnosis for two families affected with oculocutaneous albinism (OCA). Direct sequencing of TYR and P genes was performed in two albino probands. Family members were screened for corresponding mutant alleles. Prenatal genetic diagnoses were performed at early pregnancy by chorionic villus sampling (CVS) at mid-pregnancy through amniocentesis. No mutations were detected in the TYR gene in either probands, whereas 4 heterozygous mutations of the P gene were found, namely c.406C>T, c.535A>G, c.808-2A>G and c.2180T>C, among which c.535A>G and c.808-2A>G were novel. In the first round prenatal genetic testing, both fetuses were found to have the same genotypes as the probands. Both families had decided to terminate the pregnancy after genetic counseling. In the second round testing, neither of the fetuses was found to be affected by genotyping. The pregnancies continued and two healthy fetuses were born. OCA can be classified by genotyping, with which reliable prenatal diagnosis and feasible genetic counseling may be provided.

PARTIAL OCULOCUTANEOUS ALBINISM AND IMMUNODEFICIENCY SYNDROMES: TEN YEARS EXPERIENCE FROM A SINGLE CENTER IN TURKEY.

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Patiroglu, T; Akar, H H; Unal, E; Chiang, S C; Schlums, H; Tesi, B; Ozkars, M Y; Karakukcu, M

2016-01-01

Partial oculocutaneous albinism and immunodeficiency (OCA-ID) diseases are autosomal recessive syndromes characterized by partial hypopigmentation and recurrent infections. Moreover, some OCA-ID syndromes confer susceptibility to develop a life-threatening hyperinflammatory condition called hemophagocytic lymphohistiocytosis (HLH). We investigated the genetic, clinical and immunological characteristics of 20 OCA patients. Herein, we present the clinical and immunological characteristics of 20 OCA patients who referred to the Department of Pediatric Immunology, Erciyes University Medical Faculty in Kayseri, Turkey between 2004 and 2014. Of the 20 OCA patients, 7 fulfilled diagnostic criteria for HLH, 9 showed defective functions of CD8 T cells and natural killer cells, and 8 received a definitive molecular diagnosis. Among the patients, we also report a patient diagnosed with two different genetic defects, in TYR and JAK3 genes, causing, respectively, OCA and ID. Our results illustrate the variability of clinical presentations and disease severity in OCA-ID patients, with consequent challenges in diagnosing and treating these patients.

Myths, Stereotypes and Self-Perception: The Impact of Albinism on Self-Esteem

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Palmer, Carolyn

2007-01-01

Albinism has the potential to affect young people both emotionally and psychologically. Their condition is unique and is surrounded by myths and stereotypes. The unusual appearance of children with oculocutaneous albinism draws attention to them and their vision impairment can impact on their development of social skills and peer relationships. In…

The Effects of the Physical Features Associated with Albinism on the Self-Esteem of African American Youths.

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Gold, Moniqueka E.

2002-01-01

This study explored the effects of the physical features associated with albinism on three groups of African American youths (ages 14-19) with albinism: those with no disabilities, those with visual impairments, and those with oculocutaneous albinism. No significant differences in self-esteem were found among the three groups. (Contains…

[Clinical and genetic aspects of albinism].

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Arveiler, Benoit; Lasseaux, Eulalie; Morice-Picard, Fanny

Albinism is a genetic disease affecting 1/17,000 person worldwide. It constitutes the second cause of congenital loss of visual acuity after optic atrophy. Albinism is heterogeneous both at the clinical and genetic levels. It is characterized by ocular development anomalies and by a variable degree of hypopigmentation. Clinically, three forms of the disease are described: oculocutaneous, ocular and syndromic (Hermansky-Pudlak syndrome, Chediak-Higashi syndrome). Nineteen genes involved in the different types of albinism have been described so far. The broad phenotypic variability between the different forms but also within a particular form renders the establishment of phenotype-genotype correlations impossible. A genetic test exploring all 19 genes is necessary to establish the diagnosis and to distinguish between syndromic and non-syndromic forms. We present the creation of an albinism-dedicated Day Hospital at the University Hospital of Bordeaux. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Oculocutaneous Albinism and Squamous Cell Carcinoma of the Skin of the Head and Neck in Sub-Saharan Africa

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P. T. Lekalakala

2015-01-01

Full Text Available Oculocutaneous albinism which is characterised by impaired melanin biosynthesis is the most common inherited pigmentary disorder of the skin and it is common among Blacks in sub-Saharan Africa. All albinos are at great risk of developing squamous cell carcinoma of sun-exposed skin, and Black albinos in sub-Saharan Africa are at about a 1000-fold higher risk of developing squamous cell carcinoma of the skin than the general population. In Black albinos, skin carcinoma tends to run an aggressive course and is likely to recur after treatment, very probably because the aetiology and predisposing factors have not changed. Prevention or reduction of occurrence of squamous cell carcinoma of the skin in Black albinos might be achieved through educating the population to increase awareness of the harmful effects of exposure to sunlight and at the same time making available effective screening programs for early detection of premalignant and malignant skin lesions in schools and communities and for early treatment.

Identification of Five Novel Variants in Chinese Oculocutaneous Albinism by Targeted Next-Generation Sequencing.

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Qiu, Biyuan; Ma, Tao; Peng, Chunyan; Zheng, Xiaoqin; Yang, Jiyun

2018-04-01

The diagnosis of oculocutaneous albinism (OCA) is established using clinical signs and symptoms. OCA is, however, a highly genetically heterogeneous disease with mutations identified in at least nineteen unique genes, many of which produce overlapping phenotypic traits. Thus, differentiating genetic OCA subtypes for diagnoses and genetic counseling is challenging, based on clinical presentation alone, and would benefit from a comprehensive molecular diagnostic. To develop and validate a more comprehensive, targeted, next-generation-sequencing-based diagnostic for the identification of OCA-causing variants. The genomic DNA samples from 28 OCA probands were analyzed by targeted next-generation sequencing (NGS), and the candidate variants were confirmed through Sanger sequencing. We observed mutations in the TYR, OCA2, and SLC45A2 genes in 25/28 (89%) patients with OCA. We identified 38 pathogenic variants among these three genes, including 5 novel variants: c.1970G>T (p.Gly657Val), c.1669A>C (p.Thr557Pro), c.2339-2A>C, and c.1349C>G (p.Thr450Arg) in OCA2; c.459_470delTTTTGCTGCCGA (p.Ala155_Phe158del) in SLC45A2. Our findings expand the mutational spectrum of OCA in the Chinese population, and the assay we developed should be broadly useful as a molecular diagnostic, and as an aid for genetic counseling for OCA patients.

Albinism in Africa as a public health issue

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Hong, Esther S; Zeeb, Hajo; Repacholi, Michael H

2006-01-01

Background Oculocutaneous albinism (OCA) is a genetically inherited autosomal recessive condition and OCA2, tyrosine-positive albinism, is the most prevalent type found throughout Africa. Due to the lack of melanin, people with albinism are more susceptible to the harmful effects of ultraviolet radiation exposure. This population must deal with issues such as photophobia, decreased visual acuity, extreme sun sensitivity and skin cancer. People with albinism also face social discrimination as a result of their difference in appearance. The World Health Organization is currently investigating the issues concerning this vulnerable population. Methods Systematic electronic search of articles in PubMed concerning albinism in Africa. Furthermore, a World Health Organization (WHO) pilot survey of albinism was drafted in English, French and Portuguese, and distributed to African countries through WHO African Regional Offices (AFRO) in an attempt to gather further information on albinism. Results Epidemiologic data on albinism, such as prevalence, were available for South Africa, Zimbabwe, Tanzania and Nigeria. Prevalences as high as 1 in 1,000 were reported for selected populations in Zimbabwe and other specific ethnic groups in Southern Africa. An overall estimate of albinism prevalences ranges from 1/5,000 – 1/15,000. In addition, both the literature review and the survey underscored the medical and social issues facing people with albinism. Conclusion The estimated prevalence of albinism suggests the existence of tens of thousands of people living with albinism in Africa. This finding reiterates the need for increased awareness of and public health interventions for albinism in order to better address the medical, psychological and social needs of this vulnerable population. PMID:16916463

Foveal hemorrhage in an eye with foveal hypoplasia associated with albinism

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Masuda N

2014-09-01

Full Text Available Naonori Masuda, Taiji Hasegawa, Mariko Yamashita, Nahoko Ogata Department of Ophthalmology, Nara Medical University, Nara, Japan Abstract: Oculocutaneous albinism is a group of congenital disorders caused by alterations of melanin biosynthesis. We report our findings in a patient with oculocutaneous albinism who presented with foveal hypoplasia and a foveal hemorrhage. A 48-year-old man noted a dark spot in the middle of the visual field of his right eye. He had depigmented skin, white hair, white eyebrows, and white cilia. He also had horizontal nystagmus and depigmented irides. His best-corrected visual acuity was 2/100 with -14.0 diopters in the right eye and 3/100 with -5.0 diopters in the left eye. Ophthalmoscopy showed diffuse depigmentation in both eyes and a foveal hemorrhage in the right eye. Optical coherence tomography showed the absence of a foveal pit in both eyes and a subretinal hyperreflective lesion corresponding to the foveal hemorrhage in the right eye. Fluorescein angiography showed that the retinal and choroidal vessels were relatively hypofluorescent because of the lack of a blocking effect of the pigments in the retinal pigment epithelium. Fluorescein angiography and indocyanine green angiography did not show any evidence of choroidal neovascularization in either eye. The foveal hemorrhage in the right eye spontaneously regressed and finally resolved at 3 months after onset. At the final examination, the patient reported that his vision had recovered. A foveal hemorrhage is a rare condition in an eye with foveal hypoplasia associated with albinism. The hemorrhage may be related to high myopia and also to the hypoplasia of the fovea associated with albinism. Keywords: albinism, foveal hemorrhage, foveal hypoplasia, simple hemorrhage

Genetic Testing for Oculocutaneous Albinism Type 1 and 2 and Hermansky–Pudlak Syndrome Type 1 and 3 Mutations in Puerto Rico

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Santiago Borrero, Pedro J.; Rodríguez-Pérez, Yolanda; Renta, Jessicca Y.; Izquierdo, Natalio J.; del Fierro, Laura; Muñoz, Daniel; Molina, Norma López; Ramírez, Sonia; Pagán-Mercado, Glorivee; Ortíz, Idith; Rivera-Caragol, Enid; Spritz, Richard A.; Cadilla, Carmen L.

2013-01-01

Hermansky–Pudlak syndrome (HPS) (MIM #203300) is a heterogeneous group of autosomal recessive disorders characterized by oculocutaneous albinism (OCA), bleeding tendency, and lysosomal dysfunction. HPS is very common in Puerto Rico (PR), particularly in the northwest part of the island, with a frequency of ~1:1,800. Two HPS genes and mutations have been identified in PR, a 16-base pair (bp) duplication in HPS1 and a 3,904-bp deletion in HPS3. In Puerto Ricans with more typical OCA, the most common mutation of the tyrosinase (TYR) (human tyrosinase (OCA1) gene) gene was G47D. We describe screening 229 Puerto Rican OCA patients for these mutations, and for mutations in the OCA2 gene. We found the HPS1 mutation in 42.8% of cases, the HPS3 deletion in 17%, the TYR G47D mutation in 3.0%, and a 2.4-kb deletion of the OCA2 gene in 1.3%. Among Puerto Rican newborns, the frequency of the HPS1 mutation is highest in northwest PR (1:21; 4.8%) and lower in central PR (1:64; 1.6%). The HPS3 gene deletion is most frequent in central PR (1:32; 3.1%). Our findings provide insights into the genetics of albinism and HPS in PR, and provide the basis for genetic screening for these disorders in this minority population. PMID:16417222

Foveal hemorrhage in an eye with foveal hypoplasia associated with albinism.

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Masuda, Naonori; Hasegawa, Taiji; Yamashita, Mariko; Ogata, Nahoko

2014-01-01

Oculocutaneous albinism is a group of congenital disorders caused by alterations of melanin biosynthesis. We report our findings in a patient with oculocutaneous albinism who presented with foveal hypoplasia and a foveal hemorrhage. A 48-year-old man noted a dark spot in the middle of the visual field of his right eye. He had depigmented skin, white hair, white eyebrows, and white cilia. He also had horizontal nystagmus and depigmented irides. His best-corrected visual acuity was 2/100 with -14.0 diopters in the right eye and 3/100 with -5.0 diopters in the left eye. Ophthalmoscopy showed diffuse depigmentation in both eyes and a foveal hemorrhage in the right eye. Optical coherence tomography showed the absence of a foveal pit in both eyes and a subretinal hyperreflective lesion corresponding to the foveal hemorrhage in the right eye. Fluorescein angiography showed that the retinal and choroidal vessels were relatively hypofluorescent because of the lack of a blocking effect of the pigments in the retinal pigment epithelium. Fluorescein angiography and indocyanine green angiography did not show any evidence of choroidal neovascularization in either eye. The foveal hemorrhage in the right eye spontaneously regressed and finally resolved at 3 months after onset. At the final examination, the patient reported that his vision had recovered. A foveal hemorrhage is a rare condition in an eye with foveal hypoplasia associated with albinism. The hemorrhage may be related to high myopia and also to the hypoplasia of the fovea associated with albinism.

Functional characterization of two novel splicing mutations in the OCA2 gene associated with oculocutaneous albinism type II.

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Rimoldi, Valeria; Straniero, Letizia; Asselta, Rosanna; Mauri, Lucia; Manfredini, Emanuela; Penco, Silvana; Gesu, Giovanni P; Del Longo, Alessandra; Piozzi, Elena; Soldà, Giulia; Primignani, Paola

2014-03-01

Oculocutaneous albinism (OCA) is characterized by hypopigmentation of the skin, hair and eye, and by ophthalmologic abnormalities caused by a deficiency in melanin biosynthesis. OCA type II (OCA2) is one of the four commonly-recognized forms of albinism, and is determined by mutation in the OCA2 gene. In the present study, we investigated the molecular basis of OCA2 in two siblings and one unrelated patient. The mutational screening of the OCA2 gene identified two hitherto-unknown putative splicing mutations. The first one (c.1503+5G>A), identified in an Italian proband and her affected sibling, lies in the consensus sequence of the donor splice site of OCA2 intron 14 (IVS14+5G>A), in compound heterozygosity with a frameshift mutation, c.1450_1451insCTGCCCTGACA, which is predicted to determine the premature termination of the polypeptide chain (p.I484Tfs*19). In-silico prediction of the effect of the IVS14+5G>A mutation on splicing showed a score reduction for the mutant splice site and indicated the possible activation of a newly-created deep-intronic acceptor splice site. The second mutation is a synonymous transition (c.2139G>A, p.K713K) involving the last nucleotide of exon 20. This mutation was found in a young African albino patient in compound heterozygosity with a previously-reported OCA2 missense mutation (p.T404M). In-silico analysis predicted that the mutant c.2139G>A allele would result in the abolition of the splice donor site. The effects on splicing of these two novel mutations were investigated using an in-vitro hybrid-minigene approach that led to the demonstration of the causal role of the two mutations and to the identification of aberrant transcript variants. Copyright © 2013 Elsevier B.V. All rights reserved.

Macular pigment optical density spatial distribution measured in a subject with oculocutaneous albinism.

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Putnam, Christopher M; Bland, Pauline J

2014-01-01

Previous studies of macular pigment optical density (MPOD) distribution in individuals with oculocutaneous albinism (OCA) have primarily used objective measurement techniques including fundus reflectometry and autofluorescence. We report here on a subject with OCA and their corresponding MPOD distribution assessed through heterochromatic flicker photometry (HFP). A subject with a history of OCA presented with an ocular history including strabismus surgery of the LE with persistent amblyopia and mild, latent nystagmus. Best corrected visual acuity was 20/25- RE and 20/40- LE. Spectral domain optical coherence tomography (SD-OCT) and fundus photography were also obtained. Evaluation of MPOD spatial distribution up to 8 degrees eccentricity from the fovea was performed using HFP. SD-OCT indicated a persistence of multiple inner retinal layers within the foveal region in the RE and LE including symmetric foveal thickening consistent with foveal hypoplasia. Fundus photography showed mild retinal pigmented epithelial (RPE) hypopigmentation and a poorly demarcated macula. OriginPro 9 was used to plot MPOD spatial distribution of the subject and a 33-subject sample. The OCA subject demonstrated a foveal MPOD of 0.10 with undetectable levels at 6 degrees eccentricity. The study sample showed a mean foveal MPOD of 0.34 and mean 6 degree eccentricity values of 0.03. Consistent with previous macular pigment (MP) studies of OCA, overall MPOD is reduced in our subject. Mild phenotypic expression of OCA with high functional visual acuity may represent a Henle fiber layer amenable to additional MP deposition. Further study of MP supplementation in OCA patients is warranted. Copyright © 2014 Spanish General Council of Optometry. Published by Elsevier Espana. All rights reserved.

Identification of a missense mutation in the tyrosinase gene in a Chinese family with oculocutaneous albinism type 1.

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Lu, Qian; Yuan, Lamei; Xu, Hongbo; Huang, Xiangjun; Yang, Zhijian; Yi, Junhui; Ni, Bin; Chen, Yong; Deng, Hao

2017-03-01

Oculocutaneous albinism (OCA) is a group of heterogeneous and autosomal recessive disorders characterized by a reduction or complete loss of melanin biosynthesis in melanocytes. OCA type 1 (OCA1) is the most severe and common form of OCA, and is caused by mutations in the tyrosinase gene (TYR). The present study aimed to identify the genetic cause of OCA1 in a four‑generation consanguineous Chinese Han family. Complete physical examinations were performed and blood samples were collected from five members of the family and 100 unrelated healthy controls. Exome sequencing was conducted in the proband, followed by verification in other family members, using Sanger sequencing. Patients in the family presented with typical OCA1 features, including hypopigmentation of the skin and hair, and distinctive ocular changes. A homozygous missense variant, c.896G>A (p.R299H), in the TYR gene was identified in two patients, which co‑segregated with disease in the family. This variant was not present in the 100 healthy controls. These results expand the number of mutations identified to be responsible for OCA1 in the Chinese Han population, and may have implications for genetic counseling and clinical management of the disease.

Albinism in Africa: stigma, slaughter and awareness campaigns.

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Cruz-Inigo, Andres E; Ladizinski, Barry; Sethi, Aisha

2011-01-01

Oculocutaneous albinism is an autosomal recessive disorder characterized by a lack of pigment in the hair, skin, and eyes. Albinism is caused by defective or absent tyrosinase, an enzyme necessary for melanogenesis. Although rare in the western world, albinism is quite common in sub-Saharan Africa, likely as a result of consanguinity. Albinism has long been associated with stigma and superstitions, such as the belief that a white man impregnated the mother or that the child is the ghost of a European colonist. Recently, a notion has emerged that albino body parts are good-luck charms or possess magical powers. These body parts may be sold for as much as $75,000 on the black market. As a result there have been over 100 albino murders in Tanzania, Burundi, and other parts of Africa in the past decade, which is now beginning to garner international attention and thus prompting novel legislation. To ameliorate the plight of individuals with albinism in Africa, a coordinated effort must be organized, involving medical professionals (dermatologists, ophthalmologists, oncologists), public health advocates and educators, social workers, human rights and antidiscrimination activists, law-enforcement agencies, and governmental support groups. The main issues that should be addressed include skin cancer prevention education, stigma and discrimination denouncement, and swift prosecution of albino hunters and their sponsors. Copyright © 2011. Published by Elsevier Inc.

Diagnóstico laboratorial do albinismo oculocutâneo Laboratory diagnosis of oculocutaneous albinism

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Luciane de Melo Rocha

2007-02-01

Full Text Available OBJETIVO: Avaliar os métodos laboratoriais dos diferentes tipos de albinismo oculocutâneo (OCA 1 e OCA 2 de forma descritiva e analisar sua eficiência. MATERIAL E MÉTODO: O teste do bulbo capilar é um método químico usado para distinguir as duas formas, no entanto recentemente teve sua eficácia como teste padrão contestada. O avanço da biologia molecular permite a análise das mutações que causam o distúrbio e a sua localização gênica. CONCLUSÃO: O teste do bulbo é seguro apenas para o diagnóstico do OCA 1A, podendo ser usado como complemento de um método mais apurado. A análise molecular fornece um diagnóstico definitivo, permitindo distinguir OCA 1 de OCA 2, pois as mutações afetam genes em cromossomos diferentes.OBJECTIVES: To evaluate the laboratories methods of the oculocutaneous albinism (OCA 1and OCA 2 of descriptive form and to analyze its results. METHODS: The hair bulb test is a chemical method used to distinguish the two forms, however, recently had its effectiveness as an standard test contested. The advance of molecular biology allows the analysis of the mutations that cause the disturb and its genic location. CONCLUSIONS: The bulb test is secure only for the diagnosis of OCA 1A, being able to be used as complement of a more refined method. The molecular analysis supplies a diagnostic definitive allowing to distinguish OCA 1 from OCA 2, because the mutations affect genes in different chromosomes.

Increasing the complexity: new genes and new types of albinism.

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Montoliu, Lluís; Grønskov, Karen; Wei, Ai-Hua; Martínez-García, Mónica; Fernández, Almudena; Arveiler, Benoît; Morice-Picard, Fanny; Riazuddin, Saima; Suzuki, Tamio; Ahmed, Zubair M; Rosenberg, Thomas; Li, Wei

2014-01-01

Albinism is a rare genetic condition globally characterized by a number of specific deficits in the visual system, resulting in poor vision, in association with a variable hypopigmentation phenotype. This lack or reduction in pigment might affect the eyes, skin, and hair (oculocutaneous albinism, OCA), or only the eyes (ocular albinism, OA). In addition, there are several syndromic forms of albinism (e.g. Hermansky-Pudlak and Chediak-Higashi syndromes, HPS and CHS, respectively) in which the described hypopigmented and visual phenotypes coexist with more severe pathological alterations. Recently, a locus has been mapped to the 4q24 human chromosomal region and thus represents an additional genetic cause of OCA, termed OCA5, while the gene is eventually identified. In addition, two new genes have been identified as causing OCA when mutated: SLC24A5 and C10orf11, and hence designated as OCA6 and OCA7, respectively. This consensus review, involving all laboratories that have reported these new genes, aims to update and agree upon the current gene nomenclature and types of albinism, while providing additional insights from the function of these new genes in pigment cells. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Comprehensive analysis of oculocutaneous albinism among non-Hispanic caucasians shows that OCA1 is the most prevalent OCA type.

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Hutton, Saunie M; Spritz, Richard A

2008-10-01

Oculocutaneous albinism (OCA) is a genetically heterogeneous group of disorders characterized by absent or reduced pigmentation of the skin, hair, and eyes. In humans, four genes have been associated with "classical" OCA and another 12 genes with syndromic forms of OCA. To assess the prevalence of different forms of OCA and different gene mutations among non-Hispanic Caucasian patients, we performed DNA sequence analysis of the four genes associated with "classical" OCA (TYR, OCA2, TYRP1, SLC45A2), the two principal genes associated with syndromic OCA (HPS1, HPS4), and a candidate OCA gene (SILV), in 121 unrelated, unselected non-Hispanic/Latino Caucasian patients carrying the clinical diagnosis of OCA. We identified apparent pathologic TYR gene mutations in 69% of patients, OCA2 mutations in 18%, SLC45A2 mutations in 6%, and no apparent pathological mutations in 7% of patients. We found no mutations of TYRP1, HPS1, HPS4, or SILV in any patients. Although we observed a diversity of mutations for each gene, a relatively small number of different mutant alleles account for a majority of the total. This study demonstrates that, contrary to long-held clinical lore, OCA1, not OCA2, is by far the most frequent cause of OCA among Caucasian patients.

Refractive errors, visual impairment, and the use of low-vision devices in albinism in Malawi.

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Schulze Schwering, M; Kumar, N; Bohrmann, D; Msukwa, G; Kalua, K; Kayange, P; Spitzer, M S

2015-04-01

This study focuses on the refractive implications of albinism in Malawi, which is mostly associated with the burden of visual impairment. The main goal was to describe the refractive errors and to analyze whether patients with albinism in Malawi, Sub-Saharan Africa, benefit from refraction. Age, sex, refractive data, uncorrected and best-corrected visual acuity (UCVA, BCVA), colour vision, contrast sensitivity, and the prescription of sunglasses and low vision devices were collected for a group of 120 albino individuals with oculocutaneous albinism (OCA). Refractive errors were evaluated objectively and subjectively by retinoscopy, and followed by cycloplegic refraction to reconfirm the results. Best-corrected visual acuity (BCVA) was also assessed binocularly. One hundred and twenty albino subjects were examined, ranging in age from 4 to 25 years (median 12 years), 71 (59 %) boys and 49 (41 %) girls. All exhibited horizontal pendular nystagmus. Mean visual acuity improved from 0.98 (0.33) logMAR to 0.77 (0.15) logMAR after refraction (p < 0.001). The best improvement of VA was achieved in patients with mild to moderate myopia. Patients with albinism who were hyperopic more than +1.5 D hardly improved from refraction. With the rule (WTR) astigmatism was more present (37.5 %) than against the rule (ATR) astigmatism (3.8 %). Patients with astigmatism less than 1.5 D improved in 15/32 of cases (47 %) by 2 lines or more. Patients with astigmatism equal to or more than 1.5 D in any axis improved in 26/54 of cases (48 %) by 2 lines or more. Refraction improves visual acuity of children with oculocutaneous albinism in a Sub-Saharan African population in Malawi. The mean improvement was 2 logMAR units.

Abnormal lateral geniculate nucleus and optic chiasm in human albinism.

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Mcketton, Larissa; Kelly, Krista R; Schneider, Keith A

2014-08-01

Our objective was to measure how the misrouting of retinal ganglion cell (RGC) fibers affects the organization of the optic chiasm and lateral geniculate nuclei (LGN) in human albinism. We compared the chiasmal structures and the LGN in both pigmented controls and patients with albinism by using high-resolution structural magnetic resonance imaging (MRI). We studied 12 patients with oculocutaneous albinism and 12 age-matched pigmented controls. Using a 3T MRI scanner, we acquired a T1 -weighted three-dimensional magnetization-prepared rapid gradient-echo (MPRAGE) image of the whole brain, oriented so that the optic nerves, chiasm, and tracts were in the same plane. We acquired multiple proton density-weighted images centered on the thalamus and midbrain, and averaged them to increase the signal, enabling precise manual tracing of the anatomical boundaries of the LGN. Albinism patients exhibited significantly smaller diameters of the optic nerves, chiasm and tracts, and optic chiasm and LGN volume compared with controls (P albinism compared with the control group can be attributed to the abnormal crossing of optic fibers and the reduction of RGCs in the central retina. The volume of the LGN devoted to the center of the visual field may be reduced in albinism due to fewer RGCs representing the area where the fovea would normally lie. Our data may be clinically useful in addressing how genetic deficits compromise proper structural and functional development in the brain. © 2014 Wiley Periodicals, Inc.

TYPES OF ALBINISM IN THE BLACK SOUTHERN AFRICA POPULATION.

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Kromberg, J G R; Bothwell, J; Kidson, S H; Manga, P; Kerr, R; Jenkins, T

2012-01-01

Oculocutaneous albinism (OCA) is the most common inherited disorder in Southern African blacks and several types have been described. Molecular techniques, where available, can be used to confirm a clinical diagnosis and the type of OCA, if necessary, and for prenatal diagnosis. To investigate and classify the different types of albinism commonly found and to determine the clinical implications for each type. A descriptive survey. Gauteng province, South Africa, and Lesotho. Three groups of subjects with OCA (96 from a genetics clinic, 62 from a dermatology clinic, and 31 from community surveys) from the black African population participated. Subjects underwent clinical and/or dermatological examinations and were then classified according to type of OCA. Four forms of OCA were identified: most (82%) subjects had OCA2 (a tyrosinase- positive type) with three sub-types: those without large freckles (ephelides) on exposed areas (named OCA 2a in this study), those with such freckles (named OCA 2b), and those with brown albinism (BOCA); the remainder had red/rufous albinism, ROCA (OCA 3). The four forms could be distinguished from each other clinically without using molecular genetic testing. The most common types of albinism found in the black population of Southern Africa are OCA2 and OCA3. Given the high prevalence of the disorder, together with the high risk of skin cancer, and the recent persecution of affected individuals in certain East African countries, these findings and their clinical implications have significance in terms of both education and awareness for health professionals and lay people caring for those with albinism.

Dömda att leva i skuggan : En kvalitativ intervjustudie om hälsan hos personer med albinism i Rwanda, utifrån begreppen diskriminering, coping och socialt stöd

OpenAIRE

Niyonkuru, Elsie Diane

2016-01-01

Bakgrund: Oculocutaneous albinism (OCA) är en ärftlig sjukdom som fysiskt, psykiskt och socialt påverkar de drabbade individerna. Okunskap, fördomar och myter om albinism utgör de största orsakerna till den diskriminering som personer med albinism utsatts för särskilt i vissa länder i Afrika söder om Sahara. Syfte: Syftet är att beskriva hälsan hos personer med albinism i Rwanda, utifrån begreppen diskriminering, coping och socialt stöd. Metod: En kvalitativ metod med induktiv ansats ligger t...

Presence of fusion in albinism after strabismus surgery augmented with botulinum toxin (type a) injection.

Science.gov (United States)

Tavakolizadeh, Sepideh; Farahi, Azadeh

2013-08-01

It is commonly accepted that albino patients with strabismus rarely achieve binocularity and depth perception after strabismus surgery. The presence of retino-geniculo-cortical misrouting, a hallmark of the visual system in albinism, does not necessarily cause total loss of binocular vision, however, not even in albino patients with strabismus. Recently some degrees of stereopsis were reported in albinism patients with minimal clinical nystagmus, if any, in the absence of strabismus. It is possible that patients with albinism and strabismus have binocular visual potential which appears after strabismus correction and provides appropriate postoperative alignment in the long term. Here we present two cases of clinically diagnosed oculocutaneous albinism, an 18-year-old girl and a 16-year-old boy, both with exotropia ≥40 prism diopter, who gained acceptable alignment and fusion after surgical correction of their strabismus as demonstrated on Bagolini testing. In cases of albinism accompanied by visual pathway abnormalities and strabismus, binocular visual potential is not impossible, and some levels can be expected. Thus, these patients, like other cases of strabismus, may benefit from treatment of strabismus at an earlier age to achieve appropriate alignment, cosmetic satisfaction, and a possibly increased chance of fusion.

A partial gene deletion of SLC45A2 causes oculocutaneous albinism in Doberman pinscher dogs.

Directory of Open Access Journals (Sweden)

Paige A Winkler

Full Text Available The first white Doberman pinscher (WDP dog was registered by the American Kennel Club in 1976. The novelty of the white coat color resulted in extensive line breeding of this dog and her offspring. The WDP phenotype closely resembles human oculocutaneous albinism (OCA and clinicians noticed a seemingly high prevalence of pigmented masses on these dogs. This study had three specific aims: (1 produce a detailed description of the ocular phenotype of WDPs, (2 objectively determine if an increased prevalence of ocular and cutaneous melanocytic tumors was present in WDPs, and (3 determine if a genetic mutation in any of the genes known to cause human OCA is causal for the WDP phenotype. WDPs have a consistent ocular phenotype of photophobia, hypopigmented adnexal structures, blue irides with a tan periphery and hypopigmented retinal pigment epithelium and choroid. WDPs have a higher prevalence of cutaneous melanocytic neoplasms compared with control standard color Doberman pinschers (SDPs; cutaneous tumors were noted in 12/20 WDP (5 years of age: 8/8 and 1/20 SDPs (p<0.00001. Using exclusion analysis, four OCA causative genes were investigated for their association with WDP phenotype; TYR, OCA2, TYRP1 and SLC45A2. SLC45A2 was found to be linked to the phenotype and gene sequencing revealed a 4,081 base pair deletion resulting in loss of the terminus of exon seven of SLC45A2 (chr4∶77,062,968-77,067,051. This mutation is highly likely to be the cause of the WDP phenotype and is supported by a lack of detectable SLC45A2 transcript levels by reverse transcriptase PCR. The WDP provides a valuable model for studying OCA4 visual disturbances and melanocytic neoplasms in a large animal model.

Combined Occurrence of Autosomal Dominant Aniridia and Autosomal Recessive Albinism in Several Members of a Family.

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Yahalom, Claudia; Sharon, Dror; Dalia, Eli; Simhon, Shiran Ben; Shemesh, Efrat; Blumenfeld, Anat

2015-06-01

To characterize clinical and genetic aspects of a family with a unique combination of two hereditary blinding eye diseases. Comprehensive eye examination of proband and family members. Molecular analyses of the TYR and PAX6 genes. A young couple, both legally blind, requested genetic counselling regarding their ocular condition. The female was previously diagnosed with oculocutaneous albinism (OCA1A) and her spouse was diagnosed with Peters anomaly. A comprehensive clinical examination revealed that the female had OCA1A combined with signs of another ocular disease, showing some similarity to aniridia. A complete ocular examination of her family members revealed that her brother also suffered from the same combined phenotype, her father had typical OCA1A signs, and her mother and sister had aniridia-like phenotype, without clinical diagnosis until the time of presentation. Molecular analysis identified two compound heterozygous TYR mutations known to cause OCAIA and cosegregate with oculocutaneous albinism. In addition, we identified a novel heterozygous PAX6 mutation confirming the atypical aniridia phenotype. We report here a unique and rare clinical phenotype that is explained by the segregation of two severe inherited eye diseases. The clinical and genetic analysis in this family allowed them to receive accurate genetic counseling.

SLC45A2 mutation frequency in Oculocutaneous Albinism Italian patients doesn't differ from other European studies.

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Mauri, Lucia; Barone, Luca; Al Oum, Muna; Del Longo, Alessandra; Piozzi, Elena; Manfredini, Emanuela; Stanzial, Franco; Benedicenti, Francesco; Penco, Silvana; Patrosso, Maria Cristina

2014-01-01

Oculocutaneous Albinism (OCA) is a heterogeneous group of inherited diseases involving hair, skin and eyes. To date, six forms are recognized on the effects of different melanogenesis genes. OCA4 is caused by mutations in SLC45A2 showing a heterogeneous phenotype ranging from white hair, blue irides and nystagmus to brown/black hair, brown irides and no nystagmus. The high clinic variety often leads to misdiagnosis. Our aim is to contribute to OCA4 diagnosis defining SLC45A2 genetic variants in Italian patients with OCA without any TYR, OCA2 and TYRP1 gene defects. After the clinical diagnosis of OCA, all patients received genetic counseling and genetic test. Automatic sequencing of TYR, OCA2, and TYRP1 genes was performed on DNA of 117 albino patients. Multiplex Ligation-dependent Probe Amplification (MLPA) was carried out on TYR and OCA2 genes to increase the mutation rate. SLC45A2 gene sequencing was then executed in the patients with a single mutation in one of the TYR, OCA2, TYRP1 genes and in the patients, which resulted negative at the screening of these genes. SLC45A2 gene analysis was performed in 41 patients and gene alterations were found in 5 patients. Four previously reported SLC45A2 mutations were found: p.G100S, p.W202C, p.A511E and c.986delC, and three novel variants were identified: p.M265L, p.H94D, and c.1156+1G>A. All the alterations have been detected in the group of patients without mutations in the other OCA genes. Three new variants were identified in OCA4 gene; the analysis allowed the classification of a patient previously misdiagnosed as OA1 because of skin and hair pigmentation presence. The molecular defects in SLC45A2 gene represent the 3.4% in this cohort of Italian patients, similar to other Caucasian populations; our data differ from those previously published by an Italian researcher group, obtained on a smaller cohort of patients. © 2013 Elsevier B.V. All rights reserved.

Birth prevalence and mutation spectrum in danish patients with autosomal recessive albinism

DEFF Research Database (Denmark)

Grønskov, Karen; Ek, Jakob; Sand, Annie

2009-01-01

PURPOSE: The study was initiated to investigate the mutation spectrum of four OCA genes and to calculate the birth prevalence in patients with autosomal recessive albinism. METHODS: Mutation analysis using dHPLC or direct DNA sequencing of TYR, OCA2, TYRP1, and MATP was performed in 62 patients....... Two mutations in one OCA gene explained oculocutaneous albinism (OCA) in 44% of the patients. Mutations in TYR were found in 26% of patients, while OCA2 and MATP caused OCA in 15% and 3%, respectively. No mutations were found in TYRP1. Of the remaining 56% of patients, 29% were heterozygous...... for a mutation in either TYR or OCA2, and 27% were without mutations in any of the four genes. Exclusive expression of the mutant allele was found in four heterozygous patients. A minimum birth prevalence of 1 in 14,000 was calculated, based on register data on 218 patients. The proportion of OCA to autosomal...

Sequence-Based Mapping and Genome Editing Reveal Mutations in Stickleback Hps5 Cause Oculocutaneous Albinism and the casper Phenotype

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James C. Hart

2017-09-01

Full Text Available Here, we present and characterize the spontaneous X-linked recessive mutation casper, which causes oculocutaneous albinism in threespine sticklebacks (Gasterosteus aculeatus. In humans, Hermansky-Pudlak syndrome results in pigmentation defects due to disrupted formation of the melanin-containing lysosomal-related organelle (LRO, the melanosome. casper mutants display not only reduced pigmentation of melanosomes in melanophores, but also reductions in the iridescent silver color from iridophores, while the yellow pigmentation from xanthophores appears unaffected. We mapped casper using high-throughput sequencing of genomic DNA from bulked casper mutants to a region of the stickleback X chromosome (chromosome 19 near the stickleback ortholog of Hermansky-Pudlak syndrome 5 (Hps5. casper mutants have an insertion of a single nucleotide in the sixth exon of Hps5, predicted to generate an early frameshift. Genome editing using CRISPR/Cas9 induced lesions in Hps5 and phenocopied the casper mutation. Injecting single or paired Hps5 guide RNAs revealed higher incidences of genomic deletions from paired guide RNAs compared to single gRNAs. Stickleback Hps5 provides a genetic system where a hemizygous locus in XY males and a diploid locus in XX females can be used to generate an easily scored visible phenotype, facilitating quantitative studies of different genome editing approaches. Lastly, we show the ability to better visualize patterns of fluorescent transgenic reporters in Hps5 mutant fish. Thus, Hps5 mutations present an opportunity to study pigmented LROs in the emerging stickleback model system, as well as a tool to aid in assaying genome editing and visualizing enhancer activity in transgenic fish.

Oculocutaneous albinism: identifying and overcoming barriers to vision care in a Nigerian population.

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Udeh, N N; Eze, B I; Onwubiko, S N; Arinze, O C; Onwasigwe, E N; Umeh, R E

2014-06-01

To assess eye care service utilization, and identify access barriers in a south-eastern Nigerian albino population. The study was a population-based, cross-sectional survey conducted in Enugu state between August, 2011 and January, 2012. Using the data base of the state's Albino Foundation and tailored awareness creation, persons living with albinism were identified and recruited at two study centres. Data on participants' socio-demographics, perception of vision, visual needs, previous eye examination and or low vision assessment, use of glasses or low vision devices were collected. Reasons for non-utilisation of available vision care services were also obtained. Descriptive and comparative statistics were performed. A p low vision assessment and none--0.0% had used low vision device. Of the participants, 82.4% reported previous eye examination, 33.3% had not used spectacles previously, despite the existing need. Ignorance--88.9% and poor access--8.5% were the main barriers to uptake of vision care services. In Enugu, Nigeria, there is poor awareness and low utilization of vision care services among people with albinism. The identified barriers to vision care access are amenable to awareness creation and logistic change in the provision of appropriate vision care services.

Molecular basis of albinism in India: evaluation of seven potential candidate genes and some new findings.

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Mondal, M; Sengupta, M; Samanta, S; Sil, A; Ray, K

2012-12-15

Albinism represents a group of genetic disorders with a broad spectrum of hypopigmentary phenotypes dependent on the genetic background of the patients. Oculocutaneous albinism (OCA) patients have little or no pigment in their eyes, skin and hair, whereas ocular albinism (OA) primarily presents the ocular symptoms, and the skin and hair color may vary from near normal to very fair. Mutations in genes directly or indirectly regulating melanin production are responsible for different forms of albinism with overlapping clinical features. In this study, 27 albinistic individuals from 24 families were screened for causal variants by a PCR-sequencing based approach. TYR, OCA2, TYRP1, SLC45A2, SLC24A5, TYRP2 and SILV were selected as candidate genes. We identified 5 TYR and 3 OCA2 mutations, majority in homozygous state, in 8 unrelated patients including a case of autosomal recessive ocular albinism (AROA). A homozygous 4-nucleotide novel insertion in SLC24A5 was detected in a person showing with extreme cutaneous hypopigmentation. A potential causal variant was identified in the TYRP2 gene in a single patient. Haplotype analyses in the patients carrying homozygous mutations in the classical OCA genes suggested founder effect. This is the first report of an Indian AROA patient harboring a mutation in OCA2. Our results also reveal for the first time that mutations in SLC24A5 could contribute to extreme hypopigmentation in humans. Copyright © 2012 Elsevier B.V. All rights reserved.

Socio-Cultural Conception of Albinism

African Journals Online (AJOL)

DR Nneka

2015-04-14

Apr 14, 2015 ... and possibly getting married especially if they are from a wealthy home. Similarly a ... male child, than the females with albinism (FWA). ... have been abandoned by their parents and guardians, taken to the forest and ..... The lack of knowledge, misinformation and negative attitudes about albinism.

Homozygosity mapping in albinism patients using a novel panel of 13 STR markers inside the nonsyndromic OCA genes: introducing 5 novel mutations.

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Khordadpoor-Deilamani, Faravareh; Akbari, Mohammad Taghi; Karimipoor, Morteza; Javadi, Gholam Reza

2016-05-01

Albinism is a heterogeneous genetic disorder of melanin synthesis that results in hypopigmented hair, skin and eyes. It is associated with decreased visual acuity, nystagmus, strabismus and photophobia. Six genes are known to be involved in nonsyndromic oculocutaneous albinism (OCA). In this study, we aimed to find the disease causing mutations in albinism patients using homozygosity mapping. Twenty three unrelated patients with nonsyndromic OCA or autosomal recessive ocular albinism were recruited in this study. All of the patients' parents had consanguineous marriage and all were screened for TYR mutations previously. At first, we performed homozygosity mapping using fluorescently labeled primers to amplify a novel panel of 13 STR markers inside the OCA genes and then the screened loci in each family were studied using PCR and cycle sequencing methods. We found five mutations including three mutations in OCA2, one mutation in SLC45A2 and one mutation in C10ORF11 genes, all of which were novel. In cases where the disease causing mutations are identical by descent due to a common ancestor, these STR markers can enable us to screen for the responsible genes.

Molecular and Clinical Characterization of Albinism in a Large Cohort of Italian Patients

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Gargiulo, Annagiusi; Testa, Francesco; Rossi, Settimio; Di Iorio, Valentina; Fecarotta, Simona; de Berardinis, Teresa; Iovine, Antonello; Magli, Adriano; Signorini, Sabrina; Fazzi, Elisa; Galantuomo, Maria Silvana; Fossarello, Maurizio; Montefusco, Sandro; Ciccodicola, Alfredo; Neri, Alberto; Macaluso, Claudio; Simonelli, Francesca; Surace, Enrico Maria

2011-01-01

Purpose. The purpose of this study was to identify the molecular basis of albinism in a large cohort of Italian patients showing typical ocular landmarks of the disease and to provide a full characterization of the clinical ophthalmic manifestations. Methods. DNA samples from 45 patients with ocular manifestations of albinism were analyzed by direct sequencing analysis of five genes responsible for albinism: TYR, P, TYRP1, SLC45A2 (MATP), and OA1. All patients studied showed a variable degree of skin and hair hypopigmentation. Eighteen patients with distinct mutations in each gene associated with OCA were evaluated by detailed ophthalmic analysis, optical coherence tomography (OCT), and fundus autofluorescence. Results. Disease-causing mutations were identified in more than 95% of analyzed patients with OCA (28/45 [62.2%] cases with two or more mutations; 15/45 [33.3%] cases with one mutation). Thirty-five different mutant alleles were identified of which 15 were novel. Mutations in TYR were the most frequent (73.3%), whereas mutations in P occurred more rarely (13.3%) than previously reported. Novel mutations were also identified in rare loci such as TYRP1 and MATP. Mutations in the OA1 gene were not detected. Clinical assessment revealed that patients with iris and macular pigmentation had significantly higher visual acuity than did severe hypopigmented phenotypes. Conclusions. TYR gene mutations represent a relevant cause of oculocutaneous albinism in Italy, whereas mutations in P present a lower frequency than that found in other populations. Clinical analysis revealed that the severity of the ocular manifestations depends on the degree of retinal pigmentation. PMID:20861488

Molecular genetic studies and delineation of the oculocutaneous albinism phenotype in the Pakistani population

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Jaworek Thomas J

2012-06-01

Full Text Available Abstract Background Oculocutaneous albinism (OCA is caused by a group of genetically heterogeneous inherited defects that result in the loss of pigmentation in the eyes, skin and hair. Mutations in the TYR, OCA2, TYRP1 and SLC45A2 genes have been shown to cause isolated OCA. No comprehensive analysis has been conducted to study the spectrum of OCA alleles prevailing in Pakistani albino populations. Methods We enrolled 40 large Pakistani families and screened them for OCA genes and a candidate gene, SLC24A5. Protein function effects were evaluated using in silico prediction algorithms and ex vivo studies in human melanocytes. The effects of splice-site mutations were determined using an exon-trapping assay. Results Screening of the TYR gene revealed four known (p.Arg299His, p.Pro406Leu, p.Gly419Arg, p.Arg278* and three novel mutations (p.Pro21Leu, p.Cys35Arg, p.Tyr411His in ten families. Ex vivo studies revealed the retention of an EGFP-tagged mutant (p.Pro21Leu, p.Cys35Arg or p.Tyr411His tyrosinase in the endoplasmic reticulum (ER at 37°C, but a significant fraction of p.Cys35Arg and p.Tyr411His left the ER in cells grown at a permissive temperature (31°C. Three novel (p.Asp486Tyr, p.Leu527Arg, c.1045-15 T > G and two known mutations (p.Pro743Leu, p.Ala787Thr of OCA2 were found in fourteen families. Exon-trapping assays with a construct containing a novel c.1045-15 T > G mutation revealed an error in splicing. No mutation in TYRP1, SLC45A2, and SLC24A5 was found in the remaining 16 families. Clinical evaluation of the families segregating either TYR or OCA2 mutations showed nystagmus, photophobia, and loss of pigmentation in the skin or hair follicles. Most of the affected individuals had grayish-blue colored eyes. Conclusions Our results show that ten and fourteen families harbored mutations in the TYR and OCA2 genes, respectively. Our findings, along with the results of previous studies, indicate that the p.Cys35Arg, p.Arg278

Psychiatric Morbidity among Subjects with Leprosy and Albinism in ...

African Journals Online (AJOL)

Subjects and Methods: One hundred subjects with leprosy and 100 with albinism were interviewed. .... change negative mind-sets and sociocultural stereotypes about albinism in ... respondent's age, gender, marital status, occupation, the highest ... Variables such as age, sex, marital status, occupation, level of education,.

Cutaneous cancers in Nigerian albinos: a review of 22 cases | Awe ...

African Journals Online (AJOL)

Context: Albinism is an inherited disorder of hypopigmentation involving the skin, eyes, and hair. This disorder results in the absence or reduction in melanin production. There are two main types of albinism which are ocular albinism and oculocutaneous albinism. It could also be classified as syndromic or nonsyndromic the ...

A novel nonsense mutation in the tyrosinase gene is related to the albinism in a capuchin monkey (Sapajus apella).

Science.gov (United States)

Galante Rocha de Vasconcelos, Felipe Tadeu; Hauzman, Einat; Dutra Henriques, Leonardo; Kilpp Goulart, Paulo Roney; de Faria Galvão, Olavo; Sano, Ronaldo Yuiti; da Silva Souza, Givago; Lynch Alfaro, Jessica; de Lima Silveira, Luis Carlos; Fix Ventura, Dora; Oliveira Bonci, Daniela Maria

2017-05-05

Oculocutaneous Albinism (OCA) is an autosomal recessive inherited condition that affects the pigmentation of eyes, hair and skin. The OCA phenotype may be caused by mutations in the tyrosinase gene (TYR), which expresses the tyrosinase enzyme and has an important role in the synthesis of melanin pigment. The aim of this study was to identify the genetic mutation responsible for the albinism in a captive capuchin monkey, and to describe the TYR gene of normal phenotype individuals. In addition, we identified the subject's species. A homozygous nonsense mutation was identified in exon 1 of the TYR gene, with the substitution of a cytosine for a thymine nucleotide (C64T) at codon 22, leading to a premature stop codon (R22X) in the albino robust capuchin monkey. The albino and five non-albino robust capuchin monkeys were identified as Sapajus apella, based on phylogenetic analyses, pelage pattern and geographic provenance. One individual was identified as S. macrocephalus. We conclude that the point mutation C64T in the TYR gene is responsible for the OCA1 albino phenotype in the capuchin monkey, classified as Sapajus apella.

Hermansky-Pudlak syndrome

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Preena A

2017-04-01

Full Text Available Hermansky-Pudlak syndrome is a rare autosomal recessive multisystem disease, with oculocutneous albinism, pulmonary fibrosis and bleeding diathesis. Here we report a case of Hermansky-Pudlak syndrome who presented with dyspnea, oculocutaneous albinism and nystagmus.

A Missense Mutation in SLC45A2 Is Associated with Albinism in Several Small Long Haired Dog Breeds.

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Wijesena, Hiruni R; Schmutz, Sheila M

2015-01-01

Homozygosity for a large deletion in the solute carrier family 45, member 2 (SLC45A2) gene causes oculocutaneous albinism (OCA) in the Doberman Pinscher breed. An albino Lhasa Apso did not have this g.27141_31223del (CanFam2) deletion in her SLC45A2 sequence. Therefore, SLC45A2 was investigated in this female Lhasa Apso to search for other possible variants that caused her albinism. The albino Lhasa Apso was homozygous for a nonsynonymous substitution in the seventh exon, a c.1478G>A base change that resulted in a glycine to aspartic acid substitution (p.G493D). This mutation was not found in a wolf, a coyote, or any of the 15 other Lhasa Apso dogs or 32 other dogs of breeds related to the Lhasa Apso. However, an albino Pekingese, 2 albino Pomeranians, and an albino mixed breed dog that was small and long haired were also homozygous for the 493D allele. The colored puppies of the albino Lhasa Apso and the colored dam of the 2 albino Pomeranians were heterozygous for this allele. However, an albino Pug was homozygous for the 493G allele and therefore although we suggest the 493D allele causes albinism when homozygous in several small, long haired dog breeds, it does not explain all albinism in dogs. A variant effect prediction for the albino Lhasa Apso confirms that p.G493D is a deleterious substitution, and a topology prediction for SLC45A2 suggests that the 11th transmembrane domain where the 493rd amino acid was located, has an altered structure. © The American Genetic Association 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Large-scale recombinant expression and purificatoin of human tyrosinase suitabel for structural studies

NARCIS (Netherlands)

Lai, X.; Soler-Lopez, M.; Wichers, H.J.; Dijkstra, Bouke

2016-01-01

Human tyrosinase (TYR) is a glycoprotein that initiates the first two reactions in the melanin biosynthesis pathway. Mutations in its encoding gene cause Oculocutaneous Albinism type I (OCA1), the most severe form of albinism, which is a group of autosomal recessive disorders characterized by

Malignant Melanoma in an Albino | Efem | Sudan Journal of Medical ...

African Journals Online (AJOL)

Oculocutaneous albinism is a rare autosomal recessive disorder characterised by generalised depigmentation, photophobia, decreased visual acuity, and nystagmus. Malignant melanoma is rare in patients with albinism. We report a case of a large advanced fumigating tumour on the right forearm of a male Nigerian albino ...

Hermansky F, Pudlak P. Albinism associated with hemorrhagic diathesis and unusual pigmented reticular cells in the bone marrow: report of two cases with histochemical studies. Blood. 1959;14(2):162-169.

Science.gov (United States)

2016-04-07

This landmark article by Frantisek Hermansky and Paulus Pudlak, clinicians in Prague, Czechoslovakia, is the first to describe 2 unrelated individuals with what is now called Hermansky-Pudlak syndrome, a bleeding disorder that occurs in association with oculocutaneous albinism. The definition of this syndrome resulted not only in improved care of these patients but also in a functional and molecular understanding of the disease and the role of dense granule secretion in platelet function. Hermansky-Pudlak syndrome is now known to be related to defective dense granule biogenesis due to mutations in any of ≥9 different genes.

Albinism: classification, clinical characteristics, and recent findings.

Science.gov (United States)

Summers, C Gail

2009-06-01

To describe the clinical characteristics and recent findings in the heterogeneous group of inherited disorders of melanin biosynthesis grouped as "albinism." The current classification of albinism, and the cutaneous, ocular, and central nervous system characteristics are presented. Recent clinical findings are summarized. Albinism is now classified based on genes known to be responsible for albinism. Foveal hypoplasia is invariably present and individuals with albinism often have delayed visual development, reduced vision, nystagmus, a positive angle kappa, strabismus, iris transillumination, and absent or reduced melanin pigment in the fundi. A visual-evoked potential can document the excessive retinostriate decussation seen in albinism. Grating acuity can be used to document delayed visual development in preverbal children. Glasses are often needed to improve visual acuity and binocular alignment. Albinism is caused by several different genes. Heterogeneity in clinical phenotype indicates that expressivity is variable.

X-linked ocular albinism in Blacks. Ocular albinism cum pigmento.

Science.gov (United States)

O'Donnell, F E; Green, W R; Fleischman, J A; Hambrick, G W

1978-07-01

X-linked ocular albinism can be an unsuspected cause of congenital nystagmus in blacks. In this study, eight of ten black ocular albinos from two kindreds had nonalbinotic, moderately pigmented fundi and no transillumination of the iris. We refer to this paradoxical condition as "ocular albinism cum pigmento." The only constant ophthalmoscopic feature was a foveal hypoplasia. Biopsy of clinically normal skin to demonstrate giant pigment granules is the most accurate means of diagnosis.

Progressive retinal degeneration in a girl with Knobloch syndrome who presented with signs of ocular albinism.

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Gradstein, Libe; Hansen, Ronald M; Cox, Gerald F; Altschwager, Pablo; Fulton, Anne B

2017-04-01

We report for the first time electroretinographic (ERG) evidence of progressive retinal abnormalities in a girl who presented in infancy with ocular features of albinism and gradually developed choroidal sclerosis and patchy retinal atrophy leading to a diagnosis of Knobloch syndrome (KS, OMIM 267750, COL18A1). At age 2 months, nystagmus and esotropia prompted ophthalmic evaluation. The appearance of choroidal sclerosis and atrophic retinal patches led to further evaluation at age 8 years. Genetics consultation was obtained in infancy and again at age 8 years as retinal findings evolved. Full field ERG responses in both scotopic and photopic conditions were recorded at both ages and compared to those in healthy control subjects. At age 2 months ERG response parameters were within normal limits for age and tyrosinase (TYR) gene sequencing revealed one novel mutation, p.S466F, and the temperature-sensitive polymorphism, p.R402Q, suggesting the diagnosis of oculocutaneous albinism type 1 (OCA1). At age 8 years, there was significant attenuation of both scotopic and photopic ERG responses. Genetic re-analysis led to the identification of a homozygous mutation, c.3213dupC, in the COL18A1 gene, thus confirming the diagnosis of Knobloch syndrome. Our patient with Knobloch syndrome developed abnormal ERG responses similar to those found in col18a1 knockout mice. Thus, we have documented progressive attenuation of the scotopic and photopic responses in KS.

Retrospective analysis in oculocutaneous albinism patients for the 2.7 kb deletion in the OCA2 gene revealed a co-segregation of the controversial variant, p.R305W.

Science.gov (United States)

Gao, Jackson; D'Souza, Leera; Wetherby, Keith; Antolik, Christian; Reeves, Melissa; Adams, David R; Tumminia, Santa; Wang, Xinjing

2017-01-01

Oculocutaneous albinism (OCA) is an autosomal recessive disorder. A significant portion of OCA patients has been found with a single pathogenic variant either in the TYR or the OCA2 gene. Diagnostic sequencing of the TYR and OCA2 genes is routinely used for molecular diagnosis of OCA subtypes. To study the possibility that genomic abnormalities with single or multiple exon involvement may account for a portion of the potential missing pathogenic variants (the second), we retrospectively analyzed the TYR gene by long range PCR and analyzed the target 2.7 kb deletion in the OCA2 gene spanning exon 7 in OCA patients with a single pathogenic variant in the target genes. In the 108 patients analyzed, we found that one patient was heterozygous for the 2.7 kb OCA2 gene deletion and this patient was positive with one pathogenic variant and one possibly pathogenic variant [c.1103C>T (p.Ala368Val) + c.913C>T (p.R305W)]. Further analysis of maternal DNA, and two additional OCA DNA homozygous for the 2.7 kb deletion, revealed that the phenotypically normal mother is heterozygous of the 2.7 kb deletion and homozygous of the p.R305W. The two previously reported patients with homozygous of the 2.7 kb deletion are also homozygous of p.R305W. Among the reported pathogenic variants, the pathogenicity of the p.R305W has been discussed intensively in literature. Our results indicate that p.R305W is unlikely a pathogenic variant. The possibility of linkage disequilibrium between p.R305W with the 2.7 kb deletion in OCA2 gene is also suggested.

The albinism of the feral Asinara white donkeys (Equus asinus) is determined by a missense mutation in a highly conserved position of the tyrosinase (TYR) gene deduced protein.

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Utzeri, V J; Bertolini, F; Ribani, A; Schiavo, G; Dall'Olio, S; Fontanesi, L

2016-02-01

A feral donkey population (Equus asinus), living in the Asinara National Park (an island north-west of Sardinia, Italy), includes a unique white albino donkey subpopulation or colour morph that is a major attraction of this park. Disrupting mutations in the tyrosinase (TYR) gene are known to cause recessive albinisms in humans (oculocutaneous albinism Type 1; OCA1) and other species. In this study, we analysed the donkey TYR gene as a strong candidate to identify the causative mutation of the albinism of these donkeys. The TYR gene was sequenced from 13 donkeys (seven Asinara white albino and six coloured animals). Seven single nucleotide polymorphisms were identified. A missense mutation (c.604C>G; p.His202Asp) in a highly conserved amino acid position (even across kingdoms), which disrupts the first copper-binding site (CuA) of functional protein, was identified in the homozygous condition (G/G or D/D) in all Asinara white albino donkeys and in the albino son of a trio (the grey parents had genotype C/G or H/D), supporting the recessive mode of inheritance of this mutation. Genotyping 82 donkeys confirmed that Asinara albino donkeys had genotype G/G whereas all other coloured donkeys had genotype C/C or C/G. Across-population association between the c.604C>G genotypes and the albino coat colour was highly significant (P = 6.17E-18). The identification of the causative mutation of the albinism in the Asinara white donkeys might open new perspectives to study the dynamics of this putative deleterious allele in a feral population and to manage this interesting animal genetic resource. © 2015 Stichting International Foundation for Animal Genetics.

Albinism: Educational Techniques for Parents and Teachers.

Science.gov (United States)

Ashley, Julia R.; Cates, Dennis L.

1992-01-01

A survey of teachers of the visually impaired and adults with albinism or parents of children with albinism (total responses=144) found no use of Braille by the adults or children with albinism, awareness of the condition by almost all teachers, support for mainstreaming by all, and specific teaching suggestions from teachers. (DB)

Changes in brain morphology in albinism reflect reduced visual acuity.

Science.gov (United States)

Bridge, Holly; von dem Hagen, Elisabeth A H; Davies, George; Chambers, Claire; Gouws, Andre; Hoffmann, Michael; Morland, Antony B

2014-07-01

Albinism, in humans and many animal species, has a major impact on the visual system, leading to reduced acuity, lack of binocular function and nystagmus. In addition to the lack of a foveal pit, there is a disruption to the routing of the nerve fibers crossing at the optic chiasm, resulting in excessive crossing of fibers to the contralateral hemisphere. However, very little is known about the effect of this misrouting on the structure of the post-chiasmatic visual pathway, and the occipital lobes in particular. Whole-brain analyses of cortical thickness in a large cohort of subjects with albinism showed an increase in cortical thickness, relative to control subjects, particularly in posterior V1, corresponding to the foveal representation. Furthermore, mean cortical thickness across entire V1 was significantly greater in these subjects compared to controls and negatively correlated with visual acuity in albinism. Additionally, the group with albinism showed decreased gyrification in the left ventral occipital lobe. While the increase in cortical thickness in V1, also found in congenitally blind subjects, has been interpreted to reflect a lack of pruning, the decreased gyrification in the ventral extrastriate cortex may reflect the reduced input to the foveal regions of the ventral visual stream. Copyright © 2012 Elsevier Ltd. All rights reserved.

A Comparison of the Interactive Play Behaviours between Children with Albinism and Their Siblings and Children without Albinism and Their Non-Albino Siblings

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Javangwe, Gwatirera; Mukondyo, Rachel Z.

2012-01-01

The study explored the nature of the interactive play behaviours of children with albinism and children without albinism and compared the interactive behaviours of both children with albinism and children without albinism. Naturalistic observations were conducted during periods of free play, using the interactive play behaviour checklist aided by…

Psychiatric Morbidity among Subjects with Leprosy and Albinism in ...

African Journals Online (AJOL)

Background: Skin, which is the largest organ in the body, carries immense psychological significance. Disfiguring skin disorders may impact negatively on the mental health of individuals. Aim: This study compared the psychiatric morbidity of subjects with leprosy and albinism. Subjects and Methods: One hundred subjects ...

Psychiatric Morbidity among Subjects with Leprosy and Albinism in South East Nigeria: A Comparative Study

Science.gov (United States)

Attama, CM; Uwakwe, R; Onyeama, GM; Igwe, MN

2015-01-01

Background: Skin, which is the largest organ in the body, carries immense psychological significance. Disfiguring skin disorders may impact negatively on the mental health of individuals. Aim: This study compared the psychiatric morbidity of subjects with leprosy and albinism. Subjects and Methods: One hundred subjects with leprosy and 100 with albinism were interviewed. Sociodemographic questionnaire and General Health Questionnaire (GHQ-28) assessed the sociodemographic characteristics and psychiatric morbidity, respectively. GHQ positive cases and 10% of noncases for each group were interviewed with Mini International Neuropsychiatric Inventory for specific ICD-10 diagnoses. Results: Fifty-five percent (55/100) subjects with leprosy were GHQ positive cases while 41% (41/100) with albinism were GHQ positive cases. The risk of developing psychiatric morbidity was significantly higher in subjects with leprosy than in subjects with albinism (OR = 1.76, CI = 1.00 – 3.08, P = 0.04). The prevalence of specific psychiatric disorders among subjects with leprosy were depression 49% (49/100), generalized anxiety disorder (GAD) 18% (18/100), alcohol/drug abuse 16% (16/100), whereas in albinism depression was 51% (51/100), GAD 27% (27/100), and alcohol/drug abuse 7% (7/100). Male, married and uneducated subjects with leprosy had significantly higher psychiatric morbidity than the male, married and uneducated subjects with albinism, respectively. Conclusion: Psychiatric morbidity was higher in subjects with leprosy than in subjects with albinism. Male, married and uneducated subjects with leprosy significantly had higher morbidity than male, married and uneducated subjects with albinism respectively. PMID:26097762

The Student with Albinism in the Regular Classroom.

Science.gov (United States)

Ashley, Julia Robertson

This booklet, intended for regular education teachers who have children with albinism in their classes, begins with an explanation of albinism, then discusses the special needs of the student with albinism in the classroom, and presents information about adaptations and other methods for responding to these needs. Special social and emotional…

Albinism

Science.gov (United States)

... testing is helpful if you have a family history of albinism. It is also useful for certain groups of people who are known to get the disease. Your health care provider may also diagnose the condition based on the appearance of your skin, hair, and eyes. An eye doctor called an ...

Prosthodontic management of an albinism patient-dental implications and management.

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Murthy, Varsha; V, Yuvraj; Thomas, Shaji; Nair, Preeti

2013-01-22

Albinism is a congenital hypopigmentary disorder. Albinism is due to the dysfunction of the melanin-producing cells (melanocytes) resulting in defective production of melanin from tyrosine through a complex pathway of metabolic reactions. Little is known about the varied dental features that albinism presents with. This case report summarises the features encountered in albinism, the different oral findings available in the literature and also presents a case of an albinism patient treated with fixed partial denture and the precautions to be exercised for such patients.

Altered whole-brain connectivity in albinism.

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Welton, Thomas; Ather, Sarim; Proudlock, Frank A; Gottlob, Irene; Dineen, Robert A

2017-02-01

Albinism is a group of congenital disorders of the melanin synthesis pathway. Multiple ocular, white matter and cortical abnormalities occur in albinism, including a greater decussation of nerve fibres at the optic chiasm, foveal hypoplasia and nystagmus. Despite this, visual perception is largely preserved. It was proposed that this may be attributable to reorganisation among cerebral networks, including an increased interhemispheric connectivity of the primary visual areas. A graph-theoretic model was applied to explore brain connectivity networks derived from resting-state functional and diffusion-tensor magnetic resonance imaging data in 23 people with albinism and 20 controls. They tested for group differences in connectivity between primary visual areas and in summary network organisation descriptors. Main findings were supplemented with analyses of control regions, brain volumes and white matter microstructure. Significant functional interhemispheric hyperconnectivity of the primary visual areas in the albinism group were found (P = 0.012). Tests of interhemispheric connectivity based on the diffusion-tensor data showed no significant group difference (P = 0.713). Second, it was found that a range of functional whole-brain network metrics were abnormal in people with albinism, including the clustering coefficient (P = 0.005), although this may have been driven partly by overall differences in connectivity, rather than reorganisation. Based on the results, it was suggested that changes occur in albinism at the whole-brain level, and not just within the visual processing pathways. It was proposed that their findings may reflect compensatory adaptations to increased chiasmic decussation, foveal hypoplasia and nystagmus. Hum Brain Mapp 38:740-752, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

GPR143 gene mutation analysis in pediatric patients with albinism.

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Trebušak Podkrajšek, Katarina; Stirn Kranjc, Branka; Hovnik, Tinka; Kovač, Jernej; Battelino, Tadej

2012-09-01

X-linked ocular albinism type 1 is difficult to differentiate clinically from other forms of albinism in young patients. X-linked ocular albinism type 1 is caused by mutations in the GPR143 gene, encoding melanosome specific G-protein coupled receptor. Patients typically present with moderately to severely reduced visual acuity, nystagmus, strabismus, photophobia, iris translucency, hypopigmentation of the retina, foveal hypoplasia and misrouting of optic nerve fibers at the chiasm. Following clinical ophthalmological evaluation, GPR143 gene mutational analyses were performed in a cohort of 15 pediatric male patients with clinical signs of albinism. Three different mutations in the GPR143 gene were identified in four patients, including a novel c.886G>A (p.Gly296Arg) mutation occurring "de novo" and a novel intronic c.360 + 5G>A mutation, identified in two related boys. Four patients with X-linked ocular albinism type 1 were identified from a cohort of 15 boys with clinical signs of albinism using mutation detection methods. Genetic analysis offers the possibility of early definitive diagnosis of ocular albinism type 1 in a significant portion of boys with clinical signs of albinism.

Complete albinism in a Podarcis muralis newborn

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Filippo Spadola

2007-01-01

Full Text Available The authors describe a case of complete albinism in a Podarcis muralis newborn, from Chieti (Abruzzo, central Italy in September 2004. This is the first complete albinism case in a Podarcis spp. In the world.

Basosquamous carcinoma in an Indian patient with oculocutaneous albinism

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Ranjan Nitin

2009-01-01

Full Text Available A middle-aged man with type IA OCA presented to us with a large ulcerated plaque of three year duration over the forehead. Histopathology showed basosquamous carcinoma in the form of distinct areas of basal and squamous differentiation. Metastasis workup was negative. Complete surgical excision, strict photoprotection and regular follow-up were advised. A timely recognition of this potentially aggressive neoplasm is the key to curative treatment.

Albinism, stigma, subjectivity and global-local discourses in Tanzania.

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Brocco, Giorgio

2016-12-01

Societal ideas and explanations of albinism at the local level in Tanzania are conceived in terms of family history, social relations, economic status, moral-religious positions, global-local flows of information and humanitarian actions on behalf of people with the congenital condition. This paper aims to show how the subjectivities of people with albinism in Tanzania are shaped and re-shaped through local moral conceptions as well as globalizing (bio)medical explanations of albinism. An exemplary case study of a 28-year-old woman, plus episodes from the lives of seven other informants with the condition, are analyzed in order to understand, on the one hand, local social relationships between people with albinism and other individuals in family and community settings, and on the other hand, the interconnections between persons with albinism and global humanitarian actors and the broadcast media. When stigma and marginalizing behaviors are perceived by individuals with albinism in Tanzania as impeding their social lives, they employ different coping strategies and discourses to enhance social acceptance.

Clinical Insights Into Foveal Morphology in Albinism.

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McCafferty, Brandon K; Wilk, Melissa A; McAllister, John T; Stepien, Kimberly E; Dubis, Adam M; Brilliant, Murray H; Anderson, Jennifer L; Carroll, Joseph; Summers, C Gail

2015-01-01

A hallmark of albinism is foveal hypoplasia. However, literature suggests variable foveal development. This study evaluates the association between ocular phenotype and foveal morphology to demonstrate the broad structural and functional spectrum. Best-corrected visual acuity (BCVA), nystagmus, angle kappa, stereoacuity, iris transillumination, macular melanin presence, foveal avascular zone, and annular reflex were recorded in 14 patients with albinism. Spectral-domain optical coherence tomography provided macular images. The clinical phenotype was broad, with BCVA varying from 20/20 to 20/100. Better BCVA was associated with a preserved foveal avascular zone, annular macular reflex, stereoacuity, and macular melanin. Imaging demonstrated a continuum of foveal development correlating with BCVA. Individuals with a rudimentary pit had normal inner and outer segment lengthening and better BCVA. The spectrum of ocular structure and visual function in albinism is broad, suggesting a possible diagnosis of albinism in a patient with an even more normal clinical presentation. Copyright 2015, SLACK Incorporated.

Albinism in Tanzanian higher education: a case study

OpenAIRE

Kiishweko, Rose Rutagemwa

2017-01-01

My thesis focuses on the experiences of people with albinism in higher education (HE)\\ud in Tanzania. Albinism is a genetically inherited condition and it affects people of all\\ud ethnic backgrounds worldwide. In Tanzania, the condition affects one in every 1,400\\ud people. People with albinism in Tanzania often face social discrimination, superstition,\\ud and prejudice including murder threats due to myths and beliefs that their body parts are\\ud a source of wealth and prosperity. They also ...

Increasing the complexity

DEFF Research Database (Denmark)

Montoliu, Lluís; Grønskov, Karen; Wei, Ai-Hua

2014-01-01

6 and OCA7, respectively. This consensus review, involving all laboratories that have reported these new genes, aims to update and agree upon the current gene nomenclature and types of albinism, while providing additional insights from the function of these new genes in pigment cells.......Albinism is a rare genetic condition globally characterized by a number of specific deficits in the visual system, resulting in poor vision, in association with a variable hypopigmentation phenotype. This lack or reduction in pigment might affect the eyes, skin, and hair (oculocutaneous albinism......, OCA), or only the eyes (ocular albinism, OA). In addition, there are several syndromic forms of albinism (e.g. Hermansky-Pudlak and Chediak-Higashi syndromes, HPS and CHS, respectively) in which the described hypopigmented and visual phenotypes coexist with more severe pathological alterations...

Albinism: A Survey of Attitudes and Behavior.

Science.gov (United States)

Vander Kolk, Charles J.; Bright, Bobra C.

1983-01-01

Attitudes of tenth graders were more positive after receiving information about and exposure to albinism, an inherited condition affecting skin and hair color as well as visual functioning. Attitude difficulties are compounded by poor self-concept and racial factors. Albinic persons frequently know very little about the condition. (CL)

Genetics Home Reference: oculocutaneous albinism

Science.gov (United States)

... 17 [updated 2017 Sep 7]. In: Pagon RA, Adam MP, Ardinger HH, Wallace SE, Amemiya A, Bean LJH, Bird TD, Ledbetter N, Mefford HC, Smith RJH, Stephens K, editors. GeneReviews® [Internet]. Seattle (WA): ...

Albinism: particular attention to the ocular motor system.

Science.gov (United States)

Hertle, Richard W

2013-01-01

The purpose of this report is to summarize an understanding of the ocular motor system in patients with albinism. Other than the association of vertical eccentric gaze null positions and asymmetric, (a) periodic alternating nystagmus in a large percentage of patients, the ocular motor system in human albinism does not contain unique pathology, rather has "typical" types of infantile ocular oscillations and binocular disorders. Both the ocular motor and afferent visual system are affected to varying degrees in patients with albinism, thus, combined treatment of both systems will maximize visual function.

The early-stage diagnosis of albinic embryos by applying optical coherence tomography

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Yang, Bor-Wen; Wang, Shih-Yuan; Wang, Yu-Yen; Cai, Jyun-Jhang; Chang, Chung-Hao

2013-09-01

Albinism is a kind of congenital disease of abnormal metabolism. Poecilia reticulata (guppy fish) is chosen as the model to study the development of albinic embryos as it is albinic, ovoviviparous and with short life period. This study proposed an imaging method for penetrative embryo investigation using optical coherence tomography. By imaging through guppy mother’s reproduction purse, we found the embryo’s eyes were the early-developed albinism features. As human’s ocular albinism typically appear at about four weeks old, it is the time to determine if an embryo will grow into an albino.

Arrested Development: High-Resolution Imaging of Foveal Morphology in Albinism

Science.gov (United States)

McAllister, John T.; Dubis, Adam M.; Tait, Diane M.; Ostler, Shawn; Rha, Jungtae; Stepien, Kimberly E.; Summers, C. Gail; Carroll, Joseph

2010-01-01

Albinism, an inherited disorder of melanin biosynthesis, disrupts normal retinal development, with foveal hypoplasia as one of the more commonly associated ocular phenotypes. However the cellular integrity of the fovea in albinism is not well understood – there likely exist important anatomical differences that underlie phenotypic variability within the disease and that also may affect responsiveness to therapeutic intervention. Here, using spectral domain optical coherence tomography (SD-OCT) and adaptive optics (AO) retinal imaging, we obtained high-resolution images of the foveal region in six individuals with albinism. We provide a quantitative analysis of cone density and outer segment elongation demonstrating that foveal cone specialization is variable in albinism. In addition, our data reveal a continuum of foveal pit morphology, roughly aligning with schematics of normal foveal development based on post-mortem analyses. Different albinism subtypes, genetic mutations, and constitutional pigment background likely play a role in determining the degree of foveal maturation. PMID:20149815

Socio-Cultural Conception of Albinism and Sexuality Challenges ...

African Journals Online (AJOL)

Socio-Cultural Conception of Albinism and Sexuality Challenges among Persons with Albinism (PWA) in South-West, Nigeria. ... For the female PWA the risk of being used for money making rituals; not knowing a sincere partner; their more fragile nature and perceived fear of societal objection and hatred in seeing a ...

Hermansky-Pudlak syndrome type 2 manifests with fibrosing lung disease early in childhood

NARCIS (Netherlands)

Hengst, M. (Meike); Naehrlich, L. (Lutz); P. Mahavadi (Poornima); Grosse-Onnebrink, J. (Joerg); Terheggen-Lagro, S. (Suzanne); Skanke, L.Hø. (Lars Høsøien); Schuch, L.A. (Luise A.); Brasch, F. (Frank); A. Guenther (Andreas); S. Reu (Simone); Ley-Zaporozhan, J. (Julia); Griese, M. (Matthias)

2018-01-01

textabstractBackground: Hermansky-Pudlak syndrome (HPS), a hereditary multisystem disorder with oculocutaneous albinism, may be caused by mutations in one of at least 10 separate genes. The HPS-2 subtype is distinguished by the presence of neutropenia and knowledge of its pulmonary phenotype in

Higher prevalence of OCA1 in an ethnic group of eastern India is due to a founder mutation in the tyrosinase gene.

NARCIS (Netherlands)

Chaki, M.; Mukhopadhyay, A.; Chatterjee, S.; Das, M.; Samanta, S.; Ray, K.

2005-01-01

PURPOSE: Oculocutaneous albinism (OCA) is a group of autosomal recessive disorders characterized by deficient synthesis of melanin pigment and associated with common developmental abnormalities of the eye. It is one of the major causes of childhood blindness in India. The disease is common among an

Perceived effects of coloured overlays on reading material in persons with albinism

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N. T. Makgaba

2008-12-01

Full Text Available Persons with albinism often complain of glare when reading. They may therefore benefit from coloured filter overlays just as they benefit from tinted lenses. The purpose of this study was to assess the effectof coloured overlays on print perception in persons with oculocutaneous albinism (OCA.   Fifty subjects were included in this study, their ages ranged from 12 to 31 years with a mean of 16.12 years (SD = ± 4.56 years.  Following refraction and subsequent compensation for refractive errors, subjective perception of print was examined with the subject looking at the Wilkins® reading rate test chart with and without colored filter overlay/s.  The subjects were asked to respond to questions previously used in a questionnaire by Wilkins (2001. The percentage frequencies of positive (beneficial responses were used to decide whether or not a particular overlay would enhance reading performance.  McNemar’s test was used to establish significant differences between responses to questions without and with overlays. All single overlays gave greater percentages of positive responses (92.0-97.2% than without overlay (85.2%.  The single overlay that provided the highest positive responses was blue (97.2% and the least was purple (92.0%. All double overlays, except grey/grey (82.0% gave greater positive responses than without overlay (85.2%. Aqua/blue gave the greatest positive responses (possible benefits (97.2%, followed by rose/rose (96.8%.  Comparing the responses without overlay with single and double overlays, the difference in responses to the five questions was only significant (p < 0.05 with regard to brightness of the surface. The results suggest that overlays provided a more glare-free reading surface than without an overlay. It was, therefore concluded that the best advantage of the coloured overlays was in glare reduction.  Although this study showed that there were more subjects who preferred single blue and aqua/blue double

OCA1 in different ethnic groups of india is primarily due to founder mutations in the tyrosinase gene.

NARCIS (Netherlands)

Chaki, M.; Sengupta, M.S.; Mukhopadhyay, A.; Subba Rao, I.; Majumder, P.P.; Das, M.; Samanta, S.; Ray, K.

2006-01-01

Oculocutaneous albinism (OCA) is a heterogeneous group of autosomal recessive disorders characterized by an abnormally low amount of melanin in the eyes, skin and hair, and associated with common developmental abnormalities of the eye. Defects in the tyrosinase gene (TYR) cause a common type of OCA,

Chédiak-Higashi syndrome: presentation of seven cases

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Eugénia Maria Grilo Carnide

Full Text Available CONTEXT: Chédiak-Higashi Syndrome (CHS is a rare autosomal recessive disease characterized by recurrent infections, giant cytoplasmic granules, and oculocutaneous albinism. OBJECTIVE: To describe clinical and laboratory findings from CHS patients. DESIGN: Case report. SETTING: The patients were admitted into the Allergy and Immunology Unit of the Instituto da Criança, a tertiary public care institution. CASES REPORT: Seven patients had oculocutaneous albinism, recurrent infections and giant cytoplasmic granules in the leukocytes. One patient had low IgG levels and three showed impaired bactericidal activity of neutrophils. Six patients died of infectious complications during the accelerated phase. Therapy included ascorbic acid and antibiotics. Chemotherapy was used for the accelerated phase in two patients. Bone marrow transplantation (BMT was proposed for one patient. DISCUSSION: The authors emphasize the need for early diagnosis and therapy of CHS. BMT should be indicated before the accelerated phase of the disease has developed.

High frequency of albinism and tumours in free-living birds around Chernobyl.

Science.gov (United States)

Møller, A P; Bonisoli-Alquati, A; Mousseau, T A

2013-09-18

The effects of radioactive contamination on the phenotype of free-living organisms are poorly understood, mainly because of the difficulty of capturing the large numbers of individual specimens that are required to quantify rare events such as albinism and tumour formation. We hypothesized that the frequency of abnormalities like albinism and the frequency of radiation-induced diseases like cancer would increase with the level of background radiation, that the two markers of radiation would be positively correlated, and that the reduction in abundance of animals would be greater in species with a higher frequency of albinism and tumour formation, if these markers reliably reflected poor viability. Here we analyzed the frequency of albinistic feathers and tumours in a sample of 1669 birds captured during 2010-2012 at eight sites around Chernobyl that varied in level of background radiation from 0.02 to more than 200μSv/h. We recorded 111 cases of partial albinism and 25 cases of tumour formation. Nominal logistic models were used to partition the variance into components due to species and background radiation. Radiation was a strong predictor of the two markers in birds, with a small, but significant effect of species for albinism. The slope of the relationship between abundance and radiation in different bird species was significantly inversely correlated with the frequency of albinism and tumours, as was to be expected if a common underlying cause (i.e. radiation) affects both variables. These findings are consistent with the hypothesis that background radiation is a cause of albinism and tumours, that albinism and tumours are biomarkers of radiation exposure, and that high frequencies of albinism and tumours were present despite the low viability of birds with these conditions. Copyright © 2013 Elsevier B.V. All rights reserved.

Albinism-causing mutations in recombinant human tyrosinase alter intrinsic enzymatic activity.

Science.gov (United States)

Dolinska, Monika B; Kovaleva, Elena; Backlund, Peter; Wingfield, Paul T; Brooks, Brian P; Sergeev, Yuri V

2014-01-01

Tyrosinase (TYR) catalyzes the rate-limiting, first step in melanin production and its gene (TYR) is mutated in many cases of oculocutaneous albinism (OCA1), an autosomal recessive cause of childhood blindness. Patients with reduced TYR activity are classified as OCA1B; some OCA1B mutations are temperature-sensitive. Therapeutic research for OCA1 has been hampered, in part, by the absence of purified, active, recombinant wild-type and mutant human enzymes. The intra-melanosomal domain of human tyrosinase (residues 19-469) and two OCA1B related temperature-sensitive mutants, R422Q and R422W were expressed in insect cells and produced in T. ni larvae. The short trans-membrane fragment was deleted to avoid potential protein insolubility, while preserving all other functional features of the enzymes. Purified tyrosinase was obtained with a yield of >1 mg per 10 g of larval biomass. The protein was a monomeric glycoenzyme with maximum enzyme activity at 37°C and neutral pH. The two purified mutants when compared to the wild-type protein were less active and temperature sensitive. These differences are associated with conformational perturbations in secondary structure. The intramelanosomal domains of recombinant wild-type and mutant human tyrosinases are soluble monomeric glycoproteins with activities which mirror their in vivo function. This advance allows for the structure - function analyses of different mutant TYR proteins and correlation with their corresponding human phenotypes; it also provides an important tool to discover drugs that may improve tyrosinase activity and treat OCA1.

Albinism-causing mutations in recombinant human tyrosinase alter intrinsic enzymatic activity.

Directory of Open Access Journals (Sweden)

Monika B Dolinska

Full Text Available Tyrosinase (TYR catalyzes the rate-limiting, first step in melanin production and its gene (TYR is mutated in many cases of oculocutaneous albinism (OCA1, an autosomal recessive cause of childhood blindness. Patients with reduced TYR activity are classified as OCA1B; some OCA1B mutations are temperature-sensitive. Therapeutic research for OCA1 has been hampered, in part, by the absence of purified, active, recombinant wild-type and mutant human enzymes.The intra-melanosomal domain of human tyrosinase (residues 19-469 and two OCA1B related temperature-sensitive mutants, R422Q and R422W were expressed in insect cells and produced in T. ni larvae. The short trans-membrane fragment was deleted to avoid potential protein insolubility, while preserving all other functional features of the enzymes. Purified tyrosinase was obtained with a yield of >1 mg per 10 g of larval biomass. The protein was a monomeric glycoenzyme with maximum enzyme activity at 37°C and neutral pH. The two purified mutants when compared to the wild-type protein were less active and temperature sensitive. These differences are associated with conformational perturbations in secondary structure.The intramelanosomal domains of recombinant wild-type and mutant human tyrosinases are soluble monomeric glycoproteins with activities which mirror their in vivo function. This advance allows for the structure - function analyses of different mutant TYR proteins and correlation with their corresponding human phenotypes; it also provides an important tool to discover drugs that may improve tyrosinase activity and treat OCA1.

Being black in a white skin: Beliefs and stereotypes around albinism at a South African university

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Relebohile Phatoli

2015-05-01

Objectives: The study endeavoured to explore the beliefs and practices regarding albinism within a South African university, and the availability of support services. Method: The research was located within an interpretive qualitative paradigm and was framed within the theories of stigma, discrimination and ‘othering’. Interviews were conducted with five students with albinism and 10 students without albinism. Results: Findings confirmed the existence of myths and stereotypes regarding albinism. Students with albinism tended to exclude themselves from the rest of the student community to avoid discrimination and stereotypes around their condition. Conclusion: People with albinism can teach us about social constructions of race, colour and relations between minority groups and the majority culture. Results have implications for schools, disability units at universities, and albinism societies in terms of opening up channels of communication between people with albinism and the general public and fostering knowledge and awareness thereof.

Relationship between foveal cone specialization and pit morphology in albinism.

Science.gov (United States)

Wilk, Melissa A; McAllister, John T; Cooper, Robert F; Dubis, Adam M; Patitucci, Teresa N; Summerfelt, Phyllis; Anderson, Jennifer L; Stepien, Kimberly E; Costakos, Deborah M; Connor, Thomas B; Wirostko, William J; Chiang, Pei-Wen; Dubra, Alfredo; Curcio, Christine A; Brilliant, Murray H; Summers, C Gail; Carroll, Joseph

2014-05-20

Albinism is associated with disrupted foveal development, though intersubject variability is becoming appreciated. We sought to quantify this variability, and examine the relationship between foveal cone specialization and pit morphology in patients with a clinical diagnosis of albinism. We recruited 32 subjects with a clinical diagnosis of albinism. DNA was obtained from 25 subjects, and known albinism genes were analyzed for mutations. Relative inner and outer segment (IS and OS) lengthening (fovea-to-perifovea ratio) was determined from manually segmented spectral domain-optical coherence tomography (SD-OCT) B-scans. Foveal pit morphology was quantified for eight subjects from macular SD-OCT volumes. Ten subjects underwent imaging with adaptive optics scanning light ophthalmoscopy (AOSLO), and cone density was measured. We found mutations in 22 of 25 subjects, including five novel mutations. All subjects lacked complete excavation of inner retinal layers at the fovea, though four subjects had foveal pits with normal diameter and/or volume. Peak cone density and OS lengthening were variable and overlapped with that observed in normal controls. A fifth hyper-reflective band was observed in the outer retina on SD-OCT in the majority of the subjects with albinism. Foveal cone specialization and pit morphology vary greatly in albinism. Normal cone packing was observed in the absence of a foveal pit, suggesting a pit is not required for packing to occur. The degree to which retinal anatomy correlates with genotype or visual function remains unclear, and future examination of larger patient groups will provide important insight on this issue. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.

Ocular straylight in albinism

NARCIS (Netherlands)

Kruijt, Bastiaan; Franssen, Luuk; Prick, Liesbeth J. J. M.; van Vliet, Johannes M. J.; van den Berg, Thomas J. T. P.

2011-01-01

Albinism is an inherited disorder that affects the melanin biosynthesis pathway, which results in reduced or absent pigment formation. This may lead to increased light transmission through the iris and more reflected light from the fundus. Both these effects contribute to the occurrence of ocular

Genetic profiling of a rare condition: co-occurrence of albinism and multiple primary melanoma in a Caucasian family.

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De Summa, Simona; Guida, Michele; Tommasi, Stefania; Strippoli, Sabino; Pellegrini, Cristina; Fargnoli, Maria Concetta; Pilato, Brunella; Natalicchio, Iole; Guida, Gabriella; Pinto, Rosamaria

2017-05-02

Multiple primary melanoma (MPM) is a rare condition, whose genetic basis has not yet been clarified. Only 8-12% of MPM are due to germline mutations of CDKN2A. However, other genes (POT1, BRCA1/2, MC1R, MGMT) have been demonstrated to be involved in predisposition to this pathology.To our knowledge, this is the first family study based on two siblings with the rare coexistence of MPM and oculocutaneous albinism (OCA), an autosomal recessive disease characterized by the absence or decrease in pigmentation in the skin, hair, and eyes.In this study, we evaluated genes involved in melanoma predisposition (CDKN2A, CDK4, MC1R, MITF, POT1, RB1, MGMT, BRCA1, BRCA2), pathogenesis (BRAF, NRAS, PIK3CA, KIT, PTEN), skin/hair pigmentation (MC1R, MITF) and in immune pathways (CTLA4) to individuate alterations able to explain the rare onset of MPM and OCA in indexes and the transmission in their pedigree.From the analysis of the pedigree, we were able to identify a "protective" haplotype with respect to MPM, including MGMT p.I174V alteration. The second generation offspring is under strict follow up as some of them have a higher risk of developing MPM according to our model.

A cross-sectional examination of visual acuity by specific type of albinism.

Science.gov (United States)

Winsor, Caitlin Nosanov; Holleschau, Ann M; Connett, John E; Summers, C Gail

2016-10-01

Reports of best-corrected visual acuity (BCVA) in albinism are often based on overlapping clinical phenotypes. BCVA in albinism has been shown to improve with age. This study reports a large cross-sectional investigation to determine whether BCVA differs by specific type of albinism when age-corrected. This retrospective review identified 170 individuals with a specific type of albinism identified by mutation(s) in a gene known to cause albinism (for OCA1, OCA2, and Hermansky-Pudlak syndrome ([HPS]) or a specific phenotype (white hair and no melanin pigment in OCA1A; pigmentary mosaicism in the obligate carriers for males with OA1). We recorded optotype binocular BCVA at final follow-up. Patients were age-grouped (2-5 years, 6-14 years, and ≥15 years) for comparison. The greatest visual acuity deficit was found for OCA1A in all age groups. At age ≥15 years (n = 79), mean BCVA was 20/128 for OCA1A, 20/37 for OCA1B, 20/59 for OCA2, 20/63 for OA1, and 20/121 for HPS. Significant differences between BCVA at ≥15 years were found in the following: OCA1A vs OCA1B, OCA1A vs OCA2, OCA1A vs OA1, OCA1B vs HPS, OCA2 vs HPS, and OA1 vs HPS (P ≤ 0.02). This study provides a large sample size and includes only those with a specific type of albinism. BCVA varies by albinism type, and there is overlap in BCVA, particularly in the younger age groups. For ages ≥15 years, there are significant differences in BCVA between several types of albinism. Copyright © 2016 American Association for Pediatric Ophthalmology and Strabismus. Published by Elsevier Inc. All rights reserved.

Being black in a white skin: Beliefs and stereotypes around albinism at a South African university.

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Phatoli, Relebohile; Bila, Nontembeko; Ross, Eleanor

2015-01-01

Background: Partly because of the legacy of apartheid, and despite being a constitutional democracy, South Africa continues to be a deeply divided society, particularly along racial lines. In this context many people with albinism do not fit neatly into black and white categories and are likely to experience social discrimination and marginalisation. Objectives: The study endeavoured to explore the beliefs and practices regarding albinism within a South African university, and the availability of support services. Method: The research was located within an interpretive qualitative paradigm and was framed within the theories of stigma, discrimination and 'othering'. Interviews were conducted with five students with albinism and 10 students without albinism. Results: Findings confirmed the existence of myths and stereotypes regarding albinism. Students with albinism tended to exclude themselves from the rest of the student community to avoid discrimination and stereotypes around their condition. Conclusion: People with albinism can teach us about social constructions of race, colour and relations between minority groups and the majority culture. Results have implications for schools, disability units at universities, and albinism societies in terms of opening up channels of communication between people with albinism and the general public and fostering knowledge and awareness thereof.

Journal of Genetics | Indian Academy of Sciences

Indian Academy of Sciences (India)

More Details Fulltext PDF. Volume 92 Issue 2 August 2013 pp 305-308 Research Note. Analysis of MC1R variants in Indian oculocutaneous albinism patients: highlighting the risk of skin cancer among albinos · Mainak Sengupta Devroop Sarkar Maitreyee Mondal Swapan Samanta Asim Sil Kunal Ray · More Details Fulltext ...

Journal of Genetics | Indian Academy of Sciences

Indian Academy of Sciences (India)

Analysis of MC1R variants in Indian oculocutaneous albinism patients: highlighting the risk of skin cancer among albinos · Mainak Sengupta Devroop Sarkar Maitreyee Mondal Swapan Samanta Asim Sil Kunal Ray · More Details Fulltext PDF. Volume 95 Issue 2 June 2016 pp 459-461 RESEARCH NOTE. TBK1 duplication ...

Being black in a white skin: Beliefs and stereotypes around albinism at a South African university

Science.gov (United States)

Phatoli, Relebohile; Bila, Nontembeko

2015-01-01

Background: Partly because of the legacy of apartheid, and despite being a constitutional democracy, South Africa continues to be a deeply divided society, particularly along racial lines. In this context many people with albinism do not fit neatly into black and white categories and are likely to experience social discrimination and marginalisation. Objectives: The study endeavoured to explore the beliefs and practices regarding albinism within a South African university, and the availability of support services. Method: The research was located within an interpretive qualitative paradigm and was framed within the theories of stigma, discrimination and ‘othering’. Interviews were conducted with five students with albinism and 10 students without albinism. Results: Findings confirmed the existence of myths and stereotypes regarding albinism. Students with albinism tended to exclude themselves from the rest of the student community to avoid discrimination and stereotypes around their condition. Conclusion: People with albinism can teach us about social constructions of race, colour and relations between minority groups and the majority culture. Results have implications for schools, disability units at universities, and albinism societies in terms of opening up channels of communication between people with albinism and the general public and fostering knowledge and awareness thereof. PMID:28730019

Hermansky-Pudlak syndrome: A case report

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R Vani

2014-01-01

Full Text Available Hermansky-Pudlak syndrome (HPS is a rare autosomal recessive disorder, which results in oculocutaneous albinism, bleeding disorders, and storage of abnormal fat protein compound (liposomal accumulation of ceroid lipofuscin. The major complications of this disorder are pulmonary fibrosis (PF and colitis. This is a case report of an HPS patient with PF.

Diagnostic potential of iris cross-sectional imaging in albinism using optical coherence tomography.

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Sheth, Viral; Gottlob, Irene; Mohammad, Sarim; McLean, Rebecca J; Maconachie, Gail D E; Kumar, Anil; Degg, Christopher; Proudlock, Frank A

2013-10-01

To characterize in vivo anatomic abnormalities of the iris in albinism compared with healthy controls using anterior segment optical coherence tomography (AS-OCT) and to explore the diagnostic potential of this technique for albinism. We also investigated the relationship between iris abnormalities and other phenotypical features of albinism. Prospective cross-sectional study. A total of 55 individuals with albinism and 45 healthy controls. We acquired 4.37×4.37-mm volumetric scans (743 A-scans, 50 B-scans) of the nasal and temporal iris in both eyes using AS-OCT (3-μm axial resolution). Iris layers were segmented and thicknesses were measured using ImageJ software. Iris transillumination grading was graded using Summers and colleagues' classification. Retinal OCT, eye movement recordings, best-corrected visual acuity (BCVA), visual evoked potential (VEP), and grading of skin and hair pigmentation were used to quantify other phenotypical features associated with albinism. Iris AS-OCT measurements included (1) total iris thickness, (2) stroma/anterior border (SAB) layer thickness, and (3) posterior epithelial layer (PEL) thickness. Correlation with other phenotypical measurements, including (1) iris transillumination grading, (2) retinal layer measurements at the fovea, (3) nystagmus intensity, (4) BCVA, (5) VEP asymmetry, (6) skin pigmentation, and (7) hair pigmentation (of head hair, lashes, and brows). The mean iris thickness was 10.7% thicker in controls (379.3 ± 44.0 μm) compared with the albinism group (342.5 ± 52.6 μm; P>0.001), SAB layers were 5.8% thicker in controls (315.1 ± 43.8 μm) compared with the albinism group (297.7 ± 50.0 μm; P=0.044), and PEL was 44.0% thicker in controls (64.1 ± 11.7 μm) compared with the albinism group (44.5 ± 13.9 μm; Palbinism. Phenotypic features of albinism, such as skin and hair pigmentation, BCVA, and nystagmus intensity, were significantly correlated to AS-OCT iris thickness measurements. We have

Analysis of P gene mutations in patients with type II (tyrosinase-positive) oculocutaneous albinism (OCA2)

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Lee, S.T.; Nicholls, R.D.; Schnur, R. [Univ. of Wisconsin, Madison, WI (United States)]|[Case Western Reserve Univ., Cleveland, OH (United States)]|[Children`s Hospital of Philadelphia, PA (United States)] [and others

1994-09-01

OCA2 is an autosomal recessive disorder in which the biosynthesis of melanin pigment is greatly reduced in the skin, hair, and eyes. Recently, we showed that OCA2 results from mutations of the P gene, in chromosome segment 15q11-q13. In addition to OCA2, mutations of P account for OCA associated with the Prader-Willi syndrome and some cases of {open_quotes}autosomal recessive ocular albinism{close_quotes} (AROA). We have now studied 38 unrelated patients with various forms of OCA2 or AROA from a variety of different ethnic groups. None of these patients had detectable abnormalities of the tyrosinase (TYR) gene. Among 8 African-American patients with OCA2 we observed apparent locus homogeneity. We detected abnormalities of the P gene in all 8 patients, including 12 different mutations and deletions, most of which are unique to this group and none of which is predominant. In contrast, OCA2 in other populations appears to be genetically heterogeneous. Among 21 Caucasian patients we detected abnormalities of the P gene in only 8, comprising 9 different point mutations and deletions, some of which also occurred among the African-American patients. Among 3 Middle-Eastern, 3 Indo-Pakistani, and 3 Asian patients we detected mutations of the P gene in only one from each group. In a large Indo-Pakistani kindred with OCA2 we have excluded both the TYR and P genes on the basis of genetic linkage. The prevalence of mutations of the P gene thus appears to be much higher among African-Americans with OCA2 than among patients from other ethnic groups. The incidence of OCA2 in some parts of equatorial Africa is extremely high, as frequent as 1 per 1100, and the disease has been linked to P in South African Bantu. The eventual characterization of P gene mutations in Africans will be informative with regard to the origins of P gene mutations in African-American patients.

Does levodopa improve vision in albinism? Results of a randomized, controlled clinical trial.

Science.gov (United States)

Summers, C Gail; Connett, John E; Holleschau, Ann M; Anderson, Jennifer L; De Becker, Inge; McKay, Brian S; Brilliant, Murray H

2014-11-01

Dopamine is an intermediate product in the biosynthesis of melanin pigment, which is absent or reduced in albinism. Animal research has shown that supplying a precursor to dopamine, levodopa, may improve visual acuity in albinism by enhancing neural networks. This study examines the safety and effectiveness of levodopa on best-corrected visual acuity in human subjects with albinism. Prospective, randomized, placebo-controlled, double-masked clinical trial conducted at the University of Minnesota. Forty-five subjects with albinism. Subjects with albinism were randomly assigned to one of three treatment arms: levodopa 0.76 mg/kg with 25% carbidopa, levodopa 0.51 mg/kg with 25% carbidopa, or placebo and followed for 20 weeks, with best-corrected visual acuity measured at enrollment, and at weeks 5, 10, 15, and 20 after enrollment. Side-effects were recorded with a symptom survey. Blood was drawn for genotyping. Side-effects and best-corrected visual acuity 20 weeks after enrolment. All subjects had at least one mutation found in a gene known to cause albinism. Mean age was 14.5 years (range: 3.5 to 57.8 years). Follow up was 100% and compliance was good. Minor side-effects were reported; there were no serious adverse events. There was no statistically significant improvement in best-corrected visual acuity after 20 weeks with either dose of levodopa. Levodopa, in the doses used in this trial and for the time course of administration, did not improve visual acuity in subjects with albinism. © 2014 Royal Australian and New Zealand College of Ophthalmologists.

Refinement of the localization of the X-linked ocular albinism gene

NARCIS (Netherlands)

Bergen, A. A.; Zijp, P.; Schuurman, E. J.; Bleeker-Wagemakers, E. M.; Apkarian, P.; van Ommen, G. J.

1993-01-01

Although physical and genetic mapping studies assigned the X-linked ocular albinism gene to Xp22.3, the exact gene order in this region is still unclear. We present additional genetic mapping data concerning X-linked ocular albinism that suggests the consensus order Xpter-STS-DXS237-KAL-(OA1,

First report of partial albinism in genus Thrichomys (Rodentia: Echimyidae

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Antonio Carlos da S.A. Neves

2014-01-01

Full Text Available Reports about albinism in rodents are common. In the family Echimyidae, however, albinism is very rare. This is the second case of coat color variation reported within Echimyidae and the first for the genus Thrichomys. The pelages of Thrichomys pachyurus individuals with normal and variant coat color were observed under a fluorescent artificial light and were examined with a stereoscopic microscope. The descriptions of pelage color were based on the book "Color Standards and Color Nomenclature". The predominantly white pattern of coat color in individuals of T. pachyurus suggests a partial albinism caused by delay in migration time of melanoblasts from neural crest to epidermis. The habitat of T. pachyurus has a heavy vegetative cover, which offers natural protection against predators and high-quality nutrition.

Albinism in the Great Gray Owl (Strix nebulosa) and other owls

Science.gov (United States)

Pentti Alaja; Heimo Mikkola

1997-01-01

An incomplete albino Great Gray Owl (Strix nebulosa) was observed in Vesanto and Kajaani, Finland, 1994-1995. The literature pertaining to albinism in owls indicates that total and incomplete albinism has only been reported in 13 different owl species, the Great Gray Owl being the only species with more than five records. Thus six to seven incomplete...

Experiences of a feasibility study of children with albinism in Zimbabwe: a discussion paper.

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Taylor, Julie S; Lund, Patricia

2008-08-01

Feasibility studies are often a helpful prelude to constructing fundable research proposals. Where the intended research is in a foreign country, focuses on a vulnerable population, and is aggravated by political and pragmatic challenges, feasibility studies become essential. Albinism, a genetic condition of reduced melanin synthesis, is a major public health issue in southern Africa. Whilst much is known about the health needs of children with albinism, little is understood about how to address these effectively in low income countries. Further, the child care and protection needs of children with albinism are largely unexplored. Zimbabwe's current political and economic climate presents additional challenges to research on the topic. The technical, economic, legal, collaborative, operational, schedule and political feasibilities (acronym TELCOSP) to undertaking a study on children with albinism in Zimbabwe were explored over a six week period of fieldwork in the country. Using the TELSCOSP framework allowed a deconstruction of each challenge to provide innovative solutions. The economic and legal feasibility aspects presented some difficulties that will require flexibility and perseverance to overcome. With the assistance of the local communities and people with albinism in Zimbabwe, the obstacles appear surmountable. The feasibility study provided a productive framework for addressing potential challenges in studying the needs of Zimbabwe's children living with albinism.

Chediak-Higashi syndrome: brain MRI and MR spectroscopy manifestations

International Nuclear Information System (INIS)

Lolli, Valentina; Soto Ares, Gustavo; Pruvo, Jean-Pierre; Abou Chahla, Wadih; Jissendi-Tchofo, Patrice

2015-01-01

Chediak-Higashi syndrome is a rare inherited metabolic disorder characterized by partial oculocutaneous albinism, immunodeficiency, and neurological dysfunction. We present the brain magnetic resonance imaging (MRI) and MR spectroscopy (MRS) findings obtained during the accelerated phase of the disorder in an 8-year-old. The brain MRI manifestations at recurrences 15 months and 24 months later are reported as well. (orig.)

Chediak-Higashi syndrome: brain MRI and MR spectroscopy manifestations

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Lolli, Valentina; Soto Ares, Gustavo; Pruvo, Jean-Pierre [Roger Salengro Hospital, CHRU, Neuroradiology Department, Lille (France); Abou Chahla, Wadih [Jeanne de Flandre Hospital, Pediatric Hematology and Oncology Department, Lille (France); Jissendi-Tchofo, Patrice [University Hospital Saint-Pierre, Radiology Department - Pediatric Neuroradiology Section, Brussels (Belgium)

2015-08-15

Chediak-Higashi syndrome is a rare inherited metabolic disorder characterized by partial oculocutaneous albinism, immunodeficiency, and neurological dysfunction. We present the brain magnetic resonance imaging (MRI) and MR spectroscopy (MRS) findings obtained during the accelerated phase of the disorder in an 8-year-old. The brain MRI manifestations at recurrences 15 months and 24 months later are reported as well. (orig.)

Concordance of visual and structural features between siblings with albinism.

Science.gov (United States)

Heinmiller, Laura J; Holleschau, Ann; Summers, C Gail

2016-02-01

To evaluate similarities and differences in visual function and ocular structure between siblings with albinism. The medical records of all siblings diagnosed with albinism were retrospectively reviewed. Comparisons were made using examination at oldest age for younger sibling and examination closest to that age for older siblings. A total of 111 patients from 54 families were studied. Mean age was 12.9 years (range, 2 months to 44.2 years). Mean difference in ages between sibling pair examinations was 11.5 months (range, 0-87 months). Of 45 families, best-corrected visual acuity was equal in 9 (20%), within 1/2 octave in 9 (20%), >1/2 but albinism should be counseled with due caution because visual function is often disparate despite similar structural findings. Copyright © 2016 American Association for Pediatric Ophthalmology and Strabismus. Published by Elsevier Inc. All rights reserved.

The experience of people with oculocutaneous albinism

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Mmuso B.J. Pooe-Monyemore

2012-07-01

Opsomming Hierdie aanbieding is ‘n verslag oor bevindings van die ervaring van persone met okulokutaneuse albinisme in Suid-Afrika. Okulokutaneuse albinisme is ‘n oorerflike afwyking, gekenmerk deur ‘n gebrekkige melanien produksie. Daar is min of geen pigmentasie in die vel, hare en oë nie. Hierdie toestand word wêreldwyd aangetref met ‘n hoër voorkoms in sub-Sahara Afrika en groepe in Suid Amerika. Mense met hierdie toestand het dikwels ‘n stigma en daar word teen hulle gediskrimineer as gevolg van mites en bygelowe van die publiek oor die toestand. Tot datum het geen studies die psigososiale aspek van hierdie toestand ondersoek nie. ‘n Kwalitatiewe studie is in Johannesburg, Suid-Afrika uitgevoer in 2007. ‘n Doelgerigte steekproef van 15 swart mense met okulokutaneuse albinisme het deel geneem aan in diepte individuele fenomenologiese onderhoude. ‘n Sentrale vraag was gestel om die onderhoude te fasiliteer: Kan u asseblief u ervaring as ‘n persoon met albinisme deel?”’ Data van die onderhoude was geanaliseer deur van Collaizi’s se kwalitatiewe data analise metode gebruik te maak. Drie hooftemas het te voorskyn gekom, naamlik: (1 persepsies van die interne omgewing byvoorbeeld die self; (2 ervarings van die eksterne omgewing, byvoorbeeld die familie en die gemeenskap; en (3 die behoefte vir self ontwikkeling en groei gebaseer op hulle ervarings. Aanbevelings is gemaak deur die navorsers om self konsep uit te lig , en om ‘n gevoel van ‘behoort aan’, self ontwikkeling en groei in mense met okulokutaneuse albinisme te bevorder.

First case of synophthalmia and albinism in the Pacific angel shark Squatina californica.

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Escobar-Sánchez, O; Moreno-Sánchez, X G; Aguilar-Cruz, C A; Abitia-Cárdenas, L A

2014-08-01

The first record in Mexican waters of albinism and synophthalmia (partial cyclopia) in the Pacific angel shark, Squatina californica is presented. Albinism is not lethal, but synophthalmia may cause the death of the individual immediately after birth. © 2014 The Fisheries Society of the British Isles.

Retinal pigment epithelium findings in patients with albinism using wide-field polarization-sensitive optical coherence tomography.

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Schütze, Christopher; Ritter, Markus; Blum, Robert; Zotter, Stefan; Baumann, Bernhard; Pircher, Michael; Hitzenberger, Christoph K; Schmidt-Erfurth, Ursula

2014-11-01

To investigate pigmentation characteristics of the retinal pigment epithelium (RPE) in patients with albinism using wide-field polarization-sensitive optical coherence tomography compared with intensity-based spectral domain optical coherence tomography and fundus autofluorescence imaging. Five patients (10 eyes) with previously genetically diagnosed albinism and 5 healthy control subjects (10 eyes) were imaged by a wide-field polarization-sensitive optical coherence tomography system (scan angle: 40 × 40° on the retina), sensitive to melanin contained in the RPE, based on the polarization state of backscattered light. Conventional intensity-based spectral domain optical coherence tomography and fundus autofluorescence examinations were performed. Retinal pigment epithelium-pigmentation was analyzed qualitatively and quantitatively based on depolarization assessed by polarization-sensitive optical coherence tomography. This study revealed strong evidence of polarization-sensitive optical coherence tomography to specifically image melanin in the RPE. Depolarization of light backscattered by the RPE in patients with albinism was reduced compared with normal subjects. Heterogeneous RPE-specific depolarization characteristics were observed in patients with albinism. Reduction of depolarization observed in the light backscattered by the RPE in patients with albinism corresponds to expected decrease of RPE pigmentation. The degree of depigmentation of the RPE is possibly associated with visual acuity. Findings suggest that different albinism genotypes result in heterogeneous levels of RPE pigmentation. Polarization-sensitive optical coherence tomography showed a heterogeneous appearance of RPE pigmentation in patients with albinism depending on different genotypes.

Incomplete albinism in Discoglossus pictus (Otth, 1837

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Filippo Spadola

2010-12-01

Full Text Available The authors present an incomplete albinism case in a Discoglossus pictus subject found in Sicily. This is the first note for Italian territory, the second for the species and the third for Discoglossus genus.

Hermansky-Pudlak Syndrome: A Case Report

Science.gov (United States)

Berber, Ilhami; Erkurt, Mehmet Ali; Kuku, Irfan; Kaya, Emin; Koroglu, Mustafa; Gul, Mehmet; Bentli, Recep

2014-01-01

Objective. The aim of this paper is to report the case of a patient diagnosed with Hermansky-Pudlak syndrome, as a result of bleeding diathesis. Clinical Presentation and Intervention. A 23-year-old male presented with recurrent epistaxis and, upon physical examination, was found to be remarkable for albinism and suborbital ecchymosis. The absence of dense bodies in the platelets was demonstrated using electron microscopy. This patient was (slowly) administered one unit of a platelet suspension, and his bleeding decreased considerably. Conclusion. This case shows that Hermansky-Pudlak syndrome should be considered in the differential diagnosis of a patient presenting with bleeding diathesis, when the clinical presentation also includes oculocutaneous albinism and visual problems. PMID:24707413

Hermansky-Pudlak Syndrome: A Case Report

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Ilhami Berber

2014-01-01

Full Text Available Objective. The aim of this paper is to report the case of a patient diagnosed with Hermansky-Pudlak syndrome, as a result of bleeding diathesis. Clinical Presentation and Intervention. A 23-year-old male presented with recurrent epistaxis and, upon physical examination, was found to be remarkable for albinism and suborbital ecchymosis. The absence of dense bodies in the platelets was demonstrated using electron microscopy. This patient was (slowly administered one unit of a platelet suspension, and his bleeding decreased considerably. Conclusion. This case shows that Hermansky-Pudlak syndrome should be considered in the differential diagnosis of a patient presenting with bleeding diathesis, when the clinical presentation also includes oculocutaneous albinism and visual problems.

Evaluation of vision-specific quality-of-life in albinism.

Science.gov (United States)

Kutzbach, Beth R; Merrill, Kimberly S; Hogue, Kathy M; Downes, Sara J; Holleschau, Ann M; MacDonald, John T; Summers, C Gail

2009-04-01

Human albinism is a genetic condition associated with visual impairment that affects many aspects of daily life. Office measurements of visual acuity do not necessarily reflect daily visual function and health status. This study used the National Eye Institute Visual Function Questionnaire (NEI-VFQ) to determine the effect of albinism-associated ophthalmopathy on quality of life (QOL). We administered the NEI-VFQ, which consists of 25 questions about QOL (VFQ-25) and 14 questions about well-being (VFQ-39), to 44 consenting participants with albinism older than the age of 18 years. Nineteen male and 25 female subjects completed the study. Median age was 30.5 years (range, 18-79 years). Mean best-corrected visual acuity was 20/83 (range, 20/20 to 20/320). Forty-eight percent reported that they were currently able to drive with their condition. Participants perceived midscale problems with their general vision (median subscale score 60.0). Visual acuity correlated moderately with overall NEI-VFQ composite scores (r(s) = 0.40, p = 0.01 for VFQ-25 and r(s) = 0.36, p = 0.02 for VFQ-39). Most notable impairment was recorded for distance acuity, vision-specific mental health, and vision-specific role difficulties (VFQ-39 median subscale scores 66.7, 70.0, and 75.0, respectively). Differences by sex were insignificant. Greater ceiling effects were noted for the VFQ-25 than for the VFQ-39. The NEI-VFQ-39 is a method to evaluate self-reported effects of vision-related QOL in albinism and may be used as a baseline for evaluating outcomes in interventional studies in these patients.

Use of a driving simulator to assess performance under adverse weather conditions in adults with albinism.

Science.gov (United States)

Hofman, Gwen M; Summers, C Gail; Ward, Nicholas; Bhargava, Esha; Rakauskas, Michael E; Holleschau, Ann M

2012-04-01

Participants with albinism have reduced vision and nystagmus with reduced foveation times. This prospective study evaluated driving in 12 participants with albinism and 12 matched controls. Participants drove a vehicle simulator through a virtual rural course in sunny and foggy conditions. Under sunny conditions, participants with albinism showed a narrower preferred minimum safety boundary during car-following tasks than did controls, but there was no difference under foggy conditions. Their driving did not differ significantly from that of controls when approaching a stop sign or when choosing gap size between oncoming vehicles when crossing an intersection. However, when compared to control drivers, participants with albinism had a decreased minimum safety boundary for car-following that should be included in counseling regarding driving safety.

Reading skills in children and adults with albinism: the role of visual impairment.

Science.gov (United States)

MacDonald, John T; Kutzbach, Beth R; Holleschau, Ann M; Wyckoff, Suzanne; Summers, C Gail

2012-01-01

To evaluate whether visual impairment in albinism contributes significantly to the acquisition of normal reading skills. The authors administered standardized reading tests to 41 children and 18 adults with albinism. The Young Children's Achievement Test was used for children between 4 and 6 years old and the Woodcock-Johnson III was used for children 7 years and older and adults. Parents of children and adult subjects also completed a questionnaire to document developmental, academic, and/or work experiences. The Spearman test was used to evaluate the relationship between binocular best-corrected visual acuity (BCVA) and reading test results. Standardized reading tests in both children and adults with albinism showed a normal distribution of scores. BCVA did not appear to play a significant role in the development of normal reading ability in these individuals who were visually impaired except for a mild correlation of decreased reading fluency on the Woodcock-Johnson III with decreased BCVA (r = 0.287, P = .046). Many young children with albinism had superior reading skills despite having a BCVA of 20/200 or worse (legal blindness). This study of cognitively normal children and adults with albinism demonstrates that impaired vision during childhood does not by itself significantly impede a child's ability to acquire normal reading skills. However, the lower reading fluency that occurs in the more visually impaired individuals suggests they would benefit, both in the school system and workplace, with an accommodation involving more time to complete reading tasks. Copyright 2012, SLACK Incorporated.

Case Report Identification of a novel SLC45A2 mutation in albinism by targeted next-generation sequencing.

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Xue, J J; Xue, J F; Xue, H Q; Guo, Y Y; Liu, Y; Ouyang, N

2016-09-19

Albinism is a diverse group of hypopigmentary disorders caused by multiple-genetic defects. The genetic diagnosis of patients affected with albinism by Sanger sequencing is often complex, expensive, and time-consuming. In this study, we performed targeted next-generation sequencing to screen for 16 genes in a patient with albinism, and identified 21 genetic variants, including 19 known single nucleotide polymorphisms, one novel missense mutation (c.1456 G>A), and one disease-causing mutation (c.478 G>C). The novel mutation was not observed in 100 controls, and was predicted to be a damaging mutation by SIFT and Polyphen. Thus, we identified a novel mutation in SLC45A2 in a Chinese family, expanding the mutational spectrum of albinism. Our results also demonstrate that targeted next-generation sequencing is an effective genetic test for albinism.

Management of visual disturbances in albinism: a case report

Directory of Open Access Journals (Sweden)

Omar Rokiah

2012-09-01

Full Text Available Abstract Introduction A number of vision defects have been reported in association with albinism, such as photophobia, nystagmus and astigmatism. In many cases only prescription sunglasses are prescribed. In this report, the effectiveness of low-vision rehabilitation in albinism, which included prescription of multiple visual aids, is discussed. Case presentation We present the case of a 21-year-old Asian woman with albinism and associated vision defects. Her problems were blurring of distant vision, glare and her dissatisfaction with her current auto-focus spectacle-mounted telescope device, which she reported as being heavy as well as cosmetically unacceptable. We describe how low-vision rehabilitation using multiple visual aids, namely spectacles, special iris-tinted contact lenses with clear pupils, and bi-level telemicroscopic apparatus devices improved her quality of life. Subsequent to rehabilitation our patient is happier and continues to use the visual aids. Conclusions Contact lenses with a special iris tint and clear pupil area are useful aids to reduce the glare experienced by albinos. Bi-level telemicroscopic apparatus telemicroscopes fitted onto our patient’s prescription spectacles were cosmetically acceptable and able to improve her distance vision. As a result these low-vision rehabilitation approaches improved the quality of life of our albino patient.

to generation

Directory of Open Access Journals (Sweden)

Michał Otręba

2014-09-01

Full Text Available Inherited diseases of pigmentation were among the first traits studied in humans because of their easy recognition. This article presents selected hypopigmentary disorders, which can be divided into hypomelanocytoses and hypomelanoses. Hereditary hypomelanoses are caused by abnormal melanin biosynthesis as well as by abnormal transfer of mature melanosomes to melanocyte dendrites and to neighboring cells. These disorders are represented by oculocutaneous albinism, Hermansky-Pudlak syndrome, Chediak-Higashi syndrome, Griscelli syndrome, Menkes syndrome and phenylketonuria, and are caused by different mutations of the following genes: TYR, P, TRP1, MATP, HPS, CHS, MYO5A, RAB27A, MLPH, ATP7A and PAH. Oculocutaneous albinism is caused by a deficiency of melanin pigment in the skin, hair, and eye and results from mutations in the TYR, P, TRP1 and MATP genes involved in the biosynthesis of melanin pigment. Mutations in the HPS, CHS, MYO5A, RAB27A and MLPH genes, which regulate the biogenesis, maturation and transfer of me-lanosomes to neighboring cells, are responsible for such disorders as Hermansky-Pudlak, Chediak-Higashi and Griscelli syndromes. In turn, mutations of the ATP7A and PAH genes, regulating intracellular copper concentration and activity of phenylalanine hydroxylase, lead to Menkes syndrome and phenylketonuria.

Nystagmus Does Not Limit Reading Ability in Albinism

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Dysli, Muriel; Abegg, Mathias

2016-01-01

Purpose Subjects with albinism usually suffer from nystagmus and reduced visual acuity, which may impair reading performance. The contribution of nystagmus to decreased reading ability is not known. Low vision and nystagmus may have an additive effect. We aimed to address this question by motion compensation of the nystagmus in affected subjects and by simulating nystagmus in healthy controls. Methods Reading speed and eye movements were assessed in 9 subjects with nystagmus associated with albinism and in 12 healthy controls. We compared the reading ability with steady word presentation and with words presented on a gaze contingent display where words move in parallel to the nystagmus and thus correct for the nystagmus. As the control, healthy subjects were asked to read words and texts in steady reading conditions as well as text passages that moved in a pattern similar to nystagmus. Results Correcting nystagmus with a gaze contingent display neither improved nor reduced the reading speed for single words. Subjects with nystagmus and healthy participants achieved comparable reading speed when reading steady texts. However, movement of text in healthy controls caused a significantly reduced reading speed and more regressive saccades. Conclusions Our results argue against nystagmus as the rate limiting factor for reading speed when words were presented in high enough magnification and support the notion that other sensory visual impairments associated with albinism (for example reduced visual acuity) might be the primary causes for reading impairment. PMID:27391149

Nystagmus Does Not Limit Reading Ability in Albinism.

Directory of Open Access Journals (Sweden)

Muriel Dysli

Full Text Available Subjects with albinism usually suffer from nystagmus and reduced visual acuity, which may impair reading performance. The contribution of nystagmus to decreased reading ability is not known. Low vision and nystagmus may have an additive effect. We aimed to address this question by motion compensation of the nystagmus in affected subjects and by simulating nystagmus in healthy controls.Reading speed and eye movements were assessed in 9 subjects with nystagmus associated with albinism and in 12 healthy controls. We compared the reading ability with steady word presentation and with words presented on a gaze contingent display where words move in parallel to the nystagmus and thus correct for the nystagmus. As the control, healthy subjects were asked to read words and texts in steady reading conditions as well as text passages that moved in a pattern similar to nystagmus.Correcting nystagmus with a gaze contingent display neither improved nor reduced the reading speed for single words. Subjects with nystagmus and healthy participants achieved comparable reading speed when reading steady texts. However, movement of text in healthy controls caused a significantly reduced reading speed and more regressive saccades.Our results argue against nystagmus as the rate limiting factor for reading speed when words were presented in high enough magnification and support the notion that other sensory visual impairments associated with albinism (for example reduced visual acuity might be the primary causes for reading impairment.

Recessive Mutations in SLC38A8 Cause Foveal Hypoplasia and Optic Nerve Misrouting without Albinism

NARCIS (Netherlands)

Poulter, James A.; Al-Araimi, Musallam; Conte, Ivan; van Genderen, Maria M.; Sheridan, Eamonn; Carr, Ian M.; Parry, David A.; Shires, Mike; Carrella, Sabrina; Bradbury, John; Khan, Kamron; Lakeman, Phillis; Sergouniotis, Panagiotis I.; Webster, Andrew R.; Moore, Anthony T.; Pal, Bishwanath; Mohamed, Moin D.; Venkataramana, Anandula; Ramprasad, Vedam; Shetty, Rohit; Saktivel, Murugan; Kumaramanickavel, Govindasamy; Tan, Alex; Mackey, David A.; Hewitt, Alex W.; Banfi, Sandro; Ali, Manir; Inglehearn, Chris F.; Toomes, Carmel

2013-01-01

Foveal hypoplasia and optic nerve misrouting are developmental defects of the visual pathway and only co-occur in connection with albinism; to date, they have only been associated with defects in the melanin-biosynthesis pathway. Here, we report that these defects can occur independently of albinism

Mutations in c10orf11, a melanocyte-differentiation gene, cause autosomal-recessive albinism.

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Grønskov, Karen; Dooley, Christopher M; Østergaard, Elsebet; Kelsh, Robert N; Hansen, Lars; Levesque, Mitchell P; Vilhelmsen, Kaj; Møllgård, Kjeld; Stemple, Derek L; Rosenberg, Thomas

2013-03-07

Autosomal-recessive albinism is a hypopigmentation disorder with a broad phenotypic range. A substantial fraction of individuals with albinism remain genetically unresolved, and it has been hypothesized that more genes are to be identified. By using homozygosity mapping of an inbred Faroese family, we identified a 3.5 Mb homozygous region (10q22.2-q22.3) on chromosome 10. The region contains five protein-coding genes, and sequencing of one of these, C10orf11, revealed a nonsense mutation that segregated with the disease and showed a recessive inheritance pattern. Investigation of additional albinism-affected individuals from the Faroe Islands revealed that five out of eight unrelated affected persons had the nonsense mutation in C10orf11. Screening of a cohort of autosomal-recessive-albinism-affected individuals residing in Denmark showed a homozygous 1 bp duplication in C10orf11 in an individual originating from Lithuania. Immunohistochemistry showed localization of C10orf11 in melanoblasts and melanocytes in human fetal tissue, but no localization was seen in retinal pigment epithelial cells. Knockdown of the zebrafish (Danio rerio) homolog with the use of morpholinos resulted in substantially decreased pigmentation and a reduction of the apparent number of pigmented melanocytes. The morphant phenotype was rescued by wild-type C10orf11, but not by mutant C10orf11. In conclusion, we have identified a melanocyte-differentiation gene, C10orf11, which when mutated causes autosomal-recessive albinism in humans. Copyright © 2013 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

A Case of oculocutaneous albinism in a Maltese.

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Park, Shin Ae; Yi, Na Young; Kim, Min Su; Lim, Ji Hey; Jeong, Man Bok; Nam, Tchi Chou; Seo, Kang Moon

2005-12-01

A 4-month-old female maltese dog was admitted to Veterinary Medical Teaching Hospital of Seoul National University for evaluation of abnormal color of bilateral irises. This patient had the photophobia in the light and exhibited the complete absence of pigment resulting in white hair, pink muzzle, eyelids and foot-pads. Central zone of the irises were yellow in color influenced by tapetal reflex, and peripheral zone were pale blue. The iridal capillaries were transparented on the irises. Ophthalmoscopic examination revealed a yellow tapetal fundus but no pigment in the nontapetal fundus.

Nonsense mutations in ADTB3A cause complete deficiency of the beta3A subunit of adaptor complex-3 and severe Hermansky-Pudlak syndrome type 2.

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Huizing, Marjan; Scher, Charles D; Strovel, Erin; Fitzpatrick, Diana L; Hartnell, Lisa M; Anikster, Yair; Gahl, William A

2002-02-01

Hermansky-Pudlak syndrome (HPS) is an autosomal recessive disease consisting of oculocutaneous albinism and a storage pool deficiency resulting from absent platelet dense bodies. The disorder is genetically heterogeneous. The majority of patients, including members of a large genetic isolate in northwest Puerto Rico, have mutations in HPS1. Another gene, ADTB3A, was shown to cause HPS-2 in two brothers having compound heterozygous mutations that allowed for residual production of the gene product, the beta3A subunit of adaptor complex-3 (AP-3). This heterotetrameric complex serves as a coat protein-mediating formation of intracellular vesicles, e.g. the melanosome and platelet dense body, from membranes of the trans-Golgi network. We determined the genomic organization of the human ADTB3A gene, with intron/exon boundaries, and describe a third patient with beta3A deficiency. This 5-y-old boy has two nonsense mutations, C1578T (R-->X) and G2028T (E-->X), which produce no ADTB3A mRNA and no beta3A protein. The associated mu3 subunit of AP-3 is also entirely absent. In fibroblasts, the cell biologic concomitant of this deficiency is robust and aberrant trafficking through the plasma membrane of LAMP-3, an integral lysosomal membrane protein normally carried directly to the lysosome. The clinical concomitant is a severe, G-CSF-responsive neutropenia in addition to oculocutaneous albinism and platelet storage pool deficiency. Our findings expand the molecular, cellular, and clinical spectrum of HPS-2 and call for an increased index of suspicion for this diagnosis among patients with features of albinism, bleeding, and neutropenia.

Screening of TYR, OCA2, GPR143, and MC1R in patients with congenital nystagmus, macular hypoplasia, and fundus hypopigmentation indicating albinism

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Preising, Markus N.; Gonser, Miriam; Lorenz, Birgit

2011-01-01

Background A broad spectrum of pigmentation of the skin and hair is found among patients diagnosed with ocular albinism (OA) and oculocutaneous albinism (OCA). Even though complexion is variable, three ocular features, i.e., hypopigmentation of the fundus, hypoplasia of the macula, and nystagmus, are classical pathological findings in these patients. We screened 172 index patients with a clinical diagnosis of OA or OCA based on the classical findings, to evaluate the frequency of sequence variants in tyrosinase (TYR), P-gene, P-protein (OCA2), and the G-protein-coupled receptor 143 gene, OA1 (GPR143). In addition, we investigated the association of sequence variants in the melanocortin receptor 1 gene (MC1R) and OCA2. Methods Pigmentation of the hair, skin, iris, and fundus were included in the evaluation of OCA and OA. Male OA patients showing X-linked inheritance were screened for GPR143. Females showing OA without family history were regarded as representing autosomal recessive OA (OA3). Direct sequencing was applied to PCR products showing aberrant single-strand conformation polymorphism–banding patterns. Results Fifty-seven male index patients were screened for OA. We identified 16 potentially pathogenic sequence variations in GPR143 (10 novel) in 22 males. In TYR, we identified 23 (7 novel), and in OCA2 28 (11 novel) possibly pathogenic variants. Variants on both alleles were identified in TYR or OCA2 in 29/79 OCA patients and 14/71 OA patients. Sequence changes in TYR were identified almost exclusively in OCA patients, while sequence changes in OCA2 occurred in OCA and OA patients. MC1R sequencing was performed in 47 patients carrying mutations in OCA2 and revealed MC1R mutations in 42 of them. Conclusions TYR gene mutations have a more severe effect on pigmentation than mutations in OCA2 and the GPR143 gene. Nevertheless, mutations in these genes affect the development of visual function either directly or by interaction with other genes like MC1R, which

Measuring Connectivity in the Primary Visual Pathway in Human Albinism Using Diffusion Tensor Imaging and Tractography.

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Grigorian, Anahit; McKetton, Larissa; Schneider, Keith A

2016-08-11

In albinism, the number of ipsilaterally projecting retinal ganglion cells (RGCs) is significantly reduced. The retina and optic chiasm have been proposed as candidate sites for misrouting. Since a correlation between the number of lateral geniculate nucleus (LGN) relay neurons and LGN size has been shown, and based on previously reported reductions in LGN volumes in human albinism, we suggest that fiber projections from LGN to the primary visual cortex (V1) are also reduced. Studying structural differences in the visual system of albinism can improve the understanding of the mechanism of misrouting and subsequent clinical applications. Diffusion data and tractography are useful for mapping the OR (optic radiation). This manuscript describes two algorithms for OR reconstruction in order to compare brain connectivity in albinism and controls.An MRI scanner with a 32-channel head coil was used to acquire structural scans. A T1-weighted 3D-MPRAGE sequence with 1 mm(3) isotropic voxel size was used to generate high-resolution images for V1 segmentation. Multiple proton density (PD) weighted images were acquired coronally for right and left LGN localization. Diffusion tensor imaging (DTI) scans were acquired with 64 diffusion directions. Both deterministic and probabilistic tracking methods were run and compared, with LGN as the seed mask and V1 as the target mask. Though DTI provides relatively poor spatial resolution, and accurate delineation of OR may be challenging due to its low fiber density, tractography has been shown to be advantageous both in research and clinically. Tract based spatial statistics (TBSS) revealed areas of significantly reduced white matter integrity within the OR in patients with albinism compared to controls. Pairwise comparisons revealed a significant reduction in LGN to V1 connectivity in albinism compared to controls. Comparing both tracking algorithms revealed common findings, strengthening the reliability of the technique.

Dealing with the other between the ethical and the moral: albinism on the African continent.

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Imafidon, Elvis

2017-04-01

Albinism is a global public health issue but it assumes a peculiar nature in the African continent due, in part, to the social stigma faced by persons with albinism (PWAs) in Africa. I argue that there are two essential reasons for this precarious situation. First, in the African consciousness, albinism is an alterity or otherness. The PWA in Africa is not merely a physical other but also an ontological other in the African community of beings, which provides a hermeneutic for the stigmatising separateness or difference of the PWA. The second reason hinges on a distinction drawn by Jürgen Habermas between the ethical point of view and the moral point of view. While the former consists of the ethos, customs, or idea of the good shared by a group of persons with a shared tradition or way of life, the latter consists of what is good for all and transcends particular traditions or ways of life. Consequently, the African ethical point of view, the ethics of solidarity, justifies within the African worldview the established alterity and, by implication, stigmatization of PWAs. On this view, actions that promote harmony and prevent discord and disequilibrium among accepted beings in the African community are permissible. I further show that unless there is a change in the physical and ontological conception of PWAs and a leap from the ethical point of view to the moral point of view, the negative attitudes toward PWAs will not change. The leap to the moral point of view does not suggest an abandonment of the ethical point of view but only recommends that the two meet halfway in respect for universally accepted norms of human actions. To achieve this, I will show that much needs to be done in the areas of policy formulation, law, health care services, and education.

Mutational Analysis on Membrane Associated Transporter Protein (MATP) and Their Structural Consequences in Oculocutaeous Albinism Type 4 (OCA4)-A Molecular Dynamics Approach.

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Kamaraj, Balu; Purohit, Rituraj

2016-11-01

Oculocutaneous albinism type IV (OCA4) is an autosomal recessive inherited disorder which is characterized by reduced biosynthesis of melanin pigmentation in skin, hair, and eyes and caused by the genetic mutations in the membrane-associated transporter protein (MATP) encoded by SLC45A2 gene. The MATP protein consists of 530 amino acids which contains 12 putative transmembrane domains and plays an important role in pigmentation and probably functions as a membrane transporter in melanosomes. We scrutinized the most OCA4 disease-associated mutation and their structural consequences on SLC45A2 gene. To understand the atomic arrangement in 3D space, the native and mutant structures were modeled. Further the structural behavior of native and mutant MATP protein was investigated by molecular dynamics simulation (MDS) approach in explicit lipid and water background. We found Y317C as the most deleterious and disease-associated SNP on SLC45A2 gene. In MDS, mutations in MATP protein showed loss of stability and became more flexible, which alter its structural conformation and function. This phenomenon has indicated a significant role in inducing OCA4. Our study explored the understanding of molecular mechanism of MATP protein upon mutation at atomic level and further helps in the field of pharmacogenomics to develop a personalized medicine for OCA4 disorder. J. Cell. Biochem. 117: 2608-2619, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

types of albinism in the black southern africa population

African Journals Online (AJOL)

2012-01-01

Jan 1, 2012 ... RM 407, 522 First Ave, New York, 10016, USA. R. Kerr, PhD, Lecturer, and ... Objectives: To investigate and classify the different types of albinism commonly found ..... children under the age of ten years this group of subjects ...

Delineating the genetic heterogeneity of OCA in Hungarian patients

OpenAIRE

F?bos, Be?ta; Farkas, Katalin; T?th, Lola; Sul?k, Adrienn; Tripolszki, Korn?lia; Tihanyi, Mariann; N?meth, R?ka; Vas, Krisztina; Csoma, Zsanett; Kem?ny, Lajos; Sz?ll, M?rta; Nagy, Nikoletta

2017-01-01

Background Oculocutaneous albinism (OCA) is a clinically and genetically heterogenic group of pigmentation abnormalities characterized by variable hair, skin, and ocular hypopigmentation. Six known genes and a locus on human chromosome 4q24 have been implicated in the etiology of isolated OCA forms (OCA 1?7). Methods The most frequent OCA types among Caucasians are OCA1, OCA2, and OCA4. We aimed to investigate genes responsible for the development of these OCA forms in Hungarian OCA patients ...

Albinism in the domestic cat (Felis catus) is associated with a tyrosinase (TYR) mutation

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Imes, DL; Geary, LA; Grahn, RA; Lyons, LA

2006-01-01

Summary Albino phenotypes are documented in a variety of species including the domestic cat. As albino phenotypes in other species are associated with tyrosinase (TYR) mutations, TYR was proposed as a candidate gene for albinism in cats. An Oriental and Colourpoint Shorthair cat pedigree segregating for albinism was analysed for association with TYR by linkage and sequence analyses. Microsatellite FCA931, which is closely linked to TYR and TYR sequence variants were tested for segregation with the albinism phenotype. Sequence analysis of genomic DNA from wild-type and albino cats identified a cytosine deletion in TYR at position 975 in exon 2, which causes a frame shift resulting in a premature stop codon nine residues downstream from the mutation. The deletion mutation in TYR and an allele of FCA931 segregated concordantly with the albino phenotype. Taken together, our results suggest that the TYR gene corresponds to the colour locus in cats and its alleles, from dominant to recessive, are as follows: C (full colour) > cb (burmese) ≥ cs (siamese) > c (albino). PMID:16573534

A novel nonsense mutation of the GPR143 gene identified in a Chinese pedigree with ocular albinism.

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Naihong Yan

Full Text Available BACKGROUND: The purpose of this study was to elucidate the molecular basis of ocular albinism type I in a Chinese pedigree. METHODOLOGY/PRINCIPAL FINDINGS: Complete ophthalmologic examinations were performed on 4 patients, 7 carriers and 17 unaffected individuals in this five-generation family. All coding exons of four-point-one (4.1, ezrin, radixin, moesin (FERM domain-containing 7 (FRMD7 and G protein-coupled receptor 143 (GPR143 genes were amplified by polymerase chain reaction (PCR, sequenced and compared with a reference database. Ocular albinism and nystagmus were found in all patients of this family. Macular hypoplasia was present in the patients including the proband. A novel nonsense hemizygous mutation c.807T>A in the GPR143 gene was identified in four patients and the heterozygous mutation was found in seven asymptomatic individuals. This mutation is a substitution of tyrosine for adenine which leads to a premature stop codon at position 269 (p.Y269X of GPR143. CONCLUSIONS/SIGNIFICANCE: This is the first report that p.Y269X mutation of GPR143 gene is responsible for the pathogenesis of familial ocular albinism. These results expand the mutation spectrum of GPR143, and demonstrate the clinical characteristics of ocular albinism type I in Chinese population.

Surgical challenges and outcomes of rhegmatogenous retinal detachment in albinism.

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Sinha, M K; Chhablani, J; Shah, B S; Narayanan, R; Jalali, S

2016-03-01

To report the outcomes and surgical difficulties during rhegmatogenous retinal detachment (RRD) repair in patients with albinism. Retrospective analysis of 10 eyes of 9 patients with albinism that underwent RRD repair was performed. Collected data included demographic details, preoperative examination details, surgical procedure, surgical difficulties, anatomical, and visual outcomes. Outcome measures were retinal reattachment and visual acuity at the last follow-up. Mean preoperative best-corrected visual acuity (BCVA) was logMAR (Logarithm of the Minimum Angle of Resolution) 2.15 (range 0.9-3.0) with preoperative localization of causative break in six eyes. One eye had proliferative vitreoretinopathy grade C1 preoperatively. Four eyes underwent scleral buckling (SB) and six underwent 20G pars plana vitrectomy (PPV) with silicone oil injection. Intraoperative complication as iatrogenic retinal break occurred in four eyes. For retinopexy during vitrectomy, endolaser delivery was possible in three out of six eyes, whereas three eyes had cryopexy. The mean follow-up was 12 months in SB group (range 1-12; median 12 months) and 5.33 months (range 1-12; median 3 months) in PPV group. Among vitrectomized eye, two eyes had recurrence at 3 months with oil in situ. Rest of the eyes had attached retina at last follow-up. Mean BCVA at last follow-up was logMAR -1.46 (range 0.7-2.0) with mean improvement of -0.57 logMAR. Identification of break, induction of posterior vitreous detachment, and endolaser delivery may be difficult during RRD repair in patients with albinism. The incidence of PVR appeared less in these eyes. Both SB and PPV were efficacious and appear to be good surgical techniques for use in this patient population.

Loss of binocular vision as direct cause for misrouting of temporal retinal fibers in albinism.

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Banihani, Saleh M

2015-10-01

In humans, the nasal retina projects to the contralateral hemisphere, whereas the temporal retina projects ipsilaterally. The nasotemporal line that divides the retina into crossed and uncrossed parts coincides with the vertical meridian through the fovea. This normal projection of the retina is severely altered in albinism, in which the nasotemporal line shifted into the temporal retina with temporal retinal fibers cross the midline at the optic chiasm. This study proposes the loss of binocular vision as direct cause for misrouting of temporal retinal fibers and shifting of the nasotemporal line temporally in albinism. It is supported by many observations that clearly indicate that loss of binocular vision causes uncrossed retinal fibers to cross the midline. This hypothesis may alert scientists and clinicians to find ways to prevent or minimize the loss of binocular vision that may occur in some diseases such as albinism and early squint. Hopefully, this will minimize the misrouting of temporal fibers and improve vision in such diseases. Copyright © 2015 Elsevier Ltd. All rights reserved.

Monocular and binocular development in children with albinism, infantile nystagmus syndrome, and normal vision.

Science.gov (United States)

Huurneman, Bianca; Boonstra, F Nienke

2013-12-01

To compare interocular acuity differences, crowding ratios, and binocular summation ratios in 4- to 8-year-old children with albinism (n = 16), children with infantile nystagmus syndrome (n = 10), and children with normal vision (n = 72). Interocular acuity differences and binocular summation ratios were compared between groups. Crowding ratios were calculated by dividing the single Landolt C decimal acuity with the crowded Landolt C decimal acuity mono- and binocularly. A linear regression analysis was conducted to investigate the contribution of 5 predictors to the monocular and binocular crowding ratio: nystagmus amplitude, nystagmus frequency, strabismus, astigmatism, and anisometropia. Crowding ratios were higher under mono- and binocular viewing conditions for children with infantile nystagmus syndrome than for children with normal vision. Children with albinism showed higher crowding ratios in their poorer eye and under binocular viewing conditions than children with normal vision. Children with albinism and children with infantile nystagmus syndrome showed larger interocular acuity differences than children with normal vision (0.1 logMAR in our clinical groups and 0.0 logMAR in children with normal vision). Binocular summation ratios did not differ between groups. Strabismus and nystagmus amplitude predicted the crowding ratio in the poorer eye (p = 0.015 and p = 0.005, respectively). The crowding ratio in the better eye showed a marginally significant relation with nystagmus frequency and depth of anisometropia (p = 0.082 and p = 0.070, respectively). The binocular crowding ratio was not predicted by any of the variables. Children with albinism and children with infantile nystagmus syndrome show larger interocular acuity differences than children with normal vision. Strabismus and nystagmus amplitude are significant predictors of the crowding ratio in the poorer eye.

Indicii microbiologici ai familiilor de albine înaintea iernatului

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Veronica BUGNEAC

2017-12-01

Full Text Available Bee colonies are exposed to a wide variety of actions of the agricultural ecosystem and to a multitude of variations of the environment throughout the year. All these factors can affect the bees’ microbial balance. This study aimed to determine the microflora of bee families before the wintering period. The bees for the research were randomly collected at two apiaries of 17 and 24 bee families. Under laboratory conditions, insemination was performed on common, selective and differential growth media using material of the bees’ intestines. As a result of the investigations, an intensive growth of bacterial colonies was noticed on all microbial culture media. They were predominantly formed by different forms of bacteria such as streptococci, staphylococci, E. coli, Salmonellaand microscopic fungi. Most colonies of microorganisms developed on Endo and Peptonate Agar media, being represented by the microbial colonies of E. coli and streptococci, respectively. Rezumat. Coloniile de albine pe tot parcursul anului sunt expuse la o varietate largă de acțiuni ale ecosiste-melor agricole și la o multitudine de variații ale mediului, care le pot afecta echilibrul microbian. Studiul de faţă îşi propune de a stabili varietatea microflorei familiilor de albine înaintea perioadei de iernat. Albinele pentru cer-cetare au fost colectate în mod aleatoriu de la două stupine, cu 17 şi 24 de familii de albine. În condiții de labora-tor, din intestinele albinelor au fost efectuate însămânțări pe medii nutritive obișnuite, selective și diferențiale. În rezultatul investigațiilor s-a stabilit o creștere intensivă de colonii bacteriene pe toate mediile microbiene nutritive. Acestea au fost constituite preponderent din formele bacteriene precum streptococi, stafilococi, E. coli, salmoneleși fungi microscopici. Cele mai multe colonii de microorganisme s-au dezvoltat pe mediile Endo și Agarul pepto-nat, fiind reprezentate de coloniile

Albinism in Botswana Junior Secondary Schools: A Double Case Study

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Dart, Gareth; Nkanotsang, Tiroyaone; Chizwe, Ose; Kowa, Lily

2010-01-01

Pupils with albinism potentially face a number of challenges in accessing quality education in schools in Botswana. Physical issues such as poor eyesight related to the condition and the problems of sensitive skin in such a dry and warm climate are both contributing factors to making learning problematic for some pupils. This study by Gareth Dart…

Premolarized double dens in dente in albinism - A case report

Directory of Open Access Journals (Sweden)

Suprabha B

2005-09-01

Full Text Available Dens in dente are known to be associated with many dental abnormalities such as taurodontism microdontia, gemination, and dens evaginatus. This paper describes a rare case of double dens in dente in a lateral incisor with crown morphology similar to a premolar present in a patient with features of albinism. Problems associated with this condition and their management is discussed.

CHEDIAK-HIGASHI SYNDROME IN 15 MONTHS OLD BOY

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Tatjana Pavlin

2004-12-01

Full Text Available Background. Syndrome Chediak-Higashi (SCH is a rare autosome recesive hereditary disorder characterized by abnormal intracellular protein transport. A prominent feature of this disease is the accumulation of enlarged cytoplasmic granules in a variety of cells with damaging their functions. The condition is characterized by increased susceptibility for infections because of disturbance in degranulation of neutrophils, impaired chemotaxis and bactericidal activity, abnormal natural killer cell function, bleeding as a result of deficient platlet dense bodies, partial oculocutaneous albinism and progressive peripheral neuropathy. The disease is often fatal in childhood as a result of infection or an accelerated lymphoma-like phase with nonmalignant lymphohistiocytic infiltrates of various organs. An accelerated phase occurs in more than 80% of patients and it is manifested by pancytopenia, hypertriglyceridemia and bleeding disorders. Remissions, which are usually only transient in this stage of the disease, are reached with combined treatment comprising etoposide, steroids and methotrexate. The only therapeutic strategy capable of curing the disease is bone marrow transplantation.Methods and patients. We introduce a boy, who was treated for recurrent bacterial infections as an infant. He also had an oculocutaneous albinism and a neurologic involvement. At the age 15 months diagnosis of SCH in accelerated phase with involvement of liver, spleen, lymph nodes, bone marrow and brain was made. Remission of the disease was achieved by combined treatment with etoposide, steroids and methotrexate.Conclusions. This article is the first description of a patient with SCH in Slovenia. We also describe efficient treatment of accelerated phase of the disease which led to remission.

A deletion in the Hermansky-Pudlak syndrome 4 (Hps4) gene appears to be responsible for albinism in channel catfish.

Science.gov (United States)

Li, Yueru; Geng, Xin; Bao, Lisui; Elaswad, Ahmed; Huggins, Kevin W; Dunham, Rex; Liu, Zhanjiang

2017-06-01

Albinism is caused by a series of genetic abnormalities leading to reduction of melanin production. Albinism is quite frequent in catfish, but the causative gene and the molecular basis were unknown. In this study, we conducted a genome-wide association study (GWAS) using the 250 K SNP array. The GWAS analysis allowed mapping of the albino phenotype in the Hermansky-Pudlak syndrome 4 (Hps4) gene, which is known to be involved in melanosome biosynthesis. Sequencing analysis revealed that a 99-bp deletion was present in all analyzed albino catfish at the intron 2 and exon 3 junction. This deletion led to the skipping of the entire exon 3 which was confirmed by RT-PCR. Therefore, Hps4 was determined to be the candidate gene of the catfish albinism.

Formulation of a topical sun protection cream for people with albinism

African Journals Online (AJOL)

The aim of this investigation was to design and develop a sun protection product for people with albinism that is affordable, applicable to their specific skin condition, and provide them with the maximum sun protection possible. To achieve the required Sun Protection Factor value of > 20, simple creams were combined with ...

MC1R gene variants involvement in human OCA phenotype

OpenAIRE

Saleha Shamim; Khan Taj Ali; Zafar Shaista

2016-01-01

Oculocutaneous albinism (OCA) is a genetic disorder of melanin synthesis that results in hypopigmentation in hair, skin and eyes. OCA has been reported in individuals from all ethnic backgrounds but it is more common among those with Europeans ancestry. OCA is heterogeneous group of disorders and seven types of OCA are caused by mutations in TYR (OCA1), OCA2 (OCA2), TYRP1 (OCA3), SLC45A2 (OCA4), SLC24A5 (OCA6) and C10oRF11 (OCA7) genes. However, MC1R gene variants have been reported that modi...

Cutaneous Cancers in Nigerian Albinos: A Review of 22 Cases

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Oluwafemi Olasupo Awe

2018-01-01

Full Text Available Context: Albinism is an inherited disorder of hypopigmentation involving the skin, eyes, and hair. This disorder results in the absence or reduction in melanin production. There are two main types of albinism which are ocular albinism and oculocutaneous albinism. It could also be classified as syndromic or nonsyndromic the melanin, which protects from the harmful effect of ultraviolet radiation of the sun on the normal skin, is deficient in the albino, predisposing them more, to cutaneous malignancies. Aim: This study is to highlight the epidemiology of cutaneous cancers in albinos in sub-urban Nigeria. Methodology: This is a retrospective review of all albinos with histological diagnoses of cutaneous malignancies that presented to Irrua Specialist Teaching Hospital, Irrua Edo State, Nigeria between September 2010 and August 2016. The following details were extracted from the patients' case-notes, operation register, and the histopathology register. These data include age, gender, site of the lesion, the diagnosis, no of lesions excised, and duration of the lesion (s. These were collated and analyzed using SPSS version 22. Results: There were 22 albinos with histopathologically diagnosed cutaneous malignancies. There were 11 males and 11 females with male:female of 1. The age range is from 25 to 55 years with the mean of 34.68. Conclusion: Albinism is one of the most common causes of cutaneous malignancies, and majority of them present with locally advanced lesions that will need excision biopsy resulting in disfigurement. This problem can be prevented in many cases with proper community education, support, and free health care. There is also need for them to present early whenever they noticed any skin changes.

Abnormally Small Neuromuscular Junctions in the Extraocular Muscles From Subjects With Idiopathic Nystagmus and Nystagmus Associated With Albinism.

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McLoon, Linda K; Willoughby, Christy L; Anderson, Jill S; Bothun, Erick D; Stager, David; Felius, Joost; Lee, Helena; Gottlob, Irene

2016-04-01

Infantile nystagmus syndrome (INS) is often associated with abnormalities of axonal outgrowth and connectivity. To determine if this manifests in extraocular muscle innervation, specimens from children with idiopathic INS or INS and albinism were examined and compared to normal age-matched control extraocular muscles. Extraocular muscles removed during normal surgery on children with idiopathic INS or INS and albinism were immunostained for neuromuscular junctions, myofiber type, the immature form of the acetylcholine receptor, and brain-derived neurotrophic factor (BDNF) and compared to age-matched controls. Muscles from both the idiopathic INS and INS and albinism groups had neuromuscular junctions that were 35% to 71% smaller based on myofiber area and myofiber perimeter than found in age-matched controls, and this was seen on both fast and slow myosin heavy chain isoform-expressing myofibers (all P albinism showed a 7-fold increase in neuromuscular junction numbers on fast myofibers expressing the immature gamma subunit of the acetylcholine receptor. The extraocular muscles from both INS subgroups showed a significant increase in the number and size of slow myofibers compared to age-matched controls. Brain-derived neurotrophic factor was expressed in control muscle but was virtually absent in the INS muscles. These studies suggest that, relative to the final common pathway, INS is not the same between different patient etiologies. It should be possible to modulate these final common pathway abnormalities, via exogenous application of appropriate drugs, with the hope that this type of treatment may reduce the involuntary oscillatory movements in these children.

Skin flora: Differences between people affected by Albinism and those with normally pigmented skin in Northern Tanzania - cross sectional study.

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Kiprono, Samson K; Masenga, John E; Chaula, Baraka M; Naafs, Bernard

2012-07-30

Skin flora varies from one site of the body to another. Individual's health, age and gender determine the type and the density of skin flora. A 1  cm² of the skin on the sternum was rubbed with sterile cotton swab socked in 0.9% normal saline and plated on blood agar. This was cultured at 35 °C. The bacteria were identified by culturing on MacConkey agar, coagulase test, catalase test and gram staining. Swabs were obtained from 66 individuals affected by albinism and 31 individuals with normal skin pigmentation. Those with normal skin were either relatives or staying with the individuals affected by albinism who were recruited for the study. The mean age of the 97 recruited individuals was 30.6 (SD ± 14.9) years. The mean of the colony forming units was 1580.5 per cm2. Those affected by albinism had a significantly higher mean colony forming units (1680  CFU per cm²) as compared with 453.5  CFU per cm² in those with normally pigmented skin (p = 0.023). The skin type and the severity of sun- damaged skin was significantly associated with a higher number of colony forming units (p = 0.038). Individuals affected by albinism have a higher number of colony forming units which is associated with sun- damaged skin.

[Identification of a novel GPR143 mutation in a Chinese family affected with X-linked ocular albinism].

Science.gov (United States)

Zhao, Qi; Guan, Menglong; Wang, Ling; Liao, Yong; Li-Ling, Jesse; Wan, Huajing

2017-04-10

To detect mutation of GPR143 gene in a Chinese patient affected with ocular albinism. Peripheral blood samples were collected from the proband and his parents. The coding regions of the GPR143 gene were subjected to PCR amplification and Sanger sequencing. A previously unreported mutation (c.758T>A) was found in exon 6 of the GPR143 gene in the proband and his mother. The same mutation was not found in his father. As predicted, the mutation has resulted in a stop codon, causing premature termination of protein translation. A novel mutation of the GPR143 gene related to X-linked ocular albinism has been identified.

[Tapeto-retinal degeneration combined with incomplete general albinism (author's transl)].

Science.gov (United States)

Ivandić, T

1975-05-01

Report on a family, which presented the rare autosomal dominant transmitted, incomplete general albinism associated with autosomal recessive inherited, diffuse tapeto-retinal degeneration "sine pigmento". hypopigmentation of skin, eyebrows and hair, blue iris and fundus albinoticus with hypoplasia of the macula. In 3 cases additionally appeared: waxy pallor of optic disc, vascular narrowing, reflexless hypoplastic macula, pigmentless periphery, acquired blue-yellow blindness, concentric limitation of the visual field, reduced darkadaptation, abolished electroretinogram and myopic astigmatism.

Monocular and binocular development in children with albinism, infantile nystagmus syndrome, and normal vision

NARCIS (Netherlands)

Huurneman, B.; Boonstra, F.N.

2013-01-01

Abstract Background/aims: To compare interocular acuity differences, crowding ratios, and binocular summation ratios in 4- to 8-year-old children with albinism (n = 16), children with infantile nystagmus syndrome (n = 10), and children with normal vision (n = 72). Methods: Interocular acuity

Albinism in the american mink (Neovison vison) is associated with a tyrosinase nonsense mutation

DEFF Research Database (Denmark)

Anistoroaei, Razvan Marian; Fredholm, Merete; Christensen, Knud

2008-01-01

Albino phenotypes are documented in various species including the American mink. In other species the albino phenotypes are associated with tyrosinase (TYR) gene mutations; therefore TYR was considered the candidate gene for albinism in mink. Four microsatellite markers were chosen in the prodicted...

Hermansky-Pudlak syndrome in a pregnant patient: a case report.

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Harris-Glocker, Miranda; Thornburg, Loralei L; Pressman, Eva K

2013-01-01

Hermansky-Pudlak syndrome (HPS), a rare autosomal-recessive disorder encompassing multiple organs, is characterized by oculocutaneous albinism, platelet storage pool deficiency resulting in bleeding diathesis, and ceroid lipofuscin deposition which can lead to pulmonary fibrosis, colitis, cardiomyopathy and renal failure. Pregnancy in a patient with HPS can produce multiple complications such as peripartum hemorrhage and difficulties with administration of anesthesia, either regional or general. We present the case of a patient with HPS also complicated by spontaneous triplet pregnancy. A multidisciplinary approach, including the involvement of obstetric, anesthesia, and hematology teams, is the ideal for an HPS patient with the potential for multiple complications in the peripartum period.

Monocular and binocular development in children with albinism, infantile nystagmus syndrome and normal vision

NARCIS (Netherlands)

Huurneman, B.; Boonstra, F.N.

2013-01-01

Background/aims: To compare interocular acuity differences, crowding ratios, and binocular summation ratios in 4- to 8-year-old children with albinism (n = 16), children with infantile nystagmus syndrome (n = 10), and children with normal vision (n = 72). Methods: Interocular acuity differences and

X mapping in man: evidence against direct measurable linkage between ocular albinism and deutan colour blindness.

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Pearce, W G; Sanger, R

1976-01-01

A Newfoundland kindred in which ocular albinism and deutan colour blindness are segregating provides strong evidence against the loci for these two X-borne characters being within direct measurable distance of each other. PMID:1085370

Albinism in phylogenetically and geographically distinct populations of Astyanax cavefish arises through the same loss-of-function Oca2 allele

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Gross, J B; Wilkens, H

2013-01-01

The Mexican tetra, Astyanax mexicanus, comprises 29 populations of cave-adapted fish distributed across a vast karst region in northeastern Mexico. These populations have a complex evolutionary history, having descended from ‘old' and ‘young' ancestral surface-dwelling stocks that invaded the region ∼6.7 and ∼2.8 MYa, respectively. This study investigates a set of captive, pigmented Astyanax cavefish collected from the Micos cave locality in 1970, in which albinism appeared over the past two decades. We combined novel coloration analyses, coding sequence comparisons and mRNA expression level studies to investigate the origin of albinism in captive-bred Micos cavefish. We discovered that albino Micos cavefish harbor two copies of a loss-of-function ocular and cutaneous albinism type II (Oca2) allele previously identified in the geographically distant Pachón cave population. This result suggests that phylogenetically young Micos cavefish and phylogenetically old Pachón cave fish inherited this Oca2 allele from the ancestral surface-dwelling taxon. This likely resulted from the presence of the loss-of-function Oca2 haplotype in the ‘young' ancestral surface-dwelling stock that colonized the Micos cave and also introgressed into the ancient Pachón cave population. The appearance of albinism in captive Micos cavefish, caused by the same loss-of-function allele present in Pachón cavefish, implies that geographically and phylogenetically distinct cave populations can evolve the same troglomorphic phenotype from standing genetic variation present in the ancestral taxon. PMID:23572122

Multipoint linkage analysis in X-linked ocular albinism of the Nettleship-Falls type

NARCIS (Netherlands)

Bergen, A. A.; Samanns, C.; Schuurman, E. J.; van Osch, L.; van Dorp, D. B.; Pinckers, A. J.; Bakker, E.; Gal, A.; van Ommen, G. J.; Bleeker-Wagemakers, E. M.

1991-01-01

An extensive linkage analysis was performed by studying ten Xp22 loci in ten families segregating for X-linked ocular albinism of the Nettleship-Falls type (XOA). Linkage was confirmed between the XOA locus (OA1) and both DXS16 (theta max = 0.10, zeta max = 4.09) and DXS237 (theta max = 0.12, zeta

Analysis of MC1R variants in Indian oculocutaneous albinism patients

Indian Academy of Sciences (India)

1Molecular and Human Genetics Division, Council of Scientific and Industrial Research - Indian Institute of Chemical ... patients: highlighting the risk of skin cancer among albinos. .... The finer assessment of the imparted risk due to the indi-.

Chiasmal coefficient of flash and pattern visual evoked potentials for detection of chiasmal misrouting in albinism

NARCIS (Netherlands)

Pott, JWR; Jansonius, NM; Kooijman, AC

The diagnosis of albinism can be confirmed by electrophysiological examination, when chiasmal misrouting can be demonstrated. The present study describes a quantitative analysis method for this purpose. A chiasmal coefficient (CC) was calculated by correlating the differential potential over left

INCIDENCE AND CLINICOPATHOLOGICAL FEATURES OF NEUROCUTANEOUS DISORDERS

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S. Kayalvizhi Money

2017-08-01

Full Text Available BACKGROUND Neurocutaneous disorders are genetically determined disorders showing both cutaneous and neurologic involvement. The definition includes both hereditary and non-hereditary phenotypes, but excludes acquired disorders. Either they follow the established Mendelian modes of inheritance or they represent lethal mutations surviving by mosaicism or they belong to the group of chromosomal disorders. MATERIALS AND METHODS This study was conducted at the Department of Dermatology, Government KAPV Medical College, Trichy, for a period of 12 months from January 2016 to December 2016. Patients were selected among those attending the outpatient department with signs and symptoms pertaining to neurocutaneous syndromes. Preliminary information like age, sex, educational qualification, present and past illness, family history elicited. Dermatological examination consisted of thorough screening of patients to detect the cutaneous markers for neurocutaneous disorders. A detailed systemic examination was done, particularly central nervous system. RESULTS In this study, neurofibromatosis (68.8% topped the list followed by tuberous sclerosis complex (18.3% and other rarer disorders like xeroderma pigmentosum (2.7%, giant congenital melanocytic naevus (1.8%, Sturge-Weber syndrome (0.9%, Waardenburg syndrome (1.8%, epidermal naevus syndrome (1.8%, naevus comedonicus (0.9%, Elejalde syndrome (0.9%, oculocutaneous albinism (0.9% and Adams-Oliver syndrome (0.9%. CONCLUSION In this study of 109 cases of neurocutaneous syndromes, neurofibromatosis topped the list followed by tuberous sclerosis complex. Classical features of xeroderma pigmentosum was observed in 1 patient. Sturge-Weber syndrome with unilateral port wine stain with seizures was reported in our study. Two cases of Waardenburg syndrome, epidermal nevus syndrome and giant congenital melanocytic nevus were reported in my study. One case of unilateral nevus comedonicus, Elejalde syndrome, oculocutaneous

Brown′s syndrome with ocular albinism: Case report of a rare presentation and literature review

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Soumya Nambiar

2015-01-01

Full Text Available We report a rare case of Brown′s syndrome associated with ocular albinism in a 10-year-old boy. This report highlights the importance of further analysis of cases of Brown′s syndrome and throws some light on the etiology and association of this rare condition.

Chédiak–Higashi syndrome

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Javad Ghaffari

2013-05-01

Full Text Available Chédiak-Higashi syndrome is a rare autosomal recessive congenital immunodeficiency mainly characterized by a condition called oculo-cutaneous albinism. The affected subjects have light-colored hair, vision problems, blood clotting (coagulation abnormalities and in adulthood varying neurologic disorders. Recurrent infections, particularly viral infection with other disorders in childhood are usually life threatening. It has demonstrated mutations throughout the CHS1/LYST gene. The nature of the mutation can be a predictor of the severity of the disease. The current therapeutic options are: Antibiotics, chemotherapy and bone marrow transplantation. This review will discuss the clinical and molecular aspects of this syndrome for better understanding of the factors that may cause abnormalities.

Carrier detection in X-linked ocular albinism of the Nettleship-Falls type by DNA analysis

NARCIS (Netherlands)

Bergen, A. A.; Schuurman, E. J.; van den Born, L. I.; Samanns, C.; van Dorp, D. B.; Pinckers, A. J.; Bakker, E.; van Ommen, G. J.; Gal, A.; Bleeker-Wagemakers, E. M.

1992-01-01

X-linked ocular albinism (XOA) is characterized by anomalies of the eyes and hypopigmentation or absence of pigment in skin, hair and eyes due to a hereditary inborn error of metabolism affecting the pigment cells. The gene of XOA of the Nettleship-Falls type (OA1) has been mapped to Xp22.3, and

In silico analysis of miRNA-mediated gene regulation in OCA and OA genes.

Science.gov (United States)

Kamaraj, Balu; Gopalakrishnan, Chandrasekhar; Purohit, Rituraj

2014-12-01

Albinism is an autosomal recessive genetic disorder due to low secretion of melanin. The oculocutaneous albinism (OCA) and ocular albinism (OA) genes are responsible for melanin production and also act as a potential targets for miRNAs. The role of miRNA is to inhibit the protein synthesis partially or completely by binding with the 3'UTR of the mRNA thus regulating gene expression. In this analysis, we predicted the genetic variation that occurred in 3'UTR of the transcript which can be a reason for low melanin production thus causing albinism. The single nucleotide polymorphisms (SNPs) in 3'UTR cause more new binding sites for miRNA which binds with mRNA which leads to inhibit the translation process either partially or completely. The SNPs in the mRNA of OCA and OA genes can create new binding sites for miRNA which may control the gene expression and lead to hypopigmentation. We have developed a computational procedure to determine the SNPs in the 3'UTR region of mRNA of OCA (TYR, OCA2, TYRP1 and SLC45A2) and OA (GPR143) genes which will be a potential cause for albinism. We identified 37 SNPs in five genes that are predicted to create 87 new binding sites on mRNA, which may lead to abrogation of the translation process. Expression analysis confirms that these genes are highly expressed in skin and eye regions. It is well supported by enrichment analysis that these genes are mainly involved in eye pigmentation and melanin biosynthesis process. The network analysis also shows how the genes are interacting and expressing in a complex network. This insight provides clue to wet-lab researches to understand the expression pattern of OCA and OA genes and binding phenomenon of mRNA and miRNA upon mutation, which is responsible for inhibition of translation process at genomic levels.

Albinism and disease causing pathogens in Tanzania: are alleles that are associated with OCA2 being maintained by balancing selection?

Science.gov (United States)

Tuli, Abbas M; Valenzuela, Robert K; Kamugisha, Erasmus; Brilliant, Murray H

2012-12-01

Oculocutaneous albinism type 2 (OCA2) is present at significantly higher frequencies in sub-Saharan African populations compared to populations in other regions of the world. In Tanzania and other sub-Saharan countries, most OCA2 is associated with a common 2.7kb deletion allele. Leprosy is also in high prevalence in sub-Saharan African populations. The infectious agent of leprosy, Mycobacterium leprae, contains a gene, 38L, that is similar to OCA2. Hypopigmented patches of skin are early symptoms that present with infection of leprosy. In consideration of both the genetic similarity of OCA2 and the 38L gene of M. leprae and the involvement of pigmentation in both disorders, we hypothesized that the high rates of OCA2 may be due to heterozygote advantage. Hence, we hypothesized that carriers of the 2.7kb deletion allele of OCA2 may provide a protective advantage from infection with leprosy. We tested this hypothesis by determining the carrier frequency of the 2.7kb deletion allele from a sample of 240 individuals with leprosy from Tanzania. The results were inconclusive due to the small sample size; however, they enabled us to rule out a large protective effect, but perhaps not a small advantage. Mycobacterium tuberculosis is another infectious organism prevalent in sub-Saharan Africa that contains a gene, arsenic-transport integral membrane protein that is also similar to OCA2. Interestingly, chromosomal region 15q11-13, which also contains OCA2, was reported to be linked to tuberculosis susceptibility. Although variants within OCA2 were tested for association, the 2.7kb deletion allele of OCA2 was not tested. This led us to hypothesize that the deletion allele may confer resistance to susceptibility. Confirmation of our hypothesis would enable development of novel pharmocogenetic therapies for the treatment of tuberculosis, which in turn, may enable development of drugs that target other pathogens that utilize a similar infection mechanism as M. tuberculosis

Recessive mutations in SLC38A8 cause foveal hypoplasia and optic nerve misrouting without albinism.

Science.gov (United States)

Poulter, James A; Al-Araimi, Musallam; Conte, Ivan; van Genderen, Maria M; Sheridan, Eamonn; Carr, Ian M; Parry, David A; Shires, Mike; Carrella, Sabrina; Bradbury, John; Khan, Kamron; Lakeman, Phillis; Sergouniotis, Panagiotis I; Webster, Andrew R; Moore, Anthony T; Pal, Bishwanath; Mohamed, Moin D; Venkataramana, Anandula; Ramprasad, Vedam; Shetty, Rohit; Saktivel, Murugan; Kumaramanickavel, Govindasamy; Tan, Alex; Mackey, David A; Hewitt, Alex W; Banfi, Sandro; Ali, Manir; Inglehearn, Chris F; Toomes, Carmel

2013-12-05

Foveal hypoplasia and optic nerve misrouting are developmental defects of the visual pathway and only co-occur in connection with albinism; to date, they have only been associated with defects in the melanin-biosynthesis pathway. Here, we report that these defects can occur independently of albinism in people with recessive mutations in the putative glutamine transporter gene SLC38A8. Nine different mutations were identified in seven Asian and European families. Using morpholino-mediated ablation of Slc38a8 in medaka fish, we confirmed that pigmentation is unaffected by loss of SLC38A8. Furthermore, by undertaking an association study with SNPs at the SLC38A8 locus, we showed that common variants within this gene modestly affect foveal thickness in the general population. This study reveals a melanin-independent component underpinning the development of the visual pathway that requires a functional role for SLC38A8. Copyright © 2013 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

A potential benefit of albinism in Astyanax cavefish: downregulation of the oca2 gene increases tyrosine and catecholamine levels as an alternative to melanin synthesis.

Science.gov (United States)

Bilandžija, Helena; Ma, Li; Parkhurst, Amy; Jeffery, William R

2013-01-01

Albinism, the loss of melanin pigmentation, has evolved in a diverse variety of cave animals but the responsible evolutionary mechanisms are unknown. In Astyanax mexicanus, which has a pigmented surface dwelling form (surface fish) and several albino cave-dwelling forms (cavefish), albinism is caused by loss of function mutations in the oca2 gene, which operates during the first step of the melanin synthesis pathway. In addition to albinism, cavefish have evolved differences in behavior, including feeding and sleep, which are under the control of the catecholamine system. The catecholamine and melanin synthesis pathways diverge after beginning with the same substrate, L-tyrosine. Here we describe a novel relationship between the catecholamine and melanin synthesis pathways in Astyanax. Our results show significant increases in L-tyrosine, dopamine, and norepinephrine in pre-feeding larvae and adult brains of Pachón cavefish relative to surface fish. In addition, norepinephrine is elevated in cavefish adult kidneys, which contain the teleost homologs of catecholamine synthesizing adrenal cells. We further show that the oca2 gene is expressed during surface fish development but is downregulated in cavefish embryos. A key finding is that knockdown of oca2 expression in surface fish embryos delays the development of pigmented melanophores and simultaneously increases L-tyrosine and dopamine. We conclude that a potential evolutionary benefit of albinism in Astyanax cavefish may be to provide surplus L-tyrosine as a precursor for the elevated catecholamine synthesis pathway, which could be important for adaptation to the challenging cave environment.

A potential benefit of albinism in Astyanax cavefish: downregulation of the oca2 gene increases tyrosine and catecholamine levels as an alternative to melanin synthesis.

Directory of Open Access Journals (Sweden)

Helena Bilandžija

Full Text Available Albinism, the loss of melanin pigmentation, has evolved in a diverse variety of cave animals but the responsible evolutionary mechanisms are unknown. In Astyanax mexicanus, which has a pigmented surface dwelling form (surface fish and several albino cave-dwelling forms (cavefish, albinism is caused by loss of function mutations in the oca2 gene, which operates during the first step of the melanin synthesis pathway. In addition to albinism, cavefish have evolved differences in behavior, including feeding and sleep, which are under the control of the catecholamine system. The catecholamine and melanin synthesis pathways diverge after beginning with the same substrate, L-tyrosine. Here we describe a novel relationship between the catecholamine and melanin synthesis pathways in Astyanax. Our results show significant increases in L-tyrosine, dopamine, and norepinephrine in pre-feeding larvae and adult brains of Pachón cavefish relative to surface fish. In addition, norepinephrine is elevated in cavefish adult kidneys, which contain the teleost homologs of catecholamine synthesizing adrenal cells. We further show that the oca2 gene is expressed during surface fish development but is downregulated in cavefish embryos. A key finding is that knockdown of oca2 expression in surface fish embryos delays the development of pigmented melanophores and simultaneously increases L-tyrosine and dopamine. We conclude that a potential evolutionary benefit of albinism in Astyanax cavefish may be to provide surplus L-tyrosine as a precursor for the elevated catecholamine synthesis pathway, which could be important for adaptation to the challenging cave environment.

Biallelic Mutations in MITF Cause Coloboma, Osteopetrosis, Microphthalmia, Macrocephaly, Albinism, and Deafness.

Science.gov (United States)

George, Aman; Zand, Dina J; Hufnagel, Robert B; Sharma, Ruchi; Sergeev, Yuri V; Legare, Janet M; Rice, Gregory M; Scott Schwoerer, Jessica A; Rius, Mariana; Tetri, Laura; Gamm, David M; Bharti, Kapil; Brooks, Brian P

2016-12-01

Human MITF is, by convention, called the "microphthalmia-associated transcription factor" because of previously published seminal mouse genetic studies; however, mutations in MITF have never been associated with microphthalmia in humans. Here, we describe a syndrome that we term COMMAD, characterized by coloboma, osteopetrosis, microphthalmia, macrocephaly, albinism, and deafness. COMMAD is associated with biallelic MITF mutant alleles and hence suggests a role for MITF in regulating processes such as optic-fissure closure and bone development or homeostasis, which go beyond what is usually seen in individuals carrying monoallelic MITF mutations. Copyright © 2016. Published by Elsevier Inc.

Cloning of the gene for ocular albinism type 1 from the distal short arm of the X chromosome

NARCIS (Netherlands)

Bassi, M. T.; Schiaffino, M. V.; Renieri, A.; de Nigris, F.; Galli, L.; Bruttini, M.; Gebbia, M.; Bergen, A. A.; Lewis, R. A.; Ballabio, A.

1995-01-01

Ocular albinism type 1 (OA1) is an X-linked disorder characterized by severe impairment of visual acuity, retinal hypopigmentation and the presence of macromelanosomes. We isolated a novel transcript from the OA1 critical region in Xp22.3-22.2 which is expressed at high levels in RNA samples from

Are mice pigmentary genes throwing light on humans?

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Bose S

1993-01-01

Full Text Available In this article the rapid advances made in the molecular genetics of inherited disorders of hypo and hyperpigmentation during the past three years are reviewed. The main focus is on studies in mice as compared to homologues in humans. The main hypomelanotic diseases included are, piebaldism (white spotting due to mutations of c-KIT, PDGF and MGF genes; vitiligo (microphathalmia mice mutations of c-Kit and c-fms genes; Waardenburg syndrome (splotch locus mutations of mice PAX-3 or human Hup-2 genes; albinism (mutations of tyrosinase genes, Menkes disease (Mottled mouse, premature graying (mutations in light/brown locus/gp75/ TRP-1; Griscelli disease (mutations in TRP-1 and steel; Prader-willi and Angelman syndromes, tyrosinase-positive oculocutaneous albinism and hypomelanosis of lto (mutations of pink-eyed dilution gene/mapping to human chromosomes 15 q 11.2 - q12; and human platelet storage pool deficiency diseases due to defects in pallidin, an erythrocyte membrane protein (pallid mouse / mapping to 4.2 pallidin gene. The genetic characterization of hypermelanosis includes, neurofibromatosis 1 (Café-au-lait spots and McCune-Albright Syndrome. Rapid evolving knowledge about pigmentary genes will increase further the knowledge about these hypo and hyperpigmentary disorders.

Analysis of the OA1 gene reveals mutations in only one-third of patients with X-linked ocular albinism

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Schiaffino, M. V.; Bassi, M. T.; Galli, L.; Renieri, A.; Bruttini, M.; de Nigris, F.; Bergen, A. A.; Charles, S. J.; Yates, J. R.; Meindl, A.

1995-01-01

The locus for ocular albinism type 1 (OA1) has been assigned to the Xp22.3 region through both linkage and deletion mapping. The disorder was found to be genetically homogeneous, as all informative families showed convincing linkage data with markers on Xp22.3 and all identified deletions involved

Generation of human embryonic stem cells from abnormal blastocyst diagnosed with albinism.

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Sun, Yi; Zhou, Xiaoying; Chen, Jing; Du, Juan; Lu, Guangxiu; Lin, Ge; Ouyang, Qi

2016-11-01

Human embryonic stem cell (hESC) line chHES-478 was derived from abnormal blastocyst diagnosed with albinism after preimplantation genetic diagnosis (PGD) treatment. DNA sequencing analysis confirmed that chHES-478 cell line carried a compound heterozygous mutation, c.896G>A(p.Arg299His) and c.929_930insC(p.Pro310Glnfs*9), of TYR gene. Characteristic tests proved that the chHES-478 cell line presented typical markers of pluripotency and had the capability to form the three germ layers both in vitro and in vivo. Copyright © 2016 Michael Boutros, German Cancer Research Center, Heidelberg, Germany. Published by Elsevier B.V. All rights reserved.

First record of albinism in the smooth dogfish Mustelus Schimitti Springer, 1939 (Carcharhiniformes - Triakidae) from Southern Brazil

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Simone Ferreira Teixeira; Maria Lúcia Góes de Araújo

2002-01-01

This paper reports on a subadult male specimen of the smooth dogfish, Mustelus schimitti, caught in the continental shelf of Rio Grande Sul, during winter of 1993, which exhibited the characteristics of total albinism.Este trabalho registra a primeira ocorrência de albinismo total no cação Mustelus schimitti, capturado, no inverno de 1993, na plataforma continental do Rio Grande do Sul.

First record of albinism in the smooth dogfish Mustelus Schimitti Springer, 1939 (Carcharhiniformes - Triakidae from Southern Brazil

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Simone Ferreira Teixeira

2002-06-01

Full Text Available This paper reports on a subadult male specimen of the smooth dogfish, Mustelus schimitti, caught in the continental shelf of Rio Grande Sul, during winter of 1993, which exhibited the characteristics of total albinism.Este trabalho registra a primeira ocorrência de albinismo total no cação Mustelus schimitti, capturado, no inverno de 1993, na plataforma continental do Rio Grande do Sul.

GNAI3: Another Candidate Gene to Screen in Persons with Ocular Albinism

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Young, Alejandra; Sader, Avery; Farber, Debora B.

2016-01-01

Ocular albinism type 1 (OA), caused by mutations in the OA1 gene, encodes a G-protein coupled receptor, OA1, localized in melanosomal membranes of the retinal pigment epithelium (RPE). This disorder is characterized by both RPE macro-melanosomes and abnormal decussation of ganglion cell axons at the brain’s optic chiasm. We demonstrated previously that Oa1 specifically activates Gαi3, which also signals in the Oa1 transduction pathway that regulates melanosomal biogenesis. In this study, we screened the human Gαi3 gene, GNAI3, in DNA samples from 26 patients who had all clinical characteristics of OA but in whom a specific mutation in the OA1 gene had not been found, and in 6 normal control individuals. Using the Agilent HaloPlex Target Enrichment System and next-generation sequencing (NGS) on the Illumina MiSeq platform, we identified 518 variants after rigorous filtering. Many of these variants were corroborated by Sanger sequencing. Overall, 98.8% coverage of the GNAI3 gene was obtained by the HaloPlex amplicons. Of all variants, 6 non-synonymous and 3 synonymous were in exons, 41 in a non-coding exon embedded in the 3’ untranslated region (UTR), 6 in the 5’ UTR, and 462 in introns. These variants included novel SNVs, insertions, deletions, and a frameshift mutation. All were found in at least one patient but none in control samples. Using computational methods, we modeled the GNAI3 protein and its non-synonymous exonic mutations and determined that several of these may be the cause of disease in the patients studied. Thus, we have identified GNAI3 as a second gene possibly responsible for X-linked ocular albinism. PMID:27607449

GNAI3: Another Candidate Gene to Screen in Persons with Ocular Albinism.

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Alejandra Young

Full Text Available Ocular albinism type 1 (OA, caused by mutations in the OA1 gene, encodes a G-protein coupled receptor, OA1, localized in melanosomal membranes of the retinal pigment epithelium (RPE. This disorder is characterized by both RPE macro-melanosomes and abnormal decussation of ganglion cell axons at the brain's optic chiasm. We demonstrated previously that Oa1 specifically activates Gαi3, which also signals in the Oa1 transduction pathway that regulates melanosomal biogenesis. In this study, we screened the human Gαi3 gene, GNAI3, in DNA samples from 26 patients who had all clinical characteristics of OA but in whom a specific mutation in the OA1 gene had not been found, and in 6 normal control individuals. Using the Agilent HaloPlex Target Enrichment System and next-generation sequencing (NGS on the Illumina MiSeq platform, we identified 518 variants after rigorous filtering. Many of these variants were corroborated by Sanger sequencing. Overall, 98.8% coverage of the GNAI3 gene was obtained by the HaloPlex amplicons. Of all variants, 6 non-synonymous and 3 synonymous were in exons, 41 in a non-coding exon embedded in the 3' untranslated region (UTR, 6 in the 5' UTR, and 462 in introns. These variants included novel SNVs, insertions, deletions, and a frameshift mutation. All were found in at least one patient but none in control samples. Using computational methods, we modeled the GNAI3 protein and its non-synonymous exonic mutations and determined that several of these may be the cause of disease in the patients studied. Thus, we have identified GNAI3 as a second gene possibly responsible for X-linked ocular albinism.

Diverse prevalence of large deletions within the OA1 gene in ocular albinism type 1 patients from Europe and North America

NARCIS (Netherlands)

Bassi, M. T.; Bergen, A. A.; Bitoun, P.; Charles, S. J.; Clementi, M.; Gosselin, R.; Hurst, J.; Lewis, R. A.; Lorenz, B.; Meitinger, T.; Messiaen, L.; Ramesar, R. S.; Ballabio, A.; Schiaffino, M. V.

2001-01-01

Ocular albinism type 1 (OA1) is an X-linked disorder mainly characterized by congenital nystagmus and photodysphoria, moderate to severe reduction of visual acuity, hypopigmentation of the retina, and the presence of macromelanosomes in the skin and eyes. We have previously isolated the gene for OA1

Interaction between G Protein-Coupled Receptor 143 and Tyrosinase: Implications for Understanding Ocular Albinism Type 1.

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De Filippo, Elisabetta; Schiedel, Anke C; Manga, Prashiela

2017-02-01

Developmental eye defects in X-linked ocular albinism type 1 are caused by G-protein coupled receptor 143 (GPR143) mutations. Mutations result in dysfunctional melanosome biogenesis and macromelanosome formation in pigment cells, including melanocytes and retinal pigment epithelium. GPR143, primarily expressed in pigment cells, localizes exclusively to endolysosomal and melanosomal membranes unlike most G protein-coupled receptors, which localize to the plasma membrane. There is some debate regarding GPR143 function and elucidating the role of this receptor may be instrumental for understanding neurogenesis during eye development and for devising therapies for ocular albinism type I. Many G protein-coupled receptors require association with other proteins to function. These G protein-coupled receptor-interacting proteins also facilitate fine-tuning of receptor activity and tissue specificity. We therefore investigated potential GPR143 interaction partners, with a focus on the melanogenic enzyme tyrosinase. GPR143 coimmunoprecipitated with tyrosinase, while confocal microscopy demonstrated colocalization of the proteins. Furthermore, tyrosinase localized to the plasma membrane when coexpressed with a GPR143 trafficking mutant. The physical interaction between the proteins was confirmed using fluorescence resonance energy transfer. This interaction may be required in order for GPR143 to function as a monitor of melanosome maturation. Identifying tyrosinase as a potential GPR143 binding protein opens new avenues for investigating the mechanisms that regulate pigmentation and neurogenesis. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Role of the Ubiquitin Proteasome System in Regulating Skin Pigmentation

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Hideya Ando

2009-10-01

Full Text Available Pigmentation of the skin, hair and eyes is regulated by tyrosinase, the critical rate-limiting enzyme in melanin synthesis by melanocytes. Tyrosinase is degraded endogenously, at least in part, by the ubiquitin proteasome system (UPS. Several types of inherited hypopigmentary diseases, such as oculocutaneous albinism and Hermansky-Pudlak syndrome, involve the aberrant processing and/or trafficking of tyrosinase and its subsequent degradation which can occur due to the quality-control machinery. Studies on carbohydrate modifications have revealed that tyrosinase in the endoplasmic reticulum (ER is proteolyzed via ER-associated protein degradation and that tyrosinase degradation can also occur following its complete maturation in the Golgi. Among intrinsic factors that regulate the UPS, fatty acids have been shown to modulate tyrosinase degradation in contrasting manners through increased or decreased amounts of ubiquitinated tyrosinase that leads to its accelerated or decelerated degradation by proteasomes.

Localization of the X-linked ocular albinism gene (OA1) between DXS278/DXS237 and DXS143/DXS16 by linkage analysis

NARCIS (Netherlands)

Bergen, A. A.; Samanns, C.; van Dorp, D. B.; Ferguson-Smith, M. A.; Gal, A.; Bleeker-Wagemakers, E. M.

1990-01-01

Linkage analysis was performed in six families segregating for X-linked ocular albinism of the Nettleship-Falls type using four polymorphic DNA markers from the distal Xp. Linkage was found between the disease locus (OA1) and the loci DXS237 (theta max = 0.06, Zmax = 2.82), DXS278 (theta max = 0.03,

Quantification and comparison of psychiatric distress in African patients with albinism and vitiligo: a 5-year prospective study.

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Ajose, F O A; Parker, R A; Merrall, E L C; Adewuya, A O; Zachariah, M P

2014-07-01

Vitiligo and albinism are two disorders of pigmentation that make the affected African highly visible and strikingly different from their peers. Both pose considerable management challenges, attract significant stigma and profound impairment of quality of life. To determine and compare psychiatric distress in vitiligo and albinism using the Hospital Anxiety and Depression Scale (HADS). Participants were 87 albinos and 102 vitiligo adult patients seen at an urban tertiary hospital in Nigeria between 2004 and 2009. Prevalence of psycho morbidity was 59% (60/102) in vitiligo compared with 26% (23/87) in the albinos. The mean anxiety score was estimated to be 2.55 points lower for albino patients (95% CI: 1.47 to 3.64), and the mean depression score 2.76 points lower (95% CI: 1.84 to 3.68), after adjustment for age, sex and marital status. However, significant differences were not observed when comparing the vitiligo patients with the subset of albino patients with skin cancer. Older patients had significantly higher anxiety and depression scores. Females had significantly higher anxiety scores (but not depression scores) compared to males. Genital involvement in vitiligo was significantly associated with anxiety but not depression. We found that the African with vitiligo suffers significantly higher psychiatric distress than the African albino on average. Clinical evaluation of these patients would be incomplete without assessment of their psycho morbidity. There is need for increased focus on cancer prevention strategies in the African albino. © 2013 European Academy of Dermatology and Venereology.

Further delineation of the clinical spectrum in RNU4ATAC related microcephalic osteodysplastic primordial dwarfism type I.

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Abdel-Salam, Ghada M H; Abdel-Hamid, Mohamed S; Hassan, Nihal A; Issa, Mahmoud Y; Effat, Laila; Ismail, Samira; Aglan, Mona S; Zaki, Maha S

2013-08-01

We describe five patients from three different families with microcephalic osteodysplastic primordial dwarfism type I (MOPD I), which was molecularly confirmed by homozygosity for the g.51G >A and g.55G >A mutations in RNU4ATAC, respectively. The patients showed the classical phenotype and demonstrated in addition variable degrees of gyration abnormalities and malformations of the callosal body with an interhemispheric cyst. One patient also showed underdevelopment of the cerebellar vermis. This confirms that cortical malformations should be considered cardinal manifestations of MOPD I. Oculocutaneous albinism, brain hemorrhage and chilblains have been found to be associated with MOPD I. The present study showed lack of retinal pigmentation in three patients of whom two had an unusually fair complexion of hair and skin. One patient was found to have a hematoma in the left thalamus. This may indicate that both pigmentary abnormalities and vascular anomalies may be part of the phenotype of MOPD I as well. Copyright © 2013 Wiley Periodicals, Inc.

Deep intronic GPR143 mutation in a Japanese family with ocular albinism.

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Naruto, Takuya; Okamoto, Nobuhiko; Masuda, Kiyoshi; Endo, Takao; Hatsukawa, Yoshikazu; Kohmoto, Tomohiro; Imoto, Issei

2015-06-10

Deep intronic mutations are often ignored as possible causes of human disease. Using whole-exome sequencing, we analysed genomic DNAs of a Japanese family with two male siblings affected by ocular albinism and congenital nystagmus. Although mutations or copy number alterations of coding regions were not identified in candidate genes, the novel intronic mutation c.659-131 T > G within GPR143 intron 5 was identified as hemizygous in affected siblings and as heterozygous in the unaffected mother. This mutation was predicted to create a cryptic splice donor site within intron 5 and activate a cryptic acceptor site at 41nt upstream, causing the insertion into the coding sequence of an out-of-frame 41-bp pseudoexon with a premature stop codon in the aberrant transcript, which was confirmed by minigene experiments. This result expands the mutational spectrum of GPR143 and suggests the utility of next-generation sequencing integrated with in silico and experimental analyses for improving the molecular diagnosis of this disease.

Adult siblings with homozygous G6PC3 mutations expand our understanding of the severe congenital neutropenia type 4 (SCN4 phenotype

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Fernandez Bridget A

2012-11-01

Full Text Available Abstract Background Severe congenital neutropenia type 4 (SCN4 is an autosomal recessive disorder caused by mutations in the third subunit of the enzyme glucose-6-phosphatase (G6PC3. Its core features are congenital neutropenia and a prominent venous skin pattern, and affected individuals have variable birth defects. Oculocutaneous albinism type 4 (OCA4 is caused by autosomal recessive mutations in SLC45A2. Methods We report a sister and brother from Newfoundland, Canada with complex phenotypes. The sister was previously reported by Cullinane et al., 2011. We performed homozygosity mapping, next generation sequencing and conventional Sanger sequencing to identify mutations that cause the phenotype in this family. We have also summarized clinical data from 49 previously reported SCN4 cases with overlapping phenotypes and interpret the medical histories of these siblings in the context of the literature. Results The siblings’ phenotype is due in part to a homozygous mutation in G6PC3, [c.829C > T, p.Gln277X]. Their ages are 38 and 37 years respectively and they are the oldest SCN4 patients published to date. Both presented with congenital neutropenia and later developed Crohn disease. We suggest that the latter is a previously unrecognized SCN4 manifestation and that not all affected individuals have an intellectual disability. The sister also has a homozygous mutation in SLC45A2, which explains her severe oculocutaneous hypopigmentation. Her brother carried one SLC45A2 mutation and was diagnosed with “partial OCA” in childhood. Conclusions This family highlights that apparently novel syndromes can in fact be caused by two known autosomal recessive disorders.

Transatlanticism and "Natural Sympathy" in Christian Isobel Johnstone’s Clan-Albin: A National Tale (1815

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Jennifer Marie Van Vliet

2012-10-01

Full Text Available In the decades between Samuel Johnson’s and James Boswell’s tour of the Hebrides and the popular success of Walter Scott’s Waverley novels, a series of synecdochic associations gradually positioned the Highlands as the symbolic cornerstone of British romance and improvement discourses, while Scotland became an integral part of the British Empire. As the popular image of the Highlander had a distinctly martial resonance, transatlantic emigration became a national concern and contributed to the increase in attention paid to improvement in the Highlands. With Clan-Albin: A National Tale (1815, Christian Isobel Johnstone attempts to reconcile the popular imaginings of the Highlands as a pre-modern picturesque microcosm and a “nursery of soldiers” with the sociocultural effects of the Clearances, transforming a culturally and racially distinct Highland hamlet into a thriving pan-British community.

Characterization of the human RAB38 and RAB7 genes: exclusion of new major pathological loci for Japanese OCA.

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Suzuki, Tamio; Miyamura, Yoshinori; Inagaki, Katsuhiko; Tomita, Yasushi

2003-08-01

Oculocutaneous albinisms (OCAs) are due to various gene mutations that cause a disruption of melanogenesis in the melanocyte. Four different genes associated with human OCA have been reported, however, not all of OCA patients can be classified according to these four genes. We have sought to find a new major locus for Japanese OCA. Recently two genes, RAB38 and RAB7, were reported to play an important role in melanogenesis in the melanocyte, suggesting that these two genes could be good candidates for new OCA loci. To determine the structures of the human RAB38 and RAB7 genes, and examine if the two genes are new major loci for Japanese OCA. We screened mutations in these genes of 25 Japanese OCA patients who lacked mutations in the OCA1 and OCA2 genes with SSCP/heteroduplexes method. We determined the both genes, and their genomic organizations to design the primers for SSCP/heteroduplexes method. And then we screened mutations, but no mutation was detected. Neither of the genes is a new major locus for Japanese OCA.

Innate Color Preference of Zebrafish and Its Use in Behavioral Analyses.

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Park, Jong-Su; Ryu, Jae-Ho; Choi, Tae-Ik; Bae, Young-Ki; Lee, Suman; Kang, Hae Jin; Kim, Cheol-Hee

2016-10-01

Although innate color preference of motile organisms may provide clues to behavioral biases, it has remained a longstanding question. In this study, we investigated innate color preference of zebrafish larvae. A cross maze with different color sleeves around each arm was used for the color preference test (R; red, G; green, B; blue, Y; yellow). The findings showed that 5 dpf zebrafish larvae preferred blue over other colors (B > R > G > Y). To study innate color recognition further, tyrosinase mutants were generated using CRISPR/Cas9 system. As a model for oculocutaneous albinism (OCA) and color vision impairment, tyrosinase mutants demonstrated diminished color sensation, indicated mainly by hypopigmentation of the retinal pigment epithelium (RPE). Due to its relative simplicity and ease, color preference screening using zebrafish larvae is suitable for high-throughput screening applications. This system may potentially be applied to the analysis of drug effects on larval behavior or the detection of sensory deficits in neurological disorder models, such as autism-related disorders, using mutant larvae generated by the CRISPR/Cas9 technique.

Vitamin D levels in patients with albinism compared with those in normally pigmented Black patients attending dermatology clinics in the Free State province, South Africa.

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Van der Walt, Johanna E C; Sinclair, Werner

2016-09-01

Associations between vitamin D deficiency and a broad variety of independent diseases, including several bone diseases, various types of cancer, autoimmune diseases, hypertension, and cardiovascular disease, have been suggested. It is therefore important to detect and treat vitamin D deficiency in high-risk groups. Because patients with albinism (PWA) practice a policy of strict sun avoidance, they may be at risk for low levels of vitamin D. This study was conducted in patients attending dermatology clinics in the Free State, South Africa, to determine sun avoidance behavior in the patient population and to compare 25-hydroxyvitamin D (25[OH]D) levels in PWA with those in normally pigmented Black patients attending the same clinics. Serum 25(OH)D levels were assessed in 50 PWA and 50 normally pigmented Black control subjects. Questionnaires on sun exposure avoidance behaviors were administered to all participants. The present study showed no statistically significant difference in median 25(OH)D levels between PWA and controls with normally pigmented Black skin. Rather, the study found a tendency for controls to have lower 25(OH)D levels. A total of 53% (n = 53) of all study participants (PWA and controls) had a 25(OH)D level of albinism attending dermatology clinics in the Free State, South Africa, need not be viewed as specifically at risk for low vitamin D levels. © 2015 The International Society of Dermatology.

Evidence of macular pigment in the central macula in albinism.

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Wolfson, Yulia; Fletcher, Emily; Strauss, Rupert W; Scholl, Hendrik P N

2016-04-01

Albinism represents a spectrum of disorders with diminished to absent amounts of melanin pigmentation including the posterior segment of the eye. Macular pigment (MP) consists of two main carotenoids, lutein and zeaxanthin, concentrated in the macula. MP serves as blue light absorbent, antioxidant, and may reduce chromatic aberration and glare. It remains unclear if albinos have detectable MP. The purpose was to investigate the distribution of MP in albino patients with psychophysical and imaging techniques. MP was measured at the eccentricity of 0.5° by heterochromatic flicker perimetry (QuantifEye(®); Tinsley Precision Instruments Ltd.) or by scanning laser ophthalmoscopy (MPOD module, MultiColor Spectralis(®), Heidelberg Engineering, Heidelberg, Germany) in four albino patients, who were also investigated with multimodal ophthalmic imaging. Visual acuity ranged from 20/32 to 20/125, nystagmus was present in three patients, and all patients showed typical foveal hypoplasia on fundus exam and optical coherence tomography. Fundus autofluorescence (FAF) demonstrated various degrees of central FAF signal attenuation. Genetic testing was available in three patients and confirmed the diagnosis. Measurable amounts of MP were detected in all four patients and ranged from 0.05 to 0.24, which is below the normal range. We conclude that MP can be demonstrated and measured in albinos. Further studies are needed to investigate MP accumulation following carotenoid supplementation and its impact on visual performance. Copyright © 2015 Elsevier Ltd. All rights reserved.

N-Ethylmaleimide–Sensitive Factor b (nsfb) Is Required for Normal Pigmentation of the Zebrafish Retinal Pigment Epithelium

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Hanovice, Nicholas J.; Daly, Christina M. S.; Gross, Jeffrey M.

2015-01-01

Purpose Despite the number of albinism-causing mutations identified in human patients and animal models, there remain a significant number of cases for which no mutation has been identified, suggesting that our understanding of melanogenesis is incomplete. Previously, we identified two oculocutaneous albinism mutations in zebrafish, au13 and au18. Here, we sought to identify the mutated loci and determine how the affected proteins contribute to normal pigmentation of the retinal pigment epithelium (RPE). Methods Complementation analyses revealed that au13 and au18 belonged to a single complementation group, suggesting that they affected the same locus. Whole-genome sequencing and single nucleotide polymorphism (SNP) analysis was performed to identify putative mutations, which were confirmed by cDNA sequencing and mRNA rescue. Transmission electron microscopy (TEM) and image quantification were used to identify the cellular basis of hypopigmentation. Results Whole-genome sequencing and SNP mapping identified a nonsense mutation in the N-ethylmaleimide–sensitive factor b (nsfb) gene in au18 mutants. Complementary DNA sequencing confirmed the presence of the mutation (C893T), which truncates the nsfb protein by roughly two-thirds (Y297X). No coding sequence mutations were identified in au13, but quantitative PCR revealed a significant decrease in nsfb expression, and nsfb mRNA injection rescued the hypopigmentation phenotype, suggesting a regulatory mutation. In situ hybridization revealed that nsfb is broadly expressed during embryonic development, including in the RPE. Transmission electron microscopy analyses indicated that average melanosome density and maturity were significantly decreased in nsfb mutants. Conclusions au18 and au13 contain mutations in nsfb, which encodes a protein that is required for the maturation of melanosomes in zebrafish RPE. PMID:26618645

Retinal cone photoreceptors of the deer mouse Peromyscus maniculatus: development, topography, opsin expression and spectral tuning.

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Patrick Arbogast

Full Text Available A quantitative analysis of photoreceptor properties was performed in the retina of the nocturnal deer mouse, Peromyscus maniculatus, using pigmented (wildtype and albino animals. The aim was to establish whether the deer mouse is a more suitable model species than the house mouse for photoreceptor studies, and whether oculocutaneous albinism affects its photoreceptor properties. In retinal flatmounts, cone photoreceptors were identified by opsin immunostaining, and their numbers, spectral types, and distributions across the retina were determined. Rod photoreceptors were counted using differential interference contrast microscopy. Pigmented P. maniculatus have a rod-dominated retina with rod densities of about 450.000/mm(2 and cone densities of 3000-6500/mm(2. Two cone opsins, shortwave sensitive (S and middle-to-longwave sensitive (M, are present and expressed in distinct cone types. Partial sequencing of the S opsin gene strongly supports UV sensitivity of the S cone visual pigment. The S cones constitute a 5-15% minority of the cones. Different from house mouse, S and M cone distributions do not have dorsoventral gradients, and coexpression of both opsins in single cones is exceptional (<2% of the cones. In albino P. maniculatus, rod densities are reduced by approximately 40% (270.000/mm(2. Overall, cone density and the density of cones exclusively expressing S opsin are not significantly different from pigmented P. maniculatus. However, in albino retinas S opsin is coexpressed with M opsin in 60-90% of the cones and therefore the population of cones expressing only M opsin is significantly reduced to 5-25%. In conclusion, deer mouse cone properties largely conform to the general mammalian pattern, hence the deer mouse may be better suited than the house mouse for the study of certain basic cone properties, including the effects of albinism on cone opsin expression.

Loss of Oca2 disrupts the unfolded protein response and increases resistance to endoplasmic reticulum stress in melanocytes.

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Cheng, Tsing; Orlow, Seth J; Manga, Prashiela

2013-11-01

Accumulation of proteins in the endoplasmic reticulum (ER) typically induces stress and initiates the unfolded protein response (UPR) to facilitate recovery. If homeostasis is not restored, apoptosis is induced. However, adaptation to chronic UPR activation can increase resistance to subsequent acute ER stress. We therefore investigated adaptive mechanisms in Oculocutaneous albinism type 2 (Oca2)-null melanocytes where UPR signaling is arrested despite continued tyrosinase accumulation leading to resistance to the chemical ER stressor thapsigargin. Although thapsigargin triggers UPR activation, instead of Perk-mediated phosphorylation of eIF2α, in Oca2-null melanocytes, eIF2α was rapidly dephosphorylated upon treatment. Dephosphorylation was mediated by the Gadd34-PP1α phosphatase complex. Gadd34-complex inhibition blocked eIF2α dephosphorylation and significantly increased Oca2-null melanocyte sensitivity to thapsigargin. Thus, Oca2-null melanocytes adapt to acute ER stress by disruption of pro-apoptotic Perk signaling, which promotes cell survival. This is the first study to demonstrate rapid eIF2α dephosphorylation as an adaptive mechanism to ER stress. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Computational analysis of histidine mutations on the structural stability of human tyrosinases leading to albinism insurgence.

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Hassan, Mubashir; Abbas, Qamar; Raza, Hussain; Moustafa, Ahmed A; Seo, Sung-Yum

2017-07-25

Misfolding and structural alteration in proteins lead to serious malfunctions and cause various diseases in humans. Mutations at the active binding site in tyrosinase impair structural stability and cause lethal albinism by abolishing copper binding. To evaluate the histidine mutational effect, all mutated structures were built using homology modelling. The protein sequence was retrieved from the UniProt database, and 3D models of original and mutated human tyrosinase sequences were predicted by changing the residual positions within the target sequence separately. Structural and mutational analyses were performed to interpret the significance of mutated residues (N 180 , R 202 , Q 202 , R 211 , Y 363 , R 367 , Y 367 and D 390 ) at the active binding site of tyrosinases. CSpritz analysis depicted that 23.25% residues actively participate in the instability of tyrosinase. The accuracy of predicted models was confirmed through online servers ProSA-web, ERRAT score and VERIFY 3D values. The theoretical pI and GRAVY generated results also showed the accuracy of the predicted models. The CCA negative correlation results depicted that the replacement of mutated residues at His within the active binding site disturbs the structural stability of tyrosinases. The predicted CCA scores of Tyr 367 (-0.079) and Q/R 202 (0.032) revealed that both mutations have more potential to disturb the structural stability. MD simulation analyses of all predicted models justified that Gln 202 , Arg 202 , Tyr 367 and D 390 replacement made the protein structures more susceptible to destabilization. Mutational results showed that the replacement of His with Q/R 202 and Y/R 363 has a lethal effect and may cause melanin associated diseases such as OCA1. Taken together, our computational analysis depicts that the mutated residues such as Q/R 202 and Y/R 363 actively participate in instability and misfolding of tyrosinases, which may govern OCA1 through disturbing the melanin biosynthetic pathway.

Ocular Albinism Type 1 Regulates Melanogenesis in Mouse Melanocytes

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Tianzhi Chen

2016-09-01

Full Text Available To investigate whether ocular albinism type 1 (OA1 is differentially expressed in the skin of mice with different coat colors and to determine its correlation with coat color establishment in mouse, the expression patterns and tissue distribution characterization of OA1 in the skin of mice with different coat colors were qualitatively and quantitatively analyzed by real-time quantitative PCR (qRT-PCR, immunofluorescence staining and Western blot. The qRT-PCR analysis revealed that OA1 mRNA was expressed in all mice skin samples tested, with the highest expression level in brown skin, a moderate expression level in black skin and the lowest expression level in gray skin. Positive OA1 protein bands were also detected in all skin samples by Western blot analysis. The relative expression levels of OA1 protein in both black and brown skin were significantly higher than that in gray skin, but there was no significant difference between black and brown mice. Immunofluorescence assays revealed that OA1 was mainly expressed in the hair follicle matrix, the inner and outer root sheath in the skin tissues with different coat colors. To get further insight into the important role of OA1 in the melanocytes’ pigmentation, we transfected the OA1 into mouse melanocytes and then detected the relative expression levels of pigmentation-related gene. Simultaneously, we tested the melanin content of melanocytes. As a result, the overexpression of OA1 significantly increased the expression levels of microphthalmia-associated transcription factor (MITF, tyrosinase (TYR, tyrosinase-related protein 1 (TRP1 and premelanosome protein (PMEL. However, the tyrosinase-related protein 2 (TRP2 level was attenuated. By contrast, the level of glycoprotein non-metastatic melanoma protein b (GPNMB was unaffected by OA1 overexpression. Furthermore, we observed a significant increase in melanin content in mouse melanocyte transfected OA1. Therefore, we propose that OA1 may

Eight previously unidentified mutations found in the OA1 ocular albinism gene

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Dufier Jean-Louis

2006-04-01

Full Text Available Abstract Background Ocular albinism type 1 (OA1 is an X-linked ocular disorder characterized by a severe reduction in visual acuity, nystagmus, hypopigmentation of the retinal pigmented epithelium, foveal hypoplasia, macromelanosomes in pigmented skin and eye cells, and misrouting of the optical tracts. This disease is primarily caused by mutations in the OA1 gene. Methods The ophthalmologic phenotype of the patients and their family members was characterized. We screened for mutations in the OA1 gene by direct sequencing of the nine PCR-amplified exons, and for genomic deletions by PCR-amplification of large DNA fragments. Results We sequenced the nine exons of the OA1 gene in 72 individuals and found ten different mutations in seven unrelated families and three sporadic cases. The ten mutations include an amino acid substitution and a premature stop codon previously reported by our team, and eight previously unidentified mutations: three amino acid substitutions, a duplication, a deletion, an insertion and two splice-site mutations. The use of a novel Taq polymerase enabled us to amplify large genomic fragments covering the OA1 gene. and to detect very likely six distinct large deletions. Furthermore, we were able to confirm that there was no deletion in twenty one patients where no mutation had been found. Conclusion The identified mutations affect highly conserved amino acids, cause frameshifts or alternative splicing, thus affecting folding of the OA1 G protein coupled receptor, interactions of OA1 with its G protein and/or binding with its ligand.

A Case of a Newborn with Agenesis of the Corpus Callosum Complicated with Ocular Albinism

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Michiko Miki

2016-05-01

Full Text Available Purpose: To report a case of ocular albinism found in a newborn infant in whom agenesis of the corpus callosum (ACC was indicated in utero. Case Report: This study involved a female newborn who was delivered after a gestational period of 41 weeks. The patient was referred to the Obstetrics Department at Takatsuki Hospital, Takatsuki City, Japan, after the indication of ACC by magnetic resonance imaging (MRI at a nearby clinic during the fetal period. At birth, the baby’s weight was 2,590 g, and ACC and ventricular enlargement were found by cranial sonography and cranial MRI. While initial ophthalmic findings noted partial loss of pigmentation of the iris and hypopigmentation of broad areas of the fundus in both eyes, nystagmus was not observed. The patient’s hair pigment was slightly diluted, and the color of her skin was slightly off-white. At 2 years after birth, obvious mental retardation was observed. With regard to other systemic findings, no apparent heart, kidney, or immune system abnormalities were found. Conclusion: Although the patient in question is presently growing without any major systemic problems, it will be necessary in the future to pay attention to any changes in systemic and ophthalmic findings.

Novel Hypomorphic Alleles of the Mouse Tyrosinase Gene Induced by CRISPR-Cas9 Nucleases Cause Non-Albino Pigmentation Phenotypes.

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Challa, Anil K; Boitet, Evan R; Turner, Ashley N; Johnson, Larry W; Kennedy, Daniel; Downs, Ethan R; Hymel, Katherine M; Gross, Alecia K; Kesterson, Robert A

2016-01-01

Tyrosinase is a key enzyme in melanin biosynthesis. Mutations in the gene encoding tyrosinase (Tyr) cause oculocutaneous albinism (OCA1) in humans. Alleles of the Tyr gene have been useful in studying pigment biology and coat color formation. Over 100 different Tyr alleles have been reported in mice, of which ≈24% are spontaneous mutations, ≈60% are radiation-induced, and the remaining alleles were obtained by chemical mutagenesis and gene targeting. Therefore, most mutations were random and could not be predicted a priori. Using the CRISPR-Cas9 system, we targeted two distinct regions of exon 1 to induce pigmentation changes and used an in vivo visual phenotype along with heteroduplex mobility assays (HMA) as readouts of CRISPR-Cas9 activity. Most of the mutant alleles result in complete loss of tyrosinase activity leading to an albino phenotype. In this study, we describe two novel in-frame deletion alleles of Tyr, dhoosara (Sanskrit for gray) and chandana (Sanskrit for sandalwood). These alleles are hypomorphic and show lighter pigmentation phenotypes of the body and eyes. This study demonstrates the utility of CRISPR-Cas9 system in generating domain-specific in-frame deletions and helps gain further insights into structure-function of Tyr gene.

Novel Hypomorphic Alleles of the Mouse Tyrosinase Gene Induced by CRISPR-Cas9 Nucleases Cause Non-Albino Pigmentation Phenotypes.

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Anil K Challa

Full Text Available Tyrosinase is a key enzyme in melanin biosynthesis. Mutations in the gene encoding tyrosinase (Tyr cause oculocutaneous albinism (OCA1 in humans. Alleles of the Tyr gene have been useful in studying pigment biology and coat color formation. Over 100 different Tyr alleles have been reported in mice, of which ≈24% are spontaneous mutations, ≈60% are radiation-induced, and the remaining alleles were obtained by chemical mutagenesis and gene targeting. Therefore, most mutations were random and could not be predicted a priori. Using the CRISPR-Cas9 system, we targeted two distinct regions of exon 1 to induce pigmentation changes and used an in vivo visual phenotype along with heteroduplex mobility assays (HMA as readouts of CRISPR-Cas9 activity. Most of the mutant alleles result in complete loss of tyrosinase activity leading to an albino phenotype. In this study, we describe two novel in-frame deletion alleles of Tyr, dhoosara (Sanskrit for gray and chandana (Sanskrit for sandalwood. These alleles are hypomorphic and show lighter pigmentation phenotypes of the body and eyes. This study demonstrates the utility of CRISPR-Cas9 system in generating domain-specific in-frame deletions and helps gain further insights into structure-function of Tyr gene.

GPR143 mutations in Chinese patients with ocular albinism type 1.

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Jia, Xiuhua; Yuan, Jin; Jia, Xiaoyun; Ling, Shiqi; Li, Shiqiang; Guo, Xiangming

2017-05-01

The aim of the present study was to evaluate mutations of the G protein-coupled receptor 143 (GPR143) gene for ocular albinism type 1 (OA1) in Chinese patients. For the current study, 8 patients with OA1 were selected from the database of ocular genetic diseases. Genomic DNA of OA1 was prepared from venous leukocytes collected from the patients. Cycle sequencing was used to analyze the exons and adjacent introns of GPR143. The variation detected was analyzed by bidirectional DNA sequencing and further evaluated in 96 controls using heteroduplex‑single strand conformational polymorphism analysis. Additionally, slit lamp photography of anterior segment, fundus photography and optical coherence tomography (OCT) were performed to identify the clinical features of OA1. In five patients with OA1, 5 GPR143 gene mutations were identified and four of them there were novel mutations. The screening rate is 62.5%, including c.333G>A (p.W111X), c.353G>A (p.G118E) (known mutation), C.658+2T>G (splice mutation), c.215_216insCGCTGC (p.71‑72insAA) and c.17T>C (p. L6P). These mutations were absent in the 96 normal controls. Only one patient with OA1 in the present study was female. Patients with OA1 often have congenital nystagmus, refractive error, severe decline of visual acuity (from 0.1 to 0.4) and foveal hypoplasia. Different degrees of pigment loss were evident in the patients' iris and retina, whereas macular structure was not identified in the OCT examination. The findings of the present study expanded the gene mutation spectrum of GPR143 and investigated the clinical phenotype of patients with OA1 in the Chinese population. Additional evidence for clinical diagnosis was provided along with differential diagnosis and genetic counseling.

The integrated analysis of RNA-seq and microRNA-seq depicts miRNA-mRNA networks involved in Japanese flounder (Paralichthys olivaceus) albinism.

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Wang, Na; Wang, Ruoqing; Wang, Renkai; Tian, Yongsheng; Shao, Changwei; Jia, Xiaodong; Chen, Songlin

2017-01-01

Albinism, a phenomenon characterized by pigmentation deficiency on the ocular side of Japanese flounder (Paralichthys olivaceus), has caused significant damage. Limited mRNA and microRNA (miRNA) information is available on fish pigmentation deficiency. In this study, a high-throughput sequencing strategy was employed to identify the mRNA and miRNAs involved in P. olivaceus albinism. Based on P. olivaceus genome, RNA-seq identified 21,787 know genes and 711 new genes by transcripts assembly. Of those, 235 genes exhibited significantly different expression pattern (fold change ≥2 or ≤0.5 and q-value≤0.05), including 194 down-regulated genes and 41 up-regulated genes in albino versus normally pigmented individuals. These genes were enriched to 81 GO terms and 9 KEGG pathways (p≤0.05). Among those, the pigmentation related pathways-Melanogenesis and tyrosine metabolism were contained. High-throughput miRNA sequencing identified a total of 475 miRNAs, including 64 novel miRNAs. Furthermore, 33 differentially expressed miRNAs containing 13 up-regulated and 20 down-regulated miRNAs were identified in albino versus normally pigmented individuals (fold change ≥1.5 or ≤0.67 and p≤0.05). The next target prediction discovered a variety of putative target genes, of which, 134 genes including Tyrosinase (TYR), Tyrosinase-related protein 1 (TYRP1), Microphthalmia-associated transcription factor (MITF) were overlapped with differentially expressed genes derived from RNA-seq. These target genes were significantly enriched to 254 GO terms and 103 KEGG pathways (p<0.001). Of those, tyrosine metabolism, lysosomes, phototransduction pathways, etc., attracted considerable attention due to their involvement in regulating skin pigmentation. Expression patterns of differentially expressed mRNA and miRNAs were validated in 10 mRNA and 10 miRNAs by qRT-PCR. With high-throughput mRNA and miRNA sequencing and analysis, a series of interested mRNA and miRNAs involved in fish

Evidence suggesting digenic inheritance of Waardenburg syndrome type II with ocular albinism.

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Chiang, Pei-Wen; Spector, Elaine; McGregor, Tracy L

2009-12-01

Waardenburg syndrome (WS) is a series of auditory-pigmentary disorders inherited in an autosomal dominant manner. In most patients, WS2 results from mutations in the MITF gene. MITF encodes a basic helix-loop-helix transcription factor that activates transcription of tyrosinase and other melanocyte proteins. The clinical presentation of WS is highly variable, and we believe that Tietz syndrome and WS2 with ocular albinism (OA) are likely two variations of WS2 due to the presence of modifiers. One family with a molecular diagnosis of WS2 co-segregating with OA has previously been reported. A digenic mutation mechanism including both a MITF mutation and the TYR(R402Q) hypomorphic allele was proposed to be the cause of OA in this family. Here, we present a second WS2 family with OA and provide evidence suggesting the TYR(R402Q) allele does not cause OA in this family. We hypothesize the presence of a novel OCA3 mutation together with the MITF del p.R217 mutation account for the OA phenotype in this family. Since MITF is a transcription factor for pigmentation genes, a mutation in MITF plus a heterozygous mutation in OCA3 together provide an adverse effect crossing a quantitative threshold; therefore, WS2 with OA occurs. We have hypothesized previously that the clinical spectrum and mutation mechanism of OCA depend on the pigmentation threshold of an affected individual. This unique family has provided further evidence supporting this hypothesis. We suggest that by studying OCA patients alongside WS patients with various pigmentation profiles we can facilitate further understanding of the pigmentation pathway.

Apparent digenic inheritance of Waardenburg syndrome type 2 (WS2) and autosomal recessive ocular albinism (AROA).

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Morell, R; Spritz, R A; Ho, L; Pierpont, J; Guo, W; Friedman, T B; Asher, J H

1997-05-01

Waardenburg syndrome (WS) is a clinically and genetically heterogeneous disease accounting for >2% of the congenitally deaf population. It is characterized by deafness in association with pigmentary anomalies and various defects of neural crest-derived tissues. At least four types are recognized (WS1, WS2, WS3 and WS4) on the basis of clinical and genetic criteria. Two previously described families seemed to delineate a new subtype characterized by WS2 in conjunction with ocular albinism (OA). Since mutations in the MITF gene are responsible for some instances of WS2, we screened for mutations in one of the WS2-OA families and discovered a 1 bp deletion in exon 8 of MITF. OA previously has been associated with compound heterozygosity for a mutant TYR allele and the TYR(R402Q) allele, a functionally significant polymorphism that is associated with moderately reduced tyrosinase catalytic activity. In this family, all of the individuals with the OA phenotype are either homozygous or heterozygous for TYR(R402Q), and heterozyous for the 1 bp deletion in MITF This suggests that the WS2-OA phenotype may result from digenic interaction between a gene for a transcription factor (MITF) and a gene that it regulates (TYR).

Structural insight with mutational impact on tyrosinase and PKC-β interaction from Homo sapiens: Molecular modeling and docking studies for melanogenesis, albinism and increased risk for melanoma.

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Banerjee, Arundhati; Ray, Sujay

2016-10-30

Human tyrosinase, is an important protein for biosynthetic pathway of melanin. It was studied to be phosphorylated and activated by protein kinase-C, β-subunit (PKC-β) through earlier experimentations with in vivo evidences. Documentation documents that mutation in two essentially vital serine residues in C-terminal end of tyrosinase leads to albinism. Due to the deficiency of protective shield like enzyme; melanin, albinos are at an increased peril for melanoma and other skin cancers. So, computational and residue-level insight including a mutational exploration with evolutionary importance into this mechanism lies obligatory for future pathological and therapeutic developments. Therefore, functional tertiary models of the relevant proteins were analyzed after satisfying their stereo-chemical features. Evolutionarily paramount residues for the activation of tyrosinase were perceived via multiple sequence alignment phenomena. Mutant-type tyrosinase protein (S98A and S102A) was thereby modeled, maintaining the wild-type proteins' functionality. Furthermore, this present comparative study discloses the variation in the stable residual participation (for mutant-type and wild-type tyrosinase-PKCβ complex). Mainly, an increased number of polar negatively charged residues from the wild-type tyrosinase participated with PKC-β, predominantly. Fascinatingly supported by evaluation of statistical significances, mutation even led to a destabilizing impact in tyrosinase accompanied by conformational switches with a helix-to-coil transition in the mutated protein. Even the allosteric sites in the protein got poorly hampered upon mutation leading to weaker tendency for binding partners to interact. Copyright © 2016 Elsevier B.V. All rights reserved.

Two Novel Mutations Identified in an African-American Child with Chediak-Higashi Syndrome

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Kerry Morrone

2010-01-01

Full Text Available Background. Chediak-Higashi syndrome (CHS is a rare, autosomal recessive disorder characterized by oculocutaneous albinism, immunodeficiency, coagulopathy and late-onset, progressive neurological dysfunction. It also has an “accelerated phase” characterized by hemophagocytic lymphohistiocytosis (HLH. The disease is caused by mutations in the CHS1/LYST gene located on chromosome 1, which affects lysosome morphology and function. We report the case of an African-American child with CHS in Case. This 16-month old African-American girl presented with fever and lethargy. The proband had pale skin compared to her parents, with light brown eyes, silvery hair and massive hepatosplenomegaly. Her laboratory evaluation was remarkable for pancytopenia, high serum ferritin and an elevated LDH. Bone marrow aspirate revealed large inclusions in granulocytes and erythrophagocytosis consistent with HLH. Genetic evaluation revealed two novel nonsense mutations in the CHS1 gene: c.3622C>T (p.Q1208X and c.11002G>T (p.E3668X. Conclusions. Our patient is one of the few cases of CHS reported in the African American population. We identified 2 nonsense mutations in the CHS1 gene, the first mutation analysis published of an African-American child with Chediak-Higashi Syndrome. These two mutations predict a severe phenotype and thus identification of these mutations has an important clinical significance in CHS.

Identification of two novel mutations in the SLC45A2 gene in a Hungarian pedigree affected by unusual OCA type 4.

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Tóth, Lola; Fábos, Beáta; Farkas, Katalin; Sulák, Adrienn; Tripolszki, Kornélia; Széll, Márta; Nagy, Nikoletta

2017-03-15

Oculocutaneous albinism (OCA) is a clinically and genetically heterogenic group of pigmentation abnormalities. OCA type IV (OCA4, OMIM 606574) develops due to homozygous or compound heterozygous mutations in the solute carrier family 45, member 2 (SLC45A2) gene. This gene encodes a membrane-associated transport protein, which regulates tyrosinase activity and, thus, melanin content by changing melanosomal pH and disrupting the incorporation of copper into tyrosinase. Here we report two Hungarian siblings affected by an unusual OCA4 phenotype. After genomic DNA was isolated from peripheral blood of the patients, the coding regions of the SLC45A2 gene were sequenced. In silico tools were applied to identify the functional impact of the newly detected mutations. Direct sequencing of the SLC45A2 gene revealed two novel, heterozygous mutations, one missense (c.1226G > A, p.Gly409Asp) and one nonsense (c.1459C > T, p.Gln437*), which were present in both patients, suggesting the mutations were compound heterozygous. In silico tools suggest that these variations are disease causing mutations. The newly identified mutations may affect the transmembrane domains of the protein, and could impair transport function, resulting in decreases in both melanosomal pH and tyrosinase activity. Our study provides expands on the mutation spectrum of the SLC45A2 gene and the genetic background of OCA4.

Occurrence of nodular lymphocyte-predominant hodgkin lymphoma in hermansky-pudlak type 2 syndrome is associated to natural killer and natural killer T cell defects.

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Luisa Lorenzi

Full Text Available Hermansky Pudlak type 2 syndrome (HPS2 is a rare autosomal recessive primary immune deficiency caused by mutations on β3A gene (AP3B1 gene. The defect results in the impairment of the adaptor protein 3 (AP-3 complex, responsible for protein sorting to secretory lysosomes leading to oculo-cutaneous albinism, bleeding disorders and immunodeficiency. We have studied peripheral blood and lymph node biopsies from two siblings affected by HPS2. Lymph node histology showed a nodular lymphocyte predominance type Hodgkin lymphoma (NLPHL in both HPS2 siblings. By immunohistochemistry, CD8 T-cells from HPS2 NLPHL contained an increased amount of perforin (Prf + suggesting a defect in the release of this granules-associated protein. By analyzing peripheral blood immune cells we found a significant reduction of circulating NKT cells and of CD56(brightCD16(- Natural Killer (NK cells subset. Functionally, NK cells were defective in their cytotoxic activity against tumor cell lines including Hodgkin Lymphoma as well as in IFN-γ production. This defect was associated with increased baseline level of CD107a and CD63 at the surface level of unstimulated and IL-2-activated NK cells. In summary, these results suggest that a combined and profound defect of innate and adaptive effector cells might explain the susceptibility to infections and lymphoma in these HPS2 patients.

Characterization of Abnormal Optic Nerve Head Morphology in Albinism Using Optical Coherence Tomography.

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Mohammad, Sarim; Gottlob, Irene; Sheth, Viral; Pilat, Anastasia; Lee, Helena; Pollheimer, Ellen; Proudlock, Frank Anthony

2015-07-01

To characterize abnormalities in three-dimensional optic nerve head (ONH) morphology in people with albinism (PWA) using spectral-domain optical coherence tomography (SD-OCT) and to determine whether ONH abnormalities relate to other retinal and clinical abnormalities. Spectral-domain OCT was used to obtain three-dimensional images from 56 PWA and 60 age- and sex-matched control subjects. B-scans were corrected for nystagmus-associated motion artefacts. Disc, cup, and rim ONH dimensions and peripapillary retinal nerve fiber layer (ppRNFL) thickness were calculated using Copernicus and ImageJ software. Median disc areas were similar in PWA (median = 1.65 mm2) and controls (1.71 mm2, P = 0.128), although discs were significantly elongated horizontally in PWA (P < 0.001). In contrast, median optic cup area in PWA (0.088 mm2) was 23.7% of that in controls (0.373 mm2, P < 0.001), with 39.4% of eyes in PWA not demonstrating a measurable optic cup. This led to significantly smaller cup to disc ratios in PWA (P < 0.001). Median rim volume in PWA (0.273 mm3) was 136.6% of that in controls (0.200 mm3). The ppRNFL was significantly thinner in PWA compared with controls (P < 0.001), especially in the temporal quadrant. In PWA, ppRNFL thickness was correlated to ganglion cell thickness at the central fovea (P = 0.007). Several ONH abnormalities, such as cup to disc ratio, were related to higher refractive errors in PWA. In PWA, ocular maldevelopment is not just limited to the retina but also involves the ONH. Reduced ppRNFL thickness is consistent with previous reports of reduced ganglion cell numbers in PWA. The thicker rim volumes may be a result of incomplete maturation of the ONH.

Um caso de albinismo em tachã (Chauna Torquata, Oken (Aves, Anseniformes ocorrido na estação ecológica do Taím, Rio Grande do Sul, Brasil A case of albinism in Southern screamer (Chauna Torquata, Oken (Aves, Anseniformes occurred at the Ecological Station of Taim. Rio Grande do Sul, Brazil

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Luiz Alberto Veiga

1995-09-01

Full Text Available It is described herein a case study of albinism in Chauna torquata Oken, 1816 (Southern screamer occurred at the Ecological Station of Taim, Rio Grande do Sul. Brazil. Screamers are birds of marshes, wet grasslands and forest lagoons. The bill is short and curved, the head is small and slender and the neek rather short. The strong wings are armed with two large, sharp spurs on their forward edge. The feet and legs are fleshy, the lower half of the tibia is bare, and the three long front toes show just a trace of webbing between them, They are often seen walking in pairs on the floating masses of vegetation or in large groups for feeding. The albino specimen described herein was observed feeding in the midst of a group of almost fifty birds. Their plumage was white but their legs and bill were normally red pigmented, and also presented a light grey ring on its neek. It did not represent a case of total albinism, in which pigment should be totally absent.

The Loss of Vacuolar Protein Sorting 11 (vps11) Causes Retinal Pathogenesis in a Vertebrate Model of Syndromic Albinism

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Thomas, Jennifer L.; Vihtelic, Thomas S.; denDekker, Aaron D.; Willer, Gregory; Luo, Xixia; Murphy, Taylor R.; Gregg, Ronald G.; Hyde, David R.

2011-01-01

Purpose. To establish the zebrafish platinum mutant as a model for studying vision defects caused by syndromic albinism diseases such as Chediak-Higashi syndrome, Griscelli syndrome, and Hermansky-Pudlak syndrome (HPS). Methods. Bulked segregant analysis and candidate gene sequencing revealed that the zebrafish platinum mutation is a single-nucleotide insertion in the vps11 (vacuolar protein sorting 11) gene. Expression of vps11 was determined by RT-PCR and in situ hybridization. Mutants were analyzed for pigmentation defects and retinal disease by histology, immunohistochemistry, and transmission electron microscopy. Results. Phenocopy and rescue experiments determined that a loss of Vps11 results in the platinum phenotype. Expression of vps11 appeared ubiquitous during zebrafish development, with stronger expression in the developing retina and retinal pigmented epithelium (RPE). Zebrafish platinum mutants exhibited reduced pigmentation in the body and RPE; however, melanophore development, migration, and dispersion occurred normally. RPE, photoreceptors, and inner retinal neurons formed normally in zebrafish platinum mutants. However, a gradual loss of RPE, an absence of mature melanosomes, and the subsequent degradation of RPE/photoreceptor interdigitation was observed. Conclusions. These data show that Vps11 is not necessary for normal retinal development or initiation of melanin biosynthesis, but is essential for melanosome maturation and healthy maintenance of the RPE and photoreceptors. PMID:21330665

The 'evil albino' stereotype: an impediment to the right to equality.

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Mswela, Maureen

2013-03-01

This article address the 'evil albino' plot device or albino bias as portrayed in films and explores how such labelling stimulates societal intolerance and discrimination against People Living With Albinism. The article reveals how media perpetuates stereotypes of albinism through their portrayal of role players and argues that the continued existence of such stereotypes is a failure to see albinism for what it is: a medical condition. The article further discusses Albinism related stigma and discrimination against the backdrop of the 'evil albino' plot device.

Association of the Hermansky-Pudlak syndrome type-3 protein with clathrin

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Gahl William A

2005-09-01

Full Text Available Abstract Background Hermansky-Pudlak syndrome (HPS is a disorder of lysosome-related organelle biogenesis characterized by oculocutaneous albinism and prolonged bleeding. These clinical findings reflect defects in the formation of melanosomes in melanocytes and dense bodies in platelets. HPS type-3 (HPS-3 results from mutations in the HPS3 gene, which encodes a 1004 amino acid protein of unknown function that contains a predicted clathrin-binding motif (LLDFE at residues 172–176. Results Clathrin was co-immunoprecipitated by HPS3 antibodies from normal but not HPS3 null melanocytes. Normal melanocytes expressing a GFP-HPS3 fusion protein demonstrated partial co-localization of GFP-HPS3 with clathrin following a 20°C temperature block. GFP-HPS3 in which the predicted clathrin-binding domain of HPS3 was mutated (GFP-HPS3-delCBD did not co-localize with clathrin under the same conditions. Immunoelectron microscopy of normal melanocytes expressing GFP-HPS3 showed co-localization of GFP-HPS3 with clathrin, predominantly on small vesicles in the perinuclear region. In contrast, GFP-HPS3-delCBD did not co-localize with clathrin and exhibited a largely cytoplasmic distribution. Conclusion HPS3 associates with clathrin, predominantly on small clathrin-containing vesicles in the perinuclear region. This association most likely occurs directly via a functional clathrin-binding domain in HPS3. These results suggest a role for HPS3 and its protein complex, BLOC-2, in vesicle formation and trafficking.

In Silico Screening and Molecular Dynamics Simulation of Disease-Associated nsSNP in TYRP1 Gene and Its Structural Consequences in OCA3

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Balu Kamaraj

2013-01-01

Full Text Available Oculocutaneous albinism type III (OCA3, caused by mutations of TYRP1 gene, is an autosomal recessive disorder characterized by reduced biosynthesis of melanin pigment in the hair, skin, and eyes. The TYRP1 gene encodes a protein called tyrosinase-related protein-1 (Tyrp1. Tyrp1 is involved in maintaining the stability of tyrosinase protein and modulating its catalytic activity in eumelanin synthesis. Tyrp1 is also involved in maintenance of melanosome structure and affects melanocyte proliferation and cell death. In this work we implemented computational analysis to filter the most probable mutation that might be associated with OCA3. We found R326H and R356Q as most deleterious and disease associated by using PolyPhen 2.0, SIFT, PANTHER, I-mutant 3.0, PhD-SNP, SNP&GO, Pmut, and Mutpred tools. To understand the atomic arrangement in 3D space, the native and mutant (R326H and R356Q structures were modelled. Finally the structural analyses of native and mutant Tyrp1 proteins were investigated using molecular dynamics simulation (MDS approach. MDS results showed more flexibility in native Tyrp1 structure. Due to mutation in Tyrp1 protein, it became more rigid and might disturb the structural conformation and catalytic function of the structure and might also play a significant role in inducing OCA3. The results obtained from this study would facilitate wet-lab researches to develop a potent drug therapies against OCA3.

A comparison of two methods of logMAR visual acuity data scoring for statistical analysis

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O. A. Oduntan

2009-12-01

Full Text Available The purpose of this study was to compare two methods of logMAR visual acuity (VA scoring. The two methods are referred to as letter scoring (method 1 and line scoring (method 2. The two methods were applied to VA data obtained from one hundred and forty (N=140 children with oculocutaneous albinism. Descriptive, correlation andregression statistics were then used to analyze the data.  Also, where applicable, the Bland and Altman analysis was used to compare sets of data from the two methods.  The right and left eyes data were included in the study, but because the findings were similar in both eyes, only the results for the right eyes are presented in this paper.  For method 1, the mean unaided VA (mean UAOD1 = 0.39 ±0.15 logMAR. The mean aided (mean ADOD1 VA = 0.50 ± 0.16 logMAR.  For method 2, the mean unaided (mean UAOD2 VA = 0.71 ± 0.15 logMAR, while the mean aided VA (mean ADOD2 = 0.60 ± 0.16 logMAR. The range and mean values of the improvement in VA for both methods were the same. The unaided VAs (UAOD1, UAOD2 and aided (ADOD1, ADOD2 for methods 1 and 2 correlated negatively (Unaided, r = –1, p<0.05, (Aided, r = –1, p<0.05.  The improvement in VA (differences between the unaided and aided VA values (DOD1 and DOD2 were positively correlated (r = +1, p <0.05. The Bland and Altman analyses showed that the VA improvement (unaided – aided VA values (DOD1 and DOD2 were similar for the two methods. Findings indicated that only the improvement in VA could be compared when different scoring methods are used. Therefore the scoring method used in any VA research project should be stated in the publication so that appropriate comparisons could be made by other researchers.

Human ocular anatomy.

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Kels, Barry D; Grzybowski, Andrzej; Grant-Kels, Jane M

2015-01-01

We review the normal anatomy of the human globe, eyelids, and lacrimal system. This contribution explores both the form and function of numerous anatomic features of the human ocular system, which are vital to a comprehensive understanding of the pathophysiology of many oculocutaneous diseases. The review concludes with a reference glossary of selective ophthalmologic terms that are relevant to a thorough understanding of many oculocutaneous disease processes. Copyright © 2015 Elsevier Inc. All rights reserved.

Delineating the genetic heterogeneity of OCA in Hungarian patients.

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Fábos, Beáta; Farkas, Katalin; Tóth, Lola; Sulák, Adrienn; Tripolszki, Kornélia; Tihanyi, Mariann; Németh, Réka; Vas, Krisztina; Csoma, Zsanett; Kemény, Lajos; Széll, Márta; Nagy, Nikoletta

2017-06-19

Oculocutaneous albinism (OCA) is a clinically and genetically heterogenic group of pigmentation abnormalities characterized by variable hair, skin, and ocular hypopigmentation. Six known genes and a locus on human chromosome 4q24 have been implicated in the etiology of isolated OCA forms (OCA 1-7). The most frequent OCA types among Caucasians are OCA1, OCA2, and OCA4. We aimed to investigate genes responsible for the development of these OCA forms in Hungarian OCA patients (n = 13). Mutation screening and polymorphism analysis were performed by direct sequencing on TYR, OCA2, SLC45A2 genes. Although the clinical features of the investigated Hungarian OCA patients were identical, the molecular genetic data suggested OCA1 subtype in eight cases and OCA4 subtype in two cases. The molecular diagnosis was not clearly identifiable in three cases. In four patients, two different heterozygous known pathogenic or predicted to be pathogenic mutations were present. Seven patients had only one pathogenic mutation, which was associated with non-pathogenic variants in six cases. In two patients no pathogenic mutation was identified. Our results suggest that the concomitant screening of the non-pathogenic variants-which alone do not cause the development of OCA, but might have clinical significance in association with a pathogenic variant-is important. Our results also show significant variation in the disease spectrum compared to other populations. These data also confirm that the concomitant analysis of OCA genes is critical, providing new insights to the phenotypic diversity of OCA and expanding the mutation spectrum of OCA genes in Hungarian patients.

Causes of visual impairment in children with low vision.

Science.gov (United States)

Shah, Mufarriq; Khan, Mirzaman; Khan, Muhammad Tariq; Khan, Mohammad Younas; Saeed, Nasir

2011-02-01

To determine the main causes of visual impairment in children with low vision. To assess the need of spectacles and low vision devices (LVDs) in children and to evaluate visual outcome after using their LVDs for far and near distance. Observational study. Khyber Institute of Ophthalmic Medical Sciences, Peshawar, Pakistan, from June 2006 to December 2007. The clinical record of 270 children with low vision age 4-16 years attending the Low Vision Clinic were included. All those children, aged 4-16 years, who had corrected visual acuity (VA) less than 6/18 in the better eye after medical or surgical treatment, were included in the study. WHO low vision criteria were used to classify into visually impaired, severe visually impaired and blind. Results were described as percentage frequencies. One hundred and eighty nine (70%) were males and 81 (30%) were females. The male to female ratio was 2.3:1. The main causes of visual impairment included nystagmus (15%), Stargardt's disease (14%), maculopathies (13%), myopic macular degeneration (11%) and oculocutaneous albinism (7%). The percentages of visually impaired, severe visually impaired and blind were 33.8%, 27.2% and 39.0% respectively. Spectacles were prescribed to 146 patients and telescopes were prescribed to 75 patients. Spectacles and telescope both were prescribed to 179 patients while Ocutech telescope was prescribed to 4 patients. Retinal diseases nystagmus and macular conditions were mainly responsible for low vision in children. Visually impaired children especially with hereditary/congenital ocular anomalies benefit from refraction and low vision services which facilitate vision enhancement and inclusive education.

A novel iris transillumination grading scale allowing flexible assessment with quantitative image analysis and visual matching.

Science.gov (United States)

Wang, Chen; Brancusi, Flavia; Valivullah, Zaheer M; Anderson, Michael G; Cunningham, Denise; Hedberg-Buenz, Adam; Power, Bradley; Simeonov, Dimitre; Gahl, William A; Zein, Wadih M; Adams, David R; Brooks, Brian

2018-01-01

To develop a sensitive scale of iris transillumination suitable for clinical and research use, with the capability of either quantitative analysis or visual matching of images. Iris transillumination photographic images were used from 70 study subjects with ocular or oculocutaneous albinism. Subjects represented a broad range of ocular pigmentation. A subset of images was subjected to image analysis and ranking by both expert and nonexpert reviewers. Quantitative ordering of images was compared with ordering by visual inspection. Images were binned to establish an 8-point scale. Ranking consistency was evaluated using the Kendall rank correlation coefficient (Kendall's tau). Visual ranking results were assessed using Kendall's coefficient of concordance (Kendall's W) analysis. There was a high degree of correlation among the image analysis, expert-based and non-expert-based image rankings. Pairwise comparisons of the quantitative ranking with each reviewer generated an average Kendall's tau of 0.83 ± 0.04 (SD). Inter-rater correlation was also high with Kendall's W of 0.96, 0.95, and 0.95 for nonexpert, expert, and all reviewers, respectively. The current standard for assessing iris transillumination is expert assessment of clinical exam findings. We adapted an image-analysis technique to generate quantitative transillumination values. Quantitative ranking was shown to be highly similar to a ranking produced by both expert and nonexpert reviewers. This finding suggests that the image characteristics used to quantify iris transillumination do not require expert interpretation. Inter-rater rankings were also highly similar, suggesting that varied methods of transillumination ranking are robust in terms of producing reproducible results.

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

Disease: H00169 [KEGG MEDICUS

Lifescience Database Archive (English)

Full Text Available H00169 Ocular albinism; Ocular albinism, type I (OA1); Waardenburg syndrome, type ...ia, nystagmus, translucent irides, strabismus, hypermetropic refractive errors. Waardenburg syndrome type II

Identification of Novel G Protein-Coupled Receptor 143 Ligands as Pharmacologic Tools for Investigating X-Linked Ocular Albinism.

Science.gov (United States)

De Filippo, Elisabetta; Manga, Prashiela; Schiedel, Anke C

2017-06-01

GPR143 regulates melanosome biogenesis and organelle size in pigment cells. The mechanisms underlying receptor function remain unclear. G protein-coupled receptors (GPCRs) are excellent pharmacologic targets; thus, we developed and applied a screening approach to identify potential GPR143 ligands and chemical modulators. GPR143 interacts with β-arrestin; we therefore established a β-arrestin recruitment assay to screen for compounds that modulate activity. Because GPR143 is localized intracellularly, screening with the wild-type receptor would be restricted to agents absorbed by the cell. For the screen we used a mutant receptor, which shows similar basal activity as the wild type but traffics to the plasma membrane. We tested two compound libraries and investigated validated hits for their effects on melanocyte pigmentation. GPR143, which showed high constitutive activity in the β-arrestin assay, was inhibited by several compounds. The three validated inhibitors (pimozide, niclosamide, and ethacridine lactate) were assessed for impact on melanocytes. Pigmentation and expression of tyrosinase, a key melanogenic enzyme, were reduced by all compounds. Because GPR143 appears to be constitutively active, these compounds may turn off its activity. X-linked ocular albinism type I, characterized by developmental eye defects, results from GPR143 mutations. Identifying pharmacologic agents that modulate GPR143 activity will contribute significantly to our understanding of its function and provide novel tools with which to study GPCRs in melanocytes and retinal pigment epithelium. Pimozide, one of three GPR143 inhibitors identified in this study, maybe be a good lead structure for development of more potent compounds and provide a platform for design of novel therapeutic agents.

An observation of a partially albinistic zenaida macroura (Mourning Dove)

Science.gov (United States)

Berdeen, James; Otis, D.L.

2011-01-01

Abstract Three of the 4 forms of albinism that occur in avifauna have been detected in Zenaida macroura (Mourning Dove). Albinism is rare in this species, and the incidence rate of each age and sex cohort is not well known. Consequently, we examined the pigmentation of Mourning Doves encountered in the Coastal Plain of South Carolina, and classified the age and sex of all individuals. One adult male Mourning Dove had unusually light coloration of some feathers and the upper mandible. This pigmentation is consistent with partial albinism. This was the only individual out of 10,749 examined that appeared to be albinistic. This low incidence rate of albinism supports the conclusion that this condition is relatively rare in Mourning Doves (Mirarchi 1993).

Investigating the relationship between foveal morphology and refractive error in a population with infantile nystagmus syndrome.

Science.gov (United States)

Healey, Natasha; McLoone, Eibhlin; Mahon, Gerald; Jackson, A Jonathan; Saunders, Kathryn J; McClelland, Julie F

2013-04-26

We explored associations between refractive error and foveal hypoplasia in infantile nystagmus syndrome (INS). We recruited 50 participants with INS (albinism n = 33, nonalbinism infantile nystagmus [NAIN] n = 17) aged 4 to 48 years. Cycloplegic refractive error and logMAR acuity were obtained. Spherical equivalent (SER), most ametropic meridian (MAM) refractive error, and better eye acuity (VA) were used for analyses. High resolution spectral-domain optical coherence tomography (SD-OCT) was used to obtain foveal scans, which were graded using the Foveal Hypoplasia Grading Scale. Associations between grades of severity of foveal hypoplasia, and refractive error and VA were explored. Participants with more severe foveal hypoplasia had significantly higher MAMs and SERs (Kruskal-Wallis H test P = 0.005 and P = 0.008, respectively). There were no statistically significant associations between foveal hypoplasia and cylindrical refractive error (Kruskal-Wallis H test P = 0.144). Analyses demonstrated significant differences between participants with albinism or NAIN in terms of SER and MAM (Mann-Whitney U test P = 0.001). There were no statistically significant differences between astigmatic errors between participants with albinism and NAIN. Controlling for the effects of albinism, results demonstrated no significant associations between SER, and MAM and foveal hypoplasia (partial correlation P > 0.05). Poorer visual acuity was associated statistically significantly with more severe foveal hypoplasia (Kruskal-Wallis H test P = 0.001) and with a diagnosis of albinism (Mann-Whitney U test P = 0.001). Increasing severity of foveal hypoplasia is associated with poorer VA, reflecting reduced cone density in INS. Individuals with INS also demonstrate a significant association between more severe foveal hypoplasia and increasing hyperopia. However, in the absence of albinism, there is no significant relation between refractive outcome and degree of foveal hypoplasia

effects of stigmatisation on psychosocial and health well- being of ...

African Journals Online (AJOL)

In southwest Nigeria too, some indigenous movies titled: Ti Oluwa Ni-Ile .... In the same vein, some families abandon newly born children with albinism. ..... assist people living with albinism to develop self-esteem that will help them to ...

Albinism

Science.gov (United States)

... generally pink-colored Large freckle-like spots (lentigines) Sunburn and the inability to tan For some people ... skin that is very sensitive to light and sun exposure. Sunburn is one of the most serious complications ...

Author Details

African Journals Online (AJOL)

Ikuomola, AD. Vol 4, No 2 (2015) - Articles Socio-Cultural Conception of Albinism and Sexuality Challenges among Persons with Albinism (PWA) in South-West, Nigeria Abstract PDF. ISSN: 2227-5452. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about ...

When negation is not negation

OpenAIRE

Milicevic, Nataša

2008-01-01

In this paper I will discuss the formation of different types of yes/no questions in Serbian (examples in (1)), focusing on the syntactically and semantically puzzling example (1d), which involves the negative auxiliary inversion. Although there is a negative marker on the fronted auxiliary, the construction does not involve sentential negation. This coincides with the fact that the negative quantifying NPIs cannot be licensed. The question formation and sentential negation have similar synta...

Inter-chromosomal variation in the pattern of human population genetic structure

Directory of Open Access Journals (Sweden)

Baye Tesfaye M

2011-05-01

Full Text Available Abstract Emerging technologies now make it possible to genotype hundreds of thousands of genetic variations in individuals, across the genome. The study of loci at finer scales will facilitate the understanding of genetic variation at genomic and geographic levels. We examined global and chromosomal variations across HapMap populations using 3.7 million single nucleotide polymorphisms to search for the most stratified genomic regions of human populations and linked these regions to ontological annotation and functional network analysis. To achieve this, we used five complementary statistical and genetic network procedures: principal component (PC, cluster, discriminant, fixation index (FST and network/pathway analyses. At the global level, the first two PC scores were sufficient to account for major population structure; however, chromosomal level analysis detected subtle forms of population structure within continental populations, and as many as 31 PCs were required to classify individuals into homogeneous groups. Using recommended population ancestry differentiation measures, a total of 126 regions of the genome were catalogued. Gene ontology and networks analyses revealed that these regions included the genes encoding oculocutaneous albinism II (OCA2, hect domain and RLD 2 (HERC2, ectodysplasin A receptor (EDAR and solute carrier family 45, member 2 (SLC45A2. These genes are associated with melanin production, which is involved in the development of skin and hair colour, skin cancer and eye pigmentation. We also identified the genes encoding interferon-γ (IFNG and death-associated protein kinase 1 (DAPK1, which are associated with cell death, inflammatory and immunological diseases. An in-depth understanding of these genomic regions may help to explain variations in adaptation to different environments. Our approach offers a comprehensive strategy for analysing chromosome-based population structure and differentiation, and demonstrates the

Perceptual Learning in Children With Infantile Nystagmus: Effects on Visual Performance.

Science.gov (United States)

Huurneman, Bianca; Boonstra, F Nienke; Goossens, Jeroen

2016-08-01

To evaluate whether computerized training with a crowded or uncrowded letter-discrimination task reduces visual impairment (VI) in 6- to 11-year-old children with infantile nystagmus (IN) who suffer from increased foveal crowding, reduced visual acuity, and reduced stereopsis. Thirty-six children with IN were included. Eighteen had idiopathic IN and 18 had oculocutaneous albinism. These children were divided in two training groups matched on age and diagnosis: a crowded training group (n = 18) and an uncrowded training group (n = 18). Training occurred two times per week during 5 weeks (3500 trials per training). Eleven age-matched children with normal vision were included to assess baseline differences in task performance and test-retest learning. Main outcome measures were task-specific performance, distance and near visual acuity (DVA and NVA), intensity and extent of (foveal) crowding at 5 m and 40 cm, and stereopsis. Training resulted in task-specific improvements. Both training groups also showed uncrowded and crowded DVA improvements (0.10 ± 0.02 and 0.11 ± 0.02 logMAR) and improved stereopsis (670 ± 249″). Crowded NVA improved only in the crowded training group (0.15 ± 0.02 logMAR), which was also the only group showing a reduction in near crowding intensity (0.08 ± 0.03 logMAR). Effects were not due to test-retest learning. Perceptual learning with or without distractors reduces the extent of crowding and improves visual acuity in children with IN. Training with distractors improves near vision more than training with single optotypes. Perceptual learning also transfers to DVA and NVA under uncrowded and crowded conditions and even stereopsis. Learning curves indicated that improvements may be larger after longer training.

Ostracism of an albino individual by a group of pigmented catfish.

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Ondřej Slavík

Full Text Available Physiological and behavioural constraints hinder albino individuals. Albino animals are rare in the wild; this trait is associated with easy detection by predators, non-native or damaged environments, and exclusively aphotic environments in total darkness. The social aspect of albinism is reported only for human beings, and the effect is distinguishable in time and space when social benefits, are used to a limited the extent. Thus far, the social consequences of albinism for animals remain unknown. We used socially established groups of the pigmented catfish, (Silurus glanis, to observe space and temporal distance detachment of albino specimens in laboratory conditions. The albino fish were separated at larger distances from the group than pigmented individuals with the same social status determined by familiarity, and this asymmetry also varied in time. Albinism-related ostracism results in a solitary existence, usually followed by enhanced predation risk. The motivation for an individual's exclusion from a group appears to be the avoidance of the predation risk that increases not only for an odd individual but also for conspecifics within a group. Our findings indicate a role for albinism in behavioural processes related to sociality in a group of conspecifics.

Two skin cell lines from wild-type and albino Japanese flounder (Paralichthys olivaceus): establishment, characterization, virus susceptibility, efficient transfection, and application to albinism study.

Science.gov (United States)

Wang, Ruoqing; Zhang, Nianwei; Wang, Renkai; Wang, Shengpeng; Wang, Na

2017-12-01

In order to provide an applicable cell platform to study fish pathology and skin pigmentation, two cell lines derived from skin tissues of wild-type and albino Japanese flounder were established and named JFSK_wt and JFSK_alb, respectively. These two cell lines were cultured for 45 passages within approximately 300 days. JFSK_wt and JFSK_alb cells were maintained in Dulbecco's Modified Eagle's Medium and Ham's F-12 Nutrient Mixture (DMEM/F12) supplemented with antibiotics, fetal bovine serum (FBS), 2-mercaptoethanol (2-Me), N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid (HEPES), and basic fibroblast growth factor (bFGF). The optimal growth temperature for JFSK_wt and JFSK_alb cells was 24 °C, and microscopically, the two cell lines were composed of fibroblast-like cells. Chromosomal analysis revealed that JFSK_wt and JFSK_alb cells had an identical diploid karyotype with 2n = 48t. Results of viral inoculation assays revealed that both cell lines shared similar patterns of viral susceptibility to nervous necrosis virus (NNV). High transfection efficiency was observed in JFSK_wt and JFSK_alb cells transfected with a pEGFP-N3 reporter plasmid and Cy3-siRNA. The detection of dermal marker Dermo-1 showed that these two cells were both derived from the dermis. Finally, three genes involved in the melanogenesis pathway, including adenylate cyclase type 5 (adcy5), microphthalmia-associated transcription factor (mitf), and endothelin B receptor (ednrb), were downregulated in JFSK_alb versus JFSK_wt cells. Thus, the two cell lines, sampled from skin tissue of wild-type and albino Japanese flounder will be not only helpful for fish pathogen research but also beneficial for albinism-related gene function studies.

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African Journals Online (AJOL)

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2014-11-19

Nov 19, 2014 ... tannins that provide the astringent taste to wine. The phenolic acid; gallic acid and monomers - catechin .... red blood cell and white blood cell counts were determined by a ..... recessive oculocutaneous type. Clin. Genet., 17: ...

Negative snakes in JET: evidence for negative shear

International Nuclear Information System (INIS)

Gill, R.D.; Alper, B.; Edwards, A.W.

1994-01-01

The signature of the negative snakes from the soft X-ray cameras is very similar to the more usual snakes except that the localised region of the snake has, compared with its surroundings, decreased rather than increased emission. Circumstances where negative snakes have been seen are reviewed. The negative snake appears as a region of increased resistance and of increased impurity density. The relationship between the shear and the current perturbation is shown, and it seem probable that the magnetic shear is reversed at the point of the negative snake, i.e. that q is decreasing with radius. 6 refs., 6 figs

Negative snakes in JET: evidence for negative shear

Energy Technology Data Exchange (ETDEWEB)

Gill, R D; Alper, B; Edwards, A W [Commission of the European Communities, Abingdon (United Kingdom). JET Joint Undertaking; Pearson, D [Reading Univ. (United Kingdom)

1994-07-01

The signature of the negative snakes from the soft X-ray cameras is very similar to the more usual snakes except that the localised region of the snake has, compared with its surroundings, decreased rather than increased emission. Circumstances where negative snakes have been seen are reviewed. The negative snake appears as a region of increased resistance and of increased impurity density. The relationship between the shear and the current perturbation is shown, and it seem probable that the magnetic shear is reversed at the point of the negative snake, i.e. that q is decreasing with radius. 6 refs., 6 figs.

Two Variants in SLC24A5 Are Associated with “Tiger-Eye” Iris Pigmentation in Puerto Rican Paso Fino Horses

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Maura Mack

2017-08-01

Full Text Available A unique eye color, called tiger-eye, segregates in the Puerto Rican Paso Fino (PRPF horse breed and is characterized by a bright yellow, amber, or orange iris. Pedigree analysis identified a simple autosomal recessive mode of inheritance for this trait. A genome-wide association study (GWAS with 24 individuals identified a locus on ECA 1 reaching genome-wide significance (Pcorrected = 1.32 × 10−5. This ECA1 locus harbors the candidate gene, Solute Carrier Family 24 (Sodium/Potassium/Calcium Exchanger, Member 5 (SLC24A5, with known roles in pigmentation in humans, mice, and zebrafish. Humans with compound heterozygous mutations in SLC24A5 have oculocutaneous albinism (OCA type 6 (OCA6, which is characterized by dilute skin, hair, and eye pigmentation, as well as ocular anomalies. Twenty tiger-eye horses were homozygous for a nonsynonymous mutation in exon 2 (p.Phe91Tyr of SLC24A5 (called here Tiger-eye 1, which is predicted to be deleterious to protein function. Additionally, eight of the remaining 12 tiger-eye horses heterozygous for the p.Phe91Tyr variant were also heterozygous for a 628 bp deletion encompassing all of exon 7 of SLC24A5 (c.875-340_1081+82del, which we will call here the Tiger-eye 2 allele. None of the 122 brown-eyed horses were homozygous for either tiger-eye-associated allele or were compound heterozygotes. Further, neither variant was detected in 196 horses from four related breeds not known to have the tiger-eye phenotype. Here, we propose that two mutations in SLC24A5 affect iris pigmentation in tiger-eye PRPF horses. Further, unlike OCA6 in humans, the Tiger-eye 1 mutation in its homozygous state or as a compound heterozygote (Tiger-eye 1/Tiger-eye 2 does not appear to cause ocular anomalies or a change in coat color in the PRPF horse.

C-terminus glycans with critical functional role in the maturation of secretory glycoproteins.

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Daniela Cioaca

Full Text Available The N-glycans of membrane glycoproteins are mainly exposed to the extracellular space. Human tyrosinase is a transmembrane glycoprotein with six or seven bulky N-glycans exposed towards the lumen of subcellular organelles. The central active site region of human tyrosinase is modeled here within less than 2.5 Å accuracy starting from Streptomyces castaneoglobisporus tyrosinase. The model accounts for the last five C-terminus glycosylation sites of which four are occupied and indicates that these cluster in two pairs--one in close vicinity to the active site and the other on the opposite side. We have analyzed and compared the roles of all tyrosinase N-glycans during tyrosinase processing with a special focus on the proximal to the active site N-glycans, s6:N337 and s7:N371, versus s3:N161 and s4:N230 which decorate the opposite side of the domain. To this end, we have constructed mutants of human tyrosinase in which its seven N-glycosylation sites were deleted. Ablation of the s6:N337 and s7:N371 sites arrests the post-translational productive folding process resulting in terminally misfolded mutants subjected to degradation through the mannosidase driven ERAD pathway. In contrast, single mutants of the other five N-glycans located either opposite to the active site or into the N-terminus Cys1 extension of tyrosinase are temperature-sensitive mutants and recover enzymatic activity at the permissive temperature of 31°C. Sites s3 and s4 display selective calreticulin binding properties. The C-terminus sites s7 and s6 are critical for the endoplasmic reticulum retention and intracellular disposal. Results herein suggest that individual N-glycan location is critical for the stability, regional folding control and secretion of human tyrosinase and explains some tyrosinase gene missense mutations associated with oculocutaneous albinism type I.

Negative ion sources

International Nuclear Information System (INIS)

Ishikawa, Junzo; Takagi, Toshinori

1983-01-01

Negative ion sources have been originally developed at the request of tandem electrostatic accelerators, and hundreds of nA to several μA negative ion current has been obtained so far for various elements. Recently, the development of large current hydrogen negative ion sources has been demanded from the standpoint of the heating by neutral particle beam injection in nuclear fusion reactors. On the other hand, the physical properties of negative ions are interesting in the thin film formation using ions. Anyway, it is the present status that the mechanism of negative ion action has not been so fully investigated as positive ions because the history of negative ion sources is short. In this report, the many mechanisms about the generation of negative ions proposed so far are described about negative ion generating mechanism, negative ion source plasma, and negative ion generation on metal surfaces. As a result, negative ion sources are roughly divided into two schemes, plasma extraction and secondary ion extraction, and the former is further classified into the PIG ion source and its variation and Duoplasmatron and its variation; while the latter into reflecting and sputtering types. In the second half of the report, the practical negative ion sources of each scheme are described. If the mechanism of negative ion generation will be investigated more in detail and the development will be continued under the unified know-how as negative ion sources in future, the development of negative ion sources with which large current can be obtained for any element is expected. (Wakatsuki, Y.)

Impact of negation salience and cognitive resources on negation during attitude formation.

Science.gov (United States)

Boucher, Kathryn L; Rydell, Robert J

2012-10-01

Because of the increased cognitive resources required to process negations, past research has shown that explicit attitude measures are more sensitive to negations than implicit attitude measures. The current work demonstrated that the differential impact of negations on implicit and explicit attitude measures was moderated by (a) the extent to which the negation was made salient and (b) the amount of cognitive resources available during attitude formation. When negations were less visually salient, explicit but not implicit attitude measures reflected the intended valence of the negations. When negations were more visually salient, both explicit and implicit attitude measures reflected the intended valence of the negations, but only when perceivers had ample cognitive resources during encoding. Competing models of negation processing, schema-plus-tag and fusion, were examined to determine how negation salience impacts the processing of negations.

Negative mass

International Nuclear Information System (INIS)

Hammond, Richard T

2015-01-01

Some physical aspects of negative mass are examined. Several unusual properties, such as the ability of negative mass to penetrate any armor, are analysed. Other surprising effects include the bizarre system of negative mass chasing positive mass, naked singularities and the violation of cosmic censorship, wormholes, and quantum mechanical results as well. In addition, a brief look into the implications for strings is given. (paper)

Positive Effects of Negative Publicity: When Negative Reviews Increase Sales

OpenAIRE

Jonah Berger; Alan T. Sorensen; Scott J. Rasmussen

2010-01-01

Can negative information about a product increase sales, and if so, when? Although popular wisdom suggests that "any publicity is good publicity," prior research has demonstrated only downsides to negative press. Negative reviews or word of mouth, for example, have been found to hurt product evaluation and sales. Using a combination of econometric analysis and experimental methods, we unify these perspectives to delineate contexts under which negative publicity about a product will have posit...

Reversing a Negative Measurement in Process with Negative Events: A Haunted Negative Measurement and the Bifurcation of Time

CERN Document Server

Snyder, D M

2003-01-01

Reversing an ordinary measurement in process (a haunted measurement) is noted and the steps involved in reversing a negative measurement in process (a haunted negative measurement) are described. In order to discuss in a thorough manner reversing an ordinary measurement in process, one has to account for how reversing a negative measurement in process would work for the same experimental setup. The reason it is necessary to know how a negative measurement in process is reversed is because for a given experimental setup there is no physical distinction between reversing a negative measurement in process and reversing an ordinary measurement in process. In the absence of the reversal of a negative measurement in process in the same experimental setup that supports the reversal of an ordinary measurement in process, the possibility exists of which-way information concerning the negative measurement that would render theoretically implausible reversing an ordinary measuremnt in process. The steps in reversing a n...

Bilateral Sturge-Weber Syndrome and glaucoma controlled with Ahmed valve implant

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Marcelo Jarczun Kac

2015-02-01

Full Text Available Sturge-Weber Syndrome is a rare neuro-oculocutaneous disorder. The authors describe the case of a 13 years old boy, presented with bilateral Sturge-Weber Syndrome and glaucoma. Surgical treatment with Ahmed valve implantation in both eyes was carried out achieving lower levels of intraocular pressure.

Identification of three novel OA1 gene mutations identified in three families misdiagnosed with congenital nystagmus and carrier status determination by real-time quantitative PCR assay

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Hamel Christian

2003-01-01

Full Text Available Abstract Background X-linked ocular albinism type 1 (OA1 is caused by mutations in OA1 gene, which encodes a membrane glycoprotein localised to melanosomes. OA1 mainly affects pigment production in the eye, resulting in optic changes associated with albinism including hypopigmentation of the retina, nystagmus, strabismus, foveal hypoplasia, abnormal crossing of the optic fibers and reduced visual acuity. Affected Caucasian males usually appear to have normal skin and hair pigment. Results We identified three previously undescribed mutations consisting of two intragenic deletions (one encompassing exon 6, the other encompassing exons 7–8, and a point mutation (310delG in exon 2. We report the development of a new method for diagnosis of heterozygous deletions in OA1 gene based on measurement of gene copy number using real-time quantitative PCR from genomic DNA. Conclusion The identification of OA1 mutations in families earlier reported as families with hereditary nystagmus indicate that ocular albinism type 1 is probably underdiagnosed. Our method of real-time quantitative PCR of OA1 exons with DMD exon as external standard performed on the LightCycler™ allows quick and accurate carrier-status assessment for at-risk females.

Negative liability

NARCIS (Netherlands)

Dari-Mattiacci, G.

2009-01-01

Negative and positive externalities pose symmetrical problems to social welfare. The law internalizes negative externalities by providing general tort liability rules. According to such rules, those who cause harm to others should pay compensation. In theory, in the presence of positive

Negative ... concord?

NARCIS (Netherlands)

Giannakidou, A

The main claim of this paper is that a general theory of negative concord (NC) should allow for the possibility of NC involving scoping of a universal quantifier above negation. I propose that Greek NC instantiates this option. Greek n-words will be analyzed as polarity sensitive universal

Polemic and Descriptive Negations

DEFF Research Database (Denmark)

Horslund, Camilla Søballe

2011-01-01

to semantics and pragmatics, negations can be used in three different ways, which gives rise to a typology of three different types of negations: 1) the descriptive negation, 2) the polemic negation, and 3) the meta-linguistic negation (Nølke 1999, 4). This typology illuminates the fact that the negation...... common in certain social context or genres, while polemic negations are more likely to come up in other genres and social settings. Previous studies have shown a relation between articulatory prominence and register, which may further inform the analysis. Hence, the paper investigates how articulatory...... prominence and register may either work in concert or oppose each other with respect to the cues they provide for the interpretation....

Negative Ion Density Fronts

International Nuclear Information System (INIS)

Igor Kaganovich

2000-01-01

Negative ions tend to stratify in electronegative plasmas with hot electrons (electron temperature Te much larger than ion temperature Ti, Te > Ti ). The boundary separating a plasma containing negative ions, and a plasma, without negative ions, is usually thin, so that the negative ion density falls rapidly to zero-forming a negative ion density front. We review theoretical, experimental and numerical results giving the spatio-temporal evolution of negative ion density fronts during plasma ignition, the steady state, and extinction (afterglow). During plasma ignition, negative ion fronts are the result of the break of smooth plasma density profiles during nonlinear convection. In a steady-state plasma, the fronts are boundary layers with steepening of ion density profiles due to nonlinear convection also. But during plasma extinction, the ion fronts are of a completely different nature. Negative ions diffuse freely in the plasma core (no convection), whereas the negative ion front propagates towards the chamber walls with a nearly constant velocity. The concept of fronts turns out to be very effective in analysis of plasma density profile evolution in strongly non-isothermal plasmas

Negative Leadership

Science.gov (United States)

2013-03-01

Negative Leadership by Colonel David M. Oberlander United States Army United States Army War...SUBTITLE Negative Leadership 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Colonel David M...Dr. Richard C. Bullis Department of Command Leadership , and Management 8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING/MONITORING

MULTIMODAL IMAGING OF MOSAIC RETINOPATHY IN CARRIERS OF HEREDITARY X-LINKED RECESSIVE DISEASES.

Science.gov (United States)

Wu, An-Lun; Wang, Jung-Pan; Tseng, Yun-Ju; Liu, Laura; Kang, Yu-Chuan; Chen, Kuan-Jen; Chao, An-Ning; Yeh, Lung-Kun; Chen, Tun-Lu; Hwang, Yih-Shiou; Wu, Wei-Chi; Lai, Chi-Chun; Wang, Nan-Kai

2018-05-01

To investigate the clinical features in carriers of X-linked retinitis pigmentosa, X-linked ocular albinism, and choroideremia (CHM) using multimodal imaging and to assess their diagnostic value in these three mosaic retinopathies. We prospectively examined 14 carriers of 3 X-linked recessive disorders (X-linked retinitis pigmentosa, X-linked ocular albinism, and CHM). Details of abnormalities of retinal morphology were evaluated using fundus photography, fundus autofluorescence (FAF) imaging, and spectral domain optical coherence tomography. In six X-linked retinitis pigmentosa carriers, fundus appearance varied from unremarkable to the presence of tapetal-like reflex and pigmentary changes. On FAF imaging, all carriers exhibited a bright radial reflex against a dark background. By spectral domain optical coherence tomography, loss of the ellipsoid zone in the macula was observed in 3 carriers (50%). Regarding the retinal laminar architecture, 4 carriers (66.7%) showed thinning of the outer nuclear layer and a dentate appearance of the outer plexiform layer. All five X-linked ocular albinism carriers showed a characteristic mud-splatter patterned fundus, dark radial streaks against a bright background on FAF imaging, and a normal-appearing retinal structure by spectral domain optical coherence tomography imaging. Two of the 3 CHM carriers (66.7%) showed a diffuse moth-eaten appearance of the fundus, and all 3 showed irregular hyper-FAF and hypo-FAF spots throughout the affected area. In the CHM carriers, the structural changes observed by spectral domain optical coherence tomography imaging were variable. Our findings in an Asian cohort suggest that FAF imaging is a practical diagnostic test for differentiating X-linked retinitis pigmentosa, X-linked ocular albinism, and CHM carriers. Wide-field FAF is an easy and helpful adjunct to testing for the correct diagnosis and identification of lyonization in carriers of these three mosaic retinopathies.

Analogs of human genetic skin disease in domesticated animals

Directory of Open Access Journals (Sweden)

Justin Finch, MD

2017-09-01

The genetic skin diseases we will review are pigmentary mosaicism, piebaldism, albinism, Griscelli syndrome, ectodermal dysplasias, Waardenburg syndrome, and mucinosis in both humans and domesticated animals.

Turning negative into positive: public health mass media campaigns and negative advertising.

Science.gov (United States)

Apollonio, D E; Malone, R E

2009-06-01

Literature suggests that 'negative advertising' is an effective way to encourage behavioral changes, but it has enjoyed limited use in public health media campaigns. However, as public health increasingly focuses on non-communicable disease prevention, negative advertising could be more widely applied. This analysis considers an illustrative case from tobacco control. Relying on internal tobacco industry documents, surveys and experimental data and drawing from political advocacy literature, we describe tobacco industry and public health research on the American Legacy Foundation's "truth" campaign, an example of effective negative advertising in the service of public health. The tobacco industry determined that the most effective advertisements run by Legacy's "truth" campaign were negative advertisements. Although the tobacco industry's own research suggested that these negative ads identified and effectively reframed the cigarette as a harmful consumer product rather than focusing solely on tobacco companies, Philip Morris accused Legacy of 'vilifying' it. Public health researchers have demonstrated the effectiveness of the "truth" campaign in reducing smoking initiation. Research on political advocacy demonstrating the value of negative advertising has rarely been used in the development of public health media campaigns, but negative advertising can effectively communicate certain public health messages and serve to counter corporate disease promotion.

Negative-ion states

International Nuclear Information System (INIS)

Compton, R.N.

1982-01-01

In this brief review, we discuss some of the properties of atomic and molecular negative ions and their excited states. Experiments involving photon reactions with negative ions and polar dissociation are summarized. 116 references, 14 figures

The positives of negative emotions: willingness to express negative emotions promotes relationships.

Science.gov (United States)

Graham, Steven M; Huang, Julie Y; Clark, Margaret S; Helgeson, Vicki S

2008-03-01

Four studies support the hypothesis that expressing negative emotion is associated with positive relationship outcomes, including elicitation of support, building of new close relationships, and heightening of intimacy in the closest of those relationships. In Study 1, participants read vignettes in which another person was experiencing a negative emotion. Participants reported they would provide more help when the person chose to express the negative emotion. In Study 2, participants watched a confederate preparing for a speech. Participants provided more help to her when she expressed nervousness. In Study 3, self-reports of willingness to express negative emotions predicted having more friends, controlling for demographic variables and extraversion. In Study 4, self-reports of willingness to express negative emotion measured prior to arrival at college predicted formation of more relationships, greater intimacy in the closest of those relationships, and greater received support from roommates across participants' first semester of college.

Sentential Negation in English

Science.gov (United States)

Mowarin, Macaulay

2009-01-01

This paper undertakes a detailed analysis of sentential negation in the English language with Chomsky's Government-Binding theory of Transformational Grammar as theoretical model. It distinguishes between constituent and sentential negation in English. The essay identifies the exact position of Negation phrase in an English clause structure. It…

Immunophenotypic and Ultrastructural Analysis of Mast Cells in Hermansky-Pudlak Syndrome Type-1: A Possible Connection to Pulmonary Fibrosis.

Directory of Open Access Journals (Sweden)

Arnold S Kirshenbaum

Full Text Available Hermansky-Pudlak Syndrome type-1 (HPS-1 is an autosomal recessive disorder caused by mutations in HPS1 which result in reduced expression of the HPS-1 protein, defective lysosome-related organelle (LRO transport and absence of platelet delta granules. Patients with HPS-1 exhibit oculocutaneous albinism, colitis, bleeding and pulmonary fibrosis postulated to result from a dysregulated immune response. The effect of the HPS1 mutation on human mast cells (HuMCs is unknown. Since HuMC granules classify as LROs along with platelet granules and melanosomes, we set out to determine if HPS-1 cutaneous and CD34+ culture-derived HuMCs have distinct granular and cellular characteristics. Cutaneous and cultured CD34+-derived HuMCs from HPS-1 patients were compared with normal cutaneous and control HuMCs, respectively, for any morphological and functional differences. One cytokine-independent HPS-1 culture was expanded, cloned, designated the HP proMastocyte (HPM cell line and characterized. HPS-1 and idiopathic pulmonary fibrosis (IPF alveolar interstitium showed numerous HuMCs; HPS-1 dermal mast cells exhibited abnormal granules when compared to healthy controls. HPS-1 HuMCs showed increased CD63, CD203c and reduced mediator release following FcɛRI aggregation when compared with normal HuMCs. HPM cells also had the duplication defect, expressed FcɛRI and intracytoplasmic proteases and exhibited less mediator release following FcɛRI aggregation. HPM cells constitutively released IL-6, which was elevated in patients' serum, in addition to IL-8, fibronectin-1 (FN-1 and galectin-3 (LGALS3. Transduction with HPS1 rescued the abnormal HPM morphology, cytokine and matrix secretion. Microarray analysis of HPS-1 HuMCs and non-transduced HPM cells confirmed upregulation of differentially expressed genes involved in fibrogenesis and degranulation. Cultured HPS-1 HuMCs appear activated as evidenced by surface activation marker expression, a decrease in mediator

Factors associated with negative T-SPOT.TB results among smear-negative tuberculosis patients in China.

Science.gov (United States)

Kang, Wanli; Wu, Meiying; Yang, Kunyun; Ertai, A; Wu, Shucai; Geng, Shujun; Li, Zhihui; Li, Mingwu; Pang, Yu; Tang, Shenjie

2018-03-09

We compared the positive rates of T-SPOT.TB and bacterial culture in the smear-negative PTB, and analyzed the factors affecting the results of negative T-SPOT.TB and bacterial culture. Retrospective evaluation of data from smear-negative PTB patients who underwent T-SPOT.TB and bacterial culture were done. The agreement and concordance were analyzed between T-SPOT.TB and bacterial culture. Multivariable logistic regression analysis was used to explore the factors associated with positive results of T-SPOT.TB and bacterial culture in smear-negative PTB. 858 eligible smear-negative PTB patients were included in the study. The agreement rate was 25.6% (22.7~28.5%) between T-SPOT.TB and bacterial culture in smear- negative PTB patients. The positive rate of T-SPOT.TB was higher than that of bacterial culture in smear-negative PTB patients (p SPOT.TB and bacterial culture (p > 0.05). Using multivariable logistic regression analysis we found that older age ≥ 60 years (OR = 0.469, 95% CI: 0.287-0.768) and decreased albumin (OR = 0.614, 95% CI: 0.380-0.992) were associated with negative diagnostic results of T-SPOT.TB in smear-negative PTB patients. Female (OR = 0.654, 95% CI: 0.431-0.992) were associated with negative diagnostic results of bacteria culture in smear-negative PTB patients. Our results indicated that the older age and decreased albumin were independently associated with negative T-SPOT.TB responses.

Is the negative glow plasma of a direct current glow discharge negatively charged?

International Nuclear Information System (INIS)

Bogdanov, E. A.; Saifutdinov, A. I.; Demidov, V. I.; Kudryavtsev, A. A.

2015-01-01

A classic problem in gas discharge physics is discussed: what is the sign of charge density in the negative glow region of a glow discharge? It is shown that traditional interpretations in text-books on gas discharge physics that states a negative charge of the negative glow plasma are based on analogies with a simple one-dimensional model of discharge. Because the real glow discharges with a positive column are always two-dimensional, the transversal (radial) term in divergence with the electric field can provide a non-monotonic axial profile of charge density in the plasma, while maintaining a positive sign. The numerical calculation of glow discharge is presented, showing a positive space charge in the negative glow under conditions, where a one-dimensional model of the discharge would predict a negative space charge

East and Central African Journal of Pharmaceutical Sciences Vol. 7 ...

African Journals Online (AJOL)

1996-04-24

Apr 24, 1996 ... 3 Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin, Madison, ... albinism should use sunscreens labeled with a Sun .... that were subjected to stability testing. Ingredients. Form-. Form- Form-.

Negative thermal expansion materials

International Nuclear Information System (INIS)

Evans, J.S.O.

1997-01-01

The recent discovery of negative thermal expansion over an unprecedented temperature range in ZrW 2 O 8 (which contracts continuously on warming from below 2 K to above 1000 K) has stimulated considerable interest in this unusual phenomenon. Negative and low thermal expansion materials have a number of important potential uses in ceramic, optical and electronic applications. We have now found negative thermal expansion in a large new family of materials with the general formula A 2 (MO 4 ) 3 . Chemical substitution dramatically influences the thermal expansion properties of these materials allowing the production of ceramics with negative, positive or zero coefficients of thermal expansion, with the potential to control other important materials properties such as refractive index and dielectric constant. The mechanism of negative thermal expansion and the phase transitions exhibited by this important new class of low-expansion materials will be discussed. (orig.)

Negative-ion current density dependence of the surface potential of insulated electrode during negative-ion implantation

International Nuclear Information System (INIS)

Tsuji, Hiroshi; Okayama, Yoshio; Toyota, Yoshitaka; Gotoh, Yasuhito; Ishikawa, Junzo; Sakai, Shigeki; Tanjyo, Masayasu; Matsuda, Kouji.

1994-01-01

Positive ion implantation has been utilized as the method of impurity injection in ultra-LSI production, but the problem of substrate charging cannot be resolved by conventional charge compensation method. It was forecast that by negative ion implantation, this charging problem can be resolved. Recently the experiment on the negative ion implantation into insulated electrodes was carried out, and the effect of negative ion implantation to this problem was proved. However, the dependence of charged potential on the increase of negative ion current at the time of negative ion implantation is a serious problem in large current negative ion implantation hereafter. The charged potential of insulated conductor substrates was measured by the negative ion implantation using the current up to several mA/cm 2 . The experimental method is explained. Medium current density and high current density negative ion implantation and charged potential are reported. Accordingly in negative ion implantation, if current density is optimized, the negative ion implantation without charging can be realized. (K.I.)

GABA(A) Receptor Alpha5 Subunit as a Candidate Gene for Autism and Bipolar Disorder: A Proposed Endophenotype with Parent-of-Origin and Gain-of-Function Features, with or without Oculocutaneous Albinism

Science.gov (United States)

Delong, Robert

2007-01-01

Our earlier family history studies of individuals with autism found a high incidence of major affective disorder, especially bipolar disorder, and unusual talents or intellectual abilities among family members. We now describe a subgroup of such families, selected from a large clinical experience, illustrating specific features of major affective…

The Interplay Among Children's Negative Family Representations, Visual Processing of Negative Emotions, and Externalizing Symptoms.

Science.gov (United States)

Davies, Patrick T; Coe, Jesse L; Hentges, Rochelle F; Sturge-Apple, Melissa L; van der Kloet, Erika

2018-03-01

This study examined the transactional interplay among children's negative family representations, visual processing of negative emotions, and externalizing symptoms in a sample of 243 preschool children (M age  = 4.60 years). Children participated in three annual measurement occasions. Cross-lagged autoregressive models were conducted with multimethod, multi-informant data to identify mediational pathways. Consistent with schema-based top-down models, negative family representations were associated with attention to negative faces in an eye-tracking task and their externalizing symptoms. Children's negative representations of family relationships specifically predicted decreases in their attention to negative emotions, which, in turn, was associated with subsequent increases in their externalizing symptoms. Follow-up analyses indicated that the mediational role of diminished attention to negative emotions was particularly pronounced for angry faces. © 2017 The Authors. Child Development © 2017 Society for Research in Child Development, Inc.

Negative ion sourcery

International Nuclear Information System (INIS)

Os, C.F.A. van.

1989-01-01

The work described in this thesis is involved by current research programs in the field of nuclear-fusion. A brief introduction to fusion is given, anticipated problems related to current drive of the fusion plasma are pinpointed and probable suggestions to overcome these problems are described. One probable means for current drive is highlighted; Neutral Beam Injection (NBI). This is based on injecting a 1 MeV neutral hydrogen or deuterium beam into a fusion plasma. Negative ions are needed as primary particles because they can easily be neutralized at 1 MeV. The two current schemes for production of negative ions are described, volume production and negative surface ionization. The latter method is extensively studied in this thesis. (author). 171 refs.; 55 figs.; 7 tabs

Negative Attitudes, Network and Education

DEFF Research Database (Denmark)

Bennett, Patrick; la Cour, Lisbeth; Larsen, Birthe

We consider the impact of negative attitudes against immigrants and immigration on educational choice in a search and wage bargaining model including networking. We consider two cases in terms of the importance of negative attitudes againts immigrants for high and low educated individuals and find...... that more negative attitudes against immigrants has a positive impact on education in one case and a negative impact in the other and has no impact on natives. Immigration improves employment perspectives for immigrants and thereby increases immigrant education whereas endogenous negative attitudes lead...... use Danish register data to find a signficant positive correlation between negative attitudes towards immigrants and high school attendance and find a positive impact of networking on high school attendance. In both the macro and the micro-econometric analysis we run the same regressions for natives...

Training for assessment of negative symptoms of schizophrenia across languages and cultures: comparison of the NSA-16 with the PANSS Negative Subscale and Negative Symptom factor.

Science.gov (United States)

Daniel, David G; Alphs, Larry; Cazorla, Pilar; Bartko, John J; Panagides, John

2011-07-01

The 16-item Negative Symptom Assessment scale (NSA-16) has been validated in English-speaking raters. We analyzed the level of agreement achieved among raters of different nationalities using the NSA-16 and the Positive and Negative Syndrome Scale (PANSS) negative subscale and Marder negative factor. Raters participating in two international trials were trained in the use of each instrument through lectures and feedback on their ratings of at least one videotaped interview of a schizophrenic patient. Overall and regional (North America, Western Europe, Eastern Europe, South/Central America, and Australia and South Africa combined) kappa values were calculated and mean total scores were compared (1-way analysis of variance) by region for each instrument. In addition, within-scales variance was calculated by item to help identify negative symptoms that were particularly challenging to obtain agreement on across cultures. In the combined group of international raters, the kappa values for ratings of the NSA-16, PANSS negative subscale, and Marder negative factors were 0.89, 0.84, and 0.82, respectively. Kappa values calculated by geographic region ranged from 0.87 to 0.94 for the NSA-16 compared with 0.82 to 0.86 for the PANSS negative subscale and 0.79 to 0.87 for the PANSS Marder negative factor. Despite cultural and linguistic differences among raters, standardizing measurement of negative symptoms in international clinical trials is possible using available rating scales: NSA-16, PANSS negative subscale, and Marder negative subscale. Agreement among raters was at least as high using the NSA-16 as using the PANSS instruments.

Cross-Lagged Associations Between Adolescents' Depressive Symptoms and Negative Cognitive Style: The Role of Negative Life Events.

Science.gov (United States)

Kindt, Karlijn C M; Kleinjan, Marloes; Janssens, Jan M A M; Scholte, Ron H J

2015-11-01

Previous research has established that cognitive theory-based depression prevention programs aiming change in negative cognitive style in early adolescents do not have strong effects in universal settings. Although theories suggest that a negative cognitive style precedes depressive symptoms, empirical findings are mixed. We hypothesized that negative cognitive style may not predict depressive symptoms in adolescents with normative depressive symptoms. Depressive symptoms, negative cognitive style and dependent negative life events were assessed in young adolescents (N = 1343; mean age = 13.4 years, SD = 0.77; 52.3 % girls) at four time points over an 18-month period. Using a cross-lagged panel design, results revealed that depressive symptoms predicted a negative cognitive style but not vice versa. However, when including dependent negative life events as a variable, depressive symptoms did not prospect a negative cognitive style consistently. When dependent negative life events were used as a time-varying covariate, depressive symptoms and a negative cognitive style were not related. We concluded that negative cognitive style is not predictive of depressive symptoms in a community sample of young adolescents. Moreover, the findings suggest that longitudinal relationships between depressive symptoms and a negative cognitive style are not meaningful when dependent negative life events are not considered.

Isotropic Negative Thermal Expansion Metamaterials.

Science.gov (United States)

Wu, Lingling; Li, Bo; Zhou, Ji

2016-07-13

Negative thermal expansion materials are important and desirable in science and engineering applications. However, natural materials with isotropic negative thermal expansion are rare and usually unsatisfied in performance. Here, we propose a novel method to achieve two- and three-dimensional negative thermal expansion metamaterials via antichiral structures. The two-dimensional metamaterial is constructed with unit cells that combine bimaterial strips and antichiral structures, while the three-dimensional metamaterial is fabricated by a multimaterial 3D printing process. Both experimental and simulation results display isotropic negative thermal expansion property of the samples. The effective coefficient of negative thermal expansion of the proposed models is demonstrated to be dependent on the difference between the thermal expansion coefficient of the component materials, as well as on the circular node radius and the ligament length in the antichiral structures. The measured value of the linear negative thermal expansion coefficient of the three-dimensional sample is among the largest achieved in experiments to date. Our findings provide an easy and practical approach to obtaining materials with tunable negative thermal expansion on any scale.

What makes dreams positive or negative: relations to fundamental dimensions of positive and negative mood.

Science.gov (United States)

Kallmeyer, R J; Chang, E C

1998-02-01

The present study examined the general emotional content of dreams reported by individuals who typically experience "positive" versus "negative" dreams. Self-reports of the 153 participants indicated that positive versus negative dreamers (ns = 42 and 24, respectively) generally experienced more positive emotions, e.g., joviality, self-assurance, and fewer negative emotions, e.g., fear, sadness. No differences were found in the self-reports of the participants in the experience of surprise, guilt, fatigue, and shyness between the groups, hence, positive and negative dreams do not appear to reflect simply more positive and fewer negative emotions, respectively.

to view fulltext PDF

Indian Academy of Sciences (India)

SEARCHU

studied process in cell and molecular biology (Wyeth and. Albin 2004). Transcription ... Review. Computational methods to dissect cis-regulatory transcriptional networks ... on a global scale and to assign function to tens of thousands of genes.

Negation and negative information in the W3C resource description framework

NARCIS (Netherlands)

Analyti, A.; Antoniou, G.; Damásio, C.V.; Wagner, G.R.

2004-01-01

The concept of negation plays a special role in non-classical logics and also in knowledge representation formalisms where negative information has to be taken into account on par with positive information. In the tradition of mathematical logic, there is a general preference to consider positive

Negative ion detachment processes

International Nuclear Information System (INIS)

Champion, R.L.; Doverspike, L.D.

1990-10-01

This paper discusses the following topics: H - and D - collisions with atomic hydrogen; collisional decomposition of SF 6 - ; two-electron loss processes in negative ion collisions; associative electron detachment; and negative ion desorption from surfaces

Negative hydrogen ion production mechanisms

Energy Technology Data Exchange (ETDEWEB)

Bacal, M. [UPMC, LPP, Ecole Polytechnique, UMR CNRS 7648, Palaiseau (France); Wada, M. [School of Science and Engineering, Doshisha University, Kyoto 610-0321 (Japan)

2015-06-15

Negative hydrogen/deuterium ions can be formed by processes occurring in the plasma volume and on surfaces facing the plasma. The principal mechanisms leading to the formation of these negative ions are dissociative electron attachment to ro-vibrationally excited hydrogen/deuterium molecules when the reaction takes place in the plasma volume, and the direct electron transfer from the low work function metal surface to the hydrogen/deuterium atoms when formation occurs on the surface. The existing theoretical models and reported experimental results on these two mechanisms are summarized. Performance of the negative hydrogen/deuterium ion sources that emerged from studies of these mechanisms is reviewed. Contemporary negative ion sources do not have negative ion production electrodes of original surface type sources but are operated with caesium with their structures nearly identical to volume production type sources. Reasons for enhanced negative ion current due to caesium addition to these sources are discussed.

Thermodynamics of negative absolute pressures

International Nuclear Information System (INIS)

Lukacs, B.; Martinas, K.

1984-03-01

The authors show that the possibility of negative absolute pressure can be incorporated into the axiomatic thermodynamics, analogously to the negative absolute temperature. There are examples for such systems (GUT, QCD) processing negative absolute pressure in such domains where it can be expected from thermodynamical considerations. (author)

NEGATION AFFIXES IN ENGLISH

Directory of Open Access Journals (Sweden)

Dedy Subandowo -

2017-02-01

Full Text Available Abstract: This research entitled "Negation Affixes in English". This study is aimed to describe the various negation affixes in English, morphological process, morphophonemic and meaning. The research data were taken from various sources of English grammar book, morphology, research journal and the book which relatees to the research. English grammar books used in this study are written by Otto Jesperson, Marcella Frank, Greenbaum and Geoffrey Leech.  The method used in this research is the descriptive-qualitative method. While the data collection techniques are performed by using jot-down method. And the results of analysis are presented in tabular form and descriptive method. The result of the research shows that English has six types of negative affixes which are categorized by the intensity of its appearance, such as dis-, in-, non-, un-, anti- and -less. Based on the function, negation affixes are divided into several categories such as adjectives, nouns, verbs, and adverbs. The morphophonemic affix in- has four allomorphs, they are in-, im-, il- and ir- . While the analysis revealed that negation affixes have some basic meanings, such as ‘not’, ‘without’, and ‘anti’.

Negative dimensional integrals. Pt. 1

International Nuclear Information System (INIS)

Halliday, I.G.; Ricotta, R.M.

1987-01-01

We propose a new method of evaluating integrals based on negative dimensional integration. We compute Feynman graphs by considering analytic extensions. Propagators are raised to negative integer powers and integrated over negative integer dimensions. We are left with the problem of computing polynomial integrals and summing finite series. (orig.)

Income, Amenities and Negative Attitudes

DEFF Research Database (Denmark)

Waisman, Gisela; Larsen, Birthe

2016-01-01

We exploit the regional variation in negative attitudes towards immigrants to Sweden in order to analyse the consequences of negative attitudes on refugees’ utility from labour income and amenities. We find that attitudes towards immigrants are important: while they affect mainly the refugees......’ quality of life, they also affect their income. We estimate the utility effects of negative attitudes for refugees with different levels of education and gender. We also analyse how the size of the refugees’ networks relate to their quality of life and income as well as how negative attitudes towards...

Exchange rate behavior with negative interest rates: Some early negative observations

OpenAIRE

Hameed, Allaudeen S.; Rose, Andrew

2017-01-01

This paper examines exchange rate behavior during the recent period with negative nominal interest rates. We use a daily panel of data on 61 currencies from January 2010 through May 2016, during which five economies - Denmark, the European Economic and Monetary Union, Japan, Sweden, and Switzerland - experienced negative nominal interest rates. We examine both effective exchange rates and bilateral rates; the latter typically measured against the Swiss franc since Switzerland has had the long...

The clinicopathologic characteristics and prognostic significance of triple-negativity in node-negative breast cancer

International Nuclear Information System (INIS)

Rhee, Jiyoung; Kim, Tae-You; Han, Sae-Won; Oh, Do-Youn; Kim, Jee Hyun; Im, Seock-Ah; Han, Wonshik; Ae Park, In; Noh, Dong-Young; Bang, Yung-Jue

2008-01-01

Triple-negative (TN) breast cancer, which is defined as being negative for the estrogen receptor (ER), the progesterone receptor (PR), and the human epidermal growth factor receptor 2 (HER-2), represents a subset of breast cancer with different biologic behaviour. We investigated the clinicopathologic characteristics and prognostic indicators of lymph node-negative TN breast cancer. Medical records were reviewed from patients with node-negative breast cancer who underwent curative surgery at Seoul National University Hospital between Jan. 2000 and Jun. 2003. Clinicopathologic variables and clinical outcomes were evaluated. Among 683 patients included, 136 had TN breast cancer and 529 had non-TN breast cancer. TN breast cancer correlated with younger age (< 35 y, p = 0.003), and higher histologic and nuclear grade (p < 0.001). It also correlated with a molecular profile associated with biological aggressiveness: negative for bcl-2 expression (p < 0.001), positive for the epidermal growth factor receptor (p = 0.003), and a high level of p53 (p < 0.001) and Ki67 expression (p < 0.00). The relapse rates during the follow-up period (median, 56.8 months) were 14.7% for TN breast cancer and 6.6% for non-TN breast cancer (p = 0.004). Relapse free survival (RFS) was significantly shorter among patients with TN breast cancer compared with those with non-TN breast cancer (4-year RFS rate 85.5% vs. 94.2%, respectively; p = 0.001). On multivariate analysis, young age, close resection margin, and triple-negativity were independent predictors of shorter RFS. TN breast cancer had higher relapse rate and more aggressive clinicopathologic characteristics than non-TN in node-negative breast cancer. Thus, TN breast cancer should be integrated into the risk factor analysis for node-negative breast cancer

A Modality Called 'Negation'

NARCIS (Netherlands)

Berto, F.

2015-01-01

I propose a comprehensive account of negation as a modal operator, vindicating a moderate logical pluralism. Negation is taken as a quantifier on worlds, restricted by an accessibility relation encoding the basic concept of compatibility. This latter captures the core meaning of the operator. While

SM-1 negative ion source

International Nuclear Information System (INIS)

Huang Zhenjun; Wang Jianzhen

1987-01-01

The working principle and characteristics of SM-1 Negative Ion Source is mainly introduced. In the instrument, there is a device to remove O 3 . This instrument can keep high density of negative ions which is generated by the electrical coronas setting out electricity at negative high voltage and can remove the O 3 component which is harmful to the human body. The density of negative ions is higher than 2.5 x 10 6 p./cm 3 while that of O 3 components is less than 1 ppb at the distance of 50 cm from the panel of the instrument. The instrument sprays negative ions automatically without the help of electric fan, so it works noiselessly. It is widely used in national defence, industry, agriculture, forestry, stock raising, sidelines and in the places with an equipment of low density of negative ion or high concentration of O 3 components. Besides, the instrument may also be used to treat diseases, to prevent against rot, to arrest bacteria, to purify air and so on

If you negate, you may forget: negated repetitions impair memory compared with affirmative repetitions.

Science.gov (United States)

Mayo, Ruth; Schul, Yaacov; Rosenthal, Meytal

2014-08-01

One of the most robust laws of memory is that repeated activation improves memory. Our study shows that the nature of repetition matters. Specifically, although both negated repetition and affirmative repetition improve memory compared with no repetition, negated repetition hinders memory compared with affirmative repetition. After showing participants different entities, we asked them about features of these entities, leading to either "yes" or "no" responses. Our findings show that correctly negating an incorrect feature of an entity elicits an active forgetting effect compared with correctly affirming its true features. For example, after seeing someone drink a glass of white wine, answering "no" to "was it red wine?" may lead one to greater memory loss of the individual drinking wine at all compared with answering "yes" to "was it white wine?" We find this negation-induced forgetting effect in 4 experiments that differ in (a) the meaning given for the negation, (b) the type of stimuli (visual or verbal), and (c) the memory measure (recognition or free recall). We discuss possible underlying mechanisms and offer theoretical and applied implications of the negation-induced forgetting effect in relation to other known inhibition effects. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Production of rare-earth atomic negative ion beams in a cesium-sputter-type negative ion source

International Nuclear Information System (INIS)

Davis, V.T.; Covington, A.M.; Duvvuri, S.S.; Kraus, R.G.; Emmons, E.D.; Kvale, T.J.; Thompson, J.S.

2007-01-01

The desire to study negative ion structure and negative ion-photon interactions has spurred the development of ion sources for use in research and industry. The many different types of negative ion sources available today differ in their characteristics and abilities to produce anions of various species. Thus the importance of choosing the correct type of negative ion source for a particular research or industrial application is clear. In this study, the results of an investigation on the production of beams composed of negatively-charged rare-earth ions from a cylindrical-cathode-geometry, cesium-sputter-type negative ion source are presented. Beams of atomic anions have been observed for most of the first-row rare-earth elements, with typical currents ranging from hundreds of picoamps to several nanoamps

Zero-truncated negative binomial - Erlang distribution

Science.gov (United States)

Bodhisuwan, Winai; Pudprommarat, Chookait; Bodhisuwan, Rujira; Saothayanun, Luckhana

2017-11-01

The zero-truncated negative binomial-Erlang distribution is introduced. It is developed from negative binomial-Erlang distribution. In this work, the probability mass function is derived and some properties are included. The parameters of the zero-truncated negative binomial-Erlang distribution are estimated by using the maximum likelihood estimation. Finally, the proposed distribution is applied to real data, the number of methamphetamine in the Bangkok, Thailand. Based on the results, it shows that the zero-truncated negative binomial-Erlang distribution provided a better fit than the zero-truncated Poisson, zero-truncated negative binomial, zero-truncated generalized negative-binomial and zero-truncated Poisson-Lindley distributions for this data.

Negative ion sources for tandem accelerator

International Nuclear Information System (INIS)

Minehara, Eisuke

1980-08-01

Four kinds of negative ion sources (direct extraction Duoplasmatron ion source, radial extraction Penniing ion source, lithium charge exchange ion source and Middleton-type sputter ion source) have been installed in the JAERI tandem accelerator. The ion sources can generate many negative ions ranging from Hydrogen to Uranium with the exception of Ne, Ar, Kr, Xe and Rn. Discussions presented in this report include mechanisms of negative ion formation, electron affinity and stability of negative ions, performance of the ion sources and materials used for negative ion production. Finally, the author will discuss difficult problems to be overcome in order to get any negative ion sufficiently. (author)

Some Phenomena on Negative Inversion Constructions

Science.gov (United States)

Sung, Tae-Soo

2013-01-01

We examine the characteristics of NDI (negative degree inversion) and its relation with other inversion phenomena such as SVI (subject-verb inversion) and SAI (subject-auxiliary inversion). The negative element in the NDI construction may be" not," a negative adverbial, or a negative verb. In this respect, NDI has similar licensing…

Experimental Evaluation of a Negative Ion Source for a Heavy Ion Fusion Negative Ion Driver

International Nuclear Information System (INIS)

Grisham, L.R.; Hahto, S.K.; Hahto, S.T.; Kwan, J.W.; Leung, K.N.

2004-01-01

Negative halogen ions have recently been proposed as a possible alternative to positive ions for heavy ion fusion drivers because electron accumulation would not be a problem in the accelerator, and if desired, the beams could be photo-detached to neutrals. To test the ability to make suitable quality beams, an experiment was conducted at Lawrence Berkeley National Laboratory using chlorine in an RF-driven ion source. Without introducing any cesium (which is required to enhance negative ion production in hydrogen ion sources) a negative chlorine current density of 45 mA/cm 2 was obtained under the same conditions that gave 57 45 mA/cm 2 of positive chlorine, suggesting the presence of nearly as many negative ions as positive ions in the plasma near the extraction plane. The negative ion spectrum was 99.5% atomic chlorine ions, with only 0.5% molecular chlorine, and essentially no impurities. Although this experiment did not incorporate the type of electron suppression technology that i s used in negative hydrogen beam extraction, the ratio of co-extracted electrons to Cl - was as low as 7 to 1, many times lower than the ratio of their mobilities, suggesting that few electrons are present in the near-extractor plasma. This, along with the near-equivalence of the positive and negative ion currents, suggests that the plasma in this region was mostly an ion-ion plasma. The negative chlorine current density was relatively insensitive to pressure, and scaled linearly with RF power. If this linear scaling continues to hold at higher RF powers, it should permit current densities of 100 45 mA/cm 2 , sufficient for present heavy ion fusion injector concepts. The effective ion temperatures of the positive and negative ions appeared to be similar and relatively low for a plasma source

Negative chemical ionization mass spectrometry

International Nuclear Information System (INIS)

Smit, A.L.C.

1979-01-01

This thesis describes some aspects of Negative Chemical Ionization (NCI) mass spectrometry. The reasons for the growing interest in NCI are: (i) to extend the basic knowledge of negative ions and their reactions in the gas phase; (ii) to investigate whether or not this knowledge of negative ions can be used successfully to elucidate the structure of molecules by mass spectrometry. (Auth.)

Analyzing negative ties in social networks

Directory of Open Access Journals (Sweden)

Mankirat Kaur

2016-03-01

Full Text Available Online social networks are a source of sharing information and maintaining personal contacts with other people through social interactions and thus forming virtual communities online. Social networks are crowded with positive and negative relations. Positive relations are formed by support, endorsement and friendship and thus, create a network of well-connected users whereas negative relations are a result of opposition, distrust and avoidance creating disconnected networks. Due to increase in illegal activities such as masquerading, conspiring and creating fake profiles on online social networks, exploring and analyzing these negative activities becomes the need of hour. Usually negative ties are treated in same way as positive ties in many theories such as balance theory and blockmodeling analysis. But the standard concepts of social network analysis do not yield same results in respect of each tie. This paper presents a survey on analyzing negative ties in social networks through various types of network analysis techniques that are used for examining ties such as status, centrality and power measures. Due to the difference in characteristics of flow in positive and negative tie networks some of these measures are not applicable on negative ties. This paper also discusses new methods that have been developed specifically for analyzing negative ties such as negative degree, and h∗ measure along with the measures based on mixture of positive and negative ties. The different types of social network analysis approaches have been reviewed and compared to determine the best approach that can appropriately identify the negative ties in online networks. It has been analyzed that only few measures such as Degree and PN centrality are applicable for identifying outsiders in network. For applicability in online networks, the performance of PN measure needs to be verified and further, new measures should be developed based upon negative clique concept.

Congenital visual pathway abnormalities : A window onto cortical stability and plasticity

NARCIS (Netherlands)

Hoffmann, Michael B.; Dumoulin, Serge O.

2015-01-01

Sensory systems project information in a highly organized manner to the brain, where it is preserved in maps of the sensory structures. These sensory projections are altered in congenital abnormalities, such as anophthalmia, albinism, achiasma, and hemihydranencephaly. Consequently, these

A model for negative ion extraction and comparison of negative ion optics calculations to experimental results

International Nuclear Information System (INIS)

Pamela, J.

1990-10-01

Negative ion extraction is described by a model which includes electron diffusion across transverse magnetic fields in the sheath. This model allows a 2-Dimensional approximation of the problem. It is used to introduce electron space charge effects in a 2-D particle trajectory code, designed for negative ion optics calculations. Another physical effect, the stripping of negative ions on neutral gas atoms, has also been included in our model; it is found to play an important role in negative ion optics. The comparison with three sets of experimental data from very different negative ion accelerators, show that our model is able of accurate predictions

Negated bio-events: analysis and identification

Science.gov (United States)

2013-01-01

Background Negation occurs frequently in scientific literature, especially in biomedical literature. It has previously been reported that around 13% of sentences found in biomedical research articles contain negation. Historically, the main motivation for identifying negated events has been to ensure their exclusion from lists of extracted interactions. However, recently, there has been a growing interest in negative results, which has resulted in negation detection being identified as a key challenge in biomedical relation extraction. In this article, we focus on the problem of identifying negated bio-events, given gold standard event annotations. Results We have conducted a detailed analysis of three open access bio-event corpora containing negation information (i.e., GENIA Event, BioInfer and BioNLP’09 ST), and have identified the main types of negated bio-events. We have analysed the key aspects of a machine learning solution to the problem of detecting negated events, including selection of negation cues, feature engineering and the choice of learning algorithm. Combining the best solutions for each aspect of the problem, we propose a novel framework for the identification of negated bio-events. We have evaluated our system on each of the three open access corpora mentioned above. The performance of the system significantly surpasses the best results previously reported on the BioNLP’09 ST corpus, and achieves even better results on the GENIA Event and BioInfer corpora, both of which contain more varied and complex events. Conclusions Recently, in the field of biomedical text mining, the development and enhancement of event-based systems has received significant interest. The ability to identify negated events is a key performance element for these systems. We have conducted the first detailed study on the analysis and identification of negated bio-events. Our proposed framework can be integrated with state-of-the-art event extraction systems. The

Ferroelectric negative capacitance domain dynamics

Science.gov (United States)

Hoffmann, Michael; Khan, Asif Islam; Serrao, Claudy; Lu, Zhongyuan; Salahuddin, Sayeef; Pešić, Milan; Slesazeck, Stefan; Schroeder, Uwe; Mikolajick, Thomas

2018-05-01

Transient negative capacitance effects in epitaxial ferroelectric Pb(Zr0.2Ti0.8)O3 capacitors are investigated with a focus on the dynamical switching behavior governed by domain nucleation and growth. Voltage pulses are applied to a series connection of the ferroelectric capacitor and a resistor to directly measure the ferroelectric negative capacitance during switching. A time-dependent Ginzburg-Landau approach is used to investigate the underlying domain dynamics. The transient negative capacitance is shown to originate from reverse domain nucleation and unrestricted domain growth. However, with the onset of domain coalescence, the capacitance becomes positive again. The persistence of the negative capacitance state is therefore limited by the speed of domain wall motion. By changing the applied electric field, capacitor area or external resistance, this domain wall velocity can be varied predictably over several orders of magnitude. Additionally, detailed insights into the intrinsic material properties of the ferroelectric are obtainable through these measurements. A new method for reliable extraction of the average negative capacitance of the ferroelectric is presented. Furthermore, a simple analytical model is developed, which accurately describes the negative capacitance transient time as a function of the material properties and the experimental boundary conditions.

The oculocerebral syndrome in association with generalised ...

African Journals Online (AJOL)

A 14-year-old girl with generalised hypopigmentation, mental retardation, abnormal movements, and ocular anomalies is described. It is suggested that she represents a further case of oculocerebral albinism, a rare autosomal recessive condition. Reference is made to previous similar cases.

ABCD syndrome is caused by a homozygous mutation in the EDNRB gene

NARCIS (Netherlands)

Verheij, JBGM; Kunze, J; Osinga, J; van Essen, AJ; Hofstra, RMW

2002-01-01

ABCD syndrome is an autosomal recessive syndrome characterized by albinism, black lock, cell migration disorder of the neurocytes of the gut (Hirschsprung disease [HSCR]), and deafness. This phenotype clearly overlaps with the features of the Shah-Waardenburg syndrome, comprising sensorineural

Bioenergetic Defects and Oxidative Damage in Transgenic Mouse Models of Neurodegenerative Disorders

Science.gov (United States)

2005-06-01

perman- ganate, fungicides, and gasoline additives containing manganese (Albin, 2000). The symptom phenotype of manganese toxicity results from the...activity, followed by hypokinesis and locomotor de- chromosome were inserted into the appropriate position in Hdh terioration. Mice die prematurely (24-32

EFFECTS OF MEDICAL DISPUTES ON INTERNET COMMUNICATIONS OF NEGATIVE EMOTIONS AND NEGATIVE ONLINE WORD-OF-MOUTH.

Science.gov (United States)

Lee, Yi-Chih; Wu, Wei-Li

2015-08-01

Emotions play an important role in human behavior. Negative emotions resulting from medical disputes are problems for medical personnel to solve but also have a significant impact on a hospital's reputation and people's trust in the hospital. One medical dispute case was chosen from an Internet news source to assess the correlation between people's negative emotions and negative online word-of-mouth. Convenience sampling was used in school faculties and university students who had shared their medical treatment experiences online were the research participants. A total of 221 Taiwanese participants volunteered (158 women, 63 men; ages: 26.7% under 19, 22.6% 20-29, 30.8% 30-39,19.9% over 40). Four negative emotions were measured using rating scales: uncertainty, anger, disappointment, and sadness. Four negative online word-of-mouth measures were: venting, advice search, helping receiver, and revenge. A modeled relationship was assessed by partial least square method (PLS). Then, people's positive emotions were further analyzed to assess changes after spreading negative word-of-mouth. The results showed that uncertainty had a positive effect on venting and advice search. People who felt anger or regret spread word-of-mouth in order to help the receiver. Disappointment may trigger the revenge behavior of negative word-of-mouth. Negative emotions could be relieved after engaging in the behavior of helping the receiver.

Physics of negative refractive index materials

International Nuclear Information System (INIS)

Ramakrishna, S Anantha

2005-01-01

In the past few years, new developments in structured electromagnetic materials have given rise to negative refractive index materials which have both negative dielectric permittivity and negative magnetic permeability in some frequency ranges. The idea of a negative refractive index opens up new conceptual frontiers in photonics. One much-debated example is the concept of a perfect lens that enables imaging with sub-wavelength image resolution. Here we review the fundamental concepts and ideas of negative refractive index materials. First we present the ideas of structured materials or meta-materials that enable the design of new materials with a negative dielectric permittivity, negative magnetic permeability and negative refractive index. We discuss how a variety of resonance phenomena can be utilized to obtain these materials in various frequency ranges over the electromagnetic spectrum. The choice of the wave-vector in negative refractive index materials and the issues of dispersion, causality and energy transport are analysed. Various issues of wave propagation including nonlinear effects and surface modes in negative refractive materials (NRMs) are discussed. In the latter part of the review, we discuss the concept of a perfect lens consisting of a slab of a NRM. This perfect lens can image the far-field radiative components as well as the near-field evanescent components, and is not subject to the traditional diffraction limit. Different aspects of this lens such as the surface modes acting as the mechanism for the imaging of the evanescent waves, the limitations imposed by dissipation and dispersion in the negative refractive media, the generalization of this lens to optically complementary media and the possibility of magnification of the near-field images are discussed. Recent experimental developments verifying these ideas are briefly covered

Electrochemical cell and negative electrode therefor

Science.gov (United States)

Kaun, Thomas D.

1982-01-01

A secondary electrochemical cell with the positive and negative electrodes separated by a molten salt electrolyte with the negative electrode comprising a particulate mixture of lithium-aluminum alloy and electrolyte and an additive selected from graphitized carbon, Raney iron or mixtures thereof. The lithium-aluminum alloy is present in the range of from about 45 to about 80 percent by volume of the negative electrode, and the electrolyte is present in an amount not less than about 10 percent by volume of the negative electrode. The additive of graphitized carbon is present in the range of from about 1 to about 10 percent by volume of the negative electrode, and the Raney iron additive is present in the range of from about 3 to about 10 percent by volume of the negative electrode.

Genetics Home Reference: ocular albinism

Science.gov (United States)

... structures that produce and store a pigment called melanin. Melanin is the substance that gives skin, hair, and ... Accessibility FOIA Viewers & Players U.S. Department of Health & Human Services National Institutes of Health National Library of ...

Negative cognitive errors and positive illusions for negative divorce events: predictors of children's psychological adjustment.

Science.gov (United States)

Mazur, E; Wolchik, S A; Sandler, I N

1992-12-01

This study examined the relations among negative cognitive errors regarding hypothetical negative divorce events, positive illusions about those same events, actual divorce events, and psychological adjustment in 38 8- to 12-year-old children whose parents had divorced within the previous 2 years. Children's scores on a scale of negative cognitive errors (catastrophizing, overgeneralizing, and personalizing) correlated significantly with self-reported symptoms of anxiety and self-esteem, and with maternal reports of behavior problems. Children's scores on a scale measuring positive illusions (high self-regard, illusion of personal control, and optimism for the future) correlated significantly with less self-reported aggression. Both appraisal types accounted for variance in some measures of symptomatology beyond that explained by actual events. There was no significant association between children's negative cognitive errors and positive illusions. The implications of these results for theories of negative cognitive errors and of positive illusions, as well as for future research, are discussed.

Discrepant HPV/cytology cotesting results: Are there differences between cytology-negative versus HPV-negative cervical intraepithelial neoplasia?

Science.gov (United States)

Tracht, Jessica M; Davis, Antoinette D; Fasciano, Danielle N; Eltoum, Isam-Eldin A

2017-10-01

The objective of this study was to compare cervical high-grade squamous intraepithelial lesions subcategorized as cervical intraepithelial neoplasia-3 (CIN-3)-positive after a negative cytology result but positive for high-risk human papillomavirus (HR-HPV) testing to those with a negative HR-HPV test but positive cytology (atypical squamous cells of undetermined significance [ASCUS]-positive/HPV-negative) and to assess reasons for discrepancies. The authors retrospectively analyzed women who underwent screening with cytology and HPV testing from 2010 through 2013. After a review of surgical specimens and cytology, discrepancies were classified as sampling or interpretation error. Clinical and pathologic findings were compared. In total, 15,173 women (age range, 25-95 years; 7.1% were aged ASCUS-positive/HPV-positive, 11 that tested negative for intraepithelial lesion or malignancy (NILM)/HPV-positive, 10 that tested ASCUS-positive/HPV-negative, 3 that tested NILM/HPV-negative, and 5 tests that were unsatisfactory. There was no significant difference between NILM/HPV-positive and ASCUS-positive/HPV-negative CIN-3 in terms of size, time to occurrence, the presence of a cytopathic effect, screening history, race, or age. Six of 11 NILM/HPV-positive cases were reclassified as ASCUS, indicating an interpreting error of 55% and a sampling error of 45%. No ASCUS-positive/HPV-negative cases were reclassified. Seven cases of CIN-3 with positive cytology were HPV-negative. There are no significant clinical or pathologic differences between NILM/HPV-positive and ASCUS-positive/HPV-negative CIN-3-positive specimens. Cytologic sampling or interpretation remains the main reason for discrepancies. However, HPV-negative CIN-3 with positive cytology exists and may be missed by primary HPV screening. Cancer Cytopathol 2017;125:795-805. © 2017 American Cancer Society. © 2017 American Cancer Society.

Negative HPV screening test predicts low cervical cancer risk better than negative Pap test

Science.gov (United States)

Based on a study that included more than 1 million women, investigators at NCI have determined that a negative test for HPV infection compared to a negative Pap test provides greater safety, or assurance, against future risk of cervical cancer.

Recent negative ion source developments

International Nuclear Information System (INIS)

Alton, G.D.

1978-01-01

This report describes recent results obtained from studies associated with the development of negative ion sources which utilize sputtering in a diffuse cesium plasma as a means of ion beam generation. Data are presented which relate negative ion yield and important operational parameters such as cesium oven temperature and sputter probe voltage from each of the following sources: (1) A source based in principle according to the University of Aarhus design and (2) an axial geometry source. The important design aspects of the sources are given--along with a list of the negative ion intensities observed to date. Also a qualitative description and interpretation of the negative ion generation mechanism in sources which utilize sputtering in the presence of cesium is given

On Various Negative Translations

Directory of Open Access Journals (Sweden)

Gilda Ferreira

2011-01-01

Full Text Available Several proof translations of classical mathematics into intuitionistic mathematics have been proposed in the literature over the past century. These are normally referred to as negative translations or double-negation translations. Among those, the most commonly cited are translations due to Kolmogorov, Godel, Gentzen, Kuroda and Krivine (in chronological order. In this paper we propose a framework for explaining how these different translations are related to each other. More precisely, we define a notion of a (modular simplification starting from Kolmogorov translation, which leads to a partial order between different negative translations. In this derived ordering, Kuroda and Krivine are minimal elements. Two new minimal translations are introduced, with Godel and Gentzen translations sitting in between Kolmogorov and one of these new translations.

Proteomic analysis of young leaves at three developmental stages in an albino tea cultivar

Directory of Open Access Journals (Sweden)

Li Juan

2011-08-01

Full Text Available Abstract Background White leaf No.1 is a typical albino tea cultivar grown in China and it has received increased attention in recent years due to the fact that white leaves containing a high level of amino acids, which are very important components affecting the quality of tea drink. According to the color of its leaves, the development of this tea cultivar is divided into three stages: the pre-albinistic stage, the albinistic stage and the regreening stage. To understand the intricate mechanism of periodic albinism, a comparative proteomic approach based on two-dimensional electrophoresis (2-DE and mass spectrometry was adopted first time to identify proteins that changed in abundance during the three developmental periods. Results The 2-DE results showed that the expression level of 61 protein spots varied markedly during the three developmental stages. To analyze the functions of the significantly differentially expressed protein spots, 30 spots were excised from gels and analyzed by matrix-assisted laser desorption ionization-time of flight-tandem mass spectrometry. Of these, 26 spots were successfully identified. All identified protein spots were involved in metabolism of carbon, nitrogen and sulfur, photosynthesis, protein processing, stress defense and RNA processing, indicating these physiological processes may play crucial roles in the periodic albinism. Quantitative real-time RT-PCR analysis was used to assess the transcriptional level of differentially expressed proteins. In addition, the ultrastructural studies revealed that the etioplast-chloroplast transition in the leaf cell of White leaf No. 1 was inhibited and the grana in the chloroplast was destroyed at the albinistic stage. Conclusions In this work, the proteomic analysis revealed that some proteins may have important roles in the molecular events involved in periodic albinism of White leaf No. 1 and identificated many attractive candidates for further investigation. In

Takayasu's arteritis: A rare cause of cardiac death in a Caucasian teenage female patient

NARCIS (Netherlands)

S.A.M. Saïd (Salah); J.C. Koetsveld-Baart (J.); J.C. den Hollander (Jan)

1997-01-01

textabstractA Caucasian teenage Dutch schoolgirl with known chronic low visual acuity and albinism, presented with frank acute pulmonary oedema, died after 1 h of cardio-pulmonary resuscitation for bradyarrhythmia and cardiac arrest. Two weeks prior to presentation, during sport training, she

Clinical presentation of Griscelli syndrome type 2 and spectrum of RAB27A mutations

DEFF Research Database (Denmark)

Meeths, Marie; Bryceson, Yenan T; Rudd, Eva

2010-01-01

Griscelli syndrome type 2 (GS2) is an autosomal-recessive immunodeficiency caused by mutations in RAB27A, clinically characterized by partial albinism and haemophagocytic lymphohistocytosis (HLH). We evaluated the frequency of RAB27A mutations in 21 unrelated patients with haemophagocytic syndromes...

Negative creep in nickel base superalloys

DEFF Research Database (Denmark)

Dahl, Kristian Vinter; Hald, John

2004-01-01

Negative creep describes the time dependent contraction of a material as opposed to the elongation seen for a material experiencing normal creep behavior. Negative creep occurs because of solid state transformations that results in lattice contractions. For most applications negative creep will h...

A longitudinal mediation analysis of the effect of negative-self-schemas on positive symptoms via negative affect.

Science.gov (United States)

Jaya, E S; Ascone, L; Lincoln, T M

2018-06-01

Cognitive models postulate that negative-self-schemas (NSS) cause and maintain positive symptoms and that negative affect mediates this link. However, only few studies have tested the temporal mediation claim systematically using an appropriate design. A longitudinal cohort design in an online community sample (N = 962) from Germany, Indonesia, and the USA was used. NSS, negative affect and positive symptoms were measured at four time-points (T0-T3) over a 1-year period. Cross-lagged panel and longitudinal mediation analyses with structural equation modeling were used to test the temporal mediation. Independent cross-lagged panel models showed a significant unidirectional longitudinal path from NSS to positive symptoms (T2-T3, β = 0.18, p negative affect (T0-T1, γ = 0.14, p negative affect at T1 and T2 to positive symptoms at T3 (unstandardized indirect effect coefficient = 0.020, p affective pathway from NSS to positive symptoms via negative affect. Specifically, our data indicate that NSS and negative affect influence each other and build up over the course of several months before leading on to positive symptoms. We conclude that interrupting this process by targeting NSS and negative affect early in the process could be a promising strategy to prevent the exacerbation of positive symptoms.

Wages, Amenities and Negative Attitudes

DEFF Research Database (Denmark)

Waisman, Gisela; Larsen, Birthe

We exploit the regional variation in negative attitudes towards immigrants to Sweden in order to analyse the consequences of the attitudes on immigrants welfare. We find that attitudes towards immigrants are of importance: they both affect their labour market outcomes and their quality of life. We...... interpret the negative effect on wages as evidence of labour market discrimination. We estimate the welfare effects of negative attitudes, through their wage and local amenities, for immigrants with different levels of skills, origin, gender and age....

Negative Life Events and Antenatal Depression among Pregnant Women in Rural China: The Role of Negative Automatic Thoughts.

Science.gov (United States)

Wang, Yang; Wang, Xiaohua; Liu, Fangnan; Jiang, Xiaoning; Xiao, Yun; Dong, Xuehan; Kong, Xianglei; Yang, Xuemei; Tian, Donghua; Qu, Zhiyong

2016-01-01

Few studies have looked at the relationship between psychological and the mental health status of pregnant women in rural China. The current study aims to explore the potential mediating effect of negative automatic thoughts between negative life events and antenatal depression. Data were collected in June 2012 and October 2012. 495 rural pregnant women were interviewed. Depressive symptoms were measured by the Edinburgh postnatal depression scale, stresses of pregnancy were measured by the pregnancy pressure scale, negative automatic thoughts were measured by the automatic thoughts questionnaire, and negative life events were measured by the life events scale for pregnant women. We used logistic regression and path analysis to test the mediating effect. The prevalence of antenatal depression was 13.7%. In the logistic regression, the only socio-demographic and health behavior factor significantly related to antenatal depression was sleep quality. Negative life events were not associated with depression in the fully adjusted model. Path analysis showed that the eventual direct and general effects of negative automatic thoughts were 0.39 and 0.51, which were larger than the effects of negative life events. This study suggested that there was a potentially significant mediating effect of negative automatic thoughts. Pregnant women who had lower scores of negative automatic thoughts were more likely to suffer less from negative life events which might lead to antenatal depression.

Positive versus negative priming of older adults' generative value: do negative messages impair memory?

Science.gov (United States)

Hagood, Elizabeth W; Gruenewald, Tara L

2018-02-01

A considerable volume of experimental evidence demonstrates that exposure to aging stereotypes can strongly influence cognitive performance among older individuals. However, whether such effects extend to stereotypes regarding older adults' generative (i.e. contributory) worth is not yet known. The present investigation sought to evaluate the effect of exposure to positive versus negative generative value primes on an important aspect of later life functioning, memory. Participants of age 55 and older (n = 51) were randomly assigned to read a mock news article portraying older individuals as either an asset (positive prime) or a burden (negative prime) to society. Upon reading their assigned article, participants completed a post-priming memory assessment in which they were asked to recall a list of 30 words. Those exposed to the negative prime showed significantly poorer memory performance relative to those exposed to the positive prime (d = 0.75), even when controlling for baseline memory performance and sociodemographic covariates. These findings suggest that negative messages regarding older adults' generative social value impair memory relative to positive ones. Though demonstrated in the short term, these results also point to the potential consequences of long-term exposure to such negative ideologies and may indicate a need to promote more positive societal conceptualizations of older adults' generative worth.

Negative Ions in low pressure discharges

NARCIS (Netherlands)

Stoffels - Adamowicz, E.; Stoffels, W.W.; Vender, D.; Haverlag, M.; Kroesen, G.M.W.; Hoog, de F.J.

1995-01-01

Several aspects of negative ions in low pressure discharges are treated. The elementary processes, in which negative ions are produced and destroyed, are summarized. The influence of negative ions on plasma operation is analyzed in terms of transport equations. It is shown that diffusion, electric

Ice nucleation triggered by negative pressure.

Science.gov (United States)

Marcolli, Claudia

2017-11-30

Homogeneous ice nucleation needs supercooling of more than 35 K to become effective. When pressure is applied to water, the melting and the freezing points both decrease. Conversely, melting and freezing temperatures increase under negative pressure, i.e. when water is stretched. This study presents an extrapolation of homogeneous ice nucleation temperatures from positive to negative pressures as a basis for further exploration of ice nucleation under negative pressure. It predicts that increasing negative pressure at temperatures below about 262 K eventually results in homogeneous ice nucleation while at warmer temperature homogeneous cavitation, i. e. bubble nucleation, dominates. Negative pressure occurs locally and briefly when water is stretched due to mechanical shock, sonic waves, or fragmentation. The occurrence of such transient negative pressure should suffice to trigger homogeneous ice nucleation at large supercooling in the absence of ice-nucleating surfaces. In addition, negative pressure can act together with ice-inducing surfaces to enhance their intrinsic ice nucleation efficiency. Dynamic ice nucleation can be used to improve properties and uniformity of frozen products by applying ultrasonic fields and might also be relevant for the freezing of large drops in rainclouds.

On the lack of stranded negated quantifiers and inverse scope of negation in Romance

NARCIS (Netherlands)

Cirillo, R.

2013-01-01

The Germanic languages allow floating negated quantifiers (The children have not all not eaten) while the Romance languages do not. The Germanic languages also allow negation to take inverse scope over a universal quantifier (All the children have not eaten) whereas the Romance languages are very

Toward the next generation of negative symptom assessments: the collaboration to advance negative symptom assessment in schizophrenia.

Science.gov (United States)

Blanchard, Jack J; Kring, Ann M; Horan, William P; Gur, Raquel

2011-03-01

Negative symptoms in schizophrenia are related to poor functional outcome, persistent over time, a source of burden for caregivers, and only minimally responsive to currently available medications. A major challenge to developing efficacious interventions concerns the valid and reliable assessment of negative symptoms. In a recent consensus statement on negative symptoms, a central recommendation was the need to develop new assessment approaches that address the limitations of existing instruments. In the current report, we summarize the background and rationale for the Collaboration to Advance Negative Symptom Assessment in Schizophrenia (CANSAS). The CANSAS project is an National Institute of Mental Health-funded multisite study that is constructing a next-generation negative symptom scale, the Clinical Assessment Interview for Negative Symptoms (CAINS). The CAINS is being developed within a data-driven iterative process that seeks to ensure the measure's reliability, validity, and utility for both basic psychopathology and treatment development research.

Formation of hydrogen negative ions by surface and volume processes with application to negative ion sources

International Nuclear Information System (INIS)

Hiskes, J.R.

1979-01-01

During the last few decades interest in negative-hydrogen ion sources has been directed mainly toward synchrotron and other particle accelerator applications, with emphasis on high current densities delivered for short pulses. But within the last several years there has been an awareness in the magnetic fusion program of the future need for negative ions as a means for generating high energy neutral beams, beams with energies above a few hundred keV. Negative ions seem to be the only effective intermediary for efficiently producing such beams. Although methods for generating negative ion beams have relied upon synchrotron concepts, the requirements for fusion are very different: here one is interested in more moderate current densities, up to 100 m A cm -2 , but with continuous operation. Proposed source modules would accelerate of the order of 10 A of beam current and deliver several megawatts of beam power. Both H - and D - beams are being considered for application in different reactor systems. The conceptualization of negative ion sources is now in a very volatile stage. But of the great variety of proposals that have been offered to date, three general areas appear ready for development. These are: first, the double charge exchange method for converting a positive ion beam into a negative ion beam; second, electron-volume processes wherein low energy electrons interacting with molecular species lead to negative ion products via dissociative attachment or recombination; and third, generation of negative ions in surface interactions, principally via desorption and backscattering. Both our qualitative and our quantitative understanding of these processes diminishes as one proceeds from the first through the third. The physics of these three methods is considered in detail

A CLDN1-negative phenotype predicts poor prognosis in triple-negative breast cancer.

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Fei Ma

Full Text Available INTRODUCTION: Triple-negative breast cancer (TNBC is a heterogeneous disease with no definitive prognostic markers. As a major component of tight junctions, claudins (CLDNs presumably play an important role in carcinogenesis and progression of breast cancer. This study was aimed at determining the relationship between the expression of CLDNs and the clinical outcomes of TNBCs. MATERIALS AND METHODS: The surgical specimens of primary breast tumors from a consecutive cohort of 173 TNBC patients were retrospectively collected. The membranous expression of CLDN1, CLDN2, CLDN4, and CLDN7 was measured by immunohistochemistry. Then, the associations between CLDN expression, clinicopathological features, and clinical outcomes were assessed. RESULTS: Positive CLDN1, CLDN2, CLDN4, and CLDN7 membrane expression was detected in 44.5%, 54.9%, 76.9%, and 73.4% of the cohort specimens, respectively. A lack of CLDN1 expression was related to only lymph node metastasis (P = 0.014. The rate of CLDN4-positive tumors was significantly increased in tumors of a higher grade (P = 0.003. Importantly, negative CLDN1 expression was associated with worse relapse-free survival (RFS in both lymph node positive (LN+ and negative (LN- cases (both P<0.001. Similarly it was also associated with shorter overall survival (OS(P = 0.003 in LN+ cases; P = 0.018 in LN- cases. In the LN+ subgroup, CLDN2-negative cases had a significantly higher risk of recurrence (P = 0.008. Multivariate analysis revealed that negative CLDN1 expression was an independent prognostic factor for high risk of both recurrence and death (HR 5.529, 95% CI 2.664-11.475, P<0.001; HR 3.459, 95% CI 1.555-7.696, P = 0.002. However, neither CLDN4 nor CLDN7 expression was associated with survival. CONCLUSION: In TNBC, the CLDN1-negative phenotype predicts a high risk of recurrence and death. The absence of CLDN1 expression is strongly suggested to be an independent adverse prognostic factor

Ocular Surface Squamous Neoplasia in Xeroderma Pigmentosum

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Rajesh R Nayak

2013-11-01

Full Text Available Xeroderma pigmentosum (XP is a rare genetic disorder associated with multiple oculocutaneous and neurological manifestations. It occurs due to deficiency of the enzymes responsible for repairing ultraviolet radiation-induced DNA damage. Persistence of un-repaired DNA results in somatic mutations, leading to neoplasia of the skin and ocular surface. As this condition is rare, only isolated case reports of XP with ocular surface squamous neoplasia (OSSN are found in literature.

Negative Certainty

Science.gov (United States)

Ariso, José María

2017-01-01

The definitions of "negative knowledge" and the studies in this regard published to date have not considered the categorial distinction Wittgenstein established between knowledge and certainty. Hence, the important role that certainty, despite its omission, should have in these definitions and studies has not yet been shown. In this…

Negative permeability from random particle composites

Energy Technology Data Exchange (ETDEWEB)

Hussain, Shahid, E-mail: shussain2@qinetiq.com

2017-04-15

Artificial media, such as those composed of periodically-spaced wires for negative permittivity and split ring resonators for negative permeability have been extensively investigated for negative refractive index (NRI) applications (Smith et al., 2004; Pendry et al., 1999) [1,2]. This paper presents an alternative method for producing negative permeability: granular (or particulate) composites incorporating magnetic fillers. Artificial media, such as split-ring resonators, are designed to produce a magnetic resonance feature, which results in negative permeability over a narrow frequency range about the resonance frequency. The position of the feature is dependent upon the size of the inclusion. The material in this case is anisotropic, such that the feature is only observable when the materials are orientated in a specific direction relative to the applied field. A similar resonance can be generated in magnetic granular (particulate) materials: ferromagnetic resonance from the natural spin resonance of particles. Although the theoretical resonance profiles in granular composites shows the permeability dipping to negative values, this is rarely observed experimentally due to resonance damping effects. Results are presented for iron in spherical form and in flake form, dispersed in insulating host matrices. The two particle shapes show different permeability performance, with the magnetic flakes producing a negative contribution. This is attributed to the stronger coupling with the magnetic field resulting from the high aspect ratio of the flakes. The accompanying ferromagnetic resonance is strong enough to overcome the effects of damping and produce negative permeability. The size of random particle composites is not dictated by the wavelength of the applied field, so the materials are potentially much thinner than other, more traditional artificial composites at microwave frequencies. - Highlights: • Negative permeability from random particle composites is

Negative Mood Increases Selective Attention to Negatively Valenced Body Parts in Female Adolescents with Anorexia Nervosa.

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Jennifer Svaldi

Full Text Available Previous research has yielded evidence of increased attentional processing of negatively valenced body parts in women with anorexia nervosa (AN, especially for those with high depressive symptomatology. The present study extended previous research by implementing an experimental mood manipulation.In a within-subjects design, female adolescents with AN (n = 12 and an age matched female control group (CG; n = 12 were given a negative and a positive mood induction at a one-week interval. After each mood induction, participants underwent a 3-min mirror exposure, while their eye movements were recorded.After the positive mood induction, both AN and CG participants displayed longer and more frequent gazes towards their self-defined most ugly relative to their self-defined most beautiful body part. However, after the negative mood induction, only females with AN were characterized by increased attention to their most ugly compared to their most beautiful body part, while CG participants' attention distribution was balanced. Furthermore, in the negative (but not in the positive mood induction condition gaze frequency and duration towards the most ugly body part was significantly stronger in the AN group relative to the CG.The results emphasize the role of negative mood in the maintenance of pathological information processing of the self-body. This increased body-related negativity-bias during negative mood may lead to the persistence and aggravation of AN patients' body image disturbance.

Eesti munitsipaalpolitsei Lääne taustal / Allan Alaküla

Index Scriptorium Estoniae

Alaküla, Allan, 1968-

2002-01-01

Ilmunud ka: Stolitsa 5. dets. lk. 1. Riigikogu liikmete ja Euroopa politsei- ja omavalitsustegelaste arvamused munitsipaalpolitseist: Jaanus Männik, Keith Whitmore, Peter Shorer, Mai Treial, Michel Albin, Jaana Padrik, Jean Louis Renier, Eva Dohnalova, Calin Catalin Chirita, Aleksei Aleksandrov, Mohammad Nazir, Arvo Sirendi. Parlamendisaadik

Albinistic common seals (Phoca vitulina) and melanistic grey seals (Halichoerus grypus) rehabilitated in the Netherlands

NARCIS (Netherlands)

Osinga, Nynke; 't Hart, Pieter; Vader, Pieter C. van Voorst

2010-01-01

The Seal Rehabilitation and Research Centre (SRRC) in Pieterburen, The Netherlands, rehabilitates seals from the waters of the Wadden Sea, North Sea and Southwest Delta area. Incidental observations of albinism and melanism in common and grey seals are known from countries surrounding the North Sea.

Hyperbolic spaces are of strictly negative type

DEFF Research Database (Denmark)

Hjorth, Poul G.; Kokkendorff, Simon L.; Markvorsen, Steen

2002-01-01

We study finite metric spaces with elements picked from, and distances consistent with, ambient Riemannian manifolds. The concepts of negative type and strictly negative type are reviewed, and the conjecture that hyperbolic spaces are of strictly negative type is settled, in the affirmative....... The technique of the proof is subsequently applied to show that every compact manifold of negative type must have trivial fundamental group, and to obtain a necessary criterion for product manifolds to be of negative type....

Negative CO

NARCIS (Netherlands)

Meysman, F.J.R.; Montserrat, F.

2017-01-01

Negative emission technologies (NETs) target the removal of carbon dioxide (CO₂) from the atmosphere, and are being actively investigated as a strategy to limit global warming to within the 1.5–2°C targets of the 2015 UN climate agreement. Enhanced silicate weathering (ESW) proposes to

Dualising Intuitionictic Negation

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Graham Priest

2009-01-01

Full Text Available One of Da Costa's motives when he constructed the paraconsistent logic Cw was to dualise the negation of intuitionistic logic. In this paper I explore a different way of going about this task. A logic is defined by taking the Kripke semantics for intuitionistic logic, and dualising the truth conditions for negation. Various properties of the logic are established, including its relation to CWo Tableau and natural deduction systems for the logic are produced, as are appropriate algebraic structures. The paper then investigates dualising the intuitionistic conditional in the same way. This establishes various connections between the logic, and a logic called in the literature 'Brouwerian logic' or 'closed-set logic'.

Dualising Intuitionistic Negation

Directory of Open Access Journals (Sweden)

Graham Priest

2009-08-01

Full Text Available One of Da Costa’s motives when he constructed the paraconsistent logic C! was to dualise the negation of intuitionistic logic. In this paper I explore a different way of going about this task. A logic is defined by taking the Kripke semantics for intuitionistic logic, and dualising the truth conditions for negation. Various properties of the logic are established, including its relation to C!. Tableau and natural deduction systems for the logic are produced, as are appropriate algebraic structures. The paper then investigates dualising the intuitionistic conditional in the same way. This establishes various connections between the logic, and a logic called in the literature ‘Brouwerian logic’ or ‘closed-set logic’.

Affective reactions and context-dependent processing of negations

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Enrico Rubaltelli

2008-12-01

Full Text Available Three experiments demonstrate how the processing of negations is contingent on the evaluation context in which the negative information is presented. In addition, the strategy used to process the negations induced different affective reactions toward the stimuli, leading to inconsistency of preference. Participants were presented with stimuli described by either stating the presence of positive features (explicitly positive alternative or negating the presence of negative features (non-negative alternative. Alternatives were presented for either joint (JE or separate evaluation (SE. Experiment 1 showed that the non-negative stimuli were judged less attractive than the positive ones in JE but not in SE. Experiment 2 revealed that the non-negative stimuli induced a less clear and less positive feeling when they were paired with explicitly positive stimuli rather than evaluated separately. Non-negative options were also found less easy to judge than the positive ones in JE but not in SE. Finally, Experiment 3 showed that people process negations using two different models depending on the evaluation mode. Through a memory task, we found that in JE people process the non-negative attributes as negations of negative features, whereas in SE they directly process the non-negative attributes as positive features.

Non-negative Matrix Factorization for Binary Data

DEFF Research Database (Denmark)

Larsen, Jacob Søgaard; Clemmensen, Line Katrine Harder

We propose the Logistic Non-negative Matrix Factorization for decomposition of binary data. Binary data are frequently generated in e.g. text analysis, sensory data, market basket data etc. A common method for analysing non-negative data is the Non-negative Matrix Factorization, though...... this is in theory not appropriate for binary data, and thus we propose a novel Non-negative Matrix Factorization based on the logistic link function. Furthermore we generalize the method to handle missing data. The formulation of the method is compared to a previously proposed method (Tome et al., 2015). We compare...... the performance of the Logistic Non-negative Matrix Factorization to Least Squares Non-negative Matrix Factorization and Kullback-Leibler (KL) Non-negative Matrix Factorization on sets of binary data: a synthetic dataset, a set of student comments on their professors collected in a binary term-document matrix...

Negative Attitudes, Network and Education

DEFF Research Database (Denmark)

Bennett, Patrick; la Cour, Lisbeth; Larsen, Birthe

, the impact of negative attitudes and networking taking into account that these parameters may influence high and uneducated workers as well as immigrants and natives differently, creating different incentives to acquire education for the two ethnic groups. Using rich Danish administrative data, this paper......This paper explores potential explanations behind the educational gap between young natives and immigrants using two measures, negative attitudes towards immigrants and networking, which may influence natives and immigrants differently. The paper considers, both theoretically and empirically...... finds evidence that greater negative attitudes increase incentives for males to acquire education and that networking also increases immigrant education....

Negative incidental emotions augment fairness sensitivity.

Science.gov (United States)

Liu, Cuizhen; Chai, Jing Wen; Yu, Rongjun

2016-04-22

Previous studies have shown that task-unrelated emotions induced incidentally exert carryover effects on individuals' subsequent decisions in financial negotiations. However, the specificity of these emotion effects are not clear. In three experiments, we systematically investigated the role of seven transiently induced basic emotions (disgust, sadness, anger, fear, happiness, surprise and neutral) on rejection of unfair offers using the ultimatum game. We found that all negative emotions (disgust, sadness, anger and fear), but not happiness or surprise, significantly increased rejection rates, suggesting that the effect of incidental negative emotions on fairness is not specific to the type of negative emotion. Our findings highlight the role of fleeting emotions in biasing decision-making processes and suggest that all incidental negative emotions exert similar effects on fairness sensitivity, possibly by potentiating attention towards negative aspects of the situation.

Clinical Manifestations of Helicobacter pylori-Negative Gastritis.

Science.gov (United States)

Shiota, Seiji; Thrift, Aaron P; Green, Linda; Shah, Rajesh; Verstovsek, Gordana; Rugge, Massimo; Graham, David Y; El-Serag, Hashem B

2017-07-01

There are data to suggest the existence of non-Helicobacter pylori gastritis. However, the risk factors and clinical course for H pylori-negative gastritis remain unclear. We aimed to examine the prevalence and determinants of H pylori-negative gastritis in a large multiethnic clinical population. We conducted a cross-sectional study among patents scheduled for an elective esophagastroduodenoscopy or attending selected primary care clinics and eligible for screening colonoscopy at a single Veterans Affairs medical center. We identified cases of H pylor-negative gastritis, H pylori-positive gastritis, and H pylori-negative nongastritis, where gastritis was defined by the presence of neutrophils and/or mononuclear cells. Risk factors for H pylori-negative gastritis were analyzed in logistic regression models. A total of 1240 patients had information from all biopsy sites, of whom 695 (56.0%) had gastritis. H pylori-negative gastritis was present in 123 patients (9.9% of all study subjects and 17.7% of all patients with gastritis). Among all patients with gastritis, African Americans were statistically significantly less likely than non-Hispanic whites to have H pylori-negative gastritis (odds ratio, 0.25; 95% confidence interval, 0.14-0.43). Conversely, PPI users were more likely to have H pylori-negative gastritis than H pylori-positive gastritis compared with nonusers (odds ratio, 2.02; 95% confidence interval, 1.17-3.49). The cumulative incidence of gastric erosions and ulcers were higher in patients with H pylori-negative gastritis than H pylori-negative nongastritis. We found that H pylori-negative gastritis was present in approximately 18% of patients with gastritis. The potential for H pylori-negative gastritis to progress or the risk of gastric cancer of those with gastric mucosal atrophy/intestinal metaplasia remains unclear. Copyright © 2017 AGA Institute. Published by Elsevier Inc. All rights reserved.

[Stress and attitudes toward negative emotions in adolescence].

Science.gov (United States)

Ozawa, Eiji

2010-12-01

This study investigated the relationship between stress and attitudes toward negative emotions in adolescents. Adolescent students (N=1500) completed a questionnaire that measured attitudes toward negative emotions, emotional-stress reactions, and stress coping. Analysis of date yielded, two factors of the attitudes toward negative emotions: "Negative feelings about negative emotions" and "Capabilities of switching of negative emotions". In order to examine the theoretical relationships among attitudes toward negative emotions, emotional-stress reactions, and stress coping, a hypothetical model was tested by covariance structure analysis. This model predicted that students who have a high level of attitudes toward negative emotions would report enhanced problem solving which promoted stress coping. The results indicated that "Negative feelings about negative emotions" enhanced avoidable coping, and avoidable coping enhanced stress reactions. "Capabilities of switching of negative emotions" was related to a decrease of avoidable coping. Based on the results from covariance structure analysis and a multiple population analysis, the clinical significance and developmental characteristics were discussed.

Constraints on negative-energy fluxes

International Nuclear Information System (INIS)

Ford, L.H.

1991-01-01

Locally negative energy due to quantum coherence effects in quantum field theory is discussed. In a previous work, it was argued that a beam carrying negative energy must satisfy an uncertainty-principle-type inequality of the form |ΔE|Δt≤1, where |ΔE| is the magnitude of the negative energy that may be transmitted in a time Δt. This conclusion applied only to two-dimensional spacetime, and was based on an examination of particular classes of quantum states. In the present work, we give more precise formulations of this type of inequality for a free massless scalar field in both two- and four-dimensional flat spacetime. These inequalities are proven to hold for all quantum states. The physical interpretation of these inequalities is also discussed, and it is argued that they are likely to prevent negative energy from producing such large-scale effects as violations of the second law of thermodynamics or of cosmic censorship

Negative brain scintigrams in brain tumors

International Nuclear Information System (INIS)

Dalke, K.G.

1978-01-01

With 53 histologically verified and 2 histologically not identified brain tumors, that showed a negative scintigram, it was tried to find reasons for the wrong and negative dropout of these scintigrams. The electroencephalograms and angiograms, that were made simultaneously were taken into consideration with respect to their propositional capability and were compared with the scintigram findings. For the formation of the negative brain scintigrams there could be found no unique cause or causal constellation. The scintigraphic tumor representation is likely based on a complex process. Therefore the reasons for the negativity of the brain scintigrams can be a manifold of causes. An important role plays the vascularisation of the tumor, but not in a sole way. As well the tumor localisation gains some importance; especially in the temporal lobe or in the deeper structures situated tumors can be negative in the scintigram. To hold down the rate of wrong-negative quote in the case of intracranial tumor search, one is advised to continue with an further exposure after 2 to 4 hours besides the usual exposures, unless a sequential scintigraphy was made from the beginning. (orig./MG) [de

Unimode metamaterials exhibiting negative linear compressibility and negative thermal expansion

International Nuclear Information System (INIS)

Dudek, Krzysztof K; Attard, Daphne; Caruana-Gauci, Roberto; Grima, Joseph N; Wojciechowski, Krzysztof W

2016-01-01

Unimode metamaterials made from rotating rigid triangles are analysed mathematically for their mechanical and thermal expansion properties. It is shown that these unimode systems exhibit positive Poisson’s ratios irrespective of size, shape and angle of aperture, with the Poisson’s ratio exhibiting giant values for certain conformations. When the Poisson’s ratio in one loading direction is larger than +1, the systems were found to exhibit the anomalous property of negative linear compressibility along this direction, that is, the systems expand in this direction when hydrostatically compressed. Also discussed are the thermal expansion properties of these systems under the assumption that the units exhibit increased rotational agitation once subjected to an increase in temperature. The effect of the geometric parameters on the aforementioned thermo-mechanical properties of the system, are discussed, with the aim of identifying negative behaviour. (paper)

Negativity Bias in Dangerous Drivers.

Directory of Open Access Journals (Sweden)

Jing Chai

Full Text Available The behavioral and cognitive characteristics of dangerous drivers differ significantly from those of safe drivers. However, differences in emotional information processing have seldom been investigated. Previous studies have revealed that drivers with higher anger/anxiety trait scores are more likely to be involved in crashes and that individuals with higher anger traits exhibit stronger negativity biases when processing emotions compared with control groups. However, researchers have not explored the relationship between emotional information processing and driving behavior. In this study, we examined the emotional information processing differences between dangerous drivers and safe drivers. Thirty-eight non-professional drivers were divided into two groups according to the penalty points that they had accrued for traffic violations: 15 drivers with 6 or more points were included in the dangerous driver group, and 23 drivers with 3 or fewer points were included in the safe driver group. The emotional Stroop task was used to measure negativity biases, and both behavioral and electroencephalograph data were recorded. The behavioral results revealed stronger negativity biases in the dangerous drivers than in the safe drivers. The bias score was correlated with self-reported dangerous driving behavior. Drivers with strong negativity biases reported having been involved in mores crashes compared with the less-biased drivers. The event-related potentials (ERPs revealed that the dangerous drivers exhibited reduced P3 components when responding to negative stimuli, suggesting decreased inhibitory control of information that is task-irrelevant but emotionally salient. The influence of negativity bias provides one possible explanation of the effects of individual differences on dangerous driving behavior and traffic crashes.

19 (No. 1)

African Journals Online (AJOL)

2015-03-20

Mar 20, 2015 ... Tanzania Dental Association screened, demonstrated tooth brushing techniques and distributed tooth brushes and tooth pastes to a total of 705 children with various special needs e.g. People with Albinism. (PWA), Children with blindness or sight problems,. Children with deafness and mentally / physically.

Resenha de: L'Europe et le monde à la fin du XVIIIe siècle

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Eurípedes Simões de Paula

2017-04-01

Full Text Available DEVÉZE (Michel. — L'Europe et le monde à la fin du XVIIIe siècle. Coleção "L'Évolution de l'Humanité". Éditions Albin Michel. Paris. 1971. 703 pp., 7 mapas. Preço 12,00 F.

Effect of sunlight shielding on leaf structure and amino acids ...

African Journals Online (AJOL)

Light sensitive albino tea cultivar 'Jinguang' (Camellia sinensis) which grows albinism leaf in yellow colour, results to high level of amino acids but low levels of photosynthetic pigments including chlorophylls, neoxanthin, violaxanthin, phytoxanthin and β-carotene when it is exposed to high sunlight illumination in the ...

Negative Pressure Wound Therapy in Maxillofacial Applications

Directory of Open Access Journals (Sweden)

Adam J. Mellott

2016-09-01

Full Text Available Negative pressure wound therapy has greatly advanced the field of wound healing for nearly two decades, by providing a robust surgical adjunct technique for accelerating wound closure in acute and chronic wounds. However, the application of negative pressure wound therapy in maxillofacial applications has been relatively under utilized as a result of the physical articulations and contours of the head and neck that make it challenging to obtain an airtight seal for different negative pressure wound therapy systems. Adapting negative pressure wound therapies for maxillofacial applications could yield significant enhancement of wound closure in maxillofacial applications. The current review summarizes the basic science underlying negative pressure wound therapy, as well as specific maxillofacial procedures that could benefit from negative pressure wound therapy.

Negative-Pressure Pulmonary Edema.

Science.gov (United States)

Bhattacharya, Mallar; Kallet, Richard H; Ware, Lorraine B; Matthay, Michael A

2016-10-01

Negative-pressure pulmonary edema (NPPE) or postobstructive pulmonary edema is a well-described cause of acute respiratory failure that occurs after intense inspiratory effort against an obstructed airway, usually from upper airway infection, tumor, or laryngospasm. Patients with NPPE generate very negative airway pressures, which augment transvascular fluid filtration and precipitate interstitial and alveolar edema. Pulmonary edema fluid collected from most patients with NPPE has a low protein concentration, suggesting hydrostatic forces as the primary mechanism for the pathogenesis of NPPE. Supportive care should be directed at relieving the upper airway obstruction by endotracheal intubation or cricothyroidotomy, institution of lung-protective positive-pressure ventilation, and diuresis unless the patient is in shock. Resolution of the pulmonary edema is usually rapid, in part because alveolar fluid clearance mechanisms are intact. In this review, we discuss the clinical presentation, pathophysiology, and management of negative-pressure or postobstructive pulmonary edema. Copyright © 2016 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.

mTOR in breast cancer: differential expression in triple-negative and non-triple-negative tumors.

LENUS (Irish Health Repository)

Walsh, S

2012-04-01

Triple-negative breast cancer (TNBC) is defined by the absence of estrogen receptors (ER), progesterone receptors (PR) and overexpression of HER2. Targeted therapy is currently unavailable for this subgroup of breast cancer patients. mTOR controls cancer cell growth, survival and invasion and is thus a potential target for the treatment of patients with TNBC. Using immunohistochemistry, mTOR and p-mTOR were measured in 89 TNBCs and 99 non-TNBCs. While mTOR expression was confined to tumor cell cytoplasm, p-mTOR staining was located in the nucleus, perinuclear area and in the cytoplasm. Potentially important, was our finding that nuclear p-mTOR was found more frequently in triple-negative than non triple-negative cancers (p < 0.001). These results suggest that mTOR may play a more important role in the progression of TNBC compared to non-TNBC. Based on these findings, we conclude that mTOR may be a new target for the treatment of triple-negative breast cancer.

Differences in MITF gene expression and histology between albino and normal sea cucumbers ( Apostichopus japonicus Selenka)

Science.gov (United States)

Zhao, Heling; Yang, Hongsheng; Zhao, Huan; Liu, Shilin; Wang, Tianming

2012-01-01

Albino Apostichopus japonicus occur both in the wild and in captivity. The offspring of albino A. japonicus also suffer from albinism. The formation of melanin in the melanocytes is dependant on microphthalmia-associated transcription factor (MITF). To investigate the role of MITF in controlling albinism, we cloned the full-length MITF cDNA from A. japonicus and compared MITF mRNA expression in albino and normal A. japonicus. In addition, we used light and electron microscopy to compare histological samples of normal and albino A. japonicus. The body wall of albino adults was characterized by significantly lower levels of MITF expression and lower numbers of epidermal melanocytes, which also contained less melanin. In albino juvenile offspring, MITF expression levels were significantly lower 32 d after fertilization and there were fewer, and less developed, epidermal melanocytes. Thus, we conclude that albino A. japonicus have fewer melanocytes and a reduced ability to synthesize melanin, likely because of lower expression of MITF.

Fitness loss and germline mutations in barn swallows breeding in Chernobyl

Energy Technology Data Exchange (ETDEWEB)

Ellegren, Hans; Lindgren, Gabriella; Primmer, C.R. [Swedish Univ. of Agricultural Sciences, Animal Breeding and Genetics Dept., Uppsala (Sweden); Moeller, A.P. [Universite Pierre et Marie Curie. Lab. d`Ecologie, Paris, 75 (France)

1997-10-09

The severe nuclear accident at Chernobyl in 1986 resulted in the worst reported accidental exposure of radioactive material to free-living organisms. Short-term effects on human populations inhabiting polluted areas include increased incidence of thyroid cancer, infant leukaemia, and congenital malformations in newborns. Two recent studies have reported, although with some controversy, that germline mutation rates were increased in humans and voles living close to Chernobyl, but little is known about the viability of the organisms affected. Here we report an increased frequency of partial albinism, a morphological aberration associated with a loss of fitness, among barn swallows, Hirundo rustica, breeding close to Chernobyl. Heretability estimates indicate that mutations causing albinism were at least partly of germline origin. Furthermore, evidence for an increased germline mutation rate was obtained from segregation analysis at two hypervariable microsatellite loci, indicating that mutation events in barn swallows from Chernobyl were two- to tenfold higher than in birds from control areas in Ukraine and Italy. (author).

Fitness loss and germline mutations in barn swallows breeding in Chernobyl

International Nuclear Information System (INIS)

Ellegren, Hans; Lindgren, Gabriella; Primmer, C.R.; Moeller, A.P.

1997-01-01

The severe nuclear accident at Chernobyl in 1986 resulted in the worst reported accidental exposure of radioactive material to free-living organisms. Short-term effects on human populations inhabiting polluted areas include increased incidence of thyroid cancer, infant leukaemia, and congenital malformations in newborns. Two recent studies have reported, although with some controversy, that germline mutation rates were increased in humans and voles living close to Chernobyl, but little is known about the viability of the organisms affected. Here we report an increased frequency of partial albinism, a morphological aberration associated with a loss of fitness, among barn swallows, Hirundo rustica, breeding close to Chernobyl. Heretability estimates indicate that mutations causing albinism were at least partly of germline origin. Furthermore, evidence for an increased germline mutation rate was obtained from segregation analysis at two hypervariable microsatellite loci, indicating that mutation events in barn swallows from Chernobyl were two- to tenfold higher than in birds from control areas in Ukraine and Italy. (author)

BREESE-II: auxiliary routines for implementing the albedo option in the MORSE Monte Carlo code

International Nuclear Information System (INIS)

Cain, V.R.; Emmett, M.B.

1979-07-01

The routines in the BREESE package implement the albedo option in the MORSE Monte Carlo Code by providing (1) replacements for the default routines ALBIN and ALBDO in the MORSE Code, (2) an estimating routine ALBDOE compatible with the SAMBO package in MORSE, and (3) a separate program that writes a tape of albedo data in the proper format for ALBIN. These extensions of the package initially reported in 1974 were performed jointly by ORNL, Bechtel Power Corporation, and Science Applications, Inc. The first version of BREESE had a fixed number of outgoing polar angles and the number of outgoing azimuthal angles was a function of the value of the outgoing polar angle only. An examination of differential albedo data led to this modified version which allows the number of outgoing polar angles to be dependent upon the value of the incoming polar angle and the number of outgoing azimuthal angles to be a function of the value of both incoming and outgoing polar angles

Lateralization of cortical negative motor areas.

Science.gov (United States)

Borggraefe, Ingo; Catarino, Claudia B; Rémi, Jan; Vollmar, Christian; Peraud, Aurelia; Winkler, Peter A; Noachtar, Soheyl

2016-10-01

The lateral and mesial aspects of the central and frontal cortex were studied by direct electrical stimulation of the cortex in epilepsy surgery candidates in order to determine the localization of unilateral and bilateral negative motor responses. Results of electrical cortical stimulation were examined in epilepsy surgery candidates in whom invasive electrodes were implanted. The exact localization of subdural electrodes was defined by fusion of 3-dimensional reconstructed MRI and CT images in 13 patients and by analysis of plane skull X-rays and intraoperative visual localization of the electrodes in another 7 patients. Results of electrical stimulation of the cortex were evaluated in a total of 128 patients in whom invasive electrodes were implanted for planning resective epilepsy surgery. Twenty patients, in whom negative motor responses were obtained, were included in the study. Bilateral upper limb negative motor responses were more often elicited from stimulation of the mesial frontal cortex whereas stimulation of the lateral central cortex leads to contralateral upper limb negative motor responses (pfrontal gyrus whereas contralateral negative motor responses localized predominantly in the anterior part of the precentral gyrus (pgyrus and the mesial fronto-central cortex showing functional differences with regard to unilateral and bilateral upper limb representation. The lateral fronto-central negative motor area serves predominantly contralateral upper limb motor control whereas the mesial frontal negative motor area represents bilateral upper limb movement control. Copyright © 2016 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Cutaneous granulomatosis and combined immunodeficiency revealing Ataxia-Telangiectasia: a case report

OpenAIRE

Folgori, Laura; Scarselli, Alessia; Angelino, Giulia; Ferrari, Francesca; Antoccia, Antonio; Chessa, Luciana; Finocchi, Andrea

2010-01-01

Abstract Ataxia-telangiectasia (A-T) is a complex multisystem disorder characterized by progressive neurological impairment, variable immunodeficiency and oculo-cutaneous telangiectasia. A-T is a member of chromosomal breakage syndromes and it is caused by a mutation in the ataxia-telangiectasia mutated (ATM) gene. Because of a wide clinical heterogeneity, A-T is often difficult to diagnose in children. We report an unusual case of a 3-year-old boy affected by A-T who presented exclusively wi...

Atomic negative ions

International Nuclear Information System (INIS)

Brage, T.

1991-01-01

We review some of the recent progress in the studies of alkaline-earth, negative ions. Computations of autodetachment rates, electron affinities and transition wavelengths are discussed and some new and improved results are given

On multiphase negative flash for ideal solutions

DEFF Research Database (Denmark)

Yan, Wei; Stenby, Erling Halfdan

2012-01-01

simpler than the corresponding normal flash algorithm. Unlike normal flash, multiphase negative flash for ideal solutions can diverge if the feasible domain for phase amounts is not closed. This can be judged readily during the iteration process. The algorithm can also be extended to the partial negative......There is a recent interest to solve multiphase negative flash problems where the phase amounts can be negative for normal positive feed composition. Solving such a negative flash problem using successive substitution needs an inner loop for phase distribution calculation at constant fugacity...... coefficients. It is shown that this inner loop, named here as multiphase negative flash for ideal solutions, can be solved either by Michelsen's algorithm for multiphase normal flash, or by its variation which uses F−1 phase amounts as independent variables. In either case, the resulting algorithm is actually...

Surface negative ion production in ion sources

International Nuclear Information System (INIS)

Belchenko, Y.

1993-01-01

Negative ion sources and the mechanisms for negative ion production are reviewed. Several classes of sources with surface origin of negative ions are examined in detail: surface-plasma sources where ion production occurs on the electrode in contact with the plasma, and ''pure surface'' sources where ion production occurs due to conversion or desorption processes. Negative ion production by backscattering, impact desorption, and electron- and photo-stimulated desorption are discussed. The experimental efficiencies of intense surface negative ion production realized on electrodes contacted with hydrogen-cesium or pure hydrogen gas-discharge plasma are compared. Recent modifications of surface-plasma sources developed for accelerator and fusion applications are reviewed in detail

Unnaturalness of Negation – an Old Wives’ Tale Retold

Directory of Open Access Journals (Sweden)

Gašper Ilc

2006-06-01

Full Text Available Negation has a very long history of study. In the realm of logic, negation is seen as a simple operation that turns an affirmative to a negative. This assumption strongly affected the linguistic study of negation, and led to some misconceptions. For example, negation in natural languages is seen as something unnatural, artificial and syntactically as well as semantically dependant on affirmation. It is perceived as a logical/mathematical operation that turns affirmatives into negatives by way of syntactic transformation and semantic cancellation of multiple negatives. To refute some of these misconceptions, the paper investigates the nature of negation as a linguistic phenomenon, and shows that negation in logic and linguistics should not and cannot be treated in the same fashion. Special attention is paid to the problems of structural complexity, the syntactic notion of multiple negation and its different semantic interpretations. With regard to the semantic interpretation of multiple negation, languages, by and large, allow for two possibilities: negative concord and double negation. Negative concord, which interprets two negatives as a single negation, seems to represent the natural course of language development, while double negation, which allows the cancellation of two negatives resulting in affirmation, was introduced into languages under the influence of logic in the 17th and 18th centuries.

Clinical Significance of CK19 Negative Breast Cancer

Energy Technology Data Exchange (ETDEWEB)

Fujisue, Mamiko, E-mail: nishimura.reiki@cityhosp-kumamoto.jp; Nishimura, Reiki; Okumura, Yasuhiro [Department of Breast and Endocrine Surgery, Kumamoto City Hospital, 1-1-60 Kotoh, Kumamoto City, Kumamoto 862-8505 (Japan); Tashima, Rumiko [Department of Surgery, Kumamoto City Hospital, 1-1-60 Kotoh, Kumamoto City, Kumamoto 862-8505 (Japan); Nishiyama, Yasuyuki; Osako, Tomofumi [Department of Breast and Endocrine Surgery, Kumamoto City Hospital, 1-1-60 Kotoh, Kumamoto City, Kumamoto 862-8505 (Japan); Toyozumi, Yasuo; Arima, Nobuyuki [Department of Pathology, Kumamoto City Hospital, 1-1-60 Kotoh, Kumamoto City, Kumamoto 862-8505 (Japan)

2012-12-21

Analysis of sentinel lymph nodes (SLNs) by means of One-Step Nucleic Acid Amplification (OSNA) is gaining widespread use as a quick and accurate method. This assay detects the expression level of cytokeratin 19 (CK19) which is present in some but not all breast tumors. In this study, the clinical significance of negative CK19 was investigated in 219 cases of primary breast cancer. In 179 patients with clinically negative nodes, OSNA and imprint smear cytology of SLN were performed simultaneously. The OSNA revealed a node-positive rate of 24.6%. Negative CK19 correlated significantly with negative ER/PgR and higher Ki-67 values, and marginally with higher nuclear grade and p53 overexpression. The triple negative subtype showed lower CK19 expression. OSNA revealed that one of the negative CK19 cases was actually a false negative but this was corrected with the use of the imprint smear cytology. In conclusion, CK19 negativity reflected the aggressiveness of primary breast cancer. OSNA assay used to analyze SLN was useful, but there is a possibility that it will mistakenly detect false negatives in CK19 negative tumors. Therefore, in tumors with negative CK19, the imprint smear cytology may be more useful in cases with macrometastasis.

Clinical Significance of CK19 Negative Breast Cancer

Directory of Open Access Journals (Sweden)

Nobuyuki Arima

2012-12-01

Full Text Available Analysis of sentinel lymph nodes (SLNs by means of One-Step Nucleic Acid Amplification (OSNA is gaining widespread use as a quick and accurate method. This assay detects the expression level of cytokeratin 19 (CK19 which is present in some but not all breast tumors. In this study, the clinical significance of negative CK19 was investigated in 219 cases of primary breast cancer. In 179 patients with clinically negative nodes, OSNA and imprint smear cytology of SLN were performed simultaneously. The OSNA revealed a node-positive rate of 24.6%. Negative CK19 correlated significantly with negative ER/PgR and higher Ki-67 values, and marginally with higher nuclear grade and p53 overexpression. The triple negative subtype showed lower CK19 expression. OSNA revealed that one of the negative CK19 cases was actually a false negative but this was corrected with the use of the imprint smear cytology. In conclusion, CK19 negativity reflected the aggressiveness of primary breast cancer. OSNA assay used to analyze SLN was useful, but there is a possibility that it will mistakenly detect false negatives in CK19 negative tumors. Therefore, in tumors with negative CK19, the imprint smear cytology may be more useful in cases with macrometastasis.

Clinical Significance of CK19 Negative Breast Cancer

International Nuclear Information System (INIS)

Fujisue, Mamiko; Nishimura, Reiki; Okumura, Yasuhiro; Tashima, Rumiko; Nishiyama, Yasuyuki; Osako, Tomofumi; Toyozumi, Yasuo; Arima, Nobuyuki

2012-01-01

Analysis of sentinel lymph nodes (SLNs) by means of One-Step Nucleic Acid Amplification (OSNA) is gaining widespread use as a quick and accurate method. This assay detects the expression level of cytokeratin 19 (CK19) which is present in some but not all breast tumors. In this study, the clinical significance of negative CK19 was investigated in 219 cases of primary breast cancer. In 179 patients with clinically negative nodes, OSNA and imprint smear cytology of SLN were performed simultaneously. The OSNA revealed a node-positive rate of 24.6%. Negative CK19 correlated significantly with negative ER/PgR and higher Ki-67 values, and marginally with higher nuclear grade and p53 overexpression. The triple negative subtype showed lower CK19 expression. OSNA revealed that one of the negative CK19 cases was actually a false negative but this was corrected with the use of the imprint smear cytology. In conclusion, CK19 negativity reflected the aggressiveness of primary breast cancer. OSNA assay used to analyze SLN was useful, but there is a possibility that it will mistakenly detect false negatives in CK19 negative tumors. Therefore, in tumors with negative CK19, the imprint smear cytology may be more useful in cases with macrometastasis

Basal and squamous cell carcinomata on the same patients: report ...

African Journals Online (AJOL)

Background: Skin cancer is the most common cancer among the lightly pigmented individuals in Europe, North America and Australia. It occurs infrequently in darkly pigmented individuals because they have more melanin. Melanin and albinism are a known risk factors for skin cancers in Africans. Those already treated for ...

Cancers of eyelid: Report of two cases | Atipo-Tsiba | East African ...

African Journals Online (AJOL)

Acquired immunosuppression, xeroderma pigmentosum and albinism predispose to the occurrence of this cancer. The Sebaceous Carcinoma represents a little less than 5% of cases. The third type may arise in the meibomian, Zeis or sebaceous glands. Its diagnosis is often delayed because of its seemingly benign clinical ...

Cutaneous Cancers in Nigerian Albinos: A Review of 22 Cases

African Journals Online (AJOL)

2018-04-20

Apr 20, 2018 ... Context: Albinism is an inherited disorder of hypopigmentation involving the skin, eyes, and hair. ... These data include age, gender, site of the lesion, the diagnosis, no of lesions excised .... increase awareness to treatment among the albinos and their .... their identity, but anonymity cannot be guaranteed.

Natural markings and their use in determining calving intervals in ...

African Journals Online (AJOL)

1987-10-06

Oct 6, 1987 ... Since 1979, 245 right whales (excluding calves) have been individually identified in aerial ... From a simple model it is shown that .... were exposed, and notes taken of associated information .... predominantly male, or that their female component is ... In order to compare the incidence of partial albinism.

Art, Terrorism and the Negative Sublime

Directory of Open Access Journals (Sweden)

Arnold Berleant

2009-01-01

Full Text Available The range of the aesthetic has expanded to cover not only a wider range of objects and situations of daily life but also to encompass the negative. This includes terrorism, whose aesthetic impact is central to its use as a political tactic. The complex of positive and negative aesthetic values in terrorism are explored, introducing the concept of the sublime as a negative category to illuminate the analysis and the distinctive aesthetic of terrorism.

Person-centred positive emotions, object-centred negative emotions: 2-year-olds generalize negative but not positive emotions across individuals.

Science.gov (United States)

Vaish, Amrisha; Grossmann, Tobias; Woodward, Amanda

2015-09-01

Prior work suggests that young children do not generalize others' preferences to new individuals. We hypothesized (following Vaish et al., 2008, Psychol. Bull., 134, 383-403) that this may only hold for positive emotions, which inform the child about the person's attitude towards the object but not about the positivity of the object itself. It may not hold for negative emotions, which additionally inform the child about the negativity of the object itself. Two-year-old children saw one individual (the emoter) emoting positively or negatively towards one and neutrally towards a second novel object. When a second individual then requested an object, children generalized the emoter's negative but not her positive emotion to the second individual. Children thus draw different inferences from others' positive versus negative emotions: Whereas they view others' positive emotions as person centred, they may view others' negative emotions as object centred and thus generalizable across people. The results are discussed with relation to the functions and implications of the negativity bias. © 2015 The British Psychological Society.

Clinical characteristics of Helicobacter pylori-negative drug-negative peptic ulcer bleeding.

Science.gov (United States)

Chung, Woo Chul; Jeon, Eun Jung; Kim, Dae Bum; Sung, Hea Jung; Kim, Yeon-Ji; Lim, Eun Sun; Kim, Min-Ah; Oh, Jung Hwan

2015-07-28

To investigate the clinical characteristics and outcomes of idiopathic Helicobacter pylori (H. pylori)-negative and drug-negative] peptic ulcer bleeding (PUB). A consecutive series of patients who experienced PUB between 2006 and 2012 was retrospectively analyzed. A total of 232 patients were enrolled in this study. The patients were divided into four groups according to the etiologies of PUB: idiopathic, H. pylori-associated, drug-induced and combined (H. pylori-associated and drug-induced) types. We compared the clinical characteristics and outcomes between the groups. When the silver stain or rapid urease tests were H. pylori-negative, we obtained an additional biopsy specimen by endoscopic re-examination and performed an H. pylori antibody test 6-8 wk after the initial endoscopic examination. For a diagnosis of idiopathic PUB, a negative result of an H. pylori antibody test was confirmed. In all cases, re-bleeding was confirmed by endoscopic examination. For the risk assessment, the Blatchford and the Rockall scores were calculated for all patients. For PUB, the frequency of H. pylori infection was 59.5% (138/232), whereas the frequency of idiopathic cases was 8.6% (20/232). When idiopathic PUB was compared to H. pylori-associated PUB, the idiopathic PUB group showed a higher rate of re-bleeding after initial hemostasis during the hospital stay (30% vs 7.4%, P = 0.02). When idiopathic PUB was compared to drug-induced PUB, the patients in the idiopathic PUB group showed a higher rate of re-bleeding after initial hemostasis upon admission (30% vs 2.7%, P ulcer (77% vs 49%, P < 0.01). However, the Blatchford and the Rockall scores were not significantly different between the two groups. Among the patients who experienced drug-induced PUB, no significant differences were found with respect to clinical characteristics, irrespective of H. pylori infection. Idiopathic PUB has unique clinical characteristics such as re-bleeding after initial hemostasis upon admission

Negative affect, negative urgency, thought suppression, and bulimic symptoms: a moderated mediation analysis in a sample at-risk for bulimic symptoms.

Science.gov (United States)

Lavender, Jason M; Green, Daniel; Anestis, Michael D; Tull, Matthew T; Gratz, Kim L

2015-05-01

Research suggests that negative affect, negative urgency, and thought suppression are related to bulimic symptoms, either directly or indirectly. This study examined associations between these constructs in a sample at-risk for bulimic symptoms. Participants (N = 80) recruited from a residential substance abuse treatment facility completed self-report questionnaires. A regression-based bootstrapping approach was used to examine the indirect effect of negative affect on bulimic symptoms through negative urgency and the moderating role of thought suppression in the association between negative affect and negative urgency. Results revealed a significant indirect effect, significant moderation, and a significant moderated mediation effect, with an indirect effect of negative affect on bulimic symptoms through negative urgency, conditional upon low to moderate (but not high) levels of thought suppression. These findings suggest that negative affect may promote rash actions, particularly in the context of low to moderate thought suppression, leading to increased risk of bulimic symptoms. Copyright © 2015 John Wiley & Sons, Ltd and Eating Disorders Association.

Perceived social pressure not to experience negative emotion is linked to selective attention for negative information.

Science.gov (United States)

Bastian, Brock; Pe, Madeline Lee; Kuppens, Peter

2017-02-01

Social norms and values may be important predictors of how people engage with and regulate their negative emotional experiences. Previous research has shown that social expectancies (the perceived social pressure not to feel negative emotion (NE)) exacerbate feelings of sadness. In the current research, we examined whether social expectancies may be linked to how people process emotional information. Using a modified classical flanker task involving emotional rather than non-emotional stimuli, we found that, for those who experienced low levels of NE, social expectancies were linked to the selective avoidance of negative emotional information. Those who experienced high levels of NE did not show a selective avoidance of negative emotional information. The findings suggest that, for people who experience many NEs, social expectancies may lead to discrepancies between how they think they ought to feel and the kind of emotional information they pay attention to.

Negative Symptom Dimensions of the Positive and Negative Syndrome Scale Across Geographical Regions: Implications for Social, Linguistic, and Cultural Consistency.

Science.gov (United States)

Khan, Anzalee; Liharska, Lora; Harvey, Philip D; Atkins, Alexandra; Ulshen, Daniel; Keefe, Richard S E

2017-12-01

Objective: Recognizing the discrete dimensions that underlie negative symptoms in schizophrenia and how these dimensions are understood across localities might result in better understanding and treatment of these symptoms. To this end, the objectives of this study were to 1) identify the Positive and Negative Syndrome Scale negative symptom dimensions of expressive deficits and experiential deficits and 2) analyze performance on these dimensions over 15 geographical regions to determine whether the items defining them manifest similar reliability across these regions. Design: Data were obtained for the baseline Positive and Negative Syndrome Scale visits of 6,889 subjects across 15 geographical regions. Using confirmatory factor analysis, we examined whether a two-factor negative symptom structure that is found in schizophrenia (experiential deficits and expressive deficits) would be replicated in our sample, and using differential item functioning, we tested the degree to which specific items from each negative symptom subfactor performed across geographical regions in comparison with the United States. Results: The two-factor negative symptom solution was replicated in this sample. Most geographical regions showed moderate-to-large differential item functioning for Positive and Negative Syndrome Scale expressive deficit items, especially N3 Poor Rapport, as compared with Positive and Negative Syndrome Scale experiential deficit items, showing that these items might be interpreted or scored differently in different regions. Across countries, except for India, the differential item functioning values did not favor raters in the United States. Conclusion: These results suggest that the Positive and Negative Syndrome Scale negative symptom factor can be better represented by a two-factor model than by a single-factor model. Additionally, the results show significant differences in responses to items representing the Positive and Negative Syndrome Scale expressive

Hypothesis for the mechanism of negative ion production in the surface-plasma negative hydrogen ion source

International Nuclear Information System (INIS)

Hiskes, J.R.

1975-01-01

An analysis of the surface-plasma negative hydrogen ion source has shown that the tungsten cathode supports approximately a monolayer of cesium. The backscattering of protons from the cathode as energetic neutrals and the subsequent backscattering of these neutrals from the anode provides for a flux of energetic atoms incident upon the cathode which is comparable to the ion flux. A hypothesis is proposed for the generation of negative ions during the collision of these energetic atoms with the cathode. Several mechanisms for negative ion production by proton collision with the surface are discussed. (U.S.)

Negative concord and the scope of universals

NARCIS (Netherlands)

Giannakidou, A

2000-01-01

In this paper, I propose an analysis of Greek negative concord (NC) in terms of quantifier scope. It is shown that there is no evidence that Greek NC n-words are indefinites or negative quantifiers, NC n-words are analysed as universal quantifiers, which are sensitive to negative polarity, and which

Negative-assortative mating for color in wolves.

Science.gov (United States)

Hedrick, Philip W; Smith, Douglas W; Stahler, Daniel R

2016-04-01

There is strong negative-assortative mating for gray and black pelage color in the iconic wolves in Yellowstone National Park. This is the first documented case of significant negative-assortative mating in mammals and one of only a very few cases in vertebrates. Of 261 matings documented from 1995 to 2015, 63.6% were between gray and black wolves and the correlation between mates for color was -0.266. There was a similar excess of matings of both gray males × black females and black males × gray females. Using the observed frequency of negative-assortative mating in a model with both random and negative-assortative mating, the estimated proportion of negative-assortative mating was 0.430. The estimated frequency of black wolves in the population from 1996 to 2014 was 0.452 and these frequencies appear stable over this 19-year period. Using the estimated level of negative-assortative mating, the predicted equilibrium frequency of the dominant allele was 0.278, very close to the mean value of 0.253 observed. In addition, the patterns of genotype frequencies, that is, the observed proportion of black homozygotes and the observed excess of black heterozygotes, are consistent with negative-assortative mating. Importantly these results demonstrate that negative-assortative mating could be entirely responsible for the maintenance of this well-known color polymorphism. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

The developmental origins of cognitive vulnerability to depression: temperament, parenting, and negative life events in childhood as contributors to negative cognitive style.

Science.gov (United States)

Mezulis, Amy H; Hyde, Janet Shibley; Abramson, Lyn Y

2006-11-01

Cognitive models of depression have been well supported with adults, but the developmental origins of cognitive vulnerability are not well understood. The authors hypothesized that temperament, parenting, and negative life events in childhood would contribute to the development of cognitive style, with withdrawal negativity and negative parental feedback moderating the effects of negative life events to predict more depressogenic cognitive styles. These constructs were assessed in 289 children and their parents followed longitudinally from infancy to 5th grade; a subsample (n = 120) also participated in a behavioral task in which maternal feedback to child failure was observed. Results indicated that greater withdrawal negativity in interaction with negative life events was associated with more negative cognitive styles. Self-reported maternal anger expression and observed negative maternal feedback to child's failure significantly interacted with child's negative events to predict greater cognitive vulnerability. There was little evidence of paternal parenting predicting child negative cognitive style.

[Negative hallucination, self-onsciousness and ageing].

Science.gov (United States)

Hazif-Thomas, C; Stephan, F; Walter, M; Thomas, P

2015-04-01

Negative hallucinations are characterized by a defect in perception of an object or a person, or a denial of the existence of their perception. Negative hallucinations create blank spaces, due to both an impossible representation and an incapability of investment in reality. They have a close relationship with Cotard's syndrome, delusional theme of organ denial observed in melancholic syndromes in the elderly. Phenomenological approach. The phenomenology of negative hallucinations provides quite an amount of information on the origin of the psychotic symptoms when one is rather old. The connections between hallucinations, mood disorders and negative symptoms are often difficult to live with for the nearest and dearest. Negative hallucinations require a strict approach to identify their expression that is crucial because a wide heterogeneity exists within the pathological pictures, as in Cotard's syndrome. Although the negative hallucination has an anti traumatic function in elderly people fighting against mental pain, it still represents a deficiency in symbolization. The prevalence of this symptom is without doubt underestimated, although its presence often underlines thymic suffering that is more striking. These hallucinatory symptoms have an important impact on the patients' daily life, and they appear to be prisoners of a suffering, which cannot be revealed. We propose in this article to review the clinical symptoms of negative hallucinations in the elderly and the way to manage them. The medicinal approaches are not always effective. A greater place must be given to what is in connection with the body, aiming at a strong impact and thus to offer non-pharmacological approaches, such as somatic ones, which can be either invasive (electroconvulsive therapy) or not (transcranial magnetic stimulation). Copyright © 2014. Published by Elsevier Masson SAS.

Distinguishing Entailment and Presupposition Under Negation Test

Directory of Open Access Journals (Sweden)

Gatri Asti Putri Indarti

2016-12-01

Full Text Available Distinguishing entailment from presupposition is quite difficult because their semantic relation seems to be similar. Both entailment and presupposition have an automatic relationship based on the context. However, those semantic relations can still be differentiated by using negation test to show whether a pair is entailment or presupposition. This research focuses on sentences and utterances. Thus, this research aims to analyze and test pairs of entailment and pairs of presupposition by using negation in utterances. The data were twelve comic strips from the Internet and they were analysed by using a negation test. The analysis shows that negation test is useful to test entailment and presupposition in the comic strips. It can be concluded that the difficulty of distinguishing pair of entailment and presupposition in the comic strip using negation test has been successfully solved. In this case, negation test is suitable to test entailment and presupposition. This research can be developed further by other researchers to distinguish entailment and presupposition by using another test if the negation test cannot be used to any further extent.   DOI: https://doi.org/10.24071/llt.2015.180104

Negative magnetic relaxation in superconductors

Directory of Open Access Journals (Sweden)

Krasnoperov E.P.

2013-01-01

Full Text Available It was observed that the trapped magnetic moment of HTS tablets or annuli increases in time (negative relaxation if they are not completely magnetized by a pulsed magnetic field. It is shown, in the framework of the Bean critical-state model, that the radial temperature gradient appearing in tablets or annuli during a pulsed field magnetization can explain the negative magnetic relaxation in the superconductor.

Bootstrapping Visual Categorization with Relevant Negatives

NARCIS (Netherlands)

Li, X.; Snoek, C.G.M.; Worring, M.; Koelma, D.; Smeulders, A.W.M.

Learning classifiers for many visual concepts are important for image categorization and retrieval. As a classifier tends to misclassify negative examples which are visually similar to positive ones, inclusion of such misclassified and thus relevant negatives should be stressed during learning.

Social negative bootstrapping for visual categorization

NARCIS (Netherlands)

Li, X.; Snoek, C.G.M.; Worring, M.; Smeulders, A.W.M.

2011-01-01

To learn classifiers for many visual categories, obtaining labeled training examples in an efficient way is crucial. Since a classifier tends to misclassify negative examples which are visually similar to positive examples, inclusion of such informative negatives should be stressed in the learning

Detection of negative energy: 4-dimensional examples

International Nuclear Information System (INIS)

Davies, P.C.W.; Ottewill, Adrian C.

2002-01-01

We study the response of switched particle detectors to static negative energy densities and negative energy fluxes. It is demonstrated how the switching leads to excitation even in the vacuum and how negative energy can lead to a suppression of this excitation. We obtain quantum inequalities on the detection similar to those obtained for the energy density by Ford and co-workers and in an 'operational' context by Helfer. We reexamine the question 'Is there a quantum equivalence principle?' in terms of our model. Finally, we briefly address the issue of negative energy and the second law of thermodynamics

Cross-Lagged Associations Between Adolescents' Depressive Symptoms and Negative Cognitive Style: The Role of Negative Life Event

NARCIS (Netherlands)

Kindt, K.C.M.; Kleinjan, M.; Janssens, J.M.A.M.; Scholte, R.H.J.

2015-01-01

Previous research has established that cognitive theory-based depression prevention programs aiming change in negative cognitive style in early adolescents do not have strong effects in universal settings. Although theories suggest that a negative cognitive style precedes depressive symptoms,

Information Filtering Based on Users' Negative Opinions

Science.gov (United States)

Guo, Qiang; Li, Yang; Liu, Jian-Guo

2013-05-01

The process of heat conduction (HC) has recently found application in the information filtering [Zhang et al., Phys. Rev. Lett.99, 154301 (2007)], which is of high diversity but low accuracy. The classical HC model predicts users' potential interested objects based on their interesting objects regardless to the negative opinions. In terms of the users' rating scores, we present an improved user-based HC (UHC) information model by taking into account users' positive and negative opinions. Firstly, the objects rated by users are divided into positive and negative categories, then the predicted interesting and dislike object lists are generated by the UHC model. Finally, the recommendation lists are constructed by filtering out the dislike objects from the interesting lists. By implementing the new model based on nine similarity measures, the experimental results for MovieLens and Netflix datasets show that the new model considering negative opinions could greatly enhance the accuracy, measured by the average ranking score, from 0.049 to 0.036 for Netflix and from 0.1025 to 0.0570 for Movielens dataset, reduced by 26.53% and 44.39%, respectively. Since users prefer to give positive ratings rather than negative ones, the negative opinions contain much more information than the positive ones, the negative opinions, therefore, are very important for understanding users' online collective behaviors and improving the performance of HC model.

Ferroelectric Negative Capacitance Domain Dynamics

OpenAIRE

Hoffmann, Michael; Khan, Asif Islam; Serrao, Claudy; Lu, Zhongyuan; Salahuddin, Sayeef; Pešić, Milan; Slesazeck, Stefan; Schroeder, Uwe; Mikolajick, Thomas

2017-01-01

Transient negative capacitance effects in epitaxial ferroelectric Pb(Zr$_{0.2}$Ti$_{0.8}$)O$_3$ capacitors are investigated with a focus on the dynamical switching behavior governed by domain nucleation and growth. Voltage pulses are applied to a series connection of the ferroelectric capacitor and a resistor to directly measure the ferroelectric negative capacitance during switching. A time-dependent Ginzburg-Landau approach is used to investigate the underlying domain dynamics. The transien...

Negative probability in the framework of combined probability

OpenAIRE

Burgin, Mark

2013-01-01

Negative probability has found diverse applications in theoretical physics. Thus, construction of sound and rigorous mathematical foundations for negative probability is important for physics. There are different axiomatizations of conventional probability. So, it is natural that negative probability also has different axiomatic frameworks. In the previous publications (Burgin, 2009; 2010), negative probability was mathematically formalized and rigorously interpreted in the context of extende...

Brand Suicide? Memory and Liking of Negative Brand Names.

Science.gov (United States)

Guest, Duncan; Estes, Zachary; Gibbert, Michael; Mazursky, David

2016-01-01

Negative brand names are surprisingly common in the marketplace (e.g., Poison perfume; Hell pizza, and Monster energy drink), yet their effects on consumer behavior are currently unknown. Three studies investigated the effects of negative brand name valence on brand name memory and liking of a branded product. Study 1 demonstrates that relative to non-negative brand names, negative brand names and their associated logos are better recognised. Studies 2 and 3 demonstrate that negative valence of a brand name tends to have a detrimental influence on product evaluation with evaluations worsening as negative valence increases. However, evaluation is also dependent on brand name arousal, with high arousal brand names resulting in more positive evaluations, such that moderately negative brand names are equally as attractive as some non-negative brand names. Study 3 shows evidence for affective habituation, whereby the effects of negative valence reduce with repeated exposures to some classes of negative brand name.

Brand Suicide? Memory and Liking of Negative Brand Names

Science.gov (United States)

Guest, Duncan; Estes, Zachary; Gibbert, Michael; Mazursky, David

2016-01-01

Negative brand names are surprisingly common in the marketplace (e.g., Poison perfume; Hell pizza, and Monster energy drink), yet their effects on consumer behavior are currently unknown. Three studies investigated the effects of negative brand name valence on brand name memory and liking of a branded product. Study 1 demonstrates that relative to non-negative brand names, negative brand names and their associated logos are better recognised. Studies 2 and 3 demonstrate that negative valence of a brand name tends to have a detrimental influence on product evaluation with evaluations worsening as negative valence increases. However, evaluation is also dependent on brand name arousal, with high arousal brand names resulting in more positive evaluations, such that moderately negative brand names are equally as attractive as some non-negative brand names. Study 3 shows evidence for affective habituation, whereby the effects of negative valence reduce with repeated exposures to some classes of negative brand name. PMID:27023872

Genetic transformation of barley: limiting factors

Czech Academy of Sciences Publication Activity Database

Vyroubalová, Š.; Šmehilová, M.; Galuszka, P.; Ohnoutková, Ludmila

2011-01-01

Roč. 55, č. 2 (2011), s. 213-224 ISSN 0006-3134 R&D Projects: GA ČR GD522/08/H003; GA MŠk 1M06030 Institutional research plan: CEZ:AV0Z50380511 Keywords : Agrobacterium * albinism * Hordeum Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.974, year: 2011

Submarine Warfare in the 20th & 21st Centuries: A Bibliography

Science.gov (United States)

2003-12-01

energy requirements and strategic metals and for over 70 percent of its food . Despite the importance of the sealanes to Japanese security, the Japanese...l’américain par Marianne Véron avec la collab. de Jean Sabbagh]. Paris: Albin michel, 1986. 485 p. Franch translation of The Hunt for Red October

Problematic smartphone use and relations with negative affect, fear of missing out, and fear of negative and positive evaluation.

Science.gov (United States)

Wolniewicz, Claire A; Tiamiyu, Mojisola F; Weeks, Justin W; Elhai, Jon D

2018-04-01

For many individuals, excessive smartphone use interferes with everyday life. In the present study, we recruited a non-clinical sample of 296 participants for a cross-sectional survey of problematic smartphone use, social and non-social smartphone use, and psychopathology-related constructs including negative affect, fear of negative and positive evaluation, and fear of missing out (FoMO). Results demonstrated that FoMO was most strongly related to both problematic smartphone use and social smartphone use relative to negative affect and fears of negative and positive evaluation, and these relations held when controlling for age and gender. Furthermore, FoMO (cross-sectionally) mediated relations between both fear of negative and positive evaluation with both problematic and social smartphone use. Theoretical implications are considered with regard to developing problematic smartphone use. Copyright © 2017 Elsevier B.V. All rights reserved.

Honeycomb surface-plasma negative-ion source

International Nuclear Information System (INIS)

Bel'chenko, Yu.I.

1983-01-01

A honeycomb surface-plasma source (SPS) of negative hydrogen ions the cathode of which consists of a great number of cells with spherical-concave surfaces, is described. Negative ions, knocked off the cathode by cesium-hydrogen discharge fast particles are accelerated in the near-cathode potential drop layer and focused geometrically on small emission apertures in the anode. Due to this, the gas and energy efficiency of the source is increased and the power density on the cathode is decreased. The H - yield is proportional to the number of celts. A pulse beam of negative ions with current up to 4 A is obtained and accelerated to 25 kV from the cathode effective area of 10.6 cm 2 through emission ports of 0.5 cm 2 total area. The honeycomb SPSs with a greater number of cells are promising as regards obtaining negative ion-beams with the current of scores of amperes

Contextual Risk, Maternal Negative Emotionality, and the Negative Emotion Dysregulation of Preschool Children from Economically Disadvantaged Families

Science.gov (United States)

Brown, Eleanor D.; Ackerman, Brian P.

2011-01-01

Research Findings: This study examined relations between contextual risk, maternal negative emotionality, and preschool teacher reports of the negative emotion dysregulation of children from economically disadvantaged families. Contextual risk was represented by cumulative indexes of family and neighborhood adversity. The results showed a direct…

Negative (but not Positive) Parenting Interacts with Infant Negative Affect to Predict Infant Approach: Evidence of Diathesis-Stress.

Science.gov (United States)

Holzman, Jacob B; Burt, Nicole M; Edwards, Erin S; Rosinski, Leanna D; Bridgett, David J

2018-01-01

Temperament by parenting interactions may reflect that individuals with greater risk are more likely to experience negative outcomes in adverse contexts (diathesis-stress) or that these individuals are more susceptible to contextual influences in a 'for better or for worse' pattern (differential susceptibility). Although such interactions have been identified for a variety of child outcomes, prior research has not examined approach characteristics - excitement and approach toward pleasurable activities - in the first year of life. Therefore, the current study investigated whether 6-month maternal reported infant negative affect - a phenotypic marker of risk/susceptibility - interacted with 8-month observed parenting behaviors (positive parenting, negative parenting) to predict 12-month infant behavioral approach. Based a sample of mothers and their infants ( N =150), results indicated that negative parenting was inversely associated with subsequent approach for infants with high, but not low, levels of early negative affect. Similar results did not occur regarding positive parenting. These findings better fit a diathesis-stress model rather than a differential susceptibility model. Implications and limitations of these findings are discussed.

Negating the Infinitive in Biblical Hebrew

DEFF Research Database (Denmark)

Ehrensvärd, Martin Gustaf

1999-01-01

The article examines the negating of the infinitive in biblical and post-biblical Hebrew. The combination of the negation ayin with infinitive is widely claimed to belong to the linguistic layer commonly referred to as late biblical Hebrew and scholars use it to late-date texts. The article showa...

Negative Priming in Free Recall Reconsidered

Science.gov (United States)

Hanczakowski, Maciej; Beaman, C. Philip; Jones, Dylan M.

2016-01-01

Negative priming in free recall is the finding of impaired memory performance when previously ignored auditory distracters become targets of encoding and retrieval. This negative priming has been attributed to an aftereffect of deploying inhibitory mechanisms that serve to suppress auditory distraction and minimize interference with learning and…

Suggestibility and negative priming: two replication studies.

Science.gov (United States)

David, Daniel; Brown, Richard J

2002-07-01

Research suggests that inhibiting the effect of irrelevant stimuli on subsequent thought and action (cognitive inhibition) may be an important component of suggestibility. Two small correlation studies were conducted to address the relationship between different aspects of suggestibility and individual differences in cognitive inhibition, operationalized as the degree of negative priming generated by to-be-ignored stimuli in a semantic categorization task. The first study found significant positive correlations between negative priming, hypnotic suggestibility, and creative imagination; a significant negative correlation was obtained between negative priming and interrogative suggestibility, demonstrating the discriminant validity of the study results. The second study replicated the correlation between negative priming and hypnotic suggestibility, using a different suggestibility measurement procedure that assessed subjective experience and hypnotic involuntariness as well as objective responses to suggestions. These studies support the notion that the ability to engage in cognitive inhibition may be an important component of hypnotic responsivity and maybe of other forms of suggestibility.

Increasing Shareholders Value through NPV-Negative Projects

Directory of Open Access Journals (Sweden)

Paweł Mielcarz

2010-10-01

Full Text Available The concept of Net Present Value (NPV is a widely accepted tool for verification of financial rationality of planned investment projects. Projects with positive NPV increase a company's value. Similarly, those with negative NPV lead to a decline in the value of a business. This article attempts to answer the question: are projects with negative NPV always disadvantageous in terms of maximization of shareholder value and when should an NPV-negative project be considered justified? The authors discuss the issues of project valuation depending on different conditions. First, they briefly summarize the main idea of valuation - the aim of every company is to maximize shareholder value. Contemporary professional texts say that the way to achieve this goal is through projects that can generate a positive Net Present Value. When there are no such investments within reach, the company should pay dividends to its owners. The authors claim that some circumstances justify investments with a negative Net Present Value, as they still produce maximum possible shareholder value. The three model situations where this takes place are: (1 tax on dividends; (2 shareholders' perception of risk; and (3 temporary inefficiency of the markets. Taxes on dividends reduce cashflows for shareholders from distributed dividends. Therefore, they act exactly as an investment with a negative NPV. The authors conclude that this creates an opportunity to maximize shareholder value by comparing this loss with available alternate projects with negative NPV. If the loss of worth, caused by such taxes, is bigger that the negative NPV of possible investments it will be more rational to invest instead of paying dividends. And, according to the authors, a project with a negative NPV leads to maximized shareholder value. In the second situation, the authors point out that some projects may have negative fundamental (intrinsic value when valuated by the market (diversified owners because

Positive and Negative Peer Influence in Residential Care.

Science.gov (United States)

Huefner, Jonathan C; Smith, Gail L; Stevens, Amy L

2017-10-13

The potential for negative peer influence has been well established in research, and there is a growing interest in how positive peer influence also impacts youth. No research, however, has concurrently examined positive and negative peer influence in the context of residential care. Clinical records for 886 residential care youth were used in a Hierarchical Linear Model analysis to examine the impact of negative and positive peer influence on naturally occurring patterns of serious problem behavior over time. Negative peer influence, where the majority of youth in a home manifested above the average number of serious behavior problems, occurred 13.7% of the time. Positive peer influence, where the majority of youth manifested no serious problem behaviors for the month, occurred 47.7% of the time. Overall, youth problem behavior improved over time. There were significantly lower rates of serious problem behavior in target youth during positive peer influence months. Conversely, there were significantly higher rates of serious problem behaviors in target youth during negative peer influence months. Negative peer influence had a relatively greater impact on target peers' serious behavior problems than did positive peer influence. Caregiver experience significantly reduced the impact of negative peer influence, but did not significantly augment positive peer influence. Months where negative peer influence was combined with inexperienced caregivers produced the highest rates of serious problem behavior. Our results support the view that residential programs for troubled youth need to create circumstances that promote positive and control for negative peer influence.

Exclusion of identification by negative superposition

Directory of Open Access Journals (Sweden)

Takač Šandor

2012-01-01

Full Text Available The paper represents the first report of negative superposition in our country. Photo of randomly selected young, living woman was superimposed on the previously discovered female skull. Computer program Adobe Photoshop 7.0 was used in work. Digitilized photographs of the skull and face, after uploaded to computer, were superimposed on each other and displayed on the monitor in order to assess their possible similarities or differences. Special attention was payed to matching the same anthropometrical points of the skull and face, as well as following their contours. The process of fitting the skull and the photograph is usually started by setting eyes in correct position relative to the orbits. In this case, lower jaw gonions go beyond the face contour and gnathion is highly placed. By positioning the chin, mouth and nose their correct anatomical position cannot be achieved. All the difficulties associated with the superposition were recorded, with special emphasis on critical evaluation of work results in a negative superposition. Negative superposition has greater probative value (exclusion of identification than positive (possible identification. 100% negative superposition is easily achieved, but 100% positive - almost never. 'Each skull is unique and viewed from different perspectives is always a new challenge'. From this point of view, identification can be negative or of high probability.

Why we simulate negated information: a dynamic pragmatic account.

Science.gov (United States)

Tian, Ye; Breheny, Richard; Ferguson, Heather J

2010-12-01

A well-established finding in the simulation literature is that participants simulate the positive argument of negation soon after reading a negative sentence, prior to simulating a scene consistent with the negated sentence (Kaup, Ludtke, & Zwaan, 2006; Kaup, Yaxley, Madden, Zwaan, & Ludtke, 2007). One interpretation of this finding is that negation requires two steps to process: first represent what is being negated then "reject" that in favour of a representation of a negation-consistent state of affairs (Kaup et al., 2007). In this paper we argue that this finding with negative sentences could be a by-product of the dynamic way that language is interpreted relative to a common ground and not the way that negation is represented. We present a study based on Kaup et al. (2007) that tests the competing accounts. Our results suggest that some negative sentences are not processed in two steps, but provide support for the alternative, dynamic account.

Next-generation negative symptom assessment for clinical trials: validation of the Brief Negative Symptom Scale.

Science.gov (United States)

Strauss, Gregory P; Keller, William R; Buchanan, Robert W; Gold, James M; Fischer, Bernard A; McMahon, Robert P; Catalano, Lauren T; Culbreth, Adam J; Carpenter, William T; Kirkpatrick, Brian

2012-12-01

The current study examined the psychometric properties of the Brief Negative Symptom Scale (BNSS), a next-generation rating instrument developed in response to the NIMH sponsored consensus development conference on negative symptoms. Participants included 100 individuals with a DSM-IV diagnosis of schizophrenia or schizoaffective disorder who completed a clinical interview designed to assess negative, positive, disorganized, and general psychiatric symptoms, as well as functional outcome. A battery of anhedonia questionnaires and neuropsychological tests were also administered. Results indicated that the BNSS has excellent internal consistency and temporal stability, as well as good convergent and discriminant validity in its relationships with other symptom rating scales, functional outcome, self-reported anhedonia, and neuropsychological test scores. Given its brevity (13-items, 15-minute interview) and good psychometric characteristics, the BNSS can be considered a promising new instrument for use in clinical trials. Copyright © 2012 Elsevier B.V. All rights reserved.

The Morphosyntax of Negative Pronouns Constructions in Jordanian Arabic

Directory of Open Access Journals (Sweden)

Issa Abdel Razaq

2017-06-01

Full Text Available The main aim of this paper is to investigate the asymmetric distribution of negation strategies in verbless constructions in Jordanian Arabic and similar dialects. In particular, negative pronouns constructions present two major problems for analyses of sentential negation. The first problem lies in the use of the verbal negation strategy in such constructions although they are verbless. The second problem is the merger of subject pronouns that are clear maximal projections with the negative marker occupying the head of the negative projection. To solve these problems, the paper provides an analysis that is based on the morphosyntactic properties of negative pronouns as well as the discourse properties of the constructions in which they occur. To account for the merger between the pronoun and the head of the negative, the study demonstrates that such pronouns belong to the class of weak bound subject pronouns that undergo head movement to Neg to check and delete its uninterpretable [+D] feature. The proposed analysis treats negative pronouns constructions as topic-comment structures that involve a fronted DP followed by a complete string of predication. As such, the paper concludes that the use of the marked negation strategy is a natural outcome given the discourse properties associated with topic-comment constructions to which negative pronouns constructions belong.

Quantum entanglement at negative temperature

International Nuclear Information System (INIS)

Furman, G B; Meerovich, V M; Sokolovsky, V L

2013-01-01

An isolated spin system that is in internal thermodynamic equilibrium and that has an upper limit to its allowed energy states can possess a negative temperature. We calculate the thermodynamic characteristics and the concurrence in this system over the entire range of positive and negative temperatures. Our calculation was performed for different real structures, which can be used in experiments. It is found that the temperature dependence of the concurrence is substantially asymmetrical similarly to other thermodynamic characteristics. At a negative temperature the maximum concurrence and the absolute temperature of the entanglement appearance are significantly larger than those at a positive temperature. The concurrence can be characterized by two dimensionless parameters: the ratio between the Zeeman and dipolar energies and the ratio of the thermal and dipolar energies. It was shown that for all considered structures the dimensionless temperatures of the transition between entanglement and separability of the first and second spins are independent of spin structure and the number of spins. (paper)

L-DOPA is an endogenous ligand for OA1.

Directory of Open Access Journals (Sweden)

Vanessa M Lopez

2008-09-01

Full Text Available Albinism is a genetic defect characterized by a loss of pigmentation. The neurosensory retina, which is not pigmented, exhibits pathologic changes secondary to the loss of pigmentation in the retina pigment epithelium (RPE. How the loss of pigmentation in the RPE causes developmental defects in the adjacent neurosensory retina has not been determined, but offers a unique opportunity to investigate the interactions between these two important tissues. One of the genes that causes albinism encodes for an orphan GPCR (OA1 expressed only in pigmented cells, including the RPE. We investigated the function and signaling of OA1 in RPE and transfected cell lines. Our results indicate that OA1 is a selective L-DOPA receptor, with no measurable second messenger activity from two closely related compounds, tyrosine and dopamine. Radiolabeled ligand binding confirmed that OA1 exhibited a single, saturable binding site for L-DOPA. Dopamine competed with L-DOPA for the single OA1 binding site, suggesting it could function as an OA1 antagonist. OA1 response to L-DOPA was defined by several common measures of G-protein coupled receptor (GPCR activation, including influx of intracellular calcium and recruitment of beta-arrestin. Further, inhibition of tyrosinase, the enzyme that makes L-DOPA, resulted in decreased PEDF secretion by RPE. Further, stimulation of OA1 in RPE with L-DOPA resulted in increased PEDF secretion. Taken together, our results illustrate an autocrine loop between OA1 and tyrosinase linked through L-DOPA, and this loop includes the secretion of at least one very potent retinal neurotrophic factor. OA1 is a selective L-DOPA receptor whose downstream effects govern spatial patterning of the developing retina. Our results suggest that the retinal consequences of albinism caused by changes in melanin synthetic machinery may be treated by L-DOPA supplementation.

Clinical characteristics and causes of visual impairment in a low vision clinic in northern Jordan.

Science.gov (United States)

Bakkar, May M; Alzghoul, Eman A; Haddad, Mera F

2018-01-01

The aim of the study was to identify causes of visual impairment among patients attending a low vision clinic in the north of Jordan and to study the relevant demographic characteristics of these patients. The retrospective study was conducted through a review of clinical records of 135 patients who attended a low vision clinic in Irbid. Clinical characteristics of the patients were collected, including age, gender, primary cause of low vision, best corrected visual acuity, and current prescribed low vision aids. Descriptive statistics analysis using numbers and percentages were calculated to summarize categorical and nominal data. A total of 135 patients (61 [45.2%] females and 74 [54.8%] males) were recruited in the study. Mean age ± standard deviation for the study population was 24.53 ± 16.245 years; age range was 5-90 years. Of the study population, 26 patients (19.3%) had mild visual impairment, 61 patients (45.2%) had moderate visual impairment, 27 patients (20.0%) had severe visual impairment, and 21 patients (15.6%) were blind. The leading causes of visual impairment across all age groups were albinism (31.9%) and retinitis pigmentosa (RP) (18.5%). Albinism also accounted for the leading cause of visual impairment among the pediatric age group (0-15 years) while albinism, RP, and keratoconus were the primary causes of visual impairment for older patients. A total of 59 patients (43.7%) were given low vision aids either for near or distance. The only prescribed low vision aids for distances were telescopes. For near, spectacle-type low vision aid was the most commonly prescribed low vision aids. Low vision services in Jordan are still very limited. A national strategy programme to increase awareness of low vision services should be implemented, and health care policies should be enforced to cover low vision aids through the national medical insurance.

primary malignant amelanotic melanoma arising from a vitiligo patch

African Journals Online (AJOL)

2014-05-05

May 5, 2014 ... Malignant melanoma is a rare tumour in people of. African descent including those affected by albinism. (1). The incidence of malignant melanoma in Africans is estimated to ranging from 0.5 to 1.5 per 100,000 people (2). Acrolentiginous melanoma is the most common type of melanoma in this population.

Accuracy of pulse oximetry in pigmented patients

African Journals Online (AJOL)

Trempel'" KK. Barker SJ. PuI$e albinism. J Mea Gener 1966; 23: 323-327_. 21. SevennghaJJs JW, Kelleher JF. Recent developments in pulse OJlim€try. Anestilesiology 1992; 76: 1018-1038.

Effect of visual impairment on goal-directed aiming movements in children.

NARCIS (Netherlands)

Reimer, A.M.; Cox, R.F.A.; Boonstra, F.N.; Smits-Engelsman, B.C.M.

2008-01-01

This study investigated potential differences in motor control between children with a visual impairment (diagnosed albinism; n=11, mean age 8y 4mo [SD 7mo]; seven males, four females,) and children with normal vision (n=11, mean age 8y 4mo [SD 7mo]; six males, five females). Mean near visual acuity

Effect of visual impairment on goal-directed aiming movements in children

NARCIS (Netherlands)

Reimer, A.M.; Cox, R.F.A.; Boonstra, F.N.; Smits-Engelsman, B.C.M.

2008-01-01

This study investigated potential differences in motor control between children with a visual impairment (diagnosed albinism; n=11, mean age 8y 4mo [SD 7mo]; seven males, four females,) and children with normal vision (n=11, mean age 8y 4mo [SD 7mo]; six males, five females). Mean near visual acuity

Double Negative Materials (DNM), Phenomena and Applications

Science.gov (United States)

2009-07-01

5697–5711. Maksimović, M., and Z. Jakšić. “Emittance and Absorptance Tailoring by Negative Refractive Index Metamaterial-Based Cantor Multilayers.” J...TOKEN=48950826 Popov, A. K., S. A. Myslivets, T. F. George , and V. M. Shalaev. “Tailoring Transparency of Negative-Index Metamaterials With Parametric...Popov, A. K., S. A. Myslivets, T. F. George , and V. M. Shalaev. “Compensating Losses in Positive- and Negative-Index Metamaterials Through

The 4-Item Negative Symptom Assessment (NSA-4) Instrument: A Simple Tool for Evaluating Negative Symptoms in Schizophrenia Following Brief Training.

Science.gov (United States)

Alphs, Larry; Morlock, Robert; Coon, Cheryl; van Willigenburg, Arjen; Panagides, John

2010-07-01

Objective. To assess the ability of mental health professionals to use the 4-item Negative Symptom Assessment instrument, derived from the Negative Symptom Assessment-16, to rapidly determine the severity of negative symptoms of schizophrenia.Design. Open participation.Setting. Medical education conferences.Participants. Attendees at two international psychiatry conferences.Measurements. Participants read a brief set of the 4-item Negative Symptom Assessment instructions and viewed a videotape of a patient with schizophrenia. Using the 1 to 6 4-item Negative Symptom Assessment severity rating scale, they rated four negative symptom items and the overall global negative symptoms. These ratings were compared with a consensus rating determination using frequency distributions and Chi-square tests for the proportion of participant ratings that were within one point of the expert rating.Results. More than 400 medical professionals (293 physicians, 50% with a European practice, and 55% who reported past utilization of schizophrenia ratings scales) participated. Between 82.1 and 91.1 percent of the 4-items and the global rating determinations by the participants were within one rating point of the consensus expert ratings. The differences between the percentage of participant rating scores that were within one point versus the percentage that were greater than one point different from those by the consensus experts was significant (pnegative symptoms using the 4-item Negative Symptom Assessment did not generally differ among the geographic regions of practice, the professional credentialing, or their familiarity with the use of schizophrenia symptom rating instruments.Conclusion. These findings suggest that clinicians from a variety of geographic practices can, after brief training, use the 4-item Negative Symptom Assessment effectively to rapidly assess negative symptoms in patients with schizophrenia.

Negativity Bias in Media Multitasking: The Effects of Negative Social Media Messages on Attention to Television News Broadcasts.

Science.gov (United States)

Kätsyri, Jari; Kinnunen, Teemu; Kusumoto, Kenta; Oittinen, Pirkko; Ravaja, Niklas

2016-01-01

Television viewers' attention is increasingly more often divided between television and "second screens", for example when viewing television broadcasts and following their related social media discussion on a tablet computer. The attentional costs of such multitasking may vary depending on the ebb and flow of the social media channel, such as its emotional contents. In the present study, we tested the hypothesis that negative social media messages would draw more attention than similar positive messages. Specifically, news broadcasts were presented in isolation and with simultaneous positive or negative Twitter messages on a tablet to 38 participants in a controlled experiment. Recognition memory, gaze tracking, cardiac responses, and self-reports were used as attentional indices. The presence of any tweets on the tablet decreased attention to the news broadcasts. As expected, negative tweets drew longer viewing times and elicited more attention to themselves than positive tweets. Negative tweets did not, however, decrease attention to the news broadcasts. Taken together, the present results demonstrate a negativity bias exists for social media messages in media multitasking; however, this effect does not amplify the overall detrimental effects of media multitasking.

Negativity Bias in Media Multitasking: The Effects of Negative Social Media Messages on Attention to Television News Broadcasts.

Directory of Open Access Journals (Sweden)

Jari Kätsyri

Full Text Available Television viewers' attention is increasingly more often divided between television and "second screens", for example when viewing television broadcasts and following their related social media discussion on a tablet computer. The attentional costs of such multitasking may vary depending on the ebb and flow of the social media channel, such as its emotional contents. In the present study, we tested the hypothesis that negative social media messages would draw more attention than similar positive messages. Specifically, news broadcasts were presented in isolation and with simultaneous positive or negative Twitter messages on a tablet to 38 participants in a controlled experiment. Recognition memory, gaze tracking, cardiac responses, and self-reports were used as attentional indices. The presence of any tweets on the tablet decreased attention to the news broadcasts. As expected, negative tweets drew longer viewing times and elicited more attention to themselves than positive tweets. Negative tweets did not, however, decrease attention to the news broadcasts. Taken together, the present results demonstrate a negativity bias exists for social media messages in media multitasking; however, this effect does not amplify the overall detrimental effects of media multitasking.

A Psychometric Comparison of the Clinical Assessment Interview for Negative Symptoms and the Brief Negative Symptom Scale.

Science.gov (United States)

Strauss, Gregory P; Gold, James M

2016-11-01

In 2005, the National Institute of Mental Health held a consensus development conference on negative symptoms of schizophrenia. Among the important conclusions of this meeting were that there are at least 5 commonly accepted domains of negative symptoms (blunted affect, alogia, avolition, anhedonia, asociality) and that new rating scales were needed to adequately assess these constructs. Two next-generation negative symptom scales resulted from this meeting: the Brief Negative Symptom Scale (BNSS) and Clinical Assessment Interview for Negative Symptoms (CAINS). Both measures are becoming widely used and studies have demonstrated good psychometric properties for each scale. The current study provides the first direct psychometric comparison of these scales. Participants included 65 outpatients diagnosed with schizophrenia or schizoaffective disorder who completed clinical interviews, questionnaires, and neuropsychological testing. Separate raters completed the BNSS and CAINS within the same week. Results indicated that both measures had good internal consistency, convergent validity, and discriminant validity. High correspondence was observed between CAINS and BNSS blunted affect and alogia items. Moderate convergence occurred for avolition and asociality items, and low convergence was seen among anhedonia items. Findings suggest that both scales have good psychometric properties, but that there are important distinctions among the items related to motivation and pleasure. © The Author 2016. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center. All rights reserved. For permissions, please email: journals.permissions@oup.com.

[Negative symptoms in schizophrenia: psychotherapeutic approaches].

Science.gov (United States)

Azorin, J-M; Adida, M; Belzeaux, R; Pringuey, D; Micoulaud Franchi, J-A; Simon, N; Cermolacce, M; Kaladjian, A; Fakra, E

2015-12-01

Although negative symptoms are recognized as a central feature of schizophrenia, their definition as well as phenomenology have long been a vexing issue. During these last years, a major progress has been made with the delineation of two underlying subdomains of negative symptoms: diminished expression and anhedonia-avolition-apathy. As current guidelines are not always in accord on the efficacy of treatments on negative symptoms, it may be tempting to re-interpret the findings of clinical trials by looking at the effects of treatments on these two subdomains. This could concern both psychotropic treatments and psychotherapeutic interventions. Furthermore, neuroimaging as well as emotional response studies have permitted to better understand the mechanism which could be at the root of diminished expression and anhedonia in schizophrenia. On this basis, new psychotherapeutic methods have been devised which, by specifically targeting these two subdomains, are likely to be more efficient on negative symptoms. Further research is warranted to test their efficacy in randomized controlled trials. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Murine and human b locus pigmentation genes encode a glycoprotein (gp75) with catalase activity

International Nuclear Information System (INIS)

Halaban, R.; Moellmann, G.

1990-01-01

Melanogenesis is regulated in large part by tyrosinase, and defective tyrosinase leads to albinism. The mechanisms for other pigmentation determinants (e.g., those operative in tyrosinase-positive albinism and in murine coat-color mutants) are not yet known. One murine pigmentation gene, the brown (b) locus, when mutated leads to a brown (b/b) or hypopigmentated (B lt /B lt ) coat versus the wild-type black (B/B). The authors show that the b locus codes for a glycoprotein with the activity of a catalase (catalase B). Only the c locus protein is a tyrosinase. Because peroxides may be by-products of melanogenic activity and hydrogen peroxide in particular is known to destroy melanin precursors and melanin, they conclude that pigmentation is controlled not only by tyrosinase but also by a hydroperoxidase. The studies indicate that catalase B is identical with gp75, a known human melanosomal glycoprotein; that the b mutation is in a heme-associated domain; and that the B lt mutation renders the protein susceptible to rapid proteolytic degradation

Novel stimuli are negative stimuli: evidence that negative affect is reduced in the mere exposure effect.

Science.gov (United States)

Robinson, Brent M; Elias, Lorin J

2005-04-01

Repeated exposure of a nonreinforced stimulus results in an increased preference for that stimulus, the mere exposure effect. The present study repeatedly presented positive, negative, and neutrally affective faces to 48 participants while they made judgments about the emotional expression. Participants then rated the likeability of novel neutrally expressive faces and some of these previously presented faces, this time in their neutral expression. Faces originally presented as happy were rated as the most likeable, followed by faces originally presented as neutral. Negative and novel faces were not rated significantly differently from each other. These findings support the notion that the increase in preference towards repeatedly presented stimuli is the result of the reduction in negative affect, consistent with the modified two-factor uncertainty-reduction model and classical conditioning model of the mere exposure effect.

Negative leave balances

CERN Multimedia

Human Resources Department

2005-01-01

Members of the personnel entitled to annual leave and, where appropriate, saved leave and/or compensatory leave are requested to take note of the new arrangements described below, which were recommended by the Standing Concertation Committee (SCC) at its meeting on 1Â September 2005 and subsequently approved by the Director-General. The changes do not apply to members of the personnel participating in the Progressive Retirement Programme (PRP) or the Part-time Work as a pre-retirement measure, for whom the specific provisions communicated at the time of joining will continue to apply. Â Negative balances in annual leave, saved leave and/or compensatory leave accounts at the end of the leave year (30th September) and on the date on which bonuses are credited to the saved leave account (31st December): Where members of the personnel have a leave account with a negative balance on 30Â September and/or 31Â December, leave will automatically be transferred from one account to another on the relevant dates i...

Negative leave balances

CERN Multimedia

Human Resources Department

2005-01-01

Members of the personnel entitled to annual leave and, where appropriate, saved leave and/or compensatory leave are requested to take note of the new arrangements described below, which were recommended by the Standing Concertation Committee (SCC) at its meeting on 1 September 2005 and subsequently approved by the Director-General. The changes do not apply to members of the personnel participating in the Progressive Retirement Programme (PRP) or the Part-time Work as a pre-retirement measure, for whom the specific provisions communicated at the time of joining will continue to apply.  Negative balances in annual leave, saved leave and/or compensatory leave accounts at the end of the leave year (30th September) and on the date on which bonuses are credited to the saved leave account (31st December): Where members of the personnel have a leave account with a negative balance on 30 September and/or 31 December, leave will automatically be transferred from one account to another on the relevant dates in or...

Multiply-negatively charged aluminium clusters and fullerenes

Energy Technology Data Exchange (ETDEWEB)

Walsh, Noelle

2008-07-15

Multiply negatively charged aluminium clusters and fullerenes were generated in a Penning trap using the 'electron-bath' technique. Aluminium monoanions were generated using a laser vaporisation source. After this, two-, three- and four-times negatively charged aluminium clusters were generated for the first time. This research marks the first observation of tetra-anionic metal clusters in the gas phase. Additionally, doubly-negatively charged fullerenes were generated. The smallest fullerene dianion observed contained 70 atoms. (orig.)

Stop Negative Thinking Effects for Drug Dependence

OpenAIRE

Windiarti, Sri Endang; Indriati, Indriati; Surachmi, Fajar

2013-01-01

The purpose of this study was to determine the effect of therapy stop thinking negatively against drug addiction in Rehabilitation Orphanage Rumah Damai Gunung Pati Semarang. This research is quasy experiment with pretest - posttes without the control group design. Thirty respondents were taken to the reseach sujects. Stop thinking negative therapy before and after thebehavior of drug addiction there are differences (t = 0.00), so it can be stated that the therapy stop thinking negatively inf...

Charging of dust grains in a plasma with negative ions

International Nuclear Information System (INIS)

Mamun, A.A.; Shukla, P.K.

2003-01-01

The role of negative ions on the charging of dust grains in a plasma is examined. Two models for negative ion distributions are considered. These are streaming negative ions and Boltzmannian negative ions. It is found that the effects of the negative ion number density, negative ion charge, and negative ion streaming speed significantly affect the dust grain surface potential or the dust grain charge

Poststaphylococcal coagulase negative reactive arthritis: a case report.

Science.gov (United States)

Krasniqi, Xhevdet; Rexhepi, Sylejman; Gashi, Masar; Berisha, Blerim; Abazi, Flora; Koçinaj, Dardan

2009-12-18

We report a case of a 49-year-old patient who developed poststaphylococcal coagulase negative reactive arthritis. The woman presented with constitutional symptoms, arthritis, urinary infection and conjunctivitis. The blood culture was positive for the staphylococcal coagulase negative infection. Erythrocyte sedimentation rate and C-reactive protein were elevated, whereas the rheumatoid factor was negative. Radiographic findings confirmed diagnosis of pleuropneumonia, and one year later of chronic asymmetric sacroileitis. Physicians should be aware of possible reactive arthritis after staphylococcal coagulase negative bacteremia.

Fundamental properties of secondary negative ion emission by sputtering

International Nuclear Information System (INIS)

Shimizu, Toshiki; Tsuji, Hiroshi; Ishikawa, Junzo

1989-01-01

The report describes some results obtained from preliminary experiments on secondary negative ion emission from a cesiated surface by Xe-ion beam sputtering, which give the production probability. A measuring system is constructed for secondary negative ion emission. The system consists of a microwave ion source with a lens, a sputtering target holder with a heater, a cesium oven, a limiting aperture with a substrate for deposition, a negative-ion extractor and lens, and a ExB type mass separator. Observations are made on the dependence of negative ion current on cesium supply, dependence of negative ion current on target temperature, and negative ion production probability. The cesium supply and the target temperature are found to strongly influence the negative ion emission. By controlling these factors, the optimum condition for secondary negative ion emission is achieved with a minimum surface work function. The production probability of the negative ion is found to be very high, about 20% for carbon. Therefore, the secondary negative ion emission is considered a useful and highly efficient method to obtain high current ion beams. The constant in the Rasser's theoretical equation is experimentally determined to be 4.1 x 10 -4 eV sec/m. (N.K.)

Negative refraction angular characterization in one-dimensional photonic crystals.

Directory of Open Access Journals (Sweden)

Jesus Eduardo Lugo

2011-04-01

Full Text Available Photonic crystals are artificial structures that have periodic dielectric components with different refractive indices. Under certain conditions, they abnormally refract the light, a phenomenon called negative refraction. Here we experimentally characterize negative refraction in a one dimensional photonic crystal structure; near the low frequency edge of the fourth photonic bandgap. We compare the experimental results with current theory and a theory based on the group velocity developed here. We also analytically derived the negative refraction correctness condition that gives the angular region where negative refraction occurs.By using standard photonic techniques we experimentally determined the relationship between incidence and negative refraction angles and found the negative refraction range by applying the correctness condition. In order to compare both theories with experimental results an output refraction correction was utilized. The correction uses Snell's law and an effective refractive index based on two effective dielectric constants. We found good agreement between experiment and both theories in the negative refraction zone.Since both theories and the experimental observations agreed well in the negative refraction region, we can use both negative refraction theories plus the output correction to predict negative refraction angles. This can be very useful from a practical point of view for space filtering applications such as a photonic demultiplexer or for sensing applications.

Negative refraction angular characterization in one-dimensional photonic crystals.

Science.gov (United States)

Lugo, Jesus Eduardo; Doti, Rafael; Faubert, Jocelyn

2011-04-06

Photonic crystals are artificial structures that have periodic dielectric components with different refractive indices. Under certain conditions, they abnormally refract the light, a phenomenon called negative refraction. Here we experimentally characterize negative refraction in a one dimensional photonic crystal structure; near the low frequency edge of the fourth photonic bandgap. We compare the experimental results with current theory and a theory based on the group velocity developed here. We also analytically derived the negative refraction correctness condition that gives the angular region where negative refraction occurs. By using standard photonic techniques we experimentally determined the relationship between incidence and negative refraction angles and found the negative refraction range by applying the correctness condition. In order to compare both theories with experimental results an output refraction correction was utilized. The correction uses Snell's law and an effective refractive index based on two effective dielectric constants. We found good agreement between experiment and both theories in the negative refraction zone. Since both theories and the experimental observations agreed well in the negative refraction region, we can use both negative refraction theories plus the output correction to predict negative refraction angles. This can be very useful from a practical point of view for space filtering applications such as a photonic demultiplexer or for sensing applications.

The Peculiar Negative Greenhouse Effect Over Antarctica

Science.gov (United States)

Sejas, S.; Taylor, P. C.; Cai, M.

2017-12-01

Greenhouse gases warm the climate system by reducing the energy loss to space through the greenhouse effect. Thus, a common way to measure the strength of the greenhouse effect is by taking the difference between the surface longwave (LW) emission and the outgoing LW radiation. Based on this definition, a paradoxical negative greenhouse effect is found over the Antarctic Plateau, which suprisingly indicates that greenhouse gases enhance energy loss to space. Using 13 years of NASA satellite observations, we verify the existence of the negative greenhouse effect and find that the magnitude and sign of the greenhouse effect varies seasonally and spectrally. A previous explanation attributes the negative greenhouse effect solely to stratospheric CO2 and warmer than surface stratospheric temperatures. However, we surprisingly find that the negative greenhouse effect is predominantly caused by tropospheric water vapor. A novel principle-based explanation provides the first complete account of the Antarctic Plateau's negative greenhouse effect indicating that it is controlled by the vertical variation of temperature and greenhouse gas absorption strength. Our findings indicate that the strong surface-based temperature inversion and scarcity of free tropospheric water vapor over the Antarctic Plateau cause the negative greenhouse effect. These are climatological features uniquely found in the Antarctic Plateau region, explaining why the greenhouse effect is positive everywhere else.

An exposition on Friedmann cosmology with negative energy densities

International Nuclear Information System (INIS)

Nemiroff, Robert J.; Joshi, Ravi; Patla, Bijunath R.

2015-01-01

How would negative energy density affect a classic Friedmann cosmology? Although never measured and possibly unphysical, certain realizations of quantum field theories leaves the door open for such a possibility. In this paper we analyze the evolution of a universe comprising varying amounts of negative energy forms. Negative energy components have negative normalized energy densities, Ω < 0. They include negative phantom energy with an equation of state parameter w < −1, negative cosmological constant: w=−1, negative domain walls: w = −2/3, negative cosmic strings: w=−1/3, negative mass: w = 0, negative radiation: w = 1/3 and negative ultralight: w > 1/3. Assuming that such energy forms generate pressure like perfect fluids, the attractive or repulsive nature of negative energy components are reviewed. The Friedmann equation is satisfied only when negative energy forms are coupled to a greater magnitude of positive energy forms or positive curvature. We show that the solutions exhibit cyclic evolution with bounces and turnovers.The future and fate of such universes in terms of curvature, temperature, acceleration, and energy density are reviewed. The end states are dubbed ''big crunch,' '' big void,' or ''big rip' and further qualified as ''warped',''curved', or ''flat',''hot' versus ''cold', ''accelerating' versus ''decelerating' versus ''coasting'. A universe that ends by contracting to zero energy density is termed ''big poof.' Which contracting universes ''bounce' in expansion and which expanding universes ''turnover' into contraction are also reviewed

Negative Interest Rates: Central Banks Initiated an Experiment

Directory of Open Access Journals (Sweden)

Aleksey N. Burenin

2016-01-01

Full Text Available Negative interest rates appeared as a consequence of economic problems that countries with market economy came across after the crises of2007-2008. The attempts of monetary authorities to stimulate economies with the help of quantitative easing didn't bring the desired result. That's why the central banks once again resorted to a traditional tool of their monetary policy of changing interest rates. But this time they launched an experiment, they used negative interest rates. The European Central Bank, the Swedish Riksbank, the Bank of Japan, and the National Bank of Hungary introduced negative rates in order to stimulate economic growth and fight the threat of deflation, the Danish National Bank and the Swiss National Bank tried to deter appreciation of their currencies. Negative rates of the central banks brought about negative yields of government and nongovernment securities in several countries. The problem acquires an aggravated form due to the fact that negative rates appeared in several European countries simultaneously at the moment when global financial markets were not in crises. Some questions arise concerning the negative rates, for example, how low can central banks bring down the rates in the future, what is their influence on the stock markets, what is the reaction of depositors to the introduction of negative deposit rates by commercial banks, must one consider a negative rate as a rate of interest or payment to store money of the depositor, in which circumstances negative rates can be justified to fight deflation. The last question plays an important role, because recent studies find that positive economic growth is possible during deflation. If central banks don't take this nuance into consideration, they can create economic imbalances by increasing liquidity. Negative rates are not as inoffensive as it may seem at first glance. Not far ago an investor, who tried to averse risk, was buying government securities. Their yields

Effect of electrode materials on a negative ion production in a cesium seeded negative ion source

Energy Technology Data Exchange (ETDEWEB)

Shimizu, Takashi; Morishita, Takutoshi; Kashiwagi, Mieko; Hanada, Masaya; Iga, Takashi; Inoue, Takashi; Watanabe, Kazuhiro; Imai, Tsuyoshi [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment; Wada, Motoi [Doshisha Univ., Kyoto (Japan)

2003-03-01

Effects of plasma grid materials on the negative ion production efficiency in a cesium seeded ion source have been experimentally studied. Grid materials of Au, Ag, Cu, Ni, and Mo were examined. A 2.45 GHz microwave ion source was utilized in the experiment to avoid contamination of tungsten from filament cathode. Relations between the negative ion currents and work functions of the grid were measured for these materials. Influence of the contamination by tungsten on the grid was also investigated. If was clarified that the negative ion production efficiency was determined only by the work function of the grid. The efficiency did not depend on the material itself. The lowest work function of 1.42 eV was obtained for Au grid with Cs, and a high H{sup -} production efficiency of 20.7 mA/kW was measured. This efficiency is about 1.3 times larger than that of Cs/Mo and Cs/Cu. Further improvement of the production efficiency was observed by covering the plasma grid with tungsten and cesium simultaneously. Such co-deposition of W and Cs on the plasma grid produced the negative ion production efficiency of 1.7 times higher than that from the tungsten grid simply covered with Cs. (author)

Negative parenting behavior and childhood oppositional defiant disorder: differential moderation by positive and negative peer regard.

Science.gov (United States)

Tung, Irene; Lee, Steve S

2014-01-01

Although negative parenting behavior and peer status are independently associated with childhood conduct problems (e.g., oppositional defiant disorder (ODD)), relatively little is known about their interplay, particularly in relation to differentiated measures of positive and negative peer regard. To improve the specificity of the association of negative parenting behavior and peer factors with ODD, we explored the potential interaction of parenting and peer status in a sample of 169 five-to ten-year-old ethnically diverse children with and without attention-deficit/hyperactivity disorder (ADHD) assessed using multiple measures (i.e., rating scales, interview) and informants (i.e., parents, teachers). Controlling for children's age, sex, number of ADHD symptoms, and parents' race-ethnicity, peer acceptance inversely predicted and inconsistent discipline, harsh punishment, and peer rejection were each positively associated with ODD symptom severity. Interactive influences were also evident such that inconsistent discipline and harsh punishment each predicted elevated ODD but only among children experiencing low peer acceptance or high peer rejection. These findings suggest that supportive environments, including peer acceptance, may protect children from negative outcomes associated with inconsistent discipline and harsh punishment. Findings are integrated with theories of social support, and we additionally consider implications for intervention and prevention. © 2013 Wiley Periodicals, Inc.

Stochastic background of negative binomial distribution

International Nuclear Information System (INIS)

Suzuki, N.; Biyajima, M.; Wilk, G.

1991-01-01

A branching equations of the birth process with immigration is taken as a model for the particle production process. Using it we investigate cases in which its solution becomes the negative binomial distribution. Furthermore, we compare our approach with the modified negative binomial distribution proposed recently by Chliapnikov and Tchikilev and use it to analyse the observed multiplicity distributions. (orig.)

Uniaxial Negative Thermal Expansion, Negative Linear Compressibility, and Negative Poisson's Ratio Induced by Specific Topology in Zn[Au(CN)2]2.

Science.gov (United States)

Wang, Lei; Luo, Hubin; Deng, Shenghua; Sun, Ying; Wang, Cong

2017-12-18

The well-known idea of "structure determines properties" can be understood profoundly in the case of hexagonal zinc dicyanometalate. Using density functional theory (DFT) calculations, we show the uniaxial negative thermal expansion (NTE) and negative linear compressibility (NLC) properties of Zn[Au(CN) 2 ] 2 . The temperature dependence of phonon frequencies within the quasi-harmonic approximation (QHA) is investigated. The abnormal phonon hardening (frequency increase on heating) is detected in the ranges of 0-225, 320-345, and 410-430 cm -1 , which can be indicative of the unusual physical properties of Zn[Au(CN) 2 ] 2 . Due to the significance of low-energy phonon frequencies in Zn[Au(CN) 2 ] 2 , in this work, the corresponding vibrational mode of the lowest-frequency optical phonon at the zone center is analyzed. The specific topology of a springlike framework that will produce the effects of a compressed spring on heating and an extended spring under hydrostatic pressure is identified and leads to the coexistence of uniaxial-NTE and NLC behaviors in Zn[Au(CN) 2 ] 2 . The distinguishing phonon group velocity along the a axis and c axis facilitates different responses for both the axes under temperature and hydrostatic pressure field. Through an analysis and visualization of the spatial dependence of elastic tensors, it is found that a negative Poisson's ratio (NPR) is presented in all projection planes due to the specific topology.

Goffman, Parsons, and the Negational Self

Directory of Open Access Journals (Sweden)

James J. Chriss

2015-01-01

Full Text Available Erving Goffman’s emphasis on impression management in everyday life means that for the most part persons offer only partial or incomplete glimpses of themselves. Indeed, under specifiable conditions self-presentations may take the form of a negational self. If negational selves exist at the person or individual level, then they must also exist at the collective level (that is, if we are to take seriously such notions as the social mind, collective representations, or even culture. Understandings of how this negational self appears and is produced at various analytical levels (micro, meso, and macro can be anchored via a conceptual schema which merges Goffman’s own identity typology with the three-world model of Jürgen Habermas by way of Talcott Parsons.

News Media Framing of Negative Campaigning

DEFF Research Database (Denmark)

Pedersen, Rasmus Tue

2014-01-01

that news coverage of negative campaigning does apply the strategic game frame to a significantly larger degree than articles covering positive campaigning. This finding has significant implications for campaigning politicians and for scholars studying campaign and media effects.......News media coverage of election campaigns is often characterized by use of the strategic game frame and a focus on politicians’ use of negative campaigning. However, the exact relationship between these two characteristics of news coverage is largely unexplored. This article theorizes that consumer...... demand and norms of journalistic independence might induce the news media outlets to cover negative campaigning with a strategic game frame. A comprehensive content analysis based on several newspaper types, several election campaigns, and several different measurements of media framing confirms...

Author Details

African Journals Online (AJOL)

Kerr, R. Vol 89, No 1 (2012) - Articles Types of albinism in the black Southern Africa population. Abstract PDF. ISSN: 0012-835X. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL · AJOL's Partners · Terms and Conditions of Use · Contact AJOL ...

Differences in iron concentration in whole blood of animal models using NAA

International Nuclear Information System (INIS)

Bahovschi, V; Zamboni, C B; Silva, L F F Lopes; Metairon, S; Medeiros, I M M A

2015-01-01

In this study Neutron Activation Analysis technique (NAA) was applied to determine Fe concentration in whole blood samples of several animal models such as: mice (Mus musculus), Golden Hamster (Mesocricetus auratus), Wistar rats, Albinic Rabbits of New Zealand, Golden Retriever dogs and Crioulabreed horses. These results were compared with human whole blood estimation to check their similarities. (paper)

Differences in iron concentration in whole blood of animal models using NAA

Science.gov (United States)

Bahovschi, V.; Zamboni, C. B.; Lopes Silva, L. F. F.; Metairon, S.; Medeiros, I. M. M. A.

2015-07-01

In this study Neutron Activation Analysis technique (NAA) was applied to determine Fe concentration in whole blood samples of several animal models such as: mice (Mus musculus), Golden Hamster (Mesocricetus auratus), Wistar rats, Albinic Rabbits of New Zealand, Golden Retriever dogs and Crioulabreed horses. These results were compared with human whole blood estimation to check their similarities.

Negative Refraction Using Frequency-Tuned Oxide Multilayer Structure

Directory of Open Access Journals (Sweden)

Yalin Lu

2008-01-01

Full Text Available An oxide-based multilayer structure was proposed to realize negative refraction. The multilayer composes of alternative layers having negative permittivity and negative permeability, respectively. In order to realize negative refraction, their dielectric and magnetic resonances of layers will be tuned to the frequency as close as possibly via changing their temperature, composition, structure, and so forth. Such oxide-based NIMs are attractive for their potential applications as optical super lenses, imagers, optical cloaking, sensors, and so forth, those are required with low-loss, low-cost, and good fabrication flexibility.

Evaluation of radiological detriment from negative radiological examinations

International Nuclear Information System (INIS)

Frometa Suarez, I.; Jerez Vergueria, S.F.

1997-01-01

The individul doses of radiation due to diagnostic radiology are usually low, though their contribution to the collective dose is very important given the large numbers of people exposed to these. This paper presents an analysis of the number of negative radiologiacl examinations in a major Cuban Hospital, and their contribution to the collective dose, and radiation organ and tissue, effective (expressed as severe hereditary effect and the occurrence of fatal and non fatal cancers) are all evaluated. The negative findings constitute 41 % of all examinations. The total contribution of negative examinations to the collective dose is very important given the large numbers of people exposed to these. This papaer presents an analysis of the number of negative radiological examinations in major Cuban Hospital, and their contribution to the collective dose of radiation. The absorbed dose by irradiation organ and tissue, effective dose equivalent, collective dose, and radiation risk (expressed as severe herditary effect and the occureence of fatal and non fatal cancers) are all evaluated. The negative findings constitute 41% of all examinations. The total contribution of negative examinations. The total contribution of negative examinations to the collective dose are found to make up 52.9 %: 11.35 Sv-man in the studied population

7 CFR 275.13 - Review of negative cases.

Science.gov (United States)

2010-01-01

... State systems, the review date for negative cases could be the date of the agency's decision to deny... household which was listed incorrectly in the negative frame. (f) Demonstration projects/SSA processing. A... 7 Agriculture 4 2010-01-01 2010-01-01 false Review of negative cases. 275.13 Section 275.13...

Negative Sentences in Children with Specific Language Impairment

Science.gov (United States)

Thornton, Rosalind; Rombough, Kelly; Martin, Jasmine; Orton, Linda

2016-01-01

This study used elicited production methodology to investigate the negative sentences that are produced by English-speaking children with specific language impairment (SLI). Negative sentences were elicited in contexts in which adults use the negative auxiliary verb doesn't (e.g., "It doesn't fit"). This form was targeted to see how…

[Negative symptoms of schizophrenia: historical aspects].

Science.gov (United States)

Pringuey, D; Paquin, N; Cherikh, F; Giordana, B; Belzeaux, R; Cermolacce, M; Adida, M; Azorin, J-M

2015-12-01

The history of negative symptoms of schizophrenia rises early days of medicine in clinical and pathophysiological differences between positive and negative and their complex joint. Forming a set of typical core of symptoms, and some feature of a syndrome belonging to a specific pathophysiological mechanism, negative symptoms of schizophrenia emerge from old descriptions of clinical pictures, related to the overall look of madness, the heart of alienation, a central sign of early dementia, gradually more precisely describing the strange nature of the autistic withdrawal and schizophrenic apragmatism. At therapeutic era, negative symptoms have taken over the positive symptoms to establish an operational criteria whose importance lies in the progressive severity of this clinical type and in their contribution to therapeutic resistance. Despite the efforts of modern typological classifications, this work rehabilitates the old concept of "unitary psychosis" by defining a common symptomatic core to multiple clinical forms of psychosis, combining deficit of emotional expression and avolition, meaning a native psychopathology and a pathophysiology possibly in a common final way, and calling the arrival of new treatment strategies. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

How much can a negative FDG-PET be trusted?

International Nuclear Information System (INIS)

Wang Shuxia

2004-01-01

Purpose: False-negative FDG-PET constituted 22.7% of all clinically identified negative PET in a ten year retrospective review about FDG-PET on irradiated brain tumour. Uncovering possible influencing factors of false-negative FDG-PET may have significant value. Material and methods: 10 patients with a first negative and then a second positive PET during very short time separation and 6 patients with surgically confirmed false-negative PET were traced. Histological type, irradiation parameter, steroids effect were discussed. To define temporary irradiation effect on FDG uptake, interval between radiation treatment to PET examination of these two groups were compared with 24 surgically confirmed true-positive PET, 5 surgically confirmed true-negative PET Results: 80% negative-positive PET transformation happened within 31 weeks. No statistically significant difference with regard to time from irradiation could be found between groups. Steroids medication closely before PET examination was about the same before the first negative and second positive PET scan. 5/6 surgically confirmed false-negative PET patients did not take steroids before PET examination. Conclusion: Tumour histology type, temporary irradiation effect and steroids medication did not constitute the reasons for false negative PET in our patient series. PET could not identify tumour relapse in the very early stage. Therefore, if clinically indicated, second FDG-PET might be a better selection to pick up tumour relapse instead of exploratory surgery or biopsy. In that case, the suitable time point for the second PET could be within 31 weeks after the first PET examination. Keywords: false-negative, FDG-PET, influencing factor, irradiation effect, steroids. (author)

Choosing the negative: A behavioral demonstration of morbid curiosity

Science.gov (United States)

2017-01-01

This paper examined, with a behavioral paradigm, to what extent people choose to view stimuli that portray death, violence or harm. Based on briefly presented visual cues, participants made choices between highly arousing, negative images and positive or negative alternatives. The negative images displayed social scenes that involved death, violence or harm (e.g., war scene), or decontextualized, close-ups of physical harm (e.g., mutilated face) or natural threat (e.g., attacking shark). The results demonstrated that social negative images were chosen significantly more often than other negative categories. Furthermore, participants preferred social negative images over neutral images. Physical harm images and natural threat images were not preferred over neutral images, but were chosen in about thirty-five percent of the trials. These results were replicated across three different studies, including a study that presented verbal descriptions of images as pre-choice cues. Together, these results show that people deliberately subject themselves to negative images. With this, the present paper demonstrates a dynamic relationship between negative information and behavior and advances new insights into the phenomenon of morbid curiosity. PMID:28683147

Negative ion sound solitary waves revisited

Science.gov (United States)

Cairns, R. A.; Cairns

2013-12-01

Some years ago, a group including the present author and Padma Shukla showed that a suitable non-thermal electron distribution allows the formation of ion sound solitary waves with either positive or negative density perturbations, whereas with Maxwellian electrons only a positive density perturbation is possible. The present paper discusses the qualitative features of this distribution allowing the negative waves and shared with suitable two-temperature distributions.

Veillonella, Firmicutes: Microbes disguised as Gram negatives

DEFF Research Database (Denmark)

Vesth, Tammi Camilla; Ozen, Asli; Andersen, Sandra Christine

2013-01-01

Negativicutes, including the genus Veillonella, stain Gram negative. Veillonella are among the most abundant organisms of the oral and intestinal microflora of animals and humans, in spite of being strict anaerobes. In this work, the genomes of 24 Negativicutes, including eight Veillonella spp., are compared......, with the exception of a shared LPS biosynthesis pathway. The clade within the class Negativicutes to which the genus Veillonella belongs exhibits unique properties, most of which are in common with Gram-positives and some with Gram negatives. They are only distantly related to Clostridia, but are even less closely...... related to Gram-negative species. Though the Negativicutes stain Gram-negative and possess two membranes, the genome and proteome analysis presented here confirm their place within the (mainly) Gram positive phylum of the Firmicutes. Further studies are required to unveil the evolutionary history...

Does Negative Type Characterize the Round Sphere?

DEFF Research Database (Denmark)

Kokkendorff, Simon Lyngby

2007-01-01

We discuss the measure theoretic metric invariants extent, mean distance and symmetry ratio and their relation to the concept of negative type of a metric space. A conjecture stating that a compact Riemannian manifold with symmetry ratio 1 must be a round sphere, was put forward in a previous paper....... We resolve this conjecture in the class of Riemannian symmetric spaces by showing, that a Riemannian manifold with symmetry ratio 1 must be of negative type and that the only compact Riemannian symmetric spaces of negative type are the round spheres....

Negative Attitudes, Networks and Education

DEFF Research Database (Denmark)

Bennett, Patrick; la Cour, Lisbeth; Larsen, Birthe

This paper theoretically and empirically assesses the potential explanations behind the educational gap between young natives and immigrants using two measures, negative attitudes towards immigrants and networking. The paper considers that two these parameters may influence high and uneducated...... workers as well as immigrants and natives differently, creating different incentives to acquire education for the two groups. Using rich Danish administrative data, this paper finds suggestive evidence rejecting the theoretical case where negative attitudes decrease 1st generation immigrant education...... and indications that quality of networks seems to matter more for immigrants than the quantity of individuals in a potential network....

Patch Test Negative Generalized Dermatitis.

Science.gov (United States)

Spiker, Alison; Mowad, Christen

2016-01-01

Allergic contact dermatitis is a common condition in dermatology. Patch testing is the criterion standard for diagnosis. However, dermatitis is not always caused by an allergen, and patch testing does not identify a culprit in every patient. Generalized dermatitis, defined as eczematous dermatitis affecting greater than 3 body sites, is often encountered in dermatology practice, especially patch test referral centers. Management for patients with generalized dermatitis who are patch test negative is challenging. The purpose of this article is to outline an approach to this challenging scenario and summarize the paucity of existing literature on patch test negative generalized dermatitis.

False-negative diffusion-weighted imaging findings in acute stroke

International Nuclear Information System (INIS)

Ishikawa, Tatsuya; Yuasa, Naoki; Otomo, Takashi; Shiramizu, Hideki; Matsuda, Hiroshi; Kitagawa, Yasuhisa; Takagi, Shigeharu

2006-01-01

The utility of DWI (diffusion-weighted imaging) has been established in acute ischemic stroke. However, some patients with acute stroke show no abnormal signals on DWI, despite the presence of infarction (false-negative DWI). We analyzed the relationship between false-negative DWI and the clinical manifestations of acute ischemic stroke in 151 DWI-positive (89%) and 19 false-negative DWI (11%) patients. We performed MRI within 24 hours after onset at our hospital. Non-specific clinical manifestations, including vertigo and nausea, were frequently observed in false-negative DWI patients. As regards the vascular territory, false-negative DWI was noted in 15.3% of 59 patients with infarctions within the territory of the vertebrobasilar artery. Concerning the duration from onset to initial imaging, 73.7% of the patients with false-negative DWI findings underwent MRI examination within 6 hours after onset. Of the patients with false-negative DWI, 84.2% had lacunar infarction (χ 2 =16.4, P<0.001). In conclusion, false negative DWI is more frequently observed in lacunar infarction than in atherothrombotic infarction or cardiogenic embolism. It is important to examine carefully the neurological changes occurring in patients who present with acute stroke, but have negative DWI findings. (author)

On the contrast between Germanic and Romance negated quantifiers

Directory of Open Access Journals (Sweden)

Robert Cirillo

2009-01-01

Full Text Available Universal quantifiers can be stranded in the manner described by Sportiche (1988, Giusti (1990 and Shlonsky (1991 in both the Romance and Germanic languages, but a negated universal quantifier can only be stranded in the Germanic languages. The goal of this paper is to show that this contrast between the Romance and the Germanic languages can be explained if one adapts the theory of sentential negation in Zeijlstra (2004 to constituent (quantifier negation. According to Zeijlstra’s theory, a negation marker in the Romance languages is the head of a NegP that dominates vP, whereas in the Germanic languages a negation marker is a maximal projection that occupies the specifier position of a verbal phrase. I will show that the non-occurrence of stranded negated quantifiers in the Romance languages follows from the fact that negation markers in the Romance languages are highly positioned syntactic heads.

Negative capacitance in a ferroelectric capacitor.

Science.gov (United States)

Khan, Asif Islam; Chatterjee, Korok; Wang, Brian; Drapcho, Steven; You, Long; Serrao, Claudy; Bakaul, Saidur Rahman; Ramesh, Ramamoorthy; Salahuddin, Sayeef

2015-02-01

The Boltzmann distribution of electrons poses a fundamental barrier to lowering energy dissipation in conventional electronics, often termed as Boltzmann Tyranny. Negative capacitance in ferroelectric materials, which stems from the stored energy of a phase transition, could provide a solution, but a direct measurement of negative capacitance has so far been elusive. Here, we report the observation of negative capacitance in a thin, epitaxial ferroelectric film. When a voltage pulse is applied, the voltage across the ferroelectric capacitor is found to be decreasing with time--in exactly the opposite direction to which voltage for a regular capacitor should change. Analysis of this 'inductance'-like behaviour from a capacitor presents an unprecedented insight into the intrinsic energy profile of the ferroelectric material and could pave the way for completely new applications.

Preservation Copying Endangered Historic Negative Collections

DEFF Research Database (Denmark)

Kejser, Ulla Bøgvad

2008-01-01

This article discusses preservation copying of unstable B&W nitrate and acetate still photographic negatives. It focuses on evaluating two different strategies for preserving the copies from a point of view of quality and cost-effectiveness. The evaluated strategies are preservation of the master...... by describing essential characteristics of negatives, which must be passed on to the copies, and the required metadata and technical imaging specifications. Next the paper discusses strategies for preservation and makes an analysis with the LIFE2 Costing Model. The paper concludes that the most beneficial...... and cost-effective preservation solution for large format negatives is to keep the preservation copies as digital files. However, it also acknowledges that it is important to revisit such strategies regularly to monitor changes in user expectations, technologies and costs....

Bayesian network model of crowd emotion and negative behavior

Science.gov (United States)

Ramli, Nurulhuda; Ghani, Noraida Abdul; Hatta, Zulkarnain Ahmad; Hashim, Intan Hashimah Mohd; Sulong, Jasni; Mahudin, Nor Diana Mohd; Rahman, Shukran Abd; Saad, Zarina Mat

2014-12-01

The effects of overcrowding have become a major concern for event organizers. One aspect of this concern has been the idea that overcrowding can enhance the occurrence of serious incidents during events. As one of the largest Muslim religious gathering attended by pilgrims from all over the world, Hajj has become extremely overcrowded with many incidents being reported. The purpose of this study is to analyze the nature of human emotion and negative behavior resulting from overcrowding during Hajj events from data gathered in Malaysian Hajj Experience Survey in 2013. The sample comprised of 147 Malaysian pilgrims (70 males and 77 females). Utilizing a probabilistic model called Bayesian network, this paper models the dependence structure between different emotions and negative behaviors of pilgrims in the crowd. The model included the following variables of emotion: negative, negative comfortable, positive, positive comfortable and positive spiritual and variables of negative behaviors; aggressive and hazardous acts. The study demonstrated that emotions of negative, negative comfortable, positive spiritual and positive emotion have a direct influence on aggressive behavior whereas emotion of negative comfortable, positive spiritual and positive have a direct influence on hazardous acts behavior. The sensitivity analysis showed that a low level of negative and negative comfortable emotions leads to a lower level of aggressive and hazardous behavior. Findings of the study can be further improved to identify the exact cause and risk factors of crowd-related incidents in preventing crowd disasters during the mass gathering events.

Negative Symptom Dimensions of the Positive and Negative Syndrome Scale Across Geographical Regions: Implications for Social, Linguistic, and Cultural Consistency

OpenAIRE

Khan, Anzalee; Liharska, Lora; Harvey, Philip D.; Atkins, Alexandra; Ulshen, Daniel; Keefe, Richard S.E.

2017-01-01

Objective: Recognizing the discrete dimensions that underlie negative symptoms in schizophrenia and how these dimensions are understood across localities might result in better understanding and treatment of these symptoms. To this end, the objectives of this study were to 1) identify the Positive and Negative Syndrome Scale negative symptom dimensions of expressive deficits and experiential deficits and 2) analyze performance on these dimensions over 15 geographical regions to determine whet...

Cesium injection system for negative ion duoplasmatrons

International Nuclear Information System (INIS)

Kobayashi, M.; Prelec, K.; Sluyters, T.J.

1978-01-01

A design for admitting cesium vapor into a hollow hydrogen plasma discharge in a duoplasmatron ion source for the purpose of increasing the negative hydrogen ion output current is described. 60 mA beam currents for negative hydrogen ions are reported

Appendicitis: A Study of Negative Appendicectomies | Kpolugbo ...

African Journals Online (AJOL)

Post-operative complications were noted in 3% of the negative appendicectomy group but in the positive appendicectomy group complications were much more common particularly when the appendix was ruptured. (Key Words: Negative appendicectomy, perforated appendix and postoperative complications.) Sahel Med.

Initial development and preliminary validation of a new negative symptom measure: the Clinical Assessment Interview for Negative Symptoms (CAINS).

Science.gov (United States)

Forbes, Courtney; Blanchard, Jack J; Bennett, Melanie; Horan, William P; Kring, Ann; Gur, Raquel

2010-12-01

As part of an ongoing scale development process, this study provides an initial examination of the psychometric properties and validity of a new interview-based negative symptom instrument, the Clinical Assessment Interview for Negative Symptoms (CAINS), in outpatients with schizophrenia or schizoaffective disorder (N = 37). The scale was designed to address limitations of existing measures and to comprehensively assess five consensus-based negative symptoms: asociality, avolition, anhedonia (consummatory and anticipatory), affective flattening, and alogia. Results indicated satisfactory internal consistency reliability for the total CAINS scale score and promising inter-rater agreement, with clear areas identified in need of improvement. Convergent validity was evident in general agreement between the CAINS and alternative negative symptom measures. Further, CAINS subscales significantly correlated with relevant self-report emotional experience measures as well as with social functioning. Discriminant validity of the CAINS was strongly supported by its small, non-significant relations with positive symptoms, general psychiatric symptoms, and depression. These preliminary data on an early beta-version of the CAINS provide initial support for this new assessment approach to negative symptoms and suggest directions for further scale development. Copyright © 2010 Elsevier B.V. All rights reserved.

Pengaruh Negative Framing dan Adverse Selection terhadap Eskalasi Komitmen

OpenAIRE

Arimawan, Muhammad Sandi; Sukirno, Sukirno

2014-01-01

Penelitian ini dilakukan bertujuan untuk mengetahui: (1) Pengaruh negative framing terhadap eskalasi komitmen, (2) Pengaruh adverse selection terhadap eskalasi komitmen, (3) Pengaruh negative framing dan adverse selection secara bersama-sama terhadap eskalasi komitmen, (4) Pengaruh negative framing terhadap eskalasi komitmen dimoderasi locus of control, (5) Pengaruh adverse selection terhadap eskalasi komitmen dimoderasi locus of control, (6) Pengaruh negative framing dan adverse selection se...

Superconductive microstrip exhibiting negative differential resistivity

International Nuclear Information System (INIS)

Huebener, R.P.; Gallus, D.E.

1975-01-01

A device capable of exhibiting negative differential electrical resistivity over a range of values of current and voltage is formed by vapor-depositing a thin layer of a material capable of exhibiting superconductivity on an insulating substrate, establishing electrical connections at opposite ends of the deposited strip, and cooling the alloy into its superconducting range. The device will exhibit negative differential resistivity when biased in the current-induced resistive state

Focusing on the Negative: Cultural Differences in Expressions of Sympathy

Science.gov (United States)

Koopmann-Holm, Birgit; Tsai, Jeanne L.

2014-01-01

Feeling concern about the suffering of others is considered a basic human response, and yet, we know surprisingly little about the cultural factors that shape how people respond to the suffering of another person. To this end, we conducted four studies that tested the hypothesis that American expressions of sympathy focus on the negative less and positive more than German expressions of sympathy, in part because Americans want to avoid negative states more than Germans do. In Study 1, we demonstrate that American sympathy cards contained less negative and more positive content than German sympathy cards. In Study 2, we show that European Americans want to avoid negative states more than Germans do. In Study 3, we demonstrate that these cultural differences in “avoided negative affect” mediate cultural differences in how comfortable Americans and Germans felt focusing on the negative (vs. positive) when expressing sympathy for the hypothetical death of an acquaintance's father. To examine whether greater avoided negative affect results in lesser focus on the negative and greater focus on the positive when responding to another person's suffering, in Study 4, American and German participants were randomly assigned to one of two conditions: (1) to “push negative images away” (i.e., increasing desire to avoid negative affect), or (2) to “pull negative images closer” to themselves (i.e., decreasing desire to avoid negative affect). Participants were then asked to pick a card to send to an acquaintance whose father had hypothetically just died. Across cultures, participants in the “push negative away” condition were less likely to choose sympathy cards with negative (vs. positive) content than were those in the “pull negative closer” condition. Together, these studies suggest that cultures differ in their desire to avoid negative affect, and that these differences influence the degree to which expressions of sympathy focus on the negative (vs

Focusing on the negative: cultural differences in expressions of sympathy.

Science.gov (United States)

Koopmann-Holm, Birgit; Tsai, Jeanne L

2014-12-01

Feeling concern about the suffering of others is considered a basic human response, and yet we know surprisingly little about the cultural factors that shape how people respond to the suffering of another person. To this end, we conducted 4 studies that tested the hypothesis that American expressions of sympathy focus on the negative less and positive more than German expressions of sympathy, in part because Americans want to avoid negative states more than Germans do. In Study 1, we demonstrate that American sympathy cards contain less negative and more positive content than German sympathy cards. In Study 2, we show that European Americans want to avoid negative states more than Germans do. In Study 3, we demonstrate that these cultural differences in "avoided negative affect" mediate cultural differences in how comfortable Americans and Germans feel focusing on the negative (vs. positive) when expressing sympathy for the hypothetical death of an acquaintance's father. To examine whether greater avoided negative affect results in lesser focus on the negative and greater focus on the positive when responding to another person's suffering, in Study 4, American and German participants were randomly assigned to 1 of 2 conditions: (a) to "push negative images away" (i.e., increasing desire to avoid negative affect) from or (b) to "pull negative images closer" (i.e., decreasing desire to avoid negative affect) to themselves. Participants were then asked to pick a card to send to an acquaintance whose father had hypothetically just died. Across cultures, participants in the "push negative away" condition were less likely to choose sympathy cards with negative (vs. positive) content than were those in the "pull negative closer" condition. Together, these studies suggest that cultures differ in their desire to avoid negative affect and that these differences influence the degree to which expressions of sympathy focus on the negative (vs. positive). We discuss the

Interpretation of the French negation ne…pas

DEFF Research Database (Denmark)

Nølke, Henning

2017-01-01

.), I distinguish three interpretation types of sentence negation, and I propose a polyphonic analysis according to which the polemic use is fundamental. e metalinguistic and descriptive negations are derived from this primary value. I show that this pragmatic semantic analysis has some precise...

Negativity bias and task motivation: testing the effectiveness of positively versus negatively framed incentives.

Science.gov (United States)

Goldsmith, Kelly; Dhar, Ravi

2013-12-01

People are frequently challenged by goals that demand effort and persistence. As a consequence, philosophers, psychologists, economists, and others have studied the factors that enhance task motivation. Using a sample of undergraduate students and a sample of working adults, we demonstrate that the manner in which an incentive is framed has implications for individuals' task motivation. In both samples we find that individuals are less motivated when an incentive is framed as a means to accrue a gain (positive framing) as compared with when the same incentive is framed as a means to avoid a loss (negative framing). Further, we provide evidence for the role of the negativity bias in this effect, and highlight specific populations for whom positive framing may be least motivating. Interestingly, we find that people's intuitions about when they will be more motivated show the opposite pattern, with people predicting that positively framed incentives will be more motivating than negatively framed incentives. We identify a lay belief in the positive correlation between enjoyment and task motivation as one possible factor contributing to the disparity between predicted and actual motivation as a result of the framing of the incentive. We conclude with a discussion of the managerial implications for these findings. PsycINFO Database Record (c) 2013 APA, all rights reserved.

Nonlinear waves in plasma with negative ion

International Nuclear Information System (INIS)

Saito, Maki; Watanabe, Shinsuke; Tanaca, Hiroshi.

1984-01-01

The propagation of nonlinear ion wave is investigated theoretically in a plasma with electron, positive ion and negative ion. The ion wave of long wavelength is described by a modified K-dV equation instead of a K-dV equation when the nonlinear coefficient of the K-dV equation vanishes at the critical density of negative ion. In the vicinity of the critical density, the ion wave is described by a coupled K-dV and modified K-dV equation. The transition from a compressional soliton to a rarefactive soliton and vice versa are examined by the coupled equation as a function of the negative ion density. The ion wave of short wavelength is described by a nonlinear Schroedinger equation. In the plasma with a negative ion, the nonlinear coefficient of the nonlinear Schroedinger equation changes the sign and the ion wave becomes modulationally unstable. (author)

Contingent negative variation of mood disorder patients

Institute of Scientific and Technical Information of China (English)

Yingzhi Lu; Wenbin Zong; Qingtao Ren; Jinyu Pu; Jun Chen; Juan Li; Xingshi Chen; Yong Wang

2011-01-01

Studies on brain-evoked potential and contingent negative variation (CNV) in mood disorder remain controversial. To date, no CNV difference between unipolar and bipolar depression has been reported. Brain-evoked potentials were measured in the present study to analyze CNV in three subtypes of mood disorder (mania, unipolar depression, and bipolar depression), and these results were compared with normal controls. In the mania group, CNV amplitude B was greater than in controls, and the depression group exhibited lower CNV amplitude B and smaller A-S'2 area, and prolonged post-imperative negative variation latency. The CNV comparison between unipolar and bipolar depression found that the prolonged post-imperative negative variation latency was only in unipolar depression. These results suggest that prolonged post-imperative negative variation latency is a characteristic of unipolar depression, and CNV amplitude change is a state characteristic of mood disorder patients.

Dispersion characteristics of negative refraction sonic crystals

International Nuclear Information System (INIS)

Wu, L.-Y.; Chen, L.-W.; Wang, R.C.-C.

2008-01-01

Dispersion characteristics of negative refraction sonic crystals are investigated. The plane wave expansion method is used to calculate the equifrequency surface; the dependences of refractive direction on frequencies and incident angles for triangular lattices are shown. There exist the positive and negative refractive waves which include k.V g ≥0 and k.V g ≤0 in the second band for the triangular system. We also use the finite element method to demonstrate that the relative intensity of the transmitted acoustic waves is dependent on incident frequencies and angles. The positions of the partial band gaps obtained by the plane wave expansion method are in good agreement with those obtained by the finite element method. The sonic crystals with negative effective index are shown to have higher transmission intensities. By using the negative refraction behavior, we can design a sonic crystal plane lens to focus a sonic wave

Operating a redox flow battery with a negative electrolyte imbalance

Science.gov (United States)

Pham, Quoc; Chang, On; Durairaj, Sumitha

2015-03-31

Loss of flow battery electrode catalyst layers during self-discharge or charge reversal may be prevented by establishing and maintaining a negative electrolyte imbalance during at least parts of a flow battery's operation. Negative imbalance may be established and/or maintained actively, passively or both. Actively establishing a negative imbalance may involve detecting an imbalance that is less negative than a desired threshold, and processing one or both electrolytes until the imbalance reaches a desired negative level. Negative imbalance may be effectively established and maintained passively within a cell by constructing a cell with a negative electrode chamber that is larger than the cell's positive electrode chamber, thereby providing a larger quantity of negative electrolyte for reaction with positive electrolyte.

Negative affect impairs associative memory but not item memory.

Science.gov (United States)

Bisby, James A; Burgess, Neil

2013-12-17

The formation of associations between items and their context has been proposed to rely on mechanisms distinct from those supporting memory for a single item. Although emotional experiences can profoundly affect memory, our understanding of how it interacts with different aspects of memory remains unclear. We performed three experiments to examine the effects of emotion on memory for items and their associations. By presenting neutral and negative items with background contexts, Experiment 1 demonstrated that item memory was facilitated by emotional affect, whereas memory for an associated context was reduced. In Experiment 2, arousal was manipulated independently of the memoranda, by a threat of shock, whereby encoding trials occurred under conditions of threat or safety. Memory for context was equally impaired by the presence of negative affect, whether induced by threat of shock or a negative item, relative to retrieval of the context of a neutral item in safety. In Experiment 3, participants were presented with neutral and negative items as paired associates, including all combinations of neutral and negative items. The results showed both above effects: compared to a neutral item, memory for the associate of a negative item (a second item here, context in Experiments 1 and 2) is impaired, whereas retrieval of the item itself is enhanced. Our findings suggest that negative affect impairs associative memory while recognition of a negative item is enhanced. They support dual-processing models in which negative affect or stress impairs hippocampal-dependent associative memory while the storage of negative sensory/perceptual representations is spared or even strengthened.